MiningMath

MiningMath

Loading...

Increasing the sustainable value and facilitating the decision-making process of mining projects since 2010

Percent Models

Estimated reading: 3 minutes 1848 views

A percent model divides the mineral deposit into blocks while accounting for irregularities in the deposit’s shape. Instead of assuming each block is entirely filled with material, the percent model indicates the proportion of each block that actually contains valuable material.

Although this is not a mandatory step for the optimization process, the lithology can be defined considering:

  • The tonnage of a block.
  • The value of a block.

For example, consider the information of a block as depicted below:

Block information divided into lithologies OX (Oxide), MX (Mixed), PM (Primary) and Waste.
Such a block could be classified as:
  • MX, if considering the greatest parcel in terms of tonnage.
  • PM, if considering the greatest parcel in terms of value.

MiningMath calculates tonnages using the formula: [block size × density]. The average density of a block should be the weighted average, based on the lithologies present and their respective percentages.

Recoveries should also be calculated based on the amount of material recovered from each parcel of the block.

The economic value is calculated considering the amount of material recovered from each parcel, along with their respective revenues and costs.

The economic value of a block can be calculated both with and without dilution:

  • Without dilution (Option 1): Only ore parcels feed the plant

    In this case, the economic value for the process will consist of Revenue - Costs, where:
    Revenue refers to the ore parcel (70%).
    Processing Costs refer to the ore parcel (70%).
    Mining Costs refer to the entire block (100%).

    Since MiningMath processes the entire block, input a higher value for the process limit, assuming the algorithm will feed the plant with the remaining parcel of waste (30%).

    Additional steps

    1) Create Auxiliary Columns: Track and control the tonnage limits of ore, waste, and any specific lithotype you want to monitor (as shown below).

    2) Set Auxiliary Columns as "Other": During the import process, mark these auxiliary columns as "Other." This allows you to track and control the tonnages of each material.

    3) Adjust Production Charts: Ignore the default production charts and instead use the tonnage charts set as "Other Constraints."

  • With dilution (Option 2): The entire block feeds the plant.

    In this case, the economic value for the process will consist of Revenue - Costs, where:

    Revenue refers to the ore parcel (70%).
    Processing Costs refer to the entire block (100%).
    Mining Costs refer to the entire block (100%).

    Since there is dilution, the processing limit input in the interface should reflect the actual plant limit.

    Additional steps

    1) Create Auxiliary Columns: Use auxiliary columns to provide further control of the tonnages for each parcel, ensuring accurate tracking.

    2) Adjust Processing Limit: Input the real plant limit in the processing limit field to account for dilution.

    By using these adjustments, you can accurately model the economic value of blocks with dilution.

Single block example

The figure below depicts an example of calculations for a block composed of different lithotypes and its respective economic values assuming no dilution and diluted material (download the spreadsheet here).

Share this Doc

Percent Models

Or copy link

CONTENTS
Chat Icon

Hi, it's Mima here 😇 Ask me any questions!