Institute of Solid State Chemistry at the Ural Branch of the Russian Academy of Sciences, Ekaterinburg, Russia:

S. P. Yatsenko, Professor, Chif Researcher, Doctor of Chemical Sciences, e-mail: yatsenko@ihim.uran.ru
V. M. Skachkov, Senior Researcher, Candidate of Chemical Sciences, e-mail: skachkov@ihim.uran.ru
L. А. Pasechnik, Lead Researcher, Candidate of Chemical Sciences, e-mail: pasechnik@ihim.uran.ru

Kamensk Uralsky Metallurgical Works OJSC, Kamensk-Uralsky, Russia:
B. V. Ovsyannikov, Principal Foundry Engineer, Candidate of Techical Sciences, e-mail: ovsyannikovBV@kumw.ru

Alumina sludge is a large-tonnage waste containing sufficiently high concentrations of elements IIIB and IVB of subgroups of the Periodic system. The article substantiates the possibility of extracting scandium and other components from sludge in the form of oxides or fluorides and presents options for the industrial implementation of such extraction while reducing dust and gas emissions of alumina production. The technology of obtaining and application of alumino-scandium master-alloy was created and brought to an industrial scale. The block for obtaining the initial scandium oxide on a scale of hundreds of kilograms per year with the simultaneous absorption of toxic furnace gases is introduced at the Bogoslovsky Aluminum Plant. Describes the conditions of the standard alloys of scandium, zirconium, yttrium and other rare metals through alumothermic recovery of salt melts containing fluorides and oksihlorid. Describes the preparation of aluminum-scandium alloys aluminum-base A85 injection technology powder industrial oven plant of JSC “Kamensk Uralsky Metallurgical Works”. The possibility of significant purification of the alloy from impurities is shown. The method allows to reduce the process of preparation of multicomponent alloys and provide a more uniform distribution of alloying additives in comparison with the usual practice of introducing ligatures into aluminum. Besides the obtaining of products, the involvement of red mud in the production will promote also environment improvement around alumina plants. In the carbonization technology for red mud processing, its pH decreases from >10 to 8–8.5, and carbon dioxide is additionally absorbed from exhaust gases of sintering kilns, thereby considerably reducing the impacts on air.
This research has been carried out in conformance with the state assignment and the research plan of the Institute of Solid State Chemistry at the Ural Branch of the Russian Academy of Sciences.

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