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Processing of Arsenic Bearing Ores

#K-464.2


Processing of Arsenic Bearing Ores and Byproducts with Obtaining of Low Toxic Arsenic Compounds

Tech Area / Field

  • CHE-THE/Physical and Theoretical Chemistry/Chemistry
  • ENV-WDS/Waste Disposal/Environment

Status
8 Project completed

Registration date
24.03.2003

Completion date
12.03.2008

Senior Project Manager
Yakusheva A A

Leading Institute
Kazakh National Technical University, Kazakstan, Almaty

Supporting institutes

  • Institute of Industrial Biotechnology, Kazakstan, Stepnogorsk

Collaborators

  • Universita degli Studi di L`Aquila / Dipartimento di Chimica, L`Aquila\nColorado School of Mines, USA, CO, Golden\nCenter for Advanced Mineral & Metallurgical Processing, USA, MT, Butte

Project summary

The aims of the Project are justification and development of technology of processing ore and technogenous arsenic-bearing materials with removal of arsenic in the form of sulfides or metal arsenides convenient for long-term storage and burial under oxidizing conditions in the presence of microorganisms.

The main tasks of the Project: investigating of material composition of arsenic-bearing ores and products of the processes used in the nonferrous metallurgy and determination of presence in these materials of heterotrophic microorganisms able to transform arsenic compositions; justification of the parameters of the processes of sulfidization of natural and technogenous arsenic-bearing compounds and investigation of hydrochemical parameters of obtained products; testing of arsenic-bearing products for solubility under long-term storage in the presence and in the absence of microorganisms; principle solution of the process implementation; technical-economical assessment of the proposed technologies.

The realization of the proposed technologies allows: to increase the degree of removal of arsenic from the process in the least toxic form; to process arsenic-rich ores and concentrates with the use of standard equipment; to increase extraction of metals into the ready products increasing their quality; to forecast the composition and properties of the products obtained by sulfidizing roasting; to improve labor conditions at the metallurgical enterprises, to provide for safe long-term storage of arsenic-bearing wastes on the basis of the results of investigations of the behavior of arsenic-bearing compounds under oxidizing leaching in the presence of microorganisms; to utilize not used at present sulfur-bearing products; to improve the ecological situation in the vicinity of the industrial enterprises; to apply to other technologies the results of investigations of hydrochemical properties of the processing products.

Expected Results and Their Application.

The proposed investigation is a research and development Project.

The expected results:

– data on behavior of arsenic under roasting and biochemical;


– theoretical and practical data on microbiological processes of leaching arsenic from sulfides;
– extraction from technical samples and description of clean cultures of arsenic reducing bacteria, determination of optimal conditions for microbiological processes and influence of these processes on of arsenic-bearing products storage;
– the technological parameters of the sulfidization process, allowing removal of arsenic from the technological cycle in a low-toxic form with obtaining products with standard arsenic content suitable for further processing by standard technologies;
– utilization of wastes of metallurgical and oil industries – pyrite and elemental sulfur;
– recommendations on potential variant of obtaining products in the course of utilization of arsenious sublimes or compounds suitable for realization or long-term storage;
– cutting costs of burial of arsenic-bearing wastes with improvement of the ecological situation in the vicinity of the enterprises due to the decrease of effluent of arsenic into the environment.

The developed technologies will find application in processing of high-arsenious copper and gold-bearing ores and concentrates and rendering harmless oxidized arsenious waste products.

Scope of Activities.

Fulfillment of the Project embraces the following volume of activity:

1. Study of scientific and technical literature and patents.


2. Study of the material composition of typical arsenic-bearing ore and technological products of Kazakhstan and isolation of clean cultures of microorganisms and their identification.
3. Investigation of physical-chemical mechanisms of the processes of high-temperature sulfidization of natural and thechnogenous arsenic-bearing compounds and microbiological leaching of arsenic from the sulfidized products.
4. Technological investigation of the processes of sulfidization and dissolution of arsenic-bearing compounds in the presence and in the absence of microorganisms.

Role of Foreign Collaborators: informational and methodical assistance; discussion of the main investigation results; carrying out of some precision physical-chemical investigations at the equipment of the collaborator; mutual publications; advertising of the Project results; participation in the introduction of the technologies developed on the bases of the Project.

Technical Approach and Methodology.

The following methods and approaches are used in realization of the Project:

- mixing and sulfidizing roasting of ore and waste arsenic-bearing products;


- x-ray, magnetic, petrography, particle-size, electron-microscopic and chemical analyses of initial, intermediate and final products;
- determination of properties of sulfidized briquettes and solubility of sulfidized arsenic-bearing compounds under long-term storage depending on the storage (burial) conditions;
- determination of the media for sowing microorganism cultures, isolation of heterogeneous bacteria, cross sowing of bacteria cultures, fermentation, electron- microscopy of the bacteria objects, identification and description of the cultures.

Contribution of the participating organizations.

KazNTU: investigations of sulfidization processes with processing, analysis and generalization of the results; participation in working out recommendations and the technological flow-sheet, in economic evaluation of the work; conducting mutual investigations and consultations with foreign collaborators; participation in preparing publications and advertising materials, advertising of the Project results.

IPB: investigations of the processes of microbiological leaching of arsenic from sulfide compounds; isolation of bacteria cultures from arsenic-bearing ores and investigation of their ability to leach arsenic from sulfidized compounds.

Collaborators: participation in the seminars; assisting with informational provision of the Project; consulting on methodical and methodological issues; participation in mutual publications, in preparation of advertising materials and advertising Project realization results; carrying out certain precision physical-chemical analyses or granting equipment for such analyses.


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