Aluminum electrolytic tank calcining method

Abstract

An aluminum electrolytic tank baking method relates to the technology method for electrolytic preparation of the metal aluminum with alumina as raw material, especially a novel electrolytic tank current-carrying baking method in the process of electrolytic preparation. The preparing process comprises: pouring the molten liquid aluminium into the novel electrolytic tank, covering the liquid aluminum with the cryolite, and current-carrying baking until the voltage is down to 1.5-2.0V from 3V naturally, characterized by : when the tank voltage is less than 2.0V, employing the gradually lifting anode method for improving the voltage, keeping the voltage of 2.0-2.1V, improving the voltage to 3V again at the 24 hours before starting, and finishing the electrolytic tank baking when the temperature reaches 850-900 DEG C.

Description

technical field [0001] The invention relates to a roasting method for an aluminum electrolytic cell, which relates to a process method for electrolytically producing metal aluminum by using alumina as a raw material, in particular to a method for electrifying roasting of a new electrolytic cell during the electrolytic production process. Background technique [0002] The electric roasting of the new electrolytic cell is an important link in the production process of the aluminum electrolytic cell. Before the electrolyzer can enter normal production, it must go through the roasting stage. The purpose of electrolytic cell roasting is to: (1) dry the lining of the electrolytic cell and the furnace; (2) sinter the bottom carbon seam (side seam, middle seam and side seam) of the cathode chamber to form a complete furnace that can meet the needs of electrolytic production (3) Slowly heat and roast the cathode carbon block, and heat the furnace bottom temperature to above 850-900°...

AI Technical Summary

Problems solved by technology

Usually during the roasting process, since the tank voltage decreases with the resistance of the electrolytic tank, the voltage also tends to automatically drop. Generally, the roasting voltage of the electrified tank is about 3V on the day, and drops to 2.0-2.5V on the second day, and the voltage on the third day. Will be reduced to 1.5V, resulting in low baking efficiency

As the roasting time prolongs, the temperature of the electrolytic cell begins to rise gradually, and the temperature of the aluminum water can only reach 400°C to 700°C before starting, resulting in a relatively cold bottom of the furnace, and the aluminum water in the tank often cannot be completely melted, and the surrounding or part is still solidified. Aluminum makes it difficult to lift the anode when the electrolytic cell needs to start filling the electrolyte. The solidified aluminum adheres to the bottom of the anode. Sometimes the anode is lifted off but the cell voltage is not high. There is a "false phenomenon". And the voltage swing, and the electrolytic cell is easy to induce the anode immortality effect in the later stage of start-up, which causes a lot of trouble and passiveness to the production and organization