Study of the material composition of copper-sandstone ores of the Bobotog deposit

This paper presents the results of a comprehensive study of the mineral composition of copper-sandstone ores from the Bobotog deposit in the Uzun district of the Surkhandarya region, Republic of Uzbekistan, aimed at developing an efficient processing technology. A technological sample collected from banded-layered cupriferous sandstones was investigated by chemical, spectral, x-ray diffraction, mineralogical, optical-microscopic, and electron microprobe analyses. The contents of rock-forming oxides and valuable components were determined: copper content was 2.08%, silver − 6.89g/t, and gold − not less than 0.2g/t. Phase analysis showed that the share of copper sulfides in the overall balance reaches 51.59%. The principal copper-bearing minerals were established to be chalcopyrite, chalcocite, covellite, malachite, azurite and chalcanthite, while silver is mainly associated with acanthite and with the crystal lattice of chalcanthite. Particle-size analysis revealed an uneven distribution of Cu, Zn, Au and Ag across size classes: the maximum copper content (2.40%) was found in the −0.63 / +0.315mm class. The obtained data provide a scientific basis for the design of a combined flotation–hydrometallurgical flow sheet for processing this ore.

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