Starting method for aluminum cell

Abstract

A starting method for an aluminum electrobath relates to aluminum electrobath starting, in particular to a large starting method which includes being charged into a furnace, baking and starting process. The method is characterized in that: a, the material components which are added when being charged into the furnace are 7 to 8 percent of added calcined soda, 9 to 10 percent of calcium fluoride, 5 to 6 percent of magnesium fluoride, 19 to 20 percent of electrolyte blocks and the rest percent of high molecular ratio cryolite; b, the starting process is to add the high molecular ratio cryolite with an amount of 3 to 4 times as that of the high molecular ratio cryolite used for being charged into the furnace in the electrobath, to add the calcium fluoride with an amount of 19 to 20 percent of that of the calcium fluoride used for being charged into the furnace, to add the magnesium fluoride with an amount of 32 to 34 percent of that of the magnesium fluoride used for being charged into the furnace, to add the calcined soda with an amount of 23 to 25 percent of that of the calcined soda used for being charged into the furnace and to add the electrolyte blocks with an amount of 1.4 to 1.6 times as that of the electrolyte blocks used for being charged into the furnace. The method of the invention adopts the high molecular ratio cryolite and reduces the amount of the calcined soda, thus being able to lead the molecular ratio to be more than 2.8 after starting the electrobath, improving the stability of the technique technology conditions and reducing the working intensity of workers.

Description

technical field [0001] The invention discloses a method for starting an aluminum electrolytic cell, relating to a method for starting an aluminum electrolytic cell, in particular to a method for starting a large aluminum electrolytic cell. Background technique [0002] Cryolite-alumina molten salt electrolysis is the current method for industrial production of aluminum, and cryolite as a flux is irreplaceable in a short time. For a long time, aluminum electrolytic production has used ordinary molecular ratio cryolite with a molecular ratio of 2.1-2.3 for the roasting start-up of new slots. In order to ensure that the roasting of the new tank can reach a sufficient temperature and establish a regular furnace side with a high melting point after start-up, it is necessary to manually add a large amount of solid soda ash when the electrolytic tank is installed and started, so as to increase the electrolyte molecular ratio to above 2.8; The addition of too much soda ash will eas...

AI Technical Summary

Problems solved by technology

In order to ensure that the roasting of the new tank can reach a sufficient temperature and establish a regular furnace side with a high melting point after start-up, it is necessary to manually add a large amount of solid soda ash when the electrolytic tank is installed and started, so as to increase the electrolyte molecular ratio to above 2.8; The addition of too much soda ash will easily cause local concentration of soda ash, so that the local absorption of sodium in the carbon cathode is excessive, which will have an adverse effect on the cathode lining of the electrolytic cell; and the addition of soda ash will further increase the loss of cryolite and the labor intensity of workers. safety hazards and environmental pollution