Gold is a crumb in stubborn clothes

Kazakhstan is among the top 20 countries with the largest gold reserves. And metallurgists are helped to extract precious metals by scientists developing innovative technologies.

Almost the entire periodic table is contained in the bowels of Kazakhstan. However, these riches do not lie on the surface, and even after extracting them from the depths of mining, it is necessary to make great technological, energy and financial reserves in order to seize them in full.

Mother Nature managed to hide them in the ore raw materials so that a person wanted to extract them, be kind, solve a chemical problem.

– The problem is that the quality of ore raw materials is decreasing every year: its depletion is observed, the content of harmful impurities is increasing, the proportion of hard-to-enrich, resistant ores with a high content of oxidized and secondary forms and a thin sprinkling of useful components is increasing. These trends have not spared the gold metallurgy either. Solving the problems of extracting precious metals from poor off–balance sheet or arsenic-containing ores requires the creation of new effective technologies," says Serikbol Shalgymbayev, Director of the Kazmehanobr State Scientific and Production Association of Industrial Ecology, a branch of the RSE Center for Integrated Processing of Metallurgical Raw Materials (CCPMS) of the Committee for Industrial Development of the Ministry of Foreign Affairs of the Republic of Kazakhstan, Candidate of Chemical Sciences.

As the scientist notes, the processing of stubborn gold is an urgent issue relevant to the global gold mining industry, since experts associate the further increase in the precious metal with the involvement of this type of ores in the processing. As an example, he cites the stubborn carbonaceous-arsenic sulfide ore of the Suzdal deposit of JSC FIC Alel. Its special feature is the presence of gold in a finely dispersed state in association with sulfide minerals, organic and arsenic-containing compounds.

Kazmehanobra scientists have managed to "crack" this hard nut. They have adapted the innovative HiTeCC hot cyanidation technology in relation to the stale and current "tailings" of sorption leaching of stubborn carbonaceous-arsenic sulfide ore.

– Technological regulations and a project for gold extraction have been developed, on the basis of which a hot cyanidation production plant has been built and put into commercial operation. This is the second company in the world operating on the basis of this technology. The additional output of the precious metal exceeded 400 kilograms per year in the form of a high–quality Dore alloy," Serikbol Shalgymbayev explained.

According to him, another type of gold–bearing ores that is no less common in Kazakhstan is low-quality, poor in gold content. For their processing, kazmekhanobrovtsy created and implemented a technology for heap leaching of gold, followed by metal extraction from solutions using ion-exchange resins and activated carbons.

Based on this technology, heap leaching sites were built and put into commercial operation at the Zhanan, Mukur, Suzdal, Miyaly, Mizek, Balazhal, Komarovsky, Bestube, Uzboy, Zhaltyrbulak, Vasilevsky mines. This made it possible to increase the production of gold in the republic to 10 tons per year.

According to the Ministry of Foreign Affairs of the Republic of Kazakhstan, Kazmehanobra specialists, with the assistance of colleagues from CJSC GRK Altyn-Tobe, LLP GRK Andas-Altyn, JV Saga Creek Gold Company, Semgeo, JSC Altyntau Kokshetau, Zhaltyrbulak, based on highly efficient gold desorption technology and Plants for the production of Dore gold-silver alloy have been built in Ust-Kamenogorsk, Semey, Stepnogorsk and at the Zhaltyrbulak mine in the Ulytau region.

– These enterprises have implemented the technology proposed by our scientists for the electrolysis of gold from acidic solutions using cheap anodes instead of expensive platinum ones, which has had a positive impact on cost savings when starting production. The developments turned out to be so effective that they were adopted by our neighbors. They are used by the Asi plant in China, as well as the Makmala Gold Extraction Plant in Kyrgyzstan," said Lyudmila Bolotova, Candidate of Chemical Sciences, Head of the Precious Metals Laboratory at the Kazmehanobr National Research Institute.

Complex oxidized and mixed gold-copper ores cause a lot of problems for refiners. Therefore, an innovative technology has been developed for the Jubilee deposit to remove copper from cyanide-containing gold solutions. It reduces the negative effect of copper on the processes of gold leaching and sorption.

Kazmehanobra specialists have developed technological regulations for the design of gold recovery plants for processing sulfide and mixed gold-bearing ores of AK Altynalmas JSC, according to which three gold recovery plants have been built. The technological regulations of the plant for the production of precious metals in JSC "AK Altynalmas" of the Karaganda region have also been created. The republic's new technology of ultra-fine grinding of resistant flotation concentrates has been applied here.

As noted in the Ministry of Foreign Affairs of the Republic of Kazakhstan, the implementation of these projects has allowed to increase the production of raw gold in the country. Its output in 2011 was 36.7 tons, and in 2021 it increased to 118 tons. As for refined gold, its production reached 65 tons in 2021.

To date, the National Bank of the Republic of Kazakhstan has accumulated over 400 tons of refined gold as part of the state's priority right to purchase refined precious metals. During the crisis, it ensures the stability of the national economy and allows the state to solve many problems without external borrowing.

Source: kazpravda.kz