Geometallurgical estimation of comminution indices for porphyry copper deposit applying mineralogical approach

Geometallurgy is a tool which combines knowledge of geology and mineral processing to develop a spatial based model for mineral processing. Mineral processing performance could be derived with a help of so called geometallurgical tests. Geometallurgical tests are small-scale lab tests which aim at measurements of metallurgical response of the samples. Informational about response of ore in comminution circuit can be obtained with a help of geometallurgical comminution test (GCT). Classification of ore body into different geometallurgical domains based of comminution behavior, leads to a better management and design of comminutions circuits. This work presents results of geometallurgical comminution tests of Aitik samples and classification of samples into different classes depending on their comminution properties (BWi …). The samples are further classified into different groups based on modal mineralogy using principle component analysis (PCA). Experimental work includes sample preparation for GCT, chemical assays, geometallurgical comminution test, mineralogical characterization including mineralogy, modal mineralogy, mineral liberation, element to mineral conversion and sampling of Aitik’s regrinding circuit for liberation analysis. EMC helped to make a recipe for conversion of elemental assays into modal mineralogy. BWi results revealed that the main ore zone has lower grindability as compared to foot wall and diorites. Multiple linear regression gave models for prediction of BWI in whole deposit, ore zone and diorites separately. PCA classified samples into hanging wall, footwall, main ore zone and diorites. Liberation analysis of Aitik regrinding circuit showed that the mill feed already has liberated chalcopyrite and most of the pyrite is recirculated in hydrocyclone underflow to the mill. Keywords: Geometallurgy, Grindability, liberation analysis, Aitik mine, porphyry ore