Minerals of the Pb-As-Sb-S и Cu-Pb-As-Sb-S systems in the ores of berezitovoe gold-polymetallic deposit (Upper Amur region, Russia)

Composition and genesis of arsenium-antimony sulfosalts of lead from the gold-bearing ores of the Berezitovoe deposit located in the eastern part of Mongol-Okhotsk orogenic belt (Upper Amur Area) were considered. Lead sulfosalts (Cu and Pb) are presented by tsugaruite, dufrenoysite, boulangerite, menehinite, bismuthic menehinite (with Bi up to 11.5 mass%), as well as minerals of jordanite-geocronite and bournonite-seligmannite series. The studies have revealed basic features of the lead sulfosalts relationship with ore and silicate minerals in different mineral association of vain ores and regularities in their composition variations. It was found that the composite arsenium-antimony sulfosalts form quasicontinuous series of solid compounds strongly differing from each other by the rate of semimetals as well as semimetals-Pb ratio in their composition. The suggestion has been made that the main typomorphic features of composition of the arsenium-antimony sulfosalts of lead from ores of the Berezitovoe deposit were determined by the specific processes of partial melting of sulfides under the high temperature metamorphism of primary polymetallic ores.

Platinum metals on the Bam gold ore deposit of the Upper Amur region

The problems of complex extraction of noble metals (Ru, Rh, Pd, Ag, Os, Ir, Pt, Au) during the development of gold-silver deposits have recently acquired increasing practical importance and relevance, due to the clear tendency to exhaust the base of available ores, their concentration of useful components and deterioration of mining processing conditions. The aim of the work was an additional study of platinum mineralization in ore objects at the large Bam gold ore deposit of the Upper Amur region and obtaining estimates of noble metal contents by atomic absorption, electrochemistry and chemical analyzes. It is shown that industrial concentrations for mining are gold and silver, and platinum metals are present at concomitant concentrations and do not reach the values required for cost-effective industrial processing. The revealed peculiarities of the Bam deposit are superposition of high-temperature and low-temperature stages of mineralization of precious metals within the ore columns, which leads to averaging of general geochemical regularities and leveling of characteristic local differences. It is noted that platinum mineralization increases with depth and proximity to the source of volcanic heat, just like the relative sample of gold.