Features of the Presence of Precious Metals in the Zinc Production Clinker

The features of forms of occurrence of gold in technogenic raw materials—lying clinker of zinc production of the Belovsky Zinc Plant (Belovo, Kemerovo oblast)—are considered in the paper. The Belovsky plant operated from 1930 to 2003 using zinc concentrates from the Salair Mining and Concentration Plant. After the shutdown of the plant, the clinker dumps were stored at the plant’s industrial site and were repeatedly washed with acidic solutions to isolate copper. This form of storage and leaching has led to the transformation of the forms of noble metals found in clinker, which currently makes it difficult to extract gold. The gold content in clinker is at the level of 2–3 g/t, which makes gold recovery profitable. The presence of carbon in clinker complicates the known methods of both analytical detection of gold and its recovery. A method is proposed for determining the forms of occurrence and content of gold, taking into account the fact that gold may be present in the form of free fine gold and gold finely disseminated in iron and its oxides, in sulfide phases, in the quartz-silicate part of the clinker, and in the carbonaceous phase. It is shown that, depending on the storage conditions and the previous acid treatment, the forms of gold in the clinker change, which affects the choice of the technological scheme for processing the material. The share of gold available for leaching is at least 40%. The increased associativity of gold with the coal (flotation) phase and the sorption activity of coal brings significant interference into the study of the properties of gold forms in clinker, which requires preliminary carbon removal.