A SAG MILL THROUGHPUT ESTIMATE FOR $100!
Cost versus Precision
Current test methods can be adequate for calculating mill power requirements or throughput, but they are of limited use for the extensive, low-cost geometallurgical profiling required for large geometallurgy programs. This is because for these programs, quantity is usually more desirable than quality. It can be demonstrated that for a given budget or time frame, it is even more reliable, cost-effective, and time-efficient to average many cheap, lower fidelity data points than it is to perform a single, expensive, high-fidelity test.
Advantages of Geostatistics
Using large data sets for ore body characterization offers a secondary advantage. Once spatial correlation is introduced and geostatistics are used to generate a 3-D model of the deposit, the standard error of the mean estimate is reduced even further. Unfortunately, until now the use of geostatistics for grinding has been limited by the high cost of test work.
The Short SGI
With the new Short SGI (SAG Grindability Index) test we can measure the SGI at substantially lower cost. The calibration is generated as a byproduct of the standard SGI test, and when the test is coupled with the sample crushing and homogenization work flow of an assay lab or a metallurgical lab, the cost is much lower than current testing alternatives. For large geometallurgical programs, the cost can be as low as $100 per test! This means that for the same budget, you can generate five times the data as the traditional approach.
The scale-up models are open source and publicly available from Minerals Engineering. Download the paper from ScienceDirect now!