Testing Baked Anodes with an Increased Vanadium Content

Abstract

Results are given for testing baked anodes for aluminum electrolyzers prepared from high-sulfur petroleum coke. In anodes of these cokes, there is an increase in vanadium content to 600 ppm that contaminates aluminum. By boriding aluminum, the possibility is established of using high-sulfur petroleum coke with a high heavy-metal content in production. It is shown that introduction of micro-additions of boron into molten electrolyte and aluminum makes it possible to reduce the vanadium content in metal from 200–220 to 100–120 ppm. The production regime in test electrolyzers remained stable for the test period. An associated effect of boriding melts is a fixed reduction in voltage loss in the cathode by about 30 mV that corresponds to a reduction in electrical energy of about 1700 US$ per year per electrolyzer (with a price of 0.02 US$/kW·h).