|
|
Process Help MINEWD - create LG Additional Arcs for mining width |
|
Process Name |
Menu Path |
Link to Command Table |
|
MINEWD |
Access using command line only |
Introduction
Creates LG 'Additional Arcs' for mining width.
How to use
The input file is a block model file containing the ore blocks of the main reef. In addition, it should have an OREVAL field which contains a value which is to be compared with the OREMIN parameter. The MINWID parameter defines the required minimum mining width; the WIDDIR parameter defines the bearing in degrees, clockwise from the positive Y-axis (North) along which the minimum mining width extension is to be made. For example, if the main reef lies North-West to South-East and dips towards the North-East, this parameter would be set to 45 degrees. The OREMIN parameter defines the minimum value of the field OREVAL for a cell to be treated as ore. The output file contains the additional arcs which can serve as input to LGST.
Files, Fields and Parameters
Input Files
|
Name |
Description |
I/O Status |
Required |
Type |
|
IN |
Input model file containing the ore blocks of the main reef. This must be a regular model with no sub-cells. |
Input |
Yes |
Undefined |
Output Files
|
Name |
I/O Status |
Required |
Type |
Description |
|
OUT |
Output |
Yes |
Undefined |
Output additional arcs file for input to LGST. |
Fields
|
Name |
Description |
Source |
Required |
Type |
Default |
|
OREVAL |
A field in the model file which contains a value which is to be compared with OREMIN. |
Undefined |
No |
Undefined |
Undefined |
Parameters
|
Name |
Description |
Required |
Default |
Range |
Values |
|
MINWID |
Minimum mining width. |
Yes |
Undefined |
Undefined |
Undefined |
|
WIDDIR |
Bearing in degrees clockwise from the postive Y-direction (North) along which the minimum mining width extension is to be made. e.g. If the main reef lies North-West to South-East and dips down towards the North-East, this might be 45 degrees. |
Yes |
North |
Undefined |
Undefined |
|
OREMIN |
Minimum value of field OREVAL for a cell to be treated as ore. |
No |
Undefined |
Undefined |
Undefined |
Notes
The input block model must be a regular model with no sub-cells.
This process generates a file of Lerchs-Grossmann structure arcs for input to LGST as 'Additional arcs' for the structure of a block model. These arcs have the effect of ensuring that a required minimum mining width is honoured at the bottom of the pit during the Lerchs-Grossmann optimization. This approach is only appropriate when the main reef:
a) Is thin compared with the minimum mining width,
b) Dips at angle which is steeper than the required mining slope, and
c) Has a clearly defined strike direction.
By 'main reef' we mean a reef (ore body) which is mined at the full depth of the mine. Other reefs may be mined as 'bonuses', and will be considered in the Lerchs- Grossmann optimization. It is necessary to decide on which side of the main reef the extra waste is to be removed to provide the necessary mining width. Given this decision, MINEWD will set up structure arcs which cause strings of blocks of the length required to reach the minimum mining width to be treated by the optimization module as though they were one block. That is, either all blocks in a string are mined or none of them are mined. This ensures that the bottom of the pit is at least the minimum mining width across.
Example
Error and Warning Messages
|
Message |
Description |
Solution |
|
|
|
|
|
|
|
|
