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Cyanide-less Gold Extracting from Refractory Ores


The Cyanide-less Gold Extracting Technology from Refractory Gold-containing Sulfide Ores and Concentrates

Tech Area / Field

  • CHE-IND/Industrial Chemistry and Chemical Process Engineering/Chemistry
  • ENV-APC/Air Pollution and Control/Environment

8 Project completed

Registration date

Completion date

Senior Project Manager
Alexandrov K A

Leading Institute
Kyrgyz National Technical University / Chemical Technological Scientific Research Institute, Kyrgyzstan, Bishkek


  • Center for Russia and Central Asia Mineral Studies, UK, London

Project summary

The Goal of the Project is an Elaboration of the complex Ecologically Safe Technology of The Cyanide-less Gold Extraction from Concentrates of Refractory Gold Containing Sulfide Ores, Tailing Dumps of Concentrating Mills and creating (making) the Template Pilot Processing Line for Gold Extraction from concentrates of Refractory Ores with using above-mentioned Technology.

The Project is directed for creation of the Ecologically Safe Technology, for increase the Source of Raw Materials of Gold Mining, to utilize the Tailing Dumps, and for improvement of the Ecological in Regions of Processing.

The Actuality of the Project is defined by exhaustion of deposits of monometallic and simple gold-containing ores. The part of the gold extracted from the simple in technological point of view ores, for which it is possible to use the standard scheme decreases steadily. At the same time the part of the gold extracted from the refractory gold-containing ores increases. That is why in production of gold it is necessary to involve the difficult raw materials such as: Refractory Ores, and Rocks with low contents of Gold. The Refractory Gold Containing Sulfide Ores are characterized by complex structure, by extremely thin impregnation of gold in sulfide ores (so called fine-particle gold with particle size from 1 to 5 micrometer), and by presence of components, which decrease the extraction of gold under cyanidation. Using existent technologies (Cyanide Technique and etc.) don’t give high level of Gold Extraction, also demand higher expenses for it’s using and ecologically safeness.

Under these conditions it is necessary to find out Rational and Ecologically Safe Technologies of Gold Extraction from Refractory Materials (Concentrates of Gold Containing Sulfide Ores, and Tailing Dumps), to develop technologies, allowing to increase the base of raw material source for involving in processing first of all Refractory Ores, and Gold Containing Rocks with low contents of Gold in Rock, utilization of Blade of operational fields, Tailing Dumps. This Tendency is not typical only for the Kyrgyz Republic, but for World Gold Industry as a whole.

Deficiencies of refractory and non-condition gold Processing Technology leads to increasing the volume of wastes (arsenic, cyanide), most of which are ecotoxicants negatively effecting the environment. So toxicity and volume of man-caused wastes in regions of mining and processing of refractory gold-arsenic-containing sulfide ores (Kadamjay, Tereksay) caused in crisis ecological situation of the Regional Value in Kyrgyz Republic. The solution of this problem in improvement of existing technologies and elaboration of new ecologically safe technologies of complex gold and attendant elements extraction from refractory ores.

For Gold Mining Industry it is actual the problem of gold Extraction from Tails dumps of Concentrating Mills. If we consider only the Kumtor’s Tailing Dump (The Kyrgyz Republic), which has the designed planned capacity 100 million of cubic meters of wastes, development of rational Gold Extraction Technology from Tails is perspective from waste utilization and improvement of Environment Ecology point of view.

The solution of the following Main Problems is needed for the Realization of the Project Coals:

- Elaboration the perspective Ecologically Safe Complex technology of cyanide-less Gold Extraction from Concentrates of refractory gold containing ores, Tailing Dumps.

- Composition the Technological Scheme, creation, constructing and mounting Pilot Line for Cyanide-less Gold Extraction from Concentrates of refractory ores, line which will be adapted to functioning production of Gold and Antimony;

- Approbation (industrial tests) of designed technology, and an estimation of it’s ecological safety and economic efficiency. Given recommendation of introduction this Technology.

In the base of the elaborated technology improved by the authors of the Project the Thiocarbamide Method of Gold Extraction from Gold-Containing raw materials. Elaborated technology , has several advantages and improvements, what will give an opportunity to apply in industry.

The existent Technology of Thiocarbamide Gold Extraction is not free from defects, one of which is oxidative resolution of thiourea. The Authors of the Project suggest original solution of this problem, which gives possibility to decrease the amount of used Thiourea, to essentially increase the amount of extracted gold, and to reduce the time of leaching. Previously the Thiocarbamide Method was not used in the Kyrgyz Republic Gold Industry. The technology will give possibility to process the refractory gold-containing raw materials and Tailing Dumps with using more environmentally safe method, what will decrease the value of waste products and man-caused pressure on the Regions. Technology may be used in World Gold Industry. The Method was approved in Laboratory Conditions.

The Project will be carried out by the Chemical Technological Scientific Research Institute under the Kyrgyz Technical University named after Iskhaac Razzakov (CTSRI KTU)

The Technology is original in total of proposed solutions. Installation of Pilot Line for complex gold extraction from the concentrates of refractory ores and its approbation will be realized in Production Division of functioning factory. The Pilot Line will be adapted to functioning factory of gold and antimony extraction.

The Project is based on the following scientific researches and inventions of the participants in the field of “Complex utilization of Mineral Resources and Preservation of the Environment” (1982-2002 years) among which there are:

· “Method of Gold Extraction from Gold-Containing Antimony Alloys”. Patent No. 258 on February 9, 1997 of the Kyrgyz Republic;

· “Method of Antimony Getting from Waste Products of Antimony Industry”. Patent No. 168 on March 31, 1997 of the Kyrgyz Republic;

· “Method of Gold Extraction from Refractory Gold-Containing Ores and Concentrates by Cyanide-less Method”. Applied for Patent of the Kyrgyz Republic on April 10, 2002;

· Scientific Papers and Works (look at Additional Information) [1-3].

Category of the Project – “Development of the Technology”, “Technology Demonstration”

In this Project there are 55% of military scientists and specialists.

Main results of the Project realization will be:

- Perspective Ecologically Cyanide-less Technology of Gold Extraction from Hard-to-process Raw Materials: Concentrates of Refractory Ores, Tailing Dumps;

- Technological Scheme and Sample of Pilot Line for Cyanide-less Gold Extraction from Concentrates of Refractory Ores adapted for functioning Production;

- Approbation, (tests data), estimation of ecologically safety and economical expediency of Author’s Technology, and Recommendation for one possible implementation of the given Technology into Production.

Expected, given Results:

- Allow a possibility to include in production by ecologically-safe technology Refractory Ores and Tailing Dumps and increasing the base of Gold-containing Raw Resources not only the Kyrgyz Republic, but in World Gold Extraction Industry also;

- Create the prerequisites for decreasing of man-caused pressure on Gold-mining Regions in consequence of decreasing Waste value and Toxicity during mining and extracted, which improves the ecological situation in Region;

- Allow the continuation of work by improvement and creation of Ecologically Safe and economically effective Complex Technologies

Potential Role of Foreign Collaborators under fulfilling of the given Project:

- Information exchange;

- Participation in Technical estimation;

- Organization of joint Symposiums and Working Meeting (Seminars);

- Participation in practical in Solution of the Project Results;

- Technical Participation in Solution of the Project Problems.

The Project meets all ISTC requirements. The support of this Project will play an important socio-economic role for Kyrgyz Republic, because scientific potential of leading researches previously engaged into military establishments orders of former USSSR previously, will redirected on solving peaceful aims. Also the support of this Project will give possibility to the scientists of Republic to integrate into International Scientific Society, and community will help in the decision of National and International Problems. The Project Realization will promote Science, Technical, and Technology Progress, and will create the basis for the Ecology and Economic improvement of Kyrgyz Republic, and also for World Society as whole.


The International Science and Technology Center (ISTC) is an intergovernmental organization connecting scientists from Kazakhstan, Armenia, Tajikistan, Kyrgyzstan, and Georgia with their peers and research organizations in the EU, Japan, Republic of Korea, Norway and the United States.


ISTC facilitates international science projects and assists the global scientific and business community to source and engage with CIS and Georgian institutes that develop or possess an excellence of scientific know-how.

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