Integrated processing of polymetallic ores: more metals, less waste

Scientists at the National Center on Complex Processing of Mineral Raw Materials of the Republic of Kazakhstan have completed a series of research and pilot tests of an innovative technology for the integrated processing of refractory polymetallic ores from the Shalkiya and Zhairem deposits.

The development is relevant because, with traditional enrichment technologies, up to 90–95% of the processed raw materials ends up as tailings, leaving a significant portion of the valuable components unused. The new technology significantly increases the utilization of mineral resources and reduces the volume of waste generated.

The development is based on the carbothermic processing of high-silicon lead-zinc ores in ore-thermal furnaces. Unlike traditional processing methods, the silica component of the ore is not stored in tailings dams but is used to produce highly sought-after metallurgical products – ferroalloys. Lead and zinc are simultaneously converted into the gas phase, followed by concentration and extraction.

During pilot tests in furnaces with capacities ranging from 80 to 630 kVA, ferrosilicon grades FS45, FS65, and FS75, ferrosilicon aluminum, aluminosilicomanganese, and new calcium- and magnesium-containing ferroalloys were produced. Process regulations and organizational standards were developed for the manufactured products, and quality indicators were confirmed.

An important area of research was the processing of lead-zinc sublimates. Scientists developed technologies for producing high-purity zinc grade TsV0, magnesium compounds, tribasic lead sulfate, and advanced composite electrochemical coatings with enhanced corrosion resistance. The use of sublimates reduces the consumption of expensive reactive zinc and minimizes the generation of industrial waste.

One of the key results of the project was the creation of a virtually waste-free processing system. While traditional technologies completely lose silicon in the enrichment tailings, the new technology turns it into a marketable product. Moreover, the extraction rate of lead and zinc into concentrated form exceeds 99%.

During the project's implementation, 10 process regulations were developed, more than 10 patents of the Republic of Kazakhstan were obtained, and technical specifications for the design of ferroalloy production facilities and sublimates processing complexes were prepared.

According to preliminary technical and economic calculations, the implementation of the technology will ensure a profitability of approximately 21% and will more than double the cost of manufactured products per unit of input compared to existing processing technologies.

The developed technology opens up new prospects for the development of refractory deposits in Kazakhstan, the advancement of deep processing of mineral raw materials, and the creation of high-added-value industries. The project is in line with state policy priorities in the areas of rational resource use, the implementation of resource-saving technologies, and the reduction of environmental impact.

The integrated processing of polymetallic ores demonstrates the potential of modern domestic science to create effective technological solutions that simultaneously increase the recovery of valuable components, produce new types of products, and minimize waste generation.

Source: www.gov.kz/memleket