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See below the description of each Product Specification type and their impact on the optimisation process.
Cash Flows
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Cash Flows allow the user to specify an incremental Reward or Penalty for each |
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tonne/cubic meter/ounce |
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of material sent to a Destination. Cash Flows help the user to have better control over the fleet allocation, prioritising more profitable movements. If two rules satisfy the same condition, then the cash flow is the sum of values in each rule. |
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The chart above shows an example of the cash flow allocation for prioritising different ex-pit ore movements, namely:
The reward for direct ore movement from the Pit to the Crusher is $100, which makes this transaction the most profitable and therefore prioritised by the optimiser.
The reward for feeding a unit of high-grade ore from the Pit to the HG stockpile is $20, and medium-grade ore to the MG stockpile is $10, which prioritises moving of the high-grade over medium-grade material.
Similarly with the reclaiming of HG and MG stockpiles: since the reward for feeding the Crusher with high-grade material is higher than that for feeding the medium-grade, the HG stockpile will be given greater preference to reclaim.
Finally, the mineralised waste movement is the least profitable in comparison to ore flows, but may still be applicable in some periods, such as when high and medium grade ore is not available. If a negative cash flow is placed on this movement, feeding mineralized waste to the Crusher will be penalized because, for example, it may cost more in resource usage (machinery hours, fuel consumption, etc.) than will be received after processing a unit of this type of material.
Stockpiles and Crushers Cash Flows
Cash Flow rules for Stockpiles and Crushers define a dollars-per-unit rate on material types conveyed between Sources and Destinations. Once a rule is configured, the rate is specified in the Calendar.
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Set the Source(s), Material(s), Destination(s), and unit (Quantity Field) on which to apply the Cash Flow.
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$100 reward per feed tonne of HG.
$50 reward per feed tonne of MG.
$20 reward per feed tonne of LG.
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Cash Flow Values
Cash flow values are strictly relative. Setting all fields to "10" is the same as setting all fields to "10000".
Users are encouraged to pick values that express the relative importance of each transaction. For example, if high grade yields twice the revenue of low grade, give it twice the cash flow.
Cash Flows between Stockpiles
Movement between stockpiles incurs a default negative cash flow of (-1000) per bank cubic meter. This prevents the optimiser from going into circular rehandle loops.
To enable movement between stockpiles:
Press Add Product Specification button and from its dropdown select "Stockpile Cash Flow".
Name it as "RehandleThreshold_setTo1000", for example.
Set the units to "mining“mining_volume"” volume or Tonnes, depending on the units you schedule the material in these stockpiles.
Select the source Source and destination Destination stockpile.
In the Calendar, set the cash flow to 1001.
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Blend targets allow the user to specify a maximum or minimum ratio of some material sent into a crusher or stockpile.
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Blend X up to 10%
This example targets a 10% LG blend into the crusher, but still feeds if there is no LG available.
$100 reward per feed tonne of LG.
10% maximum ratio of LG into crusher feed.
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Recommended Usage
Take note of these behaviors when using blend ratios:
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As a general rule, the numerator and denominator should use the same units (either dry tonnes for the strict ratio, or wet tonnes for the weightometer ratio).
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Crusher or Stockpile.
These targets penalise the optimiser for going off-blend. The optimiser balances between positive Cash Flows and negative blend penalties to match blocks to Destinations.
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Item | Description | Example | ||
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Specify Min | Limits minimum ratio of the material fed from the Source to the Destination.
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Specify Max | Limits maximum ratio of the material fed from the Source to the Destination. |  | ||
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Specify Target | Specifying target also introduces “Content Deviation Penalty” input row in the Calendar. The difference between the Actual and the Target blend is subject to this Penalty multiplier specified by the user. The Penalty is summed with the Cash Flows to determine the reward or cost of blending materials into each Destination. The higher the deviation penalty, the better the optimizer will try to meet the target, but it may not be achieved due to other cash flows and objectives. |  | ||
Show Tram Lines | TBC | |||
Numerator and Denominator | Blend ratios are calculated using a Numerator and Denominator, as such the setup requires both to be populated.
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Destinations | The Destination(s) to which the blend target is applied. |  | ||
Quantity Field | The field to which the blend target is applied.
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Sources | The Source(s) for Numerator and Denominator to which the blend target is applied. | |||
View Database | Use the View Database button to open the Choose Records window, where you can graphically select and review the Sources. |  |
Example: blend X up to 10%
This example targets a 10% LG blend into the crusher, but still feeds if there is no LG available.
$100 reward per feed tonne of LG.
10% maximum ratio of LG into crusher feed.
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Use the Cash Flows to prioritise hitting limits and targets over certain periods. |
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Grade Targets
Grade targets allow the user to specify a strict grade range, and place penalty multipliers on deviation from the target. Different destinations may have different grade targets.
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