Method for improving capability of electrolyte in technique of electrolytic aluminium

Abstract

This invention relates to a method for improving electrolyte performance in the technology of electrolyzing Al which adds weight percentage of 1-10% NaCl in the electrolyte to effectively change the composition of Al electrolyte, improving its chemical and physical performance to reduce its melting point and reduce the electrolyzing temperature by 20deg.C and increase its conductivity and current efficiency over 1%.

Description

technical field [0001] The invention relates to the field of metal smelting, in particular to a method for improving electrolyte performance in an electrolytic aluminum process. Background technique [0002] Since the invention of aluminum electrolysis, cryolite molten salt electrolysis has been used, that is, alumina is dissolved in cryolite melt. Under the action of direct current, aluminum is precipitated at the cathode, and oxygen is precipitated at the anode. Oxygen reacts with carbon to form carbon dioxide and carbon monoxide. The gas escapes, and this electrolysis process has high temperature, low current efficiency, and high power consumption; the scientific and technological workers of aluminum electrolysis have been looking for an electrolyte that has a lower melting point and better conductance, thereby increasing the current. Efficiency, the way to reduce power consumption. At present, the electrolyte produced by aluminum electrolysis is alumina cryolite melt. D...

AI Technical Summary

Problems solved by technology

At present, the electrolyte produced by aluminum electrolysis is alumina cryolite melt. Due to the introduction of raw materials, there are still 2-4% CaF in the electrolyte. 2 , some companies add 2.5-6% MgF to the electrolyte 2 , in order to reduce the electrolysis temperature and improve the current efficiency, individual companies add Li to the electrolyte 2 CO 3 Then LiF is generated, the electrolysis temperature is lowered, and the conductivity of the electrolyte is increased, thereby improving the current efficiency and reducing power consumption, but MgF 2 The addition of Li reduces the temperature and increases the specific resistance of the electrolyte, which has advantages and disadvantages for production; Li 2 CO 3 The addition of it has a good effect on electrolytic production, but the price is very high (about 28,000 yuan / t). Although there is a good effect after use, the economic benefit is indeed very small