Siberian Federal University, Krasnoyarsk, Russia:

S. G. Shakhray, Assistant Professor (Chair of Technosphere Safety of Mining and Metallurgical Production), e-mail: shahrai56@mail.ru
A. P. Skuratov, Professor

Irkutsk State Technical University, Irkutsk, Russia:
V. V. Kondratev, Assistant Professor
V. A. Ershov, Assistant Professor

This paper presents a brief overview of cooling methods for anode gases, used at modern aluminum smelters to reduce gas amount, energy consumption for transport, size of flue networks, and fluorine desorption from hot alumina trapped by pollution control scrubbers. Modern methods of anode gases heat use for household and industrial needs (water heating, distillation or power generation with Rankin machines) are also briefly discussed. There is carried out the analysis of energy consumption for the heating of alumina, loadable into the bath, to the melt temperature and heat loss with anode gases, removed from the Soderberg cell. Together with high enthalpy anode gases, carried into the duct system, the losses of energy amount are by 3 to 4 times higher than alumina heating energy costs. The advantage of preheated alumina loading is shown using the heat transfer equations in bath and alumina areas. A technical solution, allowing the use of anode gases heat for alumina heating up to 200–250 ^oC before its loading into the bath is developed and presented. Loading of preheated alumina into the melt reduces the cell’s specific energy consumption by 80–95 kWh/t of Al; and energy consumption for refrigerated anode gases transportation are reduced by 15–20 kWh/t of Al. Material consumption of Soderberg workshop flue gas network will also be reduced. Alumina heating by the presented technical solution provides for almost 2-fold reduction of alumina feeding bins number, reduces the load on anode frame jacks and its drives power consumption, and improves the conditions of Soderberg formation.
This paper was written using the results of the works, carried out during the project 02.G25.31.0181 “Design of the super-power and energy efficient technology of obtaining of aluminium RA-550 (РА-550)” within the Program of realization of complex projects for the creation of high-technological production, approved by the regulation of the Government of Russian Federation No. 218 on April 09, 2010.

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