INFLUENCE OF PROCESS PARAMETERS ON CURRENT EFFICIENCY IN PROCESSING ANODE DEPOSITS FROM THE PRODUCTION OF HIGH-PURITY ALUMINUM

摘要

The process of electrolytic processing of anode deposits from the production of high-purity aluminum at the Krasnoyar Aluminum Plant Production Association together with cathodic separation of silicon-aluminum alloy is investigated. A formula is proposed for determining the current efficiency that takes into account the kinetics of electrode processes. It is shown that the following are the optimal technological conditions of electrolysis: current density, 0.84 A/cm~2; composition of electrolyte, 35 percent BaF_2; remainder NaF and A1F_3 with cryolite ratio <2; interpole distance, >5 cm; temperature of process, 950 deg C. Under laboratory conditions the maximum current efficiency, computed from the formula presented in the article, amounts to 92 percent on the cathode and 96 percent on the anode.