Multiple Destinations
Introduction
SimSched is capable of handling multiple destinations by simply adding more columns of economic values.
Moreover, the user can also take into account complex arrangements such as:
Multiple plants.
Multiple waste dumps.
Multiple stockpiles.
Multiple pits.
Overcoming the lack of a calculator.
Price fluctuation.
Fake destinations.
How to use multiple destinations?
Importing multiple destinations
Create as many columns of economic values on the Block Model as needed.
During the importation, assign each column of economic value to the field type Economic Value, as follows.
The columns highlighted in green (Process A, B, C, and Waste 1) represent all the destinations that are properly assigned Economic Value.
The column highlighted in red (Waste 2) is still, by default, assigned to Other, which means it will not be imported as an economic value.
To import Waste 2 as an economic value, the user must click over the column Waste 2, then assign it to economic value as its field type.
NOTE that SimSched will automatically assign some columns to the proper variable when using the variable name as the column name. Otherwise, the user needs to assign each column to the proper Field Type.
Adding multiple destinations to your scenario
On the Destination tab, the user will be able to add as many destinations as imported, assigning each one to a given function and a given recovery.
Recoveries must be defined to enable the Productions tab.
Defining production limits
Then, on the Productions tab, the user will be able to define production limits for each destination, as the illustration that follows.
AVOIDING MISTAKES
Do not forget to define meaningful header names for each destination so that you will remember which assumptions have been imposed to each function.
Multiple Destinations
Multiple destinations increase the level of complexity for projects with specific arrangements. In short, the user simply needs to add as many columns of Economic Values inside the Block Model. Then, during the importation, each column must be assigned to the variable/field type economic value (see the step-by-step in the Introduction).
Multiple Processing Streams (A)
The figure below exemplifies how a multi-plant project should have its block model structured. Note the economic value for routes A, B and C vary as each process has different costs, recoveries and, consequently, different functions.
OBSERVATION: SimSched will understand each plant as alternate choices, not as a series process.
Multiple Waste Dumps (B)
The following figure illustrates a project that has two waste dumps. Note the economic value for both is the same, as both imply in the same costs that basically consist of the mining cost in this case.
Multiple Stockpiles (C)
On SimSched, multiple stockpiles might be shaped in two ways, whether feeding the same plant or not. In all cases, the only way to add multiple stockpiles is by creating multiple processing streams.
Having the same number of processing plants and stockpiles, the user simply needs to create as many destinations as required on the model, then define stockpile limits on SimSched's interface.
Having a single plant and two (or more) stockpiles, the user needs to create fake processing plants on the model, replicating the same function for all them in order to create separate stockpiles. As all processing plants compose the same one in the reality, they should have a proportionately reduced limit:
Real Plant throughput: 30 Mt/year.
Fake Plant A throughput: 15 Mt/year.
Fake Plant B throughput: 15 Mt/year.
Multiple Pits (D)
SimSched requires a single model for each optimization. How to handle multiple pits and keep with a global optimization?
PLAN A: once you have non-rotated models and with the same block sizes, connect them by creating waste blocks.
PLAN B: in case your pits are far away from each other — adding waste blocks might be unfeasible — ignore the distances in-between each model, going back to Plan A.
NOTE on the video above that distances to each plant and/or from each pit are likely to be different so that the economic function would not be exactly the same.
How to anticipate further scenarios and their functions? (E)
What if I need to test a case similar to (A) and, then, a case similar to (B), using the same data set for different scenarios or even as the same scenario?
Is it possible without editing my block model over and over again?
Yes. It is possible, and the following image shows how the block model must be structured in this case.
To anticipate further scenarios and functions yet to be used, all the user needs is to create as many columns as needed, as shown in the figure below.
Note that the user does not necessarily have to use all the possible destinations at once. On SimSched, the user can import all the destinations and use a few ones into distinct scenarios by selecting only the appropriated for each run, as illustrated on the right.
. . .
The video below summarizes the steps needed to import one or more destinations at once.
AVOIDING MISTAKES
Do not forget to define meaningful header names for each destination so that you will remember which assumptions have been imposed to each function.
Fake Destinations
Fake destinations are an artifice to do some workarounds that cover variations (over time) in the recovery, ore price, costs, or combining everything, economic functions. Besides, fake destinations might be used to manually separate material of different qualities into different stockpiles, for example.
There are two possibilities when considering fake destinations:
Considering all (fake) destinations as part of the same one.
Real Plant throughput: 15 Mt/year.
Fake Plant A throughput: 15 Mt/year.
Fake Plant B throughput: 15 Mt/year.
Considering all (fake) destinations as the entire and non-coexisting plant.
Price Fluctuation
In the case of defining scenarios of price fluctuation, different ore prices for the same material should not coexist. Thus, each plant will use a specific function but will represent the same one in reality.
In the following example, columns CU_1 and CU_1.2 represent the economic values considering the default price for copper and an increase of 20% in this default price.
The main point here is the fact that these circumstances cannot coexist.
On the Production tab, add and define Period Ranges in which each function will exist.
Then, when Process 1 (CU_1) is active, use the proper production limit for it. For the other(s), define a production of zero in the same period.
Repeat this logic for any other period range you need.
The image below gives a clear example of it.
Fake Stockpiles: manually separating blocks of different qualities
This topic deserves a separate page due to its particularities.
Fixing Destinations
This topic deserves a separate page due to its particularities.
Applications
Fixing destinations to define pushbacks on SimSched PO.
Preventing a block with a certain characteristic (e.g. rock type) to be sent to a given destination (e.g. processing plant).