Matrix Method: Optimizing Flotation Performance
A data analysis methodology, referred to as the matrix method, is designed to present a simple distribution of the minerals of interest over a 3x3 matrix grid of size fraction by liberation class (feed matrix), with a corresponding matrix showing how well the minerals in each matrix category were actually recovered (recovery matrix). As such these two simple matrices conveniently assembles hundreds of thousands feed, concentrate and tailings particle data into the two key parameters driving mineral processing - mineral liberation and particle size.
Changes in the feed matrix from day to day, assuming a relatively consistent grind size, can indicate changes in the ore itself (e.g., a day that has a significant increase in the amount of mineral units occurring in the fine locked fraction, despite a similar grind size, may indicate a finer-grained and potentially more challenging ore).
Changes in the recovery matrix represent changes in how the flotation circuit dealt with similarly prepared material (e.g., what proportion of the coarse liberated galena was recovered that day).
In essence, the combination of the mineral feed matrix and recovery matrix, which multiply together to show the stage recovery of the system in question, discern the difference between how the mineral was prepared for flotation in grinding (feed quality), and how it was then actually recovered in flotation (flotation performance). This can be a single flotation cell or a whole flotation circuit, as long as the circuit contains no further size reduction (such as regrinding). Cumulative sum analysis can then be applied to measure and trend the specific role of both feed quality and flotation performance on overall recovery, and which of these two is responsible for variations in recovery.
The matrix method was developed in close collaboration with Blue Coast Group, a leading provider of metallurgical consulting, flow sheet development and laboratory test work services.