Production Rate Parameters
The following parameters can be used in the Parameters column of the Production rates data grid:
MAX_RATE
You use the MAX_RATE parameter to set the maximum daily rate of a resource in the specified mining locations and stockpiles.
The MAX_RATE must be defined for mining locations, or no mining occurs in the schedule.
The units for the MAX_RATE are the units that are defined in the Units column of the Resource capacities data grid. If multiple resources are assigned to the same location, they must have the same production units.
The MAX_RATE is never exceeded during scheduling calculations. The MAX_RATE is not always achieved during scheduling. Whether the MAX_RATE is achieved depends on factors such as the resource capacity, block availability, priorities, targets, and the availability of other locations where the resource is able to work.
The default value for MAX_RATE is 0, meaning that the resource is not assigned. Assigning a positive MAX_RATE value to a location assigns the resource to location.
CAPFACT
You use the CAPFACT parameter to define the capacity factor of a resource in the specified locations.
This parameter acts as a multiplier on the MAX_RATE parameter value. It is entered as a percentage. The default value of CAPFACT is 100, which has no effect on the MAX_RATE.
Note: Defining a value for CAPFACT does not affect the resource capacity.
NOMAVAIL
You use the NOMAVAIL parameter to define the nominal availability of a resource in the specified locations.
Like CAPFACT, this parameter acts as a multiplier on the MAX_RATE parameter value. NOMAVAIL is entered as a percentage. The default value for NOMAVAIL is 100, which has no effect on the MAX_RATE.
Note: Defining a value for NOMAVAIL does not affect the resource capacity.
PRODFACT
You use the PRODFACT parameter to define the production factor of a resource in a location.
Like CAPFACT and NOMAVAIL, this parameter acts as a multiplier on the MAX_RATE parameter value. PRODFACT also acts as a multiplier on the resource capacity value. This is an important difference between PRODFACT and CAPFACT and NOMAVAIL. CAPFACT and NOMAVAIL do not act as multipliers on the resource capacity.
PRODFACT is not entered as a percentage. The default value of PRODFACT is 1, which has no effect on the MAX_RATE or resource capacity.
The PRODFACT parameter can be specific to each material class. In some cases, mining rates can vary based on the material class being mined. For example, mining ore can be slower than mining waste because more care is taken, and mining of oxide material can be faster than mining of fresh rock material. To use a material-specific PRODFACT the material is included in the parameter name, separated from "PRODFACT" by a space, for example "PRODFACT OXIDE".
Note: To specify multiple material classes in a single row, you can use wildcards in the material class name.
An example of PRODFACT and how it affects the total resource capacity in a Surface scenario is as follows:
Shovel has a resource capacity of 1000. It has MAX_RATE in a location called PIT set at 1000 and a PRODFACT in this location of 0.5. The production rate from the PIT is 500 tonnes per day and 500 tonnes per day is all the shovel is capable of. There is no excess resource capacity available to be used in another location because PRODFACT also acts as a multiplier on the resource capacity.
Using the same example, if PRODFACT was not set and CAPFACT or NOMAVAIL was set to 50, the production rate from the location is the same value of 500 tonnes per day. However, because the total capacity of the shovel is set at 1000 and the total capacity is not affected by CAPFACT or NOMAVAIL, the shovel has excess capacity of 500 that is available for use in another mining location, if one is available.
An example of PRODFACT and how it affects the total resource capacity in an Underground scenario is as follows:
The resource Bogger has a resource capacity of 200. It has MAX_RATE in a location called STOPE_1101 set at 200 and a PRODFACT in this location of 0.5. The production rate from STOPE_1101 is 100 tonnes per day, and 100 tonnes per day is all the bogger is capable of. There is no excess resource capacity that available to be used in another stope because PRODFACT also acts as a multiplier on the resource capacity.
Using the same example, if PRODFACT was not set and CAPFACT or NOMAVAIL was set to 50, the production rate from the location is the same value of 100 tonnes per day. However, because the total capacity of the shovel is set at 200 and the total capacity is not affected by CAPFACT or NOMAVAIL, the shovel has excess capacity of 100 that is available for use in another mining location, if one is available.
PRODFACT_ATTRIBUTES
You use the PRODFACT_ATTRIBUTES parameter to define the attribute from which the production factor for each block is defined. For example, you can vary the production factor value for different rock types by using an attribute for which a different value is defined for each rock type in the model.
Similar to PRODFACT, PRODFACT_ATTRIBUTES affects the resource capacity and the MAX_RATE for the resources mining the location.
The value for this parameter is one or more quality names as defined in the Qualities data grid in Models tab. To assign a quality, type the quality Name, exactly as is appears in the Qualities data grid, in the Value column for the row in which you have defined the PRODFACT_ATTRIBUTES parameter. To use more than one quality, type each quality Name, separated by a space, in the Value column for the row in which you have defined the PRODFACT_ATTRIBUTES parameter.
The actual values within the mining blocks act as multipliers on the production rate when that block is being mined. A value of one has no effect on the set production rate. The production factor attributes are typically created for MineSched and calculated based on other attributes in the model.
The production factor attribute values can be any number greater than zero. Where the number is greater than one, the block is mined faster than the MAX_RATE. When the number is less than one, the block is mined slower than the MAX_RATE.
When you apply more than one quality for the PRODFACT_ATTRIBUTE, the values of all qualities are applied as multipliers to the mining rate. For example, a resource has a mining rate of 100 tonnes per day at a particular location, and PRODFACT_ATTRIBUTES at that location are defined by two qualities: QUALITY_1 and QUALITY_2. For a specific block at that location, if QUALITY_1 has a value of 0.9, and QUALITY_2 has a value of 0.85, the mining rate for that block is 100 x 0.9 x 0.85, or 76.5 tonnes per day.
Note: If grade calculations are not selected for a materials class, PRODFACT_ATTRIBUTES are not applied to the mining rate for that material class. For example, if you select grade calculations for the material class ORE and do not select grade calculations for the material class WASTE, PRODFACT_ATTRIBUTES are applied to ORE blocks but not to WASTE blocks. To use PRODFACT_ATTRIBUTES on a material class, select grade calculations for the material class.