1. Basic concept
MiningMath relies on your project constraints and Economic Values to take its decisions. Aiming to maximize the NPV, the algorithm will define destinations to send the blocks regarding all the parameters imposed.
1.1. Ore Blocks
An ore block usually has a greater/less negative economic value for the process than for the waste dump. If mined, the expected outcome for a block, in this case, is to be sent to be processed.
1.2. Waste Blocks
A waste block would have a lower/more negative economic value for the waste dump than for the process. Hence, if mined, this block should be sent to the waste dump.
In short, MiningMath understands that an ore block should be processed because it respects all the constraints inserted, based on the following hierarchy, and it increases the revenue. On the other hand, a waste block is discarded, if it disrespects any constraints and does not increase the NPV considering a global optimization view.
2. Minimum and Maximum Values
During the importation, ta pop-up will present the minimum and maximum values for each field imported, as shown in Figure 1 to 6. This screen might be overlooked, but it contains important information to confirm that everything is as it should be. Now, we will focus on its importance to identify any possible errors in regard to Economic Values.
The following situations, involving Minimum/Maximum, are worth reviewing on your functions and filters:
The minimum value at the process is greater than the maximum value for waste, which means even the less profitable block worth more when being processed than going to the waste. Therefore, all blocks might be processed in this case, shown in Figure 1.
The maximum value for the process is lower than the minimum value for waste in Figure 2. In other words, all blocks might be dumped in this case.
The maximum value for the process is quite small. The case in Figure 3 shows that even the most profitable blocks, may not generate sufficient income when processed.
The minimum value for the process is quite near to the minimum on waste, which means that sending those blocks to waste might generate similar results than processing them, as seen in Figure 4.
The maximum value for the waste is positive. This means that even waste blocks could generate a profit if dumped, as seen in Figure 5.
The values are equal for Process and Waste, like in Figure 6, which means that processing or discarding the block would have the same result. Since processing waste is usually more expensive than processing ore, it may not be worth it.
These are a lot of the validations that can be done just by analyzing it carefully. However, some of these assumptions could not reflect the reality of your project, that is why the visual validation process mentioned in the last item of this page is so important.