Institute of Chemistry of the Academy of Sciences of Republic of Tajikistan (Dushanbe, Republic of Tajikistan):

Mirzoev D. Kh., Senior Researcher, Candidate of Engineering Sciences
Boboev Kh. E., Leading Researcher, Candidate of Chemical Sciences

Tajik Technical University (Dushanbe, Republic of Tajikistan):

Mirzoev M. Kh., Lecturer

Nuclear and Radiation Safety Agency (Academy of Sciences of Republic of Tajikistan) (Dushanbe, Republic of Tajikistan):

Mirsaidov U. M., Executive Officer, Doctor of Chemical Sciences

The aim of this work is to research the hydrochloric decomposition of argillaceous ores of Chashma-Sang deposit (Republic of Tajikistan). The sulfuric and nitric acid methods of treatment of these raw materials have been already researched. Content of Al₂O₃ in the researched ore equals to 31,6 %, which makes it possible to use this compound as raw material for aluminum production.
X-ray analysis confirmed that argillaceous rocks include the following minerals: kaolinite, quartz, montmorillonite and hematite. During the process of decomposition of raw argillites without preliminary roasting, the extraction ratio of aluminium oxide equals to 15–20%. Decomposition of argillites with preliminary roasting at the temperature from 400 to 1000 ºC was studied for the purpose of increasing of extraction ratio of aluminium oxide.
Increasing of roasting temperature from 400 to 600 ºC causes the increasing of decomposition ratio of argillites.
Acid decomposition was carried out during 90 min at the temperature of 95–98 ºC. The concentration of acid was 18–20%, and the size of particles was –0,1 mm. On the basis of these data, the extraction ratio of Al₂O₃ equals to 99%, and extraction ratio of Fe₂O₃ equals to 51%.
The following conditions are recommended for the decomposition process of argillaceous ore:
-the process of roasting during 60 min at the temperature of 500-600 ºC;
-temperature of acid decomposition of 95-98 ºC;
-process of decomposition during 90 min;
-concentration of hydrochloric acid, equal to 18–20%;
-coarseness of materials, equal to -0,1 mm.
This article shows the material balance of one of experiments, which was carried out in optimal conditions at the hinge of 1 kg.

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