Abstract
This paper presents the results of studies on the optimization of crushing size for heap leaching of oxidized copper ore at the Berkarinskoe deposit (East Kazakhstan Region). The initial technological regulation for heap leaching was developed on the basisof comprehensive laboratory studies including chemical, phase-chemical, granulometric, mineralo-gical, X-ray diffraction, and thermogravimetric analyses, as well as laboratory percolation column tests on −10mm material, which yielded copper extraction of 78.8% over 90 days. Following industrial implementation, pilot-scale column tests on −25mm and −30mm fractions showed that the −25mm fraction achieves 70% copper extraction in 100 days with acid consumption of 99.4kg/t ore (10.4kg/kg Cu), versus 128 days and 114.7kg/t ore (11.3kg/kg Cu) for the −30mm fraction.The two pilot columns were charged with different ore types —oxidized ore (K-1, −25mm) and mixed ore (K-2, −30mm) –which differ markedly in phase composition (9.4% versus 54.4% secondary copper sulfides), so the comparison reflects ore type as well as crushing size; this is accounted for in the interpretation. The 3.5m columns simulated the heap height and the planned two-lift stacking.The −25mm crushing size was identified as the optimal parameter, enabling crushing plant throughput of 90,000t/month while maintaining extraction within regulation limits. Percolation properties remained stable throughout all tests, confirming the favorable physical characteristics of the ore.The study provides empirical, pilot-scale scale-up data linking the laboratory-based technological regulation to industrial crushing-size optimization for an operating heap leach facility.