Underground Mine Reserves
This command calculates quantities and qualities from drillholes
or a predefined Geologic Model. This command is very similar to
Surface Mine
Reserves, but is simplified for underground application. There
are many options for reserve calculation and they are detailed in
order of appearance below.
- Modeling Method: The
reserves can be generated on-the-fly from the selected drillholes
or read from stored grid files put into a Geologic Model file.
On-the-fly calculation of reserves is generally NOT recommended, as
this provides no method of visually inspecting the model for
geologic accuracy. Instead, users are encouraged to first create a
Geologic Model file and calculate reserves from the model.
Nonetheless, on-the-fly calculations can be done for quick checks
on estimated volume, but these results should not be reported
unless the model has been verified visually with contours, cross
sections, and visual inspection of the 3D grid files. Using the
Triangulation, Inverse Distance, Kriging, Polynomial, Linear Least
Squares, ABOS Method, or Neearest Neighbor option will calculate
reserves on-the-fly. Using either the Geologic Model or Mining
Model options will calculate reserves from an existing
model.
- Use Triangulation
Subdivision: This option only applies to the modeling
methods of Triangulation and Polynomial. It subdivides the
triangles to create smoother surfaces and ensure that contours do
not cross.
- Use Global Trend
Extrapolation: This also applies only to Triangulation and
Polynomial. This option finds the average slope and direction of
the existing data and applies this slope to extrapolating where
there is not surface data.
- Make Thickness Grids:
Turning this option on will create thickness grids of the selected
or all strata. It will prompt to create an overburden thickness
grid, a key thickness grid and a key tons grid (tons/sq ft. or
m).
- Output Grids for Each
Strata: Turning this option on will create grid files for
the bottom of each strata found in the drillholes. However, it is
recommended that strata grids are instead made withe the Strata
Grids Autorun command for easier review and repeat-ability of
the grids.
- Report Areas On One
Row: This option puts all the strata quantities and
qualities for each inclusion polyline on one row. This format is
best suited for only a few strata and for printing landscape on a
page. If it is not selected, then each strata will appear on a
separate row.
- Use Property
Boundaries: Property boundaries can be used to break up the
reserve by owner and property. The commands for laying out property
boundaries are in the Boundary menu. Essentially, property
boundaries are closed polylines with owner and property ID names.
The property polylines do not need to be clipped with the
calculation inclusion perimeter or pit polylines. The program will
internally clip the properties with the calculation areas and
report the amounts by property within each pit area. If a pit or
inclusion polyline is not covered by a property, the property name
used for these quantities is "unknown". When this option is
enabled, the program will automatically detect the property
boundaries.
- Calculate Strata
Qualities: This toggle will report the average qualities for
strata attributes such as BTU and sulfur. Otherwise the program
skips calculating qualities to save time. Besides reporting the
qualities for each strata individually, the program can also report
the total averaged qualities. By default, the qualities are weight
averaged by tons which are calculated by using the strata volume
and density.
- Recovery Percent: This
window defines the percentage of Key strata volume that was
recovered in mining and to include in the volume and strip ratio
reporting. The non-recovered key strata is added to the NonKey
volume. The recovery percent in the Reserves dialog applies to all
the Key strata. These values shoudl be entered as percentages
rather than decimals (e.g. "100" for total recovery as opposed to
"1").
- Use Strata Definitions (for
Recovery): When enabled, this option will check the current
Strata
Definition file for recovery values rather than using a
constant recovery value for all key strata.
- Use Attribute (for Recovery):
Another When enalbed, this
option will check the Geologic Model (or drillholes) for a recovery
attribute grid. This allows the program to vary the recovery by
area and strata rather than simply applying a constant value to the
entire area. When enabled, the Attribute Name will need to
perfectly match the recovery attribute found in the Geologic
Model or the Drillholes (if the attribute in the model/drillholes
is "REC", enter the exact same name in this text
box).
- Min Key Thickness To
Use: This
option adds key strata to the nonkey strata above, in areas that
have thickness less than the specified minimum thickness. Also
areas with thickness less than the minimum are not counted in the
reported strata area.
- Min Separable Parting
Thickness: This setting will add the non-key parting
quantities with the key quantities when the non-key parting
thickness is less than the specified amount. For example, if the
Min Separable Parting is set to 0.5, then a non-key strata between
two key strata would be combined with the key in areas where the
non-key thickness is less than 0.5 feet. In areas where the
thickness is greater than 0.5, the non-key quantities are not
adjusted. Combining the non-key quantities to the key will add to
the total key tons and affect the strip ratio. If the non-key
strata has qualities (i.e. ASH, Sulfur), then these non-key
qualities will be composited by nonkey tons with the key tons for
the portion of non-key that is less than the minimum parting. This
will dilute the key qualities.
- Non-Key Thickness To Add To
Key: Above Key/Below Key: These fields allow you to specify
the amount of non-key thickness above and/or below the key strata
that will be combined with the key (roof and floor dilution) This
amount will be taken from the non-key quantities and added to the
key. Similar to the Min Separable Parting Thickness, the non-key
quantities will increase the total key tons which affects the strip
ratio and key volume mined. Also any non-key strata qualities will
be combined by thickness, weighted by NonKey density, and added to
the key which dilutes the key qualities. For example, if you
estimate that 0.25 feet on average of the overburden is taken with
the coal, then you could set the Non-Key to Add to Key for Above to
0.25.
- Which Strata To
Include...: This determines what will be calculated for the
reserve. If All is chosen, then all strata in the drillholes or
Geologic Model file will be calculated and reported. If Selected is
chosen, then the next window to appear is where one or multiple
strata can be selected. This can be used for multiple reserve runs,
selecting different strata to represent each bench.
- Use Named Pit Areas:
The area for calculating quantities defaults to the limits of the
selected surface entities and drillholes if no inclusion perimeters
are selected. To control the calculation area, multiple closed
polylines for areas to include and/or exclude can be selected. An
unnamed pit polyline will limit the area of calculations. Also,
areas can be labeled with site and pit names (i.e. Site 1, Pits
101, 102, ...). Surface Mine Reserves will then calculate the strip
ratios and volumes for each site and pit area. To use site and pit
names, there are several commands for creating named pit polylines
in the Boundary menu of Underground Mining. If this is selected,
then it will look just for named pit polylines, ignoring anything
else. The Specify Names button will name the polylines from inside
this command if they are not already named using commands found
under Boundary.
The Report Formatter Options dialog is the final step of the
Underground Reserves routine. It is documented elsewhere in the
manual for more details on its operation.
Prompts
Underground Mine Reserves dialog
Select surface entities and at least 3 drillholes. (Unless
using a Geologic Model.)
Select objects: select the drillhole symbols and surface
entities Surface entities can include points, lines, and
polylines.
Select the Inclusion perimeter polylines and ENTER for none:
Select objects: select the polylines or named pit
polylines The area within these polylines will be included in
the calculations. They must be closed polylines.
Select the Exclusion perimeter polylines and ENTER for none:
Select objects: select the polylines The area within
these polylines will be excluded from the calculations. They must
be closed polylines.
Make Grid File Set grid resolution
Triangulating points ... 49
Pass> 6 NULL Z values left> 0
Processing cell 2500 ...
Finished strata Y2
The above four steps are repeated for each strata.
Report Formatter
Pulldown Menu Location: StrataCalc in Geology Module
Keyboard Command: reserves