AP05133041 Development of a cyanide-free technology for the extraction of gold from difficultly processing natural and man-made mineral raw materials

Project goal: development of an efficient and environmentally friendly technology for extracting gold from refractory raw materials using a cyanide-free technology based on thiosulfate leaching.

Scope of work

• Investigation of the forms of finding gold in the studied samples of ore and enrichment products.
• Preparation of samples of gold-bearing ores of the weathering crust for gravitational and flotation enrichment of the studied ores.
• Studies on gravity and flotation enrichment of a sample of gold ore.
• Carrying out experimental work on gravity and flotation enrichment of the studied ores.
• Studies of phase transformations of gold-bearing sulfide ores and enrichment products during their superfine grinding (20, 10 microns).
• Selection of grinding equipment.
• Machining in mineral processing technology.
• Studies on thiosulfate leaching of sulfide ores and enrichment products after their preliminary acid treatment (nitric and sulfuric acids) in various modes.

Relevance

In Kazakhstan, as well as in the world as a whole, sodium cyanide remains the main chemical tool for extracting gold from ore and concentrates. At the same time, the presence of gold in the raw material in accessible and oxidized forms makes it possible to use the cyanide leaching process directly after the corresponding crushing or grinding of the raw material. However, in most deposits of Kazakhstan, gold in ore is found in fine association with sulfide minerals of iron, arsenic, copper and other non-ferrous metals (pyrite, arsenopyrite, chalcopyrite, etc.). In addition, carbon is present at a number of gold deposits. The fine association of gold in minerals, the presence of carbon and other impurities in the lower forms of valence (Fe++, As+++, S--) create insurmountable difficulties for the extraction of gold by direct exposure to cyanide solvents. For this reason, these types of ores are usually referred to as refractory raw materials. The deposits with such types of ores in Kazakhstan include Bakyrchik, Bolshevik, Maikain, Akbakai and many others, which contain more than a third of the explored gold reserves of the republic [1]. The use of the cyanide process for these types of ores requires the use of a number of additional technological methods, which are mainly reduced to the preliminary oxidation of raw materials - radically by roasting the ore or concentrate; bacterial oxidation; treatment with nitric acid in the presence of pure oxygen under high pressure in an autoclave (redox process) or under normal conditions in the presence of atmospheric oxygen (nitrox or arseno processes), etc. Even with the inclusion in the ore processing technology of the mentioned, rather complex, additional stages, in a number of cases (at Bakyrchik, Bolshevik, etc.) it is still not possible to achieve acceptable indicators for the extraction of gold from raw materials. At the same time, all the mentioned methods do not ultimately exclude the environmental hazard of the technology resulting from the use of a cyanide reagent at the final stage of the technology.

These problems in the processing of refractory types of gold-bearing raw materials can be solved by using an environmentally friendly reagent based on thiosulfate compounds in the technology of their processing instead of cyanides.

An analysis of changes in the structure of gold ore raw materials over the past two or three decades shows that the relative amount of technologically “simple” gold ores that can be processed according to standard schemes is declining, and every year their share in the total balance of raw materials is noticeably decreasing. At the same time, the number of ores of complex composition is increasing, the successful processing of which requires the use of new technological methods, a combination of mechanical enrichment, flotation, hydro- and pyrometallurgy, including the use of new reagents for dissolving gold. Such ores are allocated to a separate category of refractory gold-bearing raw materials. The processing of this raw material can be solved only on the basis of creating a fundamentally new technology for processing refractory ores, based on the use of the simplest environmentally friendly schemes, as well as easily and quickly erected technological installations. Among such technologies is the thiosulfate technology for extracting gold from refractory ores. Therefore, the research and development of an innovative, highly efficient and environmentally friendly thiosulfate technology for extracting gold from refractory natural and technogenic minerals is an urgent task for the mining and metallurgical sector of the Republic.

Results

Technology for extracting gold from refractory raw materials using cyanide-free technology based on thiosulfate leaching. The main optimal parameters for crushing and grinding ore, oxidation and thiosulfate leaching of refractory carbonaceous-gold-arsenic concentrates (Bakyrchik), sulfide ores and enrichment products (Quartzite hills), electrochemical precipitation of gold directly from poor thiosulfate solutions are determined..

Answers to questions (to a representative of the department of science))

1) Economic efficiency of the project: the use of this technology for processing gold-bearing raw materials will solve a number of problems: complex use of mineral raw materials - involving difficult-to-dress gold-bearing ores in processing, additionally extracting useful components contained in the ore along with gold; increase gold recovery due to fine and fine gold and improve the ecological situation of the industrial zone.

2) Environmental part: This technology will allow to involve in industrial processing refractory gold-bearing ores with high technological performance without harming the environment and belong to the "Green Technology" in the field of gold production.

3) Which customers can we offer?

The results obtained (technology) can be presented to gold mining enterprises processing refractory raw materials. Such as: AK Altynalmas JSC, Kazakhaltyn JSC, Genesis Minerals LLP, etc.

4) Is there an existing technology? Difference?

The thiosulfate technology for the extraction of precious metals (gold, silver) has not yet been introduced anywhere on an industrial scale. Pilot-pilot semi-industrial volumes are being introduced in China, the USA and a number of other countries. In Kazakhstan, two units for the production of ammonium thiosulfate were built (Taraz and Semey) and semi-industrial technological schemes for the processing of gold-bearing raw materials were assembled at the Zherek and Kelinshektau deposits. However, due to underfunding, the project was stopped in 2007-2010.

Advantages:

The proposed technology for processing raw materials, in comparison with the currently used cyanide technology, is environmentally friendly and cost-effective. The hardware design of technological redistribution of gold extraction is significantly simplified, the capital intensity of production is reduced, and a multiplicative effect is achieved. High gold recovery rates are obtained, reaching up to 96%.

Names and surnames of the study group members with their identifiers:

1. Begalinov Abdrakhman, scientific adviser
2. Shautenov Mels Rakhimovich, Chief Researcher
3. Almenov Talgat Makulbekovich, Leading Researcher
4. Bektur Bakhytbek Kanybekovich, Senior Research Fellow

List of published works on the topic for 2018-2020

2018

• Begalinov A., Shautenov M.R., Medeuov Ch.K., Almenov T.M. «Besczianidnaya tekhnologiya izvlecheniya zoloto iz trudnoobogatimogo prirodnogo i tekhnogennogo mineral`nogo sy`r`ya».  Nauchno-tekhnicheskij i proizvodstvenny`j «Gorny`j zhurnal Kazakhstana», #10 Almaty`, 2018g. str. 23-28.
• Peregudov V.V., Shautenov M.R., Begalinov A.B. K metodike poiska i oczenke mestorozhdenij zolota. Materialy` XVII Mezhdunarodnoj nauchno-prakticheskoj konferenczii «Resursovosproizvodyashhie, malootkhodny`e i prirodookhranny`e tekhnologii osvoeniya nedr» v ramkakh programmy` modernizaczii obshhestvennogo soznaniya «Orientacziya na budushhee: dukhovnoe vozrozhdenie» g.Aktau, 17-20 sentyabrya 2018g., str. 109-111.
• Peregudov V.V., Shautenov M.R., Begalinov A.B., Levin V.L., Zayakina S.B. K tekhnologii obogashheniya zoloshlakovy`kh obrazovanij E`kibastuzskikh uglej. Materialy` XVII Mezhdunarodnoj nauchno-prakticheskoj konferenczii «Resursovosproizvodyashhie, malootkhodny`e i prirodookhranny`e tekhnologii osvoeniya nedr» v ramkakh programmy` modernizaczii obshhestvennogo soznaniya «Orientacziya na budushhee: dukhovnoe vozrozhdenie» g.Aktau, 17-20 sentyabrya 2018g., str. 113-114.
• Peregudov V.V., Shautenov M.R., Begalinov A.B., Levin V.L., Zayakina S.B. «O rezul`tatakh izucheniya zolotosul`fidny`kh rud (rudnoe telo #1) mestorozhdeniya kvarczitovy`e gorki (Severny`j Kazakhstan)» Materialy` XVII Mezhdunarodnoj nauchno-prakticheskoj konferenczii «Resursovosproizvodyashhie, malootkhodny`e i prirodookhranny`e tekhnologii osvoeniya nedr» v ramkakh programmy` modernizaczii obshhestvennogo soznaniya «Orientacziya na budushhee: dukhovnoe vozrozhdenie» g.Aktau, 17-20 sentyabrya 2018g., str. 115-116. 2019 god
• Begalinov, A., Shautenov, M., Almenov, T., Bektur, B., Zhanakova, R. Prospects for the effective use of reagents based on sulfur compounds in the technology of extracting gold from resistant types of gold ore (Article). Satbayev University, Kazakhstan. Journal of Advanced Research in Dynamical and Control SystemsVolume 11, Issue 8 Special Issue, 2019, Pages 1791-1796.

2019

• Peregudov V.V., Shautenov M.R., Begalinov A. Carla – tekhnologiya poiska mestorozhdenij zolota po zolotu. XII Kongresse obogatitelej strany` SNG, NITU MISiS, g.Moskva, 25 – 27 fevralya, 2019 goda.-S.65-67.
• Peregudov V.V., Shautenov M.R., Begalinov A., Levin V.L. Mineraly` – trassery` zolotoj mineralizaczii v tekhnologicheskikh produktakh. XII Kongresse obogatitelej strany` SNG, NITU MISiS, g.Moskva, 25 – 27 fevralya, 2019 goda. -S.67-69.
• Begalinov A., Medeuov Ch.K., Shautenov M.R., Almenov T.M. Perspektivy` e`ffektivnogo ispol`zovaniya reagentov na osnove soedinenij sery` v tekhnologii izvlecheniya zolota iz uporny`kh vidov sy`r`ya. XII Kongresse obogatitelej strany` SNG, NITU MISiS, g.Moskva, 25 – 27 fevralya, 2019 goda. -S.332-334.
• Shautenov M.R., Zayakina S.B., Peregudov V.V., Begalinov A. Issledovanie po pererabotke zoloshlakovy`kh otkhodov s polucheniem polezny`kh komponentov. Gorny`j zhurnal Kazakhstana, #10, 2019.

2020

• Begalinov, A., Almenov, T., Zhanakova, R., Bektur, B. «Analysis of the stress deformed state of rocks around the haulage roadway of the beskempir field (Kazakhstan)»  Satbayev University, Almaty, 50013, Kazakhstan. Mining of Mineral Deposits.Volume 14, Issue 3, 2020, Pages 28-36.
• Begalinov, A., Khomiakov, V., Serdaliyev, Y., Iskakov, Y., Zhanbolatov, A. «Formulation of methods reducing landslide phenomena and the collapse of career slopes during open-pit mining» (Conference Paper). Satbayev University, Kazakhstan. Volume 168, 6 May 2020, Nomer stat`i 000062nd International Conference Essays of Mining Science and Practice, RMGET 2020; Dnipro; Ukraine; 22 April 2020.
• Zhanakova, R.a, Pankratenko, A.b, Almenov, T.a, Bektur, V.a  «Rational selection of the form of support for the formation of genetic composition of rocks in the conditions of the Beskempir». aKazakh National Research Technical University named after K. I. Satpayev (Satpayev University), Almaty, Kazakhstan. bNational University of Science and Technology (MISIS), Moscow, Russian Federation. News of the National Academy of Sciences of the Republic of Kazakhstan, Series of Geology and Technical Sciences Volume 1, Issue 439, 2020, Pages 106-113
• Begalinov A.B., Shautenov M.R., Almenov T.M., Bektur B.K., Iskakov E.E. Monografiya / Besczianidnaya tekhnologiya pererabotki zolotosoderzhashhego mineral`nogo sy`r`ya – Almaty`: Izdatel`stvo KazNITU im. K.I.Satpaeva, 2020. -332 s.
• A.Begalinov, M.R.Shautenov, T.M.Almenov, Zhanakova R.K., B.K.Bektur. Uchebnoe posobie / Pererabotka trudnoobogatimogo zolotosoderzhashhego prirodnogo i tekhnogennogo sy`r`ya – Almaty`. Izdatel`stvo KazNITU im. K.I.Satpaeva, 2020. -229 s.
• A.Begalinov, M.Shautenov, S.Yusupov, T.M.Almenov, S.B.Yulusov Zayavka na patent / Sposob izvlecheniya zolota iz tiosul`fatny`kh rastvorov. 2020.