COMPLEX REPROCESSING OF RAW MATERIALS AND WASTES LABORATORY

Hydrides chemistry started its development from 70th years of 20th century in the Institute of Chemistry. This is very complicated direction and currently it’s is not developing very fast as it was during USSR period. In the mentioned directions, the works are mainly carried out in power engineering and thermodynamics characteristics of substances during the last years.

Fundamental investigations are carried out (“power-consuming substances” laboratory, head of the lab is U.M.Mirsaidov) in the field of power-consuming substances, basic regularities are revealed; interaction characteristics of hydrogen with light metals are defined.

Systematic investigation of phase equilibrium in triple systems “non-transitional metal borohydrides – transitional element borohydride – solvent” were carried out for the first time. Synthesis method of individual rare-earth metals (REM) borohydrides is revealed on the basis of this investigation which is based on utilization of most accessible and cheapest sodium borohydride and it is very general. The whole range of REM borohydrides, their complexes with alkali metals borohydrides and tetraalkilammonia are produced by the help of developed method for the first time. Authenticity and reliability of obtained results are certified by detailed investigation of physical and chemical properties of released compounds.

ULMAS MIRSAIDOVICH MIRSAIDOV

Scientific consultant, complex reprocessing of raw materials and wastes laboratory and ore enrichment laboratory, Leader of the theme «Physico–chemical and technological basis for mineral raw and industrial wastes reprocessing», academician AS RT, doctor of chemical sciences, professor, laureate of State award RT in the field of science and techniques Abuali Ibn Sino (2009), laureate of International premium “Islamic Educational, Scientific and Cultural Organization (ISESCO)”, holder of an Order «Dusti» (1999).

Physico–chemical analysis of several systems on the basis of hydride compounds of aluminum allowed proving the existence of complicated dual hydride complexes, to implement the simple synthesis method of earlier unknown, or known but not separated in individual conditions of hepta–, hexa– and tetrahydroaluminates of alkali and alkali-earth metals with use of binary hydrides – the most cheapest and easily accessible sources of hydrogen hydride.

Effective synthesis methods of aluminum hydride – component of solid rocket fuel are proposed on the basis of systematic investigation of binary hydrides interaction with alumohydrides metals with electron-seeking reagent of different acceptor force (chlorinated reagents, aryl (alkyl), halogenides, boro– and lithium alumohydride and etc.).

Effective method of aluminum hydride production through chloride benzyl, which is successfully passed through manufacturing tests proposed by Prof. Pulatov M.S. and other staff in 1978.

One–stage method of AlH₃ production with expected economical effect of six million rubles proposed by Prof. Gatina R.F.

A number of non-solvated lanthanides borohydrides were synthesized for the first time by doctor of chemical sciences Kurbonbekov A.

The study of chemical reactions mechanisms with participation of hydrogen atoms started in the middle of 80th year of 20th century in the Institute under the supervision of corresponding member Normatov I.Sh. The role of hydrogen atoms is shown in production of thin hydride film of the metal; electrical, magnetic properties and structure of 3-d metals’ thin films are studied. A number of valuable products are produced by plasmo-chemical method.

Works on aluminum hydride assimilation in carrying out solid-phase chemical reactions should be mentioned. AlH3 assimilation in nickel magnetic powders production was shown and the role of aluminum hydride was process initiator.

Senior research staff., doctor of chemical sciences A. Kurbonbekov

Chemical and mineral raw materials and wastes technology laboratory was established in 1987 in accordance with Republican governmental decree.

I.U.Numonov, who was at the head of V.I.Nikitin Institute of chemistry during that time, gave an instruction to deputy-director U.M.Mirsaidov to establish a laboratory and attract the relevant specialists. PhD Kh.S.Safiev (currently corresponding member of AS RT, Director, Institute of metallury) was assigned to be head of the laboratory. Currently PhD E.D.Mamatov is the head of “complex reprocessing of raw materials and wastes” laboratory which is established on the basis of “chemical and mineral raw materials and wastes technology” laboratory.

From right to left: E.D.Mamadov, head of the laboratory, A.Kurbonbekov, senior research staff., doctor of chemical sciences, P.M.Yatimov, scientific staff, D.Khudoerov, junior research staff, PhD student, A.S.Kurbonov, junior research staff.

At the present time, mineral raw materials and industrial wastes complex use are related to the problem of waste-free, low-waste and ecologically clean industrial technologies establishment, with special ranking for chemical, ore-chemical, metallurgical industrial sectors enterprises.

One of the main objectives of laboratory investigation was technology development for argil production from local raw material for Tajikistan aluminum plant.

Complex reprocessing issue of silica-alumina ores – nepheline syenite, kaoline clay, zeolite, bentonite, sialyt by acid and chloric methods were considered in the laboratory. These raw materials become important due to depletion of traditional raw materials stocks – qualitative bauxite. The wide use of mentioned silica-alumina ores is hold back, first of all, due to effective methods absence of their reprocessing. For raw materials containing large quantity of silica and less argil in comparison with qualitative bauxite, the most correct is acid methods applications, which allows already in the beginning of engineering process to carry out selective silica separation and therefore sharply reduce the material stream. However during the acid reprocessing significant problems are taking place – separation and washing out of siliceous sludge; aluminum solutions of iron purification; argil production of specific composition applicable for electrolysis; acid regeneration and acidproof apparatus application. That’s why specific attention of investigations in the whole world is focused on overcoming these problems.

Carried out investigations in the laboratory on chloric and acid decomposition of silica-alumina ores and interaction with main minerals, which are part of the ore with chlorine, sulphuric and hydrochloric acids allowed revealing optimal conditions of ore decomposition with production of high extraction indicators of valuable components simultaneously with minimum transition of silica into products.

Schematic manufacturing diagrams of complex reprocessing of nepheline syenite, kaolin, zeolite by chlorine and acid methods were proposed.

It is determined that kaoline clay and sialyts presented in large quantities in Tajikistan’s deposits are valuable initial raw materials for production of argil, coagulants and kaolins for porcelain and glazed pottery industry.

Another investigation direction of the laboratory is complex reprocessing of industry wastes. The laboratory staff revealed conditions for production of valuable products from Tajik Aluminum Plant’s wastes. Production technology of cryolite-argil concentrates from aluminum industry wastes is developed and introduced in manufacture.

The laboratory staff published more than 300 scientific articles, 5 monographs, 15 PhDs and 3 Doctoral dissertations are defended on reprocessing of mineral raw materials

30 PhDs and 7 Doctoral dissertations are defended in the field of hydride chemistry.