6.0 MicroMODEL PIT GENERATION AND RESERVES EVALUATION

6.1 Introduction

The Pit Generation and Reserves Evaluation Sub-Menu appears below:

  1. Return To Main Menu
  2. Command Shell
  3. Initialize Pit Model (required)
  4. Enter Pit Generation Parameters
  5. Digitize and Display a Pit Base (Menu)
  6. Evaluate Digitized Pit Base
  7. Update the Mined Out Rock Model
  8. Plot the Computer Generated Pit
  9. Inverse the Mined Out Pit Model
  10. Graphical Display of the Mined Out Model (Menu)
  11. Money Matrix and Cone Miner (Menu)
  12. Plot Digitized Contour Profile in Section
  13. Interactive Scheduler
  14. Clean-Up Directory

The Pit Generation and Reserves Evaluation Module enables the user to quickly evaluate volumes, tonnages, and grades within user defined or computer expanded pit design lines. Refer to Volume I, Section 4.6 for information on utilizing the programs offered within this module.

6.2 Command Shell

This menu choice enables the user to invoke commands and run external programs without exiting MicroMODEL. Refer to Section 1.1 for details.

6.3 Initialize Pit Model

The availability of a block of material to be mined is indicated in the rock model (also called the Pit Model at this stage) by positive rock codes for unmined blocks and negative rock codes for mined blocks. The Pit Initialization program serves two purposes.

First, this program takes the absolute value of all rock codes within the pit model. This step makes the rock codes for all blocks positive, making all rock blocks available to be mined. The Pit Initialization Program can be used anytime the user wants to start with an unmined pit model.

The second function of the Pit Initialization program is to inventory the rock codes within the rock model. This inventory is required for subsequent input of reserves evaluation parameters and development of the reserves statements. For this reason, the Pit Initialization program must be run prior to entering pit generation parameters and evaluating a pit base.

This program can be used in two ways. The user can either choose automatic tabulation, or override the automatic tabulation and hand enter rock codes.

When automatic tabulation is used, the program scans the rock model and finds all the unique codes. Automatic tabulation should be used in most cases. However, the user may desire to use the override option if several models are being created for a particular region. With several models, it is possible that a given rock type only appears in one model or the other. In order to make answer files for the open pit design program be compatible between models, the entire list of expected rock codes should be entered.

6.4 Enter Pit Generation Parameters

This program sets the parameters upon which subsequent pit evaluation runs are based. The primary parameters that are required by this program are:

  1. Input grade models and modeling methods.
  2. Cutoff grades and Ore, Lowgrade, and Waste classifications for the primary mineral.
  3. Material densities by rock type.
  4. Specify Optional Density Model.
  5. Specify Optional Void Fraction Model.
  6. Specify Optional Ore Indicator Model.
  7. Slope angles for base expansion by rock type.
  8. Type of reserve statement to be produced.
  9. Use of base expansion.
  10. Base expansion smoothing parameters.

These parameters are often the same for several pit runs, with only the pit bases being adjusted. Therefore, the user will probably not need to run the Enter Pit Generation Parameters program each time a pit base (or pit) is evaluated.

The Answer Set Name is entered at the top of the first input screen. This response identifies this set of answers for future program runs.

The reserve statements can report volumes and tonnages in units or thousands of units (Check box). For metric, the units are cubic meters and tonnes or cubic meters x 103 and kilotonnes. In English units, the units are cubic yards and short tons or cubic yards x 103 and thousands of short tons. Check the first checkbox to report in thousands, otherwise, leave unchecked.

The reserve statements can report multiple process types. To report multiple process types, the check box that is labelled "Check Here to Report Ore Types for Multiple Mill Processes" should be checked. When using this option, you must have created a 3-D model that contains index values to each process type. The easiest way to do this is via choice 15 "Combine Multiple Money Matrices" in the Cone Miner/Money Matrix Sub-Menu.

With multiple process types, the user must specify the number of processes (from 2 to 5), the names of each process, and also the name of the 3-D process indicator model. In addition, for each process type, the number of mineral label(s) to report, model type(s), and cutoff grades must also be entered. A completely different set of labels can be reported for each process type, if desired. The user may also choose to report the same mineral label for more than one process type.

MicroMODEL always produces a summary statement displaying all benches by rock type and an abbreviated statement displaying all benches for all rock types at the specified ore grade classifications. A DETAILED listing produces a report of the increment by rock type, by bench, and by cutoff in addition to the summary and abbreviated statements. The abbreviated statement reports the total tonnage and grade by rock type for each cutoff grade entered.

The detailed statement is usually quite large, and is generally not needed until detailed scheduling is performed. Generation of a detailed output is controlled by the next check box.

The user must choose to use or not use BASE EXPANSION (Checkbox). Base Expansion results in all polygons in the digitized pit perimeter file being used as bases which are expanded to the surface. Not using base expansion results in only the perimeters for the corresponding benches in the pit polygon file being evaluated. Generally, base expansion is used to perform incremental analysis on the deposit to define the ultimate pit. Base expansion is generally not used to calculate final pit volumes with ramps. To calculate the final pit volumes, the final pit design (with ramps) is digitized bench by bench. This digitized file is then run without base expansion, which results in the mining of only the material contained within the digitized boundaries (by bench).

Normally, in the bench by bench report, the volumes of material are reported. However, if the user is reporting more than three separate mineral labels, it may be desirable to skip the printing of the volumes in order to save space and keep the width of the printout to a manageable size. The last checkbox in the "Select Misc. Options" group contols this.

If base expansion has been selected, then slope angles must be entered for each rock type on a separate input screen. Enter the SLOPE ANGLE to be used during pit line projection for each of the rock types present in the rock model. The SLOPE ANGLE FOR AIR controls the projection of pit perimeters once a portion of the perimeter has daylighted. Normally, the air slope angle is set at 85 degrees.

MicroMODEL can smooth projected pit perimeters during base expansion if so instructed. The degree of smoothing is controlled by the "tightness" of the perimeter chord and angle parameters. The MINIMUM AND MAXIMUM CHORD LENGTHS determine the shortest and longest allowable chord lengths.

The MINIMUM EXTERNAL ANGLE controls the sharpness of noses that may develop during pit expansion. If an external angle is encountered during expansion that is less than the minimum external angle, then the program cuts the two chords surrounding the small external angle into smaller chords of length equal to the minimum chord length and distributes the previous angle into an arc over several segments.

The MAXIMUM EXTERNAL ANGLE controls the sharpness of wedges that may develop during pit expansion. If an external angle is encountered during expansion that is greater than the maximum external angle, then the program cuts the two chords surrounding the large external angle into smaller chords of length equal to the minimum chord length and distributes the previous angle into an arc over several segments.

Since the maximum allowable number of chords in a perimeter is 200, some combinations of the perimeter smoothing parameters may not be possible. Adjustments of the parameters is usually necessary to produce the desired result. For general incremental analysis, "loose" parameters often yield the best results since the combination of profitable increments tends to smooth the pit shape. The following "loose" parameters are suggested as a starting point for preliminary perimeter adjustment:

    Minimum Chord Length
      = Smaller dimension (row or column)

    Maximum Chord Length
      = 4 x larger dimension (row or column)

    Minimum Exterior Angle
      = 75 degrees

    Maximum Exterior Angle
      = 285 degrees

Ore grades are calculated based on the user specified grade models. The user is required to choose how many mineral labels to report (model grades), and select MODEL TYPE and LABEL for each mineral that will be reported. The number of labels is selected via the integer input field at the top of the "Select Mineral Label(s) to Report" group box. Up to eight mineral labels can reported in a single run.

For each mineral to report, the user must also choose the "digits after decimal." This number controls the appearance of the grade printouts for each mineral. Each column has a total field width of seven characters. One of these fields is always taken up by the decimal point. The six remaining positions are split up by specifying the number of digits that should follow the decimal. Consequently, the user has considerable flexibility in the reporting format of the grade values for each mineral.

The user may optionally choose to use a variable density model (Checkbox), in which each block in the 3-D model is given its own density value. If a variable density model is used, then it must be selected by pressing the command button adjacent to the checkbox. If a variable density model is used, then the fixed density values for each rock type do not have to be entered. However, if the density model contains any unestimated values (missing), then the reserve programs will replace the missing value with the fixed density value for that particular rock type.The user is strongly encouraged to run statistics by rock type on the density model to insure that reasonable values have been entered.

The user may optionally choose to use a void adjustment model (Checkbox), for which each block in the 3-D model is given a value from zero to one hundred (0-100). If the model contains any missing values, they are set to zero prior to use. Void adjustment can be used to make allowances for prior underground mining, etc. When reserves are calculated, the block volume is adjusted by this percentage. A void adjustment value of 100 means that the block is totally solid, so no adjustment is made. A void adjustment value of 0 (zero) means the block is totally air, so the tonnage from that block is zero. If the void adjustment box is checked, then the user must specify the MODEL to use via the command button directly to the right of the checkbox.

The user may optionally choose to use an ore indicator model (Checkbox), for which each block in the 3-D model is given a value from zero to one (0-1). If the model contains any missing values, they are set to one (1.0) prior to use. Ore indicator models are used to make adjustments in the percentage of each block that is ore. An ore indicator value of 1 means that the block is totally ore. An ore indicator value of 0 (zero) means the block is totally waste. If the use ore indicator box is checked, then the user must specify the MODEL to use via the command button directly to the right of the checkbox.

The cutoff grades are specified by the NUMBER OF CUTOFFS and the ascending CUTOFF GRADES. At this point, the cutoffs are not classified as ore, lowgrade, or waste. Cutoffs are made relative to the primary mineral.

The grade categories are selected via two pulldown menus at the base of the cutoff entry fields. If no lowgrade interval is desired, then choose the same cutoff for ORE and for LOWGRADE. The ORE cutoff must be higher than the LOWGRADE cutoff.

The fixed DENSITIES for each rock type are entered in the second input screen, using units of cubic feet per ton (English) or tonnes per cubic meter (metric) for each of the rock types present in the rock model.

The fixed slope angles for pit expansion are entered in the third input screen. For each rock type, enter the slope angle from horizontal in degrees. A slope of 45 degrees is equivalent to a 1:1 slope. A slope of 30 degrees is shallower than 1:1, and a slope of 60 degrees is steeper than 1:1. Note that the slope angles entered here may also be used to define a slope template for the PolyMap pit digitizing program.

6.5 Digitize and Display Pit Base (Menu)

6.5.1 Introduction

The purpose of this submenu is to capture and display plan view polygons that are used in subsequent pit generation and reserves evaluation runs. Blocks whose centroids fall within the digitized pit base polygon or expanded perimeter are completely mined during evaluation. See Volume I, Sections 3.9 and 4.6 more information on pit generation conventions and methodology. The Digitize and Display Pit Base menu offers the following options:

    DIGITIZE AND DISPLAY A PIT BASE
  1. Return To Submenu
  2. Command Shell
  3. Interactive Capture of Data in Plan View
  4. Digitize Data in Plan View
  5. Plot Digitized Data in Plan View
  6. Plot Digitized Data in Perspective

Options 1 and 2 perform as in all menus. Option 3 allows the user to digitize coordinates from the keyboard, while Option 4 allows the user to digitize coordinates using a digitizing tablet. Options 5 and 6 plot the digitized data in plan view and perspective.

6.5.2 Command Shell

This menu choice enables the user to invoke commands and run external programs without exiting MicroMODEL. Refer to section 1.2 for details.

6.5.3 Set Digitizer Communication Parameters

This option allows the user to enter the button labels for the digitizing tablet that will be used with MicroMODEL. This program MUST be run before the user attempts to digitize topography or rock zones. Once this program has been successfully run, the user need not run it again, unless the digitizer puck configuration changes.

Refer to section 2.3.3 for Details.

6.5.4 Digitize Data in Plan View

This option allows the user to capture plan view polygons from pit planning and design maps. The pit polygons are used in subsequent grade and tonnage evaluation of the volume contained within the expanded or not expanded pit base.

The polygons are captured in global Northings, Eastings, and polygon elevations. The digitizer captures the Northings and Eastings. The elevations for each polygon are specified by the user at the computer keyboard.

In order to use the pit expansion feature, the polygons cannot contain any "figure eights", nor can they contain any "horse-shoe" shapes. Refer to Figure 6.1 for details.

                               FIGURE 6.1
                        DISALLOWED POLYGON SHAPES
                            FOR PIT EXPANSION

This program works in exactly the same fashion as the program in section 2.3.4. Refer to that section for details.

6.5.5 Plot Digitized Data in Plan View

The purpose of this program is to plot the plan view polygons previously entered (either interactively or with the digitizer). The output can be used to verify that the polygons and elevations have been entered correctly.

This program works in exactly the same manner as the one described in section 2.3.5.

6.5.6 Plot Digitized Data in Perspective

This option allows the user to produce a three-dimensional plot of the previously digitized polygon data for display purposes only. The perspective plot can be viewed from any point in space that lies above the grid. Several other options are available to produce the desired output.

This program plots the contents of either an ASCII file, which defaults to "POLY.PIT", or of a PolyMap map. Refer to section 2.3.6 for details.

6.6 Evaluate Digitized Pit Base

This option allows the user to evaluate the current rock model (mined or unmined) with the previously entered pit generation parameters and a digitized pit base. The rock model should be set to the configuration the user desires, with or without the last increment removed, before this program is run. For more information on utilizing the Open Pit Design (OPD) programs, refer to Volume I, Section 4.6.1.

If an OPD run has been made, and the previous increment was not updated, this program warns the user that the previous increment was not updated. This prompt serves as a warning only, reminding the user that the last increment was not updated.

If the user had intended to include the last increment in the pit model, he can exit the program at this point and update the last increment (Section 6.7).

If the user did not want the previously evaluated increment to become part of the pit model, then the user may press the "OK" button. The previously evaluated increment is overwritten by this new increment. Otherwise, press the "CANCEL"button, and update the previous increment (refer to section 6.7)

The user must enter an ANSWERSET NAME. This is also used as a RUNTIME TITLE. A checkbox allows the user to elect to automatically update the mined-out rock model at the end of the run. By selecting this checkbox, the user can avoid the need to run the program described in section 6.7.

A second checkbox allows the user to automatically convert the ending mined-out surface from this run into a cone surface. The checkbox must be selected, and the user must choose the cone surface in which to store the ending mined-out surface from the pulldown menu.

The user may apply category limits in reporting the reserves. For example, a proven/probable/possible model can be supplied, and then proven/probable reserves can be reported. To use this feature, a model label and type must be provided (e.g. IDP PPP). The user must also specify whether the limit applies only to ore, or to all blocks.

If the category limit applies only to ore, then any blocks not meeting the limit criteria are "wasted" (considered waste blocks). If the category limit applies to ore or waste, then blocks not meeting the limit criteria are ignored and are treated as though they were air blocks.

When category limits are invoked, the user must supply a list of valid codes that appear in the category model, and check the codes that the user wishes to include. The user may optionally add a description of the codes.

The user may elect to enter a separate file prefix to use for storing the results of this run. the prefix can be anything from 1 to 64 characters in length. Characters must be valid filename characters, and no internal blanks are allowed. If the prefix is left blank, then a separate set of output files is not generated. Otherwise, in addition to the standard set of output files, the a second set of same prefix files will be generated. Assume that the prefix "PHASE1-A" was entered:

    Standard Output File      Prefix File

        OPD.TON               PHASE1-A.TON
        OPDABR.PRN            PHASE1-A.ABR
        OPDSUM.PRN            PHASE1-A.SUM
        OPDDET.PRN            PHASE1-A.DET

The pit evaluation program evaluates the digitized pit bases according to the parameters specified, and then produces the appropriate output. If the increment meets the criteria for inclusion in the pit model, then this increment should be updated (Section 6.7). If the increment is not acceptable, then it should not be updated and the next increment is digitized. Volume I, Section 4.6 discusses the use of OPD in greater detail.

6.7 Update the Mined-Out Rock Model

After a pit evaluation run has completed (except when the user chose to automatically update the mined out model), two pit models are present in the database. The first is the rock model as it existed prior to the most recent OPD run (R200). The second rock model is a copy of the first rock model, but also includes the mined out blocks contained within the most recent OPD run (R300).

After the OPD run, the user can accept the increment by UPDATING the rock model with the last increment. This causes the increment to be included in the rock model by deleting R200 and renaming R300 to R200.

If the most recent OPD run is unacceptable, then the increment is not updated, and the next increment is evaluated. See Volume I, Section 4.6 for a discussion on the use of OPD in greater detail.

6.8 Plot the Computer Generated Pit

This program produces a plan view map of the polygons used and generated for the most recent OPD run. The program plot shows how the pit perimeters are projected through different rock types and to daylight. This program does not merge perimeter expansions from different polygon bases and is generally used to confirm the polygons generated during pit evaluation.

This program is similar to the one to Plot Digitized Data in Plan View (Section 2.3.5). Several options are not available. The user cannot specify contour labeling interval, the pen color for digitized lines is always 1, no min/max level limits can be entered, and the user is not given the option to change the digitized points file name.

6.9 Inverse the Mined Out Pit Model

This option allows the user to reverse the sign of all blocks within the rock model such that previously mined blocks become available, and previously unmined blocks become unavailable. This is useful for obtaining a sum of several increments, and phasing or scheduling within a previously defined ultimate pit shape.

To reverse the pit model, the user confirms that a reversal is desired. Since the signs of the rock codes are reversed, the rock model can be reversed a second time to obtain a nonreversed rock model. Volume I, Section 4.6 discusses the uses of a reversed rock model.

6.10 Graphical Display of the Mined Out Model (Menu)

6.10.1 Introduction

The graphical display programs, when accessed from the pit Generation and Reserves Evaluation Module, enable the user to display the rock model and post-mining topography in several methods. The Graphical Display Menu offers the following options:

    GRAPHICAL DISPLAY OF THE MINED OUT MODEL (MENU)
  1. Return To Submenu
  2. Command Shell
  3. Printer-plot of grid values
  4. Plan View Cell plot of grid values
  5. Contour grid values
  6. Perspective view of grid values
  7. Plot Cell Values in Section

The types of grid displays available are:

  1. Printer Plot (digit map - not to scale)
  2. Plan View Cell Plot showing numeric cell values (scale map)
  3. Contour Plot (scale map)
  4. Perspective View (three-dimensional fishnet - not to scale)
  5. Cell Cross Section Plot showing numeric block values (scale map)

The Printer Plot, Contouring, and Perspective Fishnet plotting programs only access the current pit model from this submodule. The Plan View Cell and Cross Section Cell plotting programs use the current pit model and/or grade models as input from this submodule. Generally, the Printer-Plot, Plan-View Cell Plotting, and Cross-Section Cell Plotting programs are the most useful for displaying the pit model.

6.10.2 Command Shell

This menu choice enables the user to invoke commands and run external programs without exiting MicroMODEL. Refer to section 1.2 for details.

6.10.3 Printer Plot of Grid Values

This program produces a single digit map of the pit model, with both positive and negative rock codes. Each digit represents a range of rock codes, and the key for the digits is printed below the digit map. This map is generally used for quick verification only, as it is not to scale.

The Answer Set Name is used to identify this particular answer set.

The user can instruct the program to print all values in the grid (no specified range) by selecting to Use Computer Search. Otherwise, the user may enter a range a range of values to be plotted on the printer plot. This range is specified by a MINIMUM and MAXIMUM VALUE. If the user enters a value range, cells outside of the range are specified by the appropriate "<" or ">" symbol.

The range of values, user defined or computer search, is divided into a user specified NUMBER OF INTERVALS. For example, given a rock model with rock codes 1 through 5, the desired range is .5 to 5.5 with intervals of 1 rock code each, the number of intervals would be:

    N = ((5.5 - 0.5) / 1) = 5

In this example, rock code 1 would be represented by the digit for 0.5 to 1.5. Rock code 2 would be the range 1.5 to 2.5, and so on. Air blocks would be designated by a "<" symbol.

With prudent selection of range values and the number of intervals, this program is very useful for quick verification and analysis of grid results.

Row and Column Clipping allows the user to plot a partial section (window) of the model area. The user defines this window with STARTING and STOPPING COLUMN, ROW and LEVEL, by entering these values into the appropriate fields. For further explanation on ROW and COLUMN CLIPPING, see chapter 8, Plotting.

6.10.4 Plan View Cell Plot of Grid Values

When accessed from the Pit Evaluation and Reserves Evaluation submenu, the Plan View Cell Plot program produces a plot that numerically displays the elevations of the combined original surface grid and mined-out OPD pit. The plots can be produced at any map scale needed. Several options are available which enable the user to design his plots as needed. Refer to section 2.9.4 for details.

6.10.5 Contour Grid Values

When accessed from the Pit Evaluation and Reserves Evaluation submenu, the Contouring program produces a topography map of the surface model merged with a mined out rock model. The rock model cannot be reversed, i.e. the rock codes inside the pit must be negative and the rock codes outside the pit must be positive.

The user can design the contour maps as needed by selecting from a variety of plotting options. The contour plots can be produced at any map scale.

Refer to section 2.9.5 for more information on the contouring program.

The post-mining topographic map is normally generated at elevation intervals equal to the bench height. If no offset is specified, the contour lines are plotted at the location of the bench toe. By specifying an offset of one-half the bench height, contour lines can be plotted at bench midpoints.

6.10.6 Perspective View of Grid Values

This option allows the user to produce a three-dimensional fishnet view of the combined mined out rock model and original topographic surface. The plots generated by this program are usually used for visualization assistance and report preparation rather than producing actual working maps.

The fishnet plot can be viewed from any point in space that lies above the grid. Several other options are available to produce the desired output.

Refer to section 2.9.6 for details on this program.

6.10.7 Plot Cell Values in Section

The Cell Cross Section option produces a cross section of the block values for the rock model and any grade model through any row or column in the model. It does not work on diagonals. Refer to section 3.8.7 for details on this program.

6.11 Money Matrix and Cone Miner (Menu)

This selection under the Pit Generation and Reserves Evaluation Module enables the user to access the money matrix generator, floating cone pit design program, and associated programs.

6.11.1 Introduction

This module enables the user to perform floating cone evaluations of a mineral deposit. A three-dimensional file of net values, called a money matrix, must be generated before running the floating cone program. The money matrix file can be displayed using the suite of display programs available in MicroMODEL. Floating cones can be displayed and evaluated using the utility programs that exist within this menu.

The Money Matrix/MicroCONER Cone Miner Menu appears below:

  1. Return To Submenu
  2. Command Shell
  3. Create Money Matrix
  4. Floating Cone Pit Design
  5. Calculate Cone Reserves
  6. List Current Cone Pits
  7. Contour Plot of Cone Pit
  8. Plan View Cell Plot of Cone Pit Topography Grid
  9. Convert current OPD pit to cone
  10. Create "cone" for doing geologic reserves
  11. Single Digit Printer Map of Cone Phases
  12. Change name of Cone
  13. Plot Cone Profiles in Section
  14. Plot Exposed Cells in Plan View

6.11.2 Command Shell

This menu choice enables the user to invoke commands and run external programs without exiting MicroMODEL. Refer to Section 1.2 for details.

6.11.3 Create Money Matrix

This menu choice runs the program that creates a money matrix file, which is needed for running floating cones. Prior to running Create Money Matrix, the user should be sure that the following items have been addressed:

  1. A GRADE MODEL LABEL must exist where the Money Matrix file will be stored.
  2. A ROCK MODEL and GRADE MODEL must exist that will be used in calculating the Money Matrix.
  3. The Initialize Pit Model and Enter Pit Generation Parameters programs must be run (see Volume II, Section 6.3 and 6.4).
  4. The Create Surface Topography program must have been run, and there can be no missing values in the 2-dimensional surface grid file. The Money Matrix Generation program will not run if there are missing surface grid values.
  5. All economic parameters should be determined, including metal prices and recoveries, mining and milling costs, G&A costs, and SRF charges.
  6. Internal and external cutoffs must be calculated, based on economic parameters. Cutoffs should be set to external values for money matrix generation. Refer to section 1.3.3.
  7. If the user plans on applying a proven/probable/possible model to the money matrix calculation, then a sub-category model needs to be created. The sub-category model can then be used to "waste" ore tons that don't meet the required confidence level. For example, a cone can be "driven" by only proven and probable material.

If prompting for OPD answersets is enabled, then the user is prompted to select the OPD answer set he wishes to use for this money matrix calculation. The user should select the desired answer set. OPD parameters for that answer set are then displayed on the screen. These should be checked and verified before continuing. If the values are correct, then enter RETURN to continue. If the values are not correct, enter RETURN, then enter QUIT at the next prompt to exit the program. If the lowgrade cutoff and the ore cutoff are the same for the OPD answer set selected, then the user is only allowed to enter information for an ore-only case.

Note that if a variable density model or void percentage model have been selected in the OPD setup, then these models will be used in calculating block tons for the money matrix generation.

The user enters the name of this set of answers in the first edit field in Screen #1. If the user has created a money matrix file by some other method, such as through the File Manipulator program or with another modeling system, then check box "Check Here for User Created Money Matrix" should be checked. Otherwise, a leave the check box unchecked and the program allows input of all the necessary parameters.

The user must select the GRADE MODEL LABEL where the money values will be stored. By convention, the money matrix must always stored in the KRIGED grade model for that label. For example, if the grade model label is specified as number 6, then the money matrix values are stored in file G106.

CUTOFFS can be entered for each rock type, if desired. The user specifies how cutoffs will be specified in the second input screen. If the user opts for using the same cutoffs for every rock type, then the lowgrade cutoff and ore cutoff are taken from the OPD answer set. Otherwise, the user is prompted for the lowgrade cutoff and ore cutoff to use for each rock type. A large number (e.g. 999.99) can be entered as a cutoff to eliminate a rock type from being considered as lowgrade or ore.

The MINING COST should be entered in units of dollars/ton. A single mining cost can be entered for all types of material, or a cost can be entered for each ore class, rock type, or each ore class/rock type combination. The way in which these costs will be specified is chosen in the second input screen.

This mining cost should cover grade control, blasting, and loading. Mining cost is almost always split into Waste, Lowgrade, and Ore categories. In general, it is less expensive to mine waste than ore. There may be instances where the mining cost must be further separated into rock type categories. For example, one rock type may have a higher blasting cost than another. The four following examples demonstrate the various cases for mining cost entry.

Case 1:

    Split out mining cost by ore class?	(No)
    Split out mining cost by rock type?	(No)

    User enters a single mining cost (0.90)

    Rock Code   Waste   Lowgrade  Ore
       1        0.90    0.90      0.90
       2        0.90    0.90      0.90
       5        0.90    0.90      0.90

Case 2:

    Split out mining cost by ore class?	(Yes)
    Split out mining cost by rock type?	(No)

    User enters a mining cost for each ore class

    Rock Code   Waste   Lowgrade  Ore
       1        0.90    0.95      1.00
       2        0.90    0.95      1.00
       5        0.90    0.95      1.00

Case 3:

    Split out mining cost by ore class?	(No)
    Split out mining cost by rock type?	(Yes)

    User enters a mining cost for each rock type

    Rock Code   Waste   Lowgrade  Ore
       1        0.90    0.90      0.90
       2        0.95    0.95      0.95
       5        1.00    1.00      1.00

Case 4:

    Split out mining cost by ore class?	(Yes)
    Split out mining cost by rock type?	(Yes)

    User enters a mining cost for each ore class and rock type

    Rock Code   Waste   Lowgrade  Ore
       1        0.90    0.95      1.00
       2        1.00    1.10      1.25
       5        1.00    1.05      1.20

HAULAGE COSTS can be entered by level, ore class, or a combination of level and ore class. The method by which haul costs are entered is specified in input screen #2.

Haulage costs are entered in units of dollars/ton. If a single haulage cost is used, then it can either be entered here, or incorporated into the MINING COST. If haulage costs are broken out by level, then the user must enter the total NUMBER OF LEVELS which require a specific cost, the appropriate LEVEL, and the HAULAGE COST for that level. The Money Matrix Program linearly interpolates haulage costs between levels specified.

As an example of how to specify haulage costs for a complicated situation, assume that we are entering separate haulage costs for waste, lowgrade, and ore. Out of the 10 levels in our mine, we enter haulage costs for four of these levels and let the money matrix program linearly interpolate the haulage costs on other levels. Our input data is:

 Level  Waste   Lowgrade Ore

    1   0.10    0.10    0.10
    6   0.05    0.05    0.05
    8   0.03    0.05    0.04
    10  0.00    0.00    0.04

The money matrix program calculates our haulage costs as follows:

 Level  Waste   Lowgrade Ore

    1   0.10    0.10    0.10
    2   0.09    0.09    0.09
    3   0.08    0.08    0.08
    4   0.07    0.07    0.07
    5   0.06    0.06    0.06
    6   0.05    0.05    0.05
    7   0.04    0.05    0.045
    8   0.03    0.05    0.04
    9   0.015   0.025   0.04
    10  0.00    0.00    0.04

The MILLING COST is entered in units of dollars/ton. This is the cost of grinding, leaching (or flotation, etc.), tailings disposal, etc. Like mining cost, the milling cost can be entered as one value, or broken out into either rock type, ore class, or both rock type and ore class. The method of entry is chosen in input screen #2.

General and Administrative costs (corporate overhead) should be included in the milling costs. Normally, these costs are added to the ore milling costs. For example, with an overhead charge of $2 million per year and a milling rate of 1 million tons per year, add a G&A cost of $2/ton to the ore milling cost.

The user may define an area in which mining will be prohibited by using a POLYGON LIMIT file. The user must select the <Yes> choice button for the "Use Polygon file to Prohibit Mining" question. If the user elects to prohibit mining, then the name of the POLYGON LIMIT file must be entered in the adjoining edit field. Normally, this file is called "POLY.NMN". Refer to section 1.3.4 for details.

The ROUNDOFF FACTOR is used to convert the calculated net block values before actually storing them in the money matrix file. The rounding factor adjusts the values down to a smaller order of magnitude so that less digits are needed to display the values. The converted values are then in a range that is more easily plotted on cell maps, etc. For large blocks, the money matrix value can easily be in the hundreds of thousands of dollars, before rounding.

The MINERAL RECOVERY is specified as a combination of percent (1 to 100) and a constant tail. A single set of recovery values can be specified, or the recovery can be broken out either by rock type, ore class, or by both rock type and ore class. For each category, the user is required to enter the recovery percent and constant tail value. If more than one mineral has been specified in the OPD parameters, then the user is required to specify recovery parameters for each individual mineral.

The recovery is calculated by first subtracting the constant tail value, and then multiplying the result by the percent recovery. For scenarios that indicate the recovery is simply a fixed percentage, the constant tail deduct is set to zero.

The SRF COST (Smelting, Refining and Freight) is specified for each mineral type, and should be entered in units of dollars/assay-unit. If your mineral is assayed in ounces, then your SRF cost should be entered in dollars/ounce. If your mineral is assayed in percent, then the SRF cost must be entered in dollars/percent. Note that dollars/percent is equivalent to twenty times the dollars/pound for an English unit project. This cost is applied to the recovered ounces, pounds, etc., for each mineral. Separate SRF charges can be entered for each rock type, if desired.

The MINERAL VALUE is specified for each mineral type, and is entered in units of dollars/assay-unit. Normally, one mineral value is entered for all rock types, but the mineral value can be split out by rock type if desired. For a gold price of $400/oz and assay in ounces, the mineral value is $400.

The MINERAL VALUE is specified for each mineral type, and is entered in units of dollars/assay-unit. Normally, one mineral value is entered for all rock types, but the mineral value can be split out by rock type if desired. For a gold price of $400/oz and assay in ounces, the mineral value is $400.

A Sub-Category Model can be used to control what type of material is used to "drive" a cone. The most common way this feature is used is to drive the cone only with proven or probable material. The model containing the sub category codes is selected, and the valid codes to use are entered. Codes that will count as ore blocks must be checked using the check box on the left column.

6.11.3.1 Example Money Matrix Calculation

The following examples demonstrate how the money matrix program assigns a net value to each block based on the program input parameters and OPD tonnage factors. To simplify these examples, it is assumed that cost and value parameters are the same for all rock types. All blocks are assumed to be on level 10, which has a haulage cost of $0.05/ton. These examples are for a hypothetical gold/silver mine.

Given:


         Block Size = 25 x 25 x 10 feet
     Tonnage Factor = 12.5 cu. ft./ton
    Lowgrade Cutoff = 0.018 ounces
   Highgrade Cutoff = 0.025 ounces
    Primary Mineral = 1 (Gold)
  Secondary Mineral = 2 (Silver)
Mining Cost (Waste) = $0.85
 Mining Cost (L.G.) = $0.90
  Mining Cost (Ore) = $1.00
Milling Cost (L.G.) = $2.75
 Milling Cost (Ore) = $8.00 (includes G&A)
       Haulage Cost = $0.05 (level 10)
         Gold Value = $400.00/oz
       Silver Value = $6.00/oz
    Gold SRF Charge = $5.00/oz
  Silver SRF Charge = $0.25/oz
    Rounding Factor = 100
         Tons/Block = (25x25x10)/12.5 = 500

Recoveries for Ore:

 Gold Recovery

   Constant tail = 0.005
        Recovery = 100.0 percent

 Silver Recovery

   Constant tail = 0.00
        Recovery = 60 percent

Recoveries for Lowgrade:

 Gold Recovery

   Constant tail = 0.005
        Recovery = 100.0 percent

 Silver Recovery

   Constant tail = 0.00
        Recovery = 40.0 percent


Example 1:

Example 2:

Example 3:

  • Block grades are gold = 0.040, silver = 1.0
  • Block gold grade of 0.040 is above ore cutoff of 0.025, therefore, treat this as an ore block.
  • Cost to mine 1 ton = 1.00
  • Cost to haul 1 ton = 0.05
  • Milling cost = 8.00
  • Mine/Mill Total cost = 9.05
  • Recovered gold/ton = (0.040 - 0.005) x 100 = 0.035 oz
  • Recovered silver/ton = (1.0-0.0) x 0.60 = 0.60 oz
  • Value/ton gold = 0.035 x (400.00 - 5.00) = 13.83
  • Value/ton silver = 0.60 x(6.00 - 0.25) = 3.45
  • Total metal value = 13.83 + 3.45 = 17.28
  • Net Value = 17.28 - 9.05 = 8.23
  • Value per block = 8.23 x 500 = 4115.00
  • Round for storage = 4115.00/100 = 41.15
  • Some of the formulas used in the above calculations are:

      Recovered Grade = (Grade - Constant Tail) x (Percent Recovery)
    
      Value = Recovered Grade x ( Mineral Value - SRF Cost )
    

    6.11.3.2 Checking Results

    After running the money matrix program, the user should carefully check a section and/or plan map plot of grades, rock, and money matrix value. Money matrix values should be calculated for several randomly selected blocks to verify the money calculations. The minimum money value calculated (refer to the money program printout) should correspond to the mining cost of a waste block. The maximum money value calculated should correspond to the highest grade block. If these minimum and maximum values do not make sense, it is possible that the cutoff values that were selected are not appropriate for the economic parameters that were used. Refer to section 6.11.3.3 for more information on selecting cutoffs.

    6.11.3.3 Cutoff Selection

    Determination of cutoff is a very important step in the floating cone analysis. Floating cones are normally designed to mine up to a break-even increment. For a set of economic parameters, there are actually two cutoff values to consider: internal break-even cutoff, and external break-even cutoff (also known as the design cutoff).

    External Break-Even Cutoff

    The External Break-Even Cutoff (EBEC) is the cutoff at which the net revenue from the mineral just covers the cost of mining and processing. If a material of this grade were sitting in the bottom of your pit, you would be ambivalent as to whether or not you mined it and processed it. The EBEC is calculated as follows:

      NET COST = NET REVENUE
    
      (cmine + chaul + cmill) = (value - SRF) x pay
    
      Where:
    
         cmine = mining cost
         chaul = haul cost
         cmill = milling cost
         value = value per unit for mineral
           SRF = SRF charges
           pay = payable portion of mineral at grade EBEC
    

    The EBEC for lowgrade in the example case discussed in the money matrix calculation would be:

        (0.90 + 0.05 + 2.75) = [( 400.00 - 5.00 ) x ( EBEC - 0.005 )]
        Solving for EBEC; EBEC = 0.0144
    

    Floating cones should be run using the External Break-Even Cutoff (EBEC). Using the EBEC, a cone will mine up to the point where an incremental slice will just pay for the mining and processing of that slice. After the cone has been designed, then reserves should be calculated using the Internal Break-Even Cutoff (IBEC).

    The IBEC is used to determine whether a block of material should be wasted or processed, as that internal block will be mined anyway (i.e., a block inside the ultimate pit limit).

    Internal Break-Even Cutoff

    The Internal Break-Even Cutoff (IBEC) is the cutoff at which the net revenue from the mineral just covers the cost of processing. If a material of this grade were loaded in a truck at the rim of your pit, you would be ambivalent as to whether or not you processed it. The IBEC is calculated as follows:

      MILL COST = NET REVENUE
    
      cmill = (value - SRF) x pay
    
      Where:
    
         cmill = milling cost
         value = value per unit for mineral
           SRF = SRF charges
           pay = payable portion of mineral at grade IBEC
    

    The IBEC for lowgrade in the example case discussed in the money matrix calculation would be:

        (2.75) = (400.00 - 5.00) x (IBEC - 0.005)
    
        Solving for IBEC; IBEC = 0.0120
    
    

    6.11.3.4 Prohibiting Mining by the Coner

    The money matrix generation program has a built-in feature that allows the user to prohibit mining in an area defined by a closed polygon. This option can be used in situations where mining must be restricted due to land ownership, environmental concerns, etc. To enable this option, the user must create a file (normally called "POLY.NMN") in the project directory. The format of this file is as follows:

    Eastings and northings must be entered in world coordinates. The last point in the file does not need to be the same as the first point, because the program assumes closure for the polygon.

    In the input portion of the money matrix, there is a choice box for electing to use a polygon file to prohibit mining. By choosing YES, and then specifying the file name, this feature is invoked. The inhibit mining works as follows:

    1. Each block in the money matrix model is calculated as it normally would be.
    2. For every level in a vertical column of material of a row and column that falls within the polygon boundary, the money matrix is changed to a high negative value. This effectively "poisons" these blocks.
    3. All other blocks maintain their original value.

    When the cone mining program is run on this money matrix model, any cones that try to mine into the poisoned area must carry the high cost of these blocks. It is possible that a cone may mine one or two blocks into a poisoned area. If this happens, then the polygon boundary may have to be pushed in to compensate. If the boundary is changed, the money matrix program must be rerun. In most cases, the effect of poisoning is sufficient to prevent any mining in the area defined by the polygon file.

    6.11.4 Floating Cone Pit Design

    This menu choice runs the floating cone program. Prior to running floating cones, you must have:

    The ANSWER SET NAME is used to identify this set of cone run parameters.

    The STARTING PIT NUMBER refers to the pit number in the cone pit data base that is used as a starting surface topography for this cone run. If this is the first cone run, then the starting pit number should be entered as "0" to select original topography.

    The ENDING PIT NUMBER refers to the pit number in the cone pit data base that is used to store the resulting topography surface from this cone run. As an example, if the user selects "7" as the ENDING PIT NUMBER, then the final topographic surface from this cone run would be stored in cone pit surface 7. The surface grid file name is T207.

    The MINIMUM NET PROFIT is the minimum profit per block needed before a cone is mined. The user should note that this value is specified on a per block basis, as opposed to a per ton basis. Enter "0" to design a break-even cone pit. Enter a positive number to design an above break-even pit. This feature is useful for designing multiple phases.

    The MINIMUM MINING RADIUS controls the size of the flat area at a cone apex. If this value is set to zero, then cones are mined with a "pointed" apex. A more reasonable value is one-half the block width. This value can be set to a large distance to insure that there is sufficient clearance on the bottom bench for equipment movement. Refer to Figures 6.2 and 6.3 for more details.

                     FIGURE 6.2
        CONE DESIGN WITH MINUMUM MINING RADIUS = 0
    
                     FIGURE 6.3
        CONE DESIGN WITH MINUMUM MINING RADIUS = 20
    

    The user should be careful, in situations where the target ore zone is relatively thin in plan view. If the minimum radius is set to a large value, then the cone can "set down" on a spot which is not optimal for the ore zone. Refer to Figure 6.4 for details.

                     FIGURE 6.4
        CONE DESIGN WITH MINUMUM MINING RADIUS
        TOO BIG FOR RELATIVELY SMALL ORE ZONE
    

    The LOWEST LEVEL to mine from can be used to limit downward progression when designing a multiple phased pit. For ultimate pit design, set this level to 1 (model bottom). The cone mining program does not evaluate cones with apex blocks on levels that are below the level containing the lowest positive money matrix value, regardless of how low this value is set.

    The NUMBER OF SCOURING RUNS specifies the number of additional runs that are made after the first cone pass. Usually, two scouring runs are needed to insure that no economic material is left in the pit. It is recommended that the user always choose the default specification of 5 scouring runs, since the cone miner program stops scouring if a particular scouring run does not mine any material. Refer to Figures 6.5 through 6.8 for an explanation of why scouring is sometimes necessary.

                   FIGURE 6.5
      STEP 1: Cone for block "A" is Evaluated.
              Cone "A" is not economic.  Column
              A is flagged as checked.
    
                   FIGURE 6.6
      STEP 2: Cone for block "B" is Evaluated.
              Cone "B" is economic, so cone "B"
              is mined.  Since column A is not
              disturbed, block "A" will not be
              rechecked.
    
                   FIGURE 6.7
      STEP 3: Start of scouring run.  Block "A"
              is re-evaluated.  Block "A" is now
              economic because mining block "B"
              removed some of the wast contained
              in the original cone for block "A".
    
                   FIGURE 6.8
      STEP 4: Block "A" is mined.  Final surface.
    
    

    The MONEY MATRIX GRADE LABEL NUMBER is the grade label number for your money matrix model. Remember that MicroMODEL automatically assumes that all money matrix models are stored as Kriged Models. Thus, if the user has a money matrix stored in grade label number 6, then the money matrix file is G106.

    Select DEGREES or RUN/RISE, depending on the slope specification convention that is used. A slope of 45 DEGREES is the same as a RUN/RISE of 1. A slope of 60 DEGREES is steeper than a slope of 45 DEGREES and is equivalent to a RUN/RISE of 0.577. A slope of 30 DEGREES is shallower than a slope of 45 DEGREES and is equivalent to a RUN/RISE of 1.73.

    The user may limit APEX SELECTION by entering the name of an apex limiting polygon file. The default name for this file is "POLY.APX". If this feature is selected, only cones with apex blocks that are located within this polygon limit (in plan view) can be considered for mining. This option is useful in cases where one project contains several distinct ore deposits within the 3-dimensional model, and each deposit needs to have a unique set of cone mining parameters. The user simply creates an apex limiting polygon file for each deposit, and then makes a separate cone run for each deposit, using the appropriate limiting polygon for each run. Refer to section 6.11.3.4 for details on the format of this file. It is exactly the same as the format of the file for inhibiting mining.

    The NUMBER OF AZIMUTH/SLOPE COMBINATIONS is used to specify the number of different slope sectors in the cone slope template. The minimum number of slope sectors is 1, while the maximum is 20. Refer to Figure 6.9 for details.

                 FIGURE 6.9
     CONE DESIGN AZIMUTH/SLOPE TEMPLATE
     AZIMUTH #1 = 60  SLOPE #1 = 45
     AZIMUTH #2 = 60  SLOPE #1 = 48
     AZIMUTH #3 =160  SLOPE #1 = 48
     AZIMUTH #4 =160  SLOPE #1 = 40
     AZIMUTH #5 =300  SLOPE #1 = 40
     AZIMUTH #6 =300  SLOPE #1 = 45
    
    

    In situations where the slope changes very much (more than a degree or so) from one sector to another, small transition zones must be inserted to minimize the edge effects that can occur between such sectors. Refer to Figure 6.10 and 6.11 for details. These figures are contour maps of a single cone "popping" from a single high grade block below a totally flat starting topo surface.

                 FIGURE 6.10
     CONE DESIGN WITH NO TRANSITION ZONES
     NOTE THE ALMOST VERTICAL CLIFFS BETWEEN
     SLOPE DOMAINS.  SLOPE TEMPLATE USED IS
     THAT IN FIGURE 6.9
    
    
                 FIGURE 6.11
     CONE DESIGN WITH SLOPE TRANSITION ZONES
     AZIMUTH #1 = 50  SLOPE #1 = 45
     AZIMUTH #2 = 70  SLOPE #1 = 48
     AZIMUTH #3 =150  SLOPE #1 = 48
     AZIMUTH #4 =170  SLOPE #1 = 40
     AZIMUTH #5 =290  SLOPE #1 = 40
     AZIMUTH #6 =310  SLOPE #1 = 45
    
    

    The AZIMUTH specifies the starting azimuth in world coordinates for a given slope. If only one azimuth is specified, then the slope that is entered for that azimuth is used everywhere.

    The SLOPE specifies the pit slope to use for the corresponding azimuth. The slope must be entered in units of DEGREES or RUN/RISE, whichever was entered previously. The cone miner linearly interpolates slope between each azimuth. To maintain a constant slope between two azimuths, the same slope must be entered at both azimuths.

    6.11.5 Calculate Cone Reserves

    This program calculates mineral reserves between two cone surfaces. The user is only required to enter the number of the upper and lower cone pits, and a run title. Reserves can be limited to an area defined in a polygon limit file.

    Reserves are reported in the same format as OPD reserves. The user should refer to Volume II, Section 6.6 for details. Once a cone surface has been created, the OPD parameters can be changed at any time if reserves must be reported in a different format. For example, the user may want to change reported cutoffs, switch to detailed output format, etc.

    The STARTING SURFACE is the cone pit surface in the cone pit data base that is used as the upper surface for reserve calculations.

    The ENDING SURFACE is the cone pit surface in the cone pit data base that is used as the lower surface for reserve calculations.

    The cone reserve program ignores vertical columns of material where the elevation of the ENDING PIT NUMBER is higher than the elevation of the STARTING PIT SURFACE. This situation should not occur in the normal progression of cone pit design.

    6.11.5.1 Limiting Reserves

    A feature exists within the cone reserve calculation program that allows the user to determine reserves within a polygonal area. This feature is useful, for example, when two separate cone pits "pop" for a given set of economic parameters. In order to summarize reserves separately for the two pits, the user should create polygon files that are of the same format as "POLY.NMN", namely:

    The user then selects the appropriate limiting polygon file name for each separate reserve run. For example, if there are two pits, the user can create two files called "POLY.ONE" and "POLY.TWO".

    6.11.6 List Current Cone Pits

    This option allows the user to list the current cone pit data base. This data base includes starting pit for the cone, date of the run, money matrix used, blocks mined, and other information. There are no prompts for this program.

    6.11.7 Contour Plot of Cone Pit

    This option allows the user to plot a contour map of a cone surface in the same manner that the original surface topography can be contoured (see section 2.9.5). In addition to the prompts from the surface contouring program, the user is asked which pit surface to use from the cone pit data base. By specifying pit surface 0 (zero), the user can display a contour plot of the original topographic surface.

    6.11.8 Plan View Cell Plot of Cone Pit Topography Values

    This option allows the user to plot surface grid cell elevations for any of the cones in the cone pit data base. The program functions the same as the plan view cell plot program for surface topography. The only difference is that the user must select which cone pit surface in the cone pit data base to display from a pulldown menu.

    6.11.9 Convert Current OPD Pit to a Cone

    The program allows the user to convert the current OPD pit model into a cone surface. One situation where this may desirable is where the user has digitized and evaluated an end-of-year pit with OPD, and now wants to design a floating cone ultimate pit starting with the end-of-year configuration instead of starting from original topography.

    The user should refer to Volume II, Section 6.9 which describes the means by which OPD changes the rock model to indicate mined vs. unmined blocks in the rock model file (R200). This program creates a 2-dimensional surface grid (cone surface file) based on the rock model values and original topographic surface elevations. For each row and column location in the model, the program checks all levels in the rock model to see if any mining has occurred at that row and column (as indicated by negative rock codes). If mining has occurred, then the surface grid is assigned the elevation of the toe of the lowest mined out level found. Otherwise, if no mining has occurred, the new surface is assigned the same elevation as the original surface grid.

    To ENTER CONE PIT SURFACE in which to store OPD configuration, the user should select the cone pit number in the cone pit data base where this OPD configuration will be stored. If the user is overwriting an existing pit, a warning is displayed to allow the user to select a different pit number, if desired.

    6.11.10 Create Cone for Running Geologic Reserves

    This option allows the user to create a surface that represents the bottom of the project. This surface can be used in conjunction with the cone reserve calculation program to determine the total geologic resource for a project.

    There are only two prompts. First, ENTER PIT NUMBER TO STORE SURFACE in. It is suggested that the user always specify the pit number corresponding to the maximum number of cone pits that can be stored (currently 20). If the specified pit has already been used, then the user is warned.

    Second, the user is asked to enter a NAME FOR THE SURFACE. Normally, the default name (Bottom of Model Surface) is used.

    6.11.11 Create Single Digit Printer Maps of Cone Phases

    This program allows the user to create single digit printer maps of the rock model or a grade model. Normally, this program is used to display blocks within a single "phase", or for multiple "phases". A "phase" is all of the material that is located between two cone surfaces.

    Three types of display are available:

    1. Ore/Waste blocks by phase
    2. Grade intervals within a phase
    3. Rock type codes for ore within a phase

    The Answerset is used to identify this set of answers.

    Select the MAP TYPE desired using the radio buttons (plan, E-W section, N-S section). To display level maps, select plans. To display sections along rows, select E-W sections. To display sections along columns, select N-S sections.

    Print every n-th level, row, or section. This option allows the user to select a subset of levels, rows, or sections to print. Only every other "n" levels, rows, or sections are printed. For example, to print every 5th level from level 5 to 80, select a minimum level of 5, a maximum level of 80, and print every "5"th level.

    Select the range of rows, columns, and levels to display. These limits define the maximum extent of blocks that can be displayed. Currently, this program has a memory limitation which restricts the number of rows x columns x levels to be less than 400000. For example, if the user wants to print level maps that are 40 rows wide by 80 columns, then the maximum number of levels that can be printed in one run is 125 (40 x 80 x 125 = 400000). This limitation means that, in some cases, it may be necessary to make several runs in order to print all levels/rows/columns that are needed.

    The STARTING COLUMN is the first column to display. The ENDING COLUMN is the last column to display.

    The STARTING ROW is the first row to display. The ENDING ROW is the last row to display.

    The STARTING LEVEL is the lowest level to display. The ENDING LEVEL is the highest level to display.

    If a GRADE MODEL is to be used, then the "use grade model" checkbox should be checked. The button adjacent to the checkbox should be used to select the model.

    If the user desires to differentiate between ore and waste blocks in a phase, then a GRADE MODEL must be used. For example, if the ore/waste cutoff is to be based on a money matrix, then specify the money matrix model. With no ore/waste differentiation, all blocks are assumed to be ore.

    The first display type, "ore/waste blocks by phase", allows the user to print a digit map showing the ore blocks and waste blocks for up to ten different phases. Each phase is defined by a cone surface (e.g., cone number 6). Ore blocks for the first phase are displayed as upper case "A", while waste blocks from the first phase are displayed as lower case "a". Ore blocks for the second phase are displayed as upper case "B", while waste blocks from the second phase are displayed as lower case "b", and so on.

    Air blocks are displayed as blanks. Ore blocks outside of any phase are displayed as "+", and waste blocks outside of any phase are displayed as "-".

    The second display type, "grade intervals within a phase", allows the user to print single characters representing different grade intervals within a single phase. Waste blocks within the phase are designated by a "-" code. Blocks outside the phase are designated by a "*" code.

    The third type of display, "rock type codes for ore within a phase", allows the user to display single characters representing different rock codes within a phase.

    The grade range symbols are entered via an input grid. The user chooses the number of codes, enters an alpha-numeric code for each choice, and a cutoff value for each choice. If rock codes within a phase was chosen, then the rock codes are entered in the Cutoff column.

    There are four RESERVED CODES, which are "_" (blank), "-", "*", and "@". These codes are used in the printouts to designate air blocks, waste inside the phase, non-air blocks that are outside the phase, and blocks that are above cutoff but below the first grade interval specified, respectively.

    Cutoff values must be entered in increasing value. The first cutoff value specified should be the same as the ore/waste cutoff. If it is higher, then blocks that are between the ore/waste cutoff and the first grade cutoff specified is printed as "@".

    The CUTOFF value that defines the ore/waste limit must be entered and is applied to the grade model that was selected. Blocks that are greater than or equal to this value are considered ore, while blocks that are less than this value are considered waste.

    On the second screen, The NUMBER OF PHASES is entered if the plot type is ore/waste blocks within a phase. Otherwise, the the number of different phases is fixed at 2 (Upper and Lower). For ore/waste blocks within a phase, original surface topography (surface number 0), is always included. It should not be counted as a phase, nor should it ever be entered as one of the phase surfaces.

    Select the phases to display via the pulldown menus.

    The UPPER PHASE is the top surface. By specifying "(0) Original Topography Surface", the user selects original surface topography.

    The LOWER PHASE is the bottom surface.

    6.11.12 Change Name of Cone

    The program allows the user to change the name of a cone that currently exists in the cone mining data base. The user is prompted for the CONE PIT NUMBER. If that pit exists, then the old name is displayed and the user is allowed to change the name of the cone surface.

    6.11.13 Plot Cone Profiles in Section

    The program allows the user to plot one or more cone profiles in section view. The program is similar to the Plot Drillholes in Cross Section Program. Section endpoints are defined, and the cone surface profiles to display are chosen. This program is especially useful in conjunction with other section plot programs, such as the Plot Cell Values in Section program. Use the MicroMODEL plot overlay capabilities to combine section plots.

    The section line of the cross section is defined by the NORTHING and EASTING of the LEFT-HAND and RIGHT-HAND points as the cross section is viewed. The TOLERANCE of the section determines the plan view distance on each side of the section line (for consistency with the drillhole section program).

    The user defines the TOP and BOTTOM ELEVATION of the cross section. VERTICAL SCALE FACTOR (greater than 1.0) or reduction (less than 1.0) of the cross section can be chosen if needed. A vertical scale factor of 1 means the cross section scale is equal to the plan view scale. It should be noted that any vertical exaggeration (or reduction) changes the character size accordingly.

    As Miscellaneous Plot Options, the user can chose from the following items.

    ELEVATION GRID LINES can be plotted across the cross section if desired at a user specified ELEVATION LINE PLOTTING INTERVAL.

    A PLAN VIEW MAP of the cross section can be displayed. If selected, A plan view the width of two times the cross section tolerance is plotted below the cross section. The user specifies whether GLOBAL GRID LINES are to be plotted, and at what GLOBAL GRID INTERVAL for the plan view box.

    The user can elect to display surface TOPOGRAPHY in profile. However, if a surface model has not yet been created (Volume II, Section 2), no topography trace appears on the plot. The PEN COLOR for the Topography Line controls the color of this item.

    The user must specify PEN COLORS for Elevation Lines, Topography Line, Northing and Easting Numbers, Cross Section Title, Plan View Title, Section Line Title, Global Grid Lines, and Section and Plan View Boxes.

    The user must enter the OVERPLOT SEPARATION TOLERANCE. Two profiles that are separated by this distance, or greater, will be displayed as two separate lines. For profiles closer than this distance, only the lower numbered cone profile will display.

    Finally, for each cone surface from 1 to 99, the user must specify a PEN COLOR to use for plotting that surface's profile. Enter zero (0) to skip the plotting of this profile. Generally, most entries for this input will be zero. Enter a positive PEN COLOR for those profiles that should be displayed.

    The TITLE BLOCK COLUMN questions are for modifying the PLOT FRAME, TITLE BLOCK or SCALE. PLOT FRAME questions deal with the PLOT FRAME EXTENT SPACE and PEN COLOR of the PLOT FRAME EXTENT LINE. The TITLE BLOCK questions concern the dimensions of the SIDE BOX, the TITLE BOX, and the COMPANY NAME BOX. The user specifies widths and heights, the title names, character heights, project number, figure number and the pen color of the internal lines. The SCALE questions control the number of intervals, the length of the intervals, the pen number and the maximum expected plot scale. For a complete discussion of the TITLE BLOCK QUESTIONS, see chapter 10, Plotting.

    The Digitized Profile program produces a scaled plot that can be output at any user specified map scale (see Volume I, Section 6.3.7).

    6.11.14 Plot Exposed Cells in Plan View

    This program plots the model blocks from a selected 3-D grade model which would be exposed for a given cone surface (2-D surface grid). It works in similar fashion to the program that plots cell values in plan view for a given bench (see section 3.8.4). However, instead of plotting values from a single bench, this program plots the block that would be exposed at the surface of the user specified cone surface.

    One use of this program would be to show the ore and waste blocks that are exposed at the bottom of an OPD mining phase. Another use is to plot the rock type that is exposed in the walls of a mined out pit.

    This program is identical to the one which produces a Plan View Cell Plot of Grid Values (Refer to Section 3.8.4). The exception is that, instead of entering a starting and stopping level number to display, the user must select the EXPOSED CONE SURFACE and the MASKING CONE SURFACE.

    The program displays blocks that are exposed at the surface of the EXPOSED SURFACE. If the elevation of this surface at a given column and row location is equal to the toe elevation for a given level, then the block that is displayed (the exposed block) will be the one level below that bench. Otherwise, the block that is displayed (the exposed block) will be the one on the level for which the surface elevation is greater than the toe and less than or equal to the crest.

    The MASKING SURFACE defines a surface that will be used to mask (keep blocks from being displayed) exposed blocks. This option is generally used to show only the blocks that have been exposed by mining (either by cone or by OPD). Exposed blocks that would be at the original surface do not plot. To skip this option and show all exposed blocks, leave the check box "Use Masking Surface" unchecked.

    The Plot Exposed Cells in Plan View program produces a scaled plot that can be output at any user specified map scale (see Volume I, Section 6.3.7).

    6.11.15 Combine Money Matrices

    This program will combine two or more money matrices, and take the "best" money value for each block in the model. The best money value is stored in the Combine Money Matrix Output file. A Process Indicator File is also created.

    The main reason this program exists is to facilitate the use of multiple process types in the OPD and coner system. Let's assume you have a deposit that contains two ore types that will be processed as two separate mill inputs. To identify which process will generate the highest revenue for each block in the model, you can create two separate money matrices. One money matrix will be based on running every block through the first milling procedure. The second money matrix will be based on running every block through the second milling procedure. For both money matrix calculations, leave the mining cost at zero. For the two money models that are generated, the one with the highest value tells us the process that generates the most revenue. If both money matrices have negative values, then that tells us that neither process is a break even proposition, and that block should be treated as waste (for the internal cutoff case).

    There needs to be one additional money matrix, which represents the block values if all blocks are treated as though they are waste. This *MUST* always be the last money matrix in the list. Process types can be assigned under two different cutoff scenarios. For pit designs, use the internal cutoff. Once a pit has been designed, you may want to reclassify things using the external cutoff choice.

    For the internal cutoff case, if the money matrix net value for an ore block is zero or negative, then this block is not considered as a possible candidate for best value. For the external cutoff case, even if the money matrix net value for an ore block goes negative, it is still considered as a possible candidate for best value. That way, as long as the net value is still higher than the waste mining cost, the process is still in the running to be selected.

    You should carefully check the results of this program, to be sure the proper process number is getting defined.

    6.12 Plot Digitized Contour Profile in Section

    This program allows the user to plot the section profiles of a given digitized surface file. Generally, these digitized surfaces are open pit designs or waste dumps.

    The section line of the cross section is defined by the NORTHING and EASTING of the LEFT-HAND and RIGHT-HAND points as the cross section is viewed. The TOLERANCE of the section determines the plan view distance on each side of the section line within which drill holes and portions of drill holes are included in the cross section. The TOLERANCE input is available so that these plots may be more easily overlayed with actual drillhole section plots.

    The user defines the TOP and BOTTOM ELEVATION of the cross section. VERTICAL EXAGGERATION (greater than 1.0) or reduction (less than 1.0) of the cross section can be chosen if needed. A vertical exaggeration of 1 means the cross section scale is equal to the plan view scale. It should be noted that any vertical exaggeration (or reduction) changes the character size accordingly.

    The program is similar to the Plot Drillholes in Cross Section Program. Section endpoints are defined, and the digitized surface profile to display are chosen. This program is especially useful in conjunction with other section plot programs, such as the Plot Cell Values in Section program. Use the MicroMODEL plot overlay capabilities to combine section plots.

    The section line of the cross section is defined by the NORTHING and EASTING of the LEFT-HAND and RIGHT-HAND points as the cross section is viewed. The TOLERANCE of the section determines the plan view distance on each side of the section line (for consistency with the drillhole section program).

    The user defines the TOP and BOTTOM ELEVATION of the cross section. VERTICAL SCALE FACTOR (greater than 1.0) or reduction (less than 1.0) of the cross section can be chosen if needed. A vertical scale factor of 1 means the cross section scale is equal to the plan view scale. It should be noted that any vertical exaggeration (or reduction) changes the character size accordingly.

    As Miscellaneous Plot Options, the user can chose from the following items.

    ELEVATION GRID LINES can be plotted on the cross section if desired at a user specified ELEVATION LINE PLOTTING INTERVAL.

    A PLAN VIEW MAP of the cross section can be displayed. If selected, A plan view the width of two times the cross section tolerance is plotted below the cross section. The user specifies whether GLOBAL GRID LINES are to be plotted, and at what GLOBAL GRID INTERVAL for the plan view box.

    The user can elect to display surface TOPOGRAPHY in profile. However, if a surface model has not yet been created (Volume II, Section 2), no topography trace appears on the plot. The PEN COLOR for the Topography Line controls the color of this item.

    The user must specify pen colors for Elevation Lines, Topography Line, Northing and Easting Numbers, Cross Section Title, Plan View Title, Section Line Title, Global Grid Lines, and Section and Plan View Boxes. The user also specifies the pen number to use for the profile of the digitized "pit."

    The digitized profile can be merged with a Cone Surface, if desired. Select the CONE SURFACE. To skip this feature, leave the check box unchecked.

    This program is meant to be used to plot either waste dump profiles or pit profiles. It will attempt to draw the profile showing face slopes and catch benches. The user is required to enter the PIT FACE ANGLE and the PIT BENCH HEIGHT.

    The user can indicate that the digitized input file is for a waste dump by checking a check button. The user must also indicate that the contours are digitized at toe elevations with a second check button. Otherwise, the program assumes that the contours are digitized at mid-bench elevations.

    Finally, the user selects the source of the digitized data for which a profile is to be plotted. The user can select an ASCII file name by pressing the "Access *.PIT Files" button. Alternatively, the user may select a PolyMap map to display by pressing the "Access PolyMap" button.

    The TITLE BLOCK COLUMN questions are for modifying the PLOT FRAME, TITLE BLOCK or SCALE. PLOT FRAME questions deal with the PLOT FRAME EXTENT SPACE and PEN COLOR of the PLOT FRAME EXTENT LINE. The TITLE BLOCK questions concern the dimensions of the SIDE BOX, the TITLE BOX, and the COMPANY NAME BOX. The user specifies widths and heights, the title names, character heights, project number, figure number and the pen color of the internal lines. The SCALE questions control the number of intervals, the length of the intervals, the pen number and the maximum expected plot scale. For a complete discussion of the TITLE BLOCK QUESTIONS, see chapter 10, Plotting.

    The Digitized Profile Section program produces a scaled plot that can be output at any user specified map scale (see Volume I, Section 6.3.7).

    6.13 Interactive Scheduler

    The Interactive Scheduler is used in scheduling multiple mineralized material types (ore) and waste. This computerized scheduling tool handles multi-phase, bench-by-bench material sequencing with variable or steady state cutoff grade strategies, and individual or combined tonnage targets by time period. The bench-by-bench sequencing of material in each phase is from the top bench to bottom bench and multiple phases can be scheduled during a time period. Partial benches (i.e. any tonnage of mineralized material or waste) can be scheduled from each phase within any time period. MANSCHED does preclude "undermining" a bench by requiring that each bench in a given phase be completely mined before the next bench below it can be started. While this constraint eliminates the possibility of "drop cutting" into ore on a bench below the current bench being mined, it does force the mine planner to sequence the material in a feasible manner and is acknowledged as a "conservative" approach.

    Prior to using the Interactive Scheduler, the mine planner must have already designed one or more mining phases and evaluated them with the OPD program. For each phase, an OPD.TON type reserves file must have been generated. The Interactive Scheduler can be used to schedule material from multiple deposits with different bench parameter definitions (bottom toe, height, number of benches).

    Mansched will allow the user to schedule mining phases that contain reserve information for multiple process types. The user must specify that multiple ore types are included in the phases, and a separate cutmat.dat file must be created for each process type.

    Special Note: When using multiple process types, the user must be sure that the primary mineral model for a given process has a non-missing grade value for all model blocks that are designated as being for that process. In addition, the user should use a very small positive cutoff value (e.g. 0.001) as the first cutoff. If multiple processes are being used, then the ore/waste separation has already been made, and there is no need to use cutoff values as a means of ore/waste separation.

    On the first input screen, the user enters the Answer Set Name, which is used to identify this particular set of input parameters. The name of the "Print by Bench File" is selected. This file contains the scheduling output by bench for each period in the schedule. The name of the "Print by Rock File" is also selected. This file contains the material scheduled in each period grouped by rock type.

    The name of the "Journal File" specifies the file which will contain a list of the scheduled mining sequence. Mining occurs in a series of steps which are entered by the user. The user defines each mining step by specifying that material comes from a certain phase, or from the stockpile. Each step is further defined by either specifying that all of the phase or stockpile is mined, or that a portion of the phase or stockpile is mined. The user can choose individual types of ore or waste, and can specify that either all the material is mined, or that a given tonnage of material is mined. The Journal File contains a list of the mining commands that were entered by the user, in sequential order. The file is a plain text file, and can be edited with the TextPad editor that is supplied with MicroMODEL.

    The user must specify the "Total Periods to Schedule". This is the total number of periods that will be scheduled, and is usually dependent on the total tons of ore available, and the yearly production target for ore. If the user is unsure of the total number of periods, then the default value of 99 should be entered. The only drawback to this is that the user must enter a target production for each ore type and for waste for every period, starting with period 1 and up to the total periods. Although it is a fairly simple process to fill in each of these values, there is no sense in filling out 99 grid boxes when all that is needed are 20 periods worth of information!

    A time period in the scheduler may be any unit of time such as months, quarters, or years. To schedule an entire deposit, the number of time periods is estimated by the summation of the production targets per period equalling the estimated total tonnage of mineralized material and waste. It follows that, adjustment of production targets per period for each ore type and waste can be used to reflect either a change in time period length or a change in production capacity for similar time period lengths.

    The "Number of Phases" is simply the total number mine phases that will be included in the schedule.

    The "Number of Ore Types" is the number of different ore types that will be scheduled. There can be up to five different ore types. Typically, there will only be two or three types of ore to schedule. The ore types are defined via a matrix of rock codes and cutoffs. A cutoff matrix is defined for every period that is scheduled.

    The display precision (number of digits after the decimal) for Tonnages and Grade are defined in two separate integer input fields. Generally, tons can be displayed to the nearest ton (set # Decimal Digits for Tons to 0).

    For each ore type that is specified, the user can enter an optional Ore Label.

    The scheduler allows the user to group ore types together into "Common Goals". This feature is generally used when more than one type of ore can be processed through a single mill circuit of fixed capacity. For example, refractory and oxide ores can both be processed by the same mill circuit, and the total capacity of the mill is 3,000,000 tons per year. Under this scenario, refractory ore and oxide ore could be grouped into Common Goal 1, and the ore target for Common Goal 1 would be set to 3 million tons per year.

    Period Names, Ore Targets, and Waste Targets are entered on the second input screen. Period Names can be up to 20 characters in length. Default names are "Period 1", "Period 2", etc. Names such as "Preproduction", "Year 2001", "Year 2002", etc. can be used. Ore and Waste targets should be entered in the same units as they were reported in the OPD program. These will either be in tons, or thousands of tons. For example, if tons were originally reported in thousands of tons, and the period production target is 2 million tons, then enter 2000. If common goals were selected, then the ton targets for ore are entered as common goal targets.

    Production targets must be provided for waste and each ore type for each time period. Material can be scheduled from the current bench of any phase. When production targets for individual ore types are met, additional material scheduled for the same ore type is stockpiled and the amount of stockpiled material is subtracted from the remaining waste capacity. This deduction from the available waste capacity help the user to maintain a total material movement within a given time period. When the production targets of both waste and all material types are exceeded, the amount of waste needed will become negative which indicates the number of tons by which the schedule has exceeded the overall total productivity target for all material moved. If during a period all of a particular material type is to be stockpiled (i.e. lowgrade material), a production target of zero will cause all of that material which is scheduled to be placed into stockpile.

    The last piece of information MANSCHED needs for each time period is a cutoff grade matrix file. This file can be the same for each time period or can be adjusted and given a different file name for each time period. The file contains a record for each rock type. The first field of each record is the rock code number. The remaining fields contain the cutoff grades each of the ore types in the same order in which they were input at the ore type prompt. Waste rocks and ore types which do not exist in a given rock type are designated as a field of 999.9. An example of the cutoff grade matrix file is shown below.

    
       1,      .005,      .013
       2,      .005,      .013
       3,      .005,      .013
       4,      .005,      .013
       5,      .005,      .013
       6,      .005,      .013
       9,      .005,      .013
      99,      .005,      .013
    
    

    The cutoff matrix file can be easily generated from the third input screen. Simply fill in the columns and rows of the input grid, and then press the "Save to Cutoff File" button. The first column should contain a list of all rock codes used in ascending order. The second column contains the cutoff value to use for ore type number 1, the third column contains the cutoff value to use for ore type number 2, etc.

    Finally, the user must define each phase that is used in the schedule. On the final input screen, the user enters the name of the phase, and selects the OPD.TON (reserve tons) file that contains the reserve information for that phase. The file name is selected by pressing the appriopriate button. The user must also specify the number of grade labels that were used, the number of rock types that were used, and whether or not the variable density option was used. Also, the value of each rock code must be entered.

    The bottom bench elevation, number of benches, and bench height of the model that was used to generate the phase reserve file must be entered. The user specifies how many cutoffs were used, and enters the value of each cutoff.

    It is strongly suggested that the user should automatically enter all of the phase information by pressing the "Autoscan a Project Directory" button, located at the bottom center of the screen. After the button is pressed, the user is then asked to select the directory (folder) containing the MicroMODEL project files for the current phase. Once the directory is selected, then the user then selects the OPD answerset that was used in generating the phase reserves. Once a phase has been defined, subsequent phases can be easily set to the same responses by selecting a phase from the pulldown menu located directly above the rock code input grid on the left side of the screen.

    Interactive Scheduler Dialog

    The "screen" which appears after the appropriate input information has been entered lists the phase number, the current bench elevation for each phase, the waste and material tonnage on each current bench, current stockpile tonnages, waste and material targets for the first period, any material currently scheduled and the remaining tonnage needed to meet target amounts, as shown in Figure 1. If a previous schedule has been run and the journal file from this run exists, then the user is asked "Use current journal file?" To use the journal file, select "Yes", to start from scratch and ignore the journal file, select "No."

    The journal file is a plain text backup file which can be edited with any text editor. This allows the user to stop a schedule if it becomes apparent that it will be infeasible and "erase" parts of the schedule or entire periods in the schedule which are undesirable and then continue the schedule rather than starting over from the very beginning.

    The scheduling process is controlled via entry of commands in the edit field located in the bottom center of the screen. These commands control the phase or stockpile, the waste or material type from the current bench of the chosen phase or stockpile, and the tonnage of each material type which is scheduled. The commands are entered in the following form:

         ?Phase ([F]inish, [S]tock, or #)Type and Tons ([A]ll or Value)
    
    Examples of responses can take the following forms:
    
         Command             Explanation
    
         F                   Finished scheduling for this time period
         1 0 A               Phase #1, 0=Waste, All the tons
         2 A                 Phase #2, Schedule all tons on the current bench
         3 2 1546            Phase #3, material type #2, 1546 tons
         S 3 785             Stockpile, material type #3, 785 tons
    
    Use a space to separate the phase, material type, and tonnage.
    

    The scheduler can be stopped immediately to make edits to any of the input data by selecting File-Exit. Another way to exit is to repeatedly enter "F" (for Finish) until the final period has been completed. An easier method is to select Finish-Finished with Total Schedule from the pulldown menu. After the last period has been "scheduled", the program stops. At this point, any required edits can be been made to the input data, MANSCHED can be run, and the journal file can be used as a starting point to continue scheduling from the edited point of exit.

    First Pass Scheduling Approach

    Although there are many ways to approach scheduling, one is chosen for discussion here which follows a step by step approach.

    1. Input data for pit phases in the order which you anticipate they will be mined. The scheduler allows you to mine phases in any order you want, but the phases appear on the dialog from top to bottom in the order in which they are input.
    2. Determine the "ore" production targets for each period.
    3. Do a "trial schedule" and meet the targets for each material type in each period. Don't worry about waste or total material movement during the "trial schedule".
    4. Upon completion of the "trial schedule" determine which periods exceed the total material movement capabilities of the mine.
    5. "Smooth" the schedule to eliminate "spikes" in total material movement by either stripping waste in an earlier period to uncover enough mineralized material by the time it is needed, or use stockpile material (if available) to meet ore production during periods of shortfall.

    Program Output

    The scheduler keeps track of each scheduling decision and, upon completion of all the time periods (entered as input for number of periods), writes results to two output files. The default file names are SCHEDBEN.PRN and SCHEDRCK.PRN. SCHEDBEN.PRN contains the phases, bench numbers, tons of waste, tons and grade by ore type, net tonnage from stockpiles, total tons and grade scheduled, ending stockpile tons and grade, total material mined and total material reclaimed from the stockpiles, for each bench scheduled. SCHEDRCK.PRN contains the tonnage and grade of each ore type summerized by rock type, by period.

    Important Note: When the scheduler runs, it creates a journal file and writes to standard print files that were specified by the user (default names SCHEDRCK.PRN and SCHEDBEN.PRN). If any input data is changed when the scheduler is rerun, these three files will be overwritten and the previous schedule data will be lost. Copy or rename these files to avoid this from happening if you wish to save a schedule and make another different schedule for consideration. Take advantage of the multiple answerset feature of MicroMODEL to simply copy the old schedule answers to a new answer set, change the file names, and start your new schedule.

    6.14 Clean-Up Directory

    This option allows the user to delete all output files created in the Data Entry Module that are no longer needed in the MicroMODEL system. The files that will be deleted are listed when the program is invoked. The output files that are deleted can always be recreated by MicroMODEL at a later date as needed. Periodically running this program increases usable disk space.