绿色矿冶

The 350kA electrolysis series in a Chinese plant adopted high Li-K alumina for production. As the enrichment of Li and K in the electrolyte, an electrolyte system of Na₃AlF₆-Al₂O₃-AlF₃-CaF₂-MgF₂-LiF-KF was formed, meanwhile, the production became unstable and indicators were deteriorated. Against this background, laboratory and field tests were carried out to measure the properties of the electrolyte, and industrial tests were conducted using the trial-and-error method to analyze the impact of electrolyte compositions on current efficiency, liquidus temperature, conductivity and alumina solubility, and finally proper electrolyte compositions were determined, that is, molecular ratio of 2.50±0.05, CaF₂≤4.77%, MgF₂≤0.68%, LiF≤5% and KF≤3%. The test results were further put into industrial application, and good effects have been obtained by combining process and operation management, which were reflected by reduced noise level, anode effect within control, improved hearth condition, current efficiency improved by 2.91% and DC power consumption reduced by 326kWh/t.