A kind of electrolytic production method of prebaked aluminum without anode butt

Abstract

The invention discloses a pre-baked aluminum electrolysis production method capable of preventing anode scrap from being generated. An anode steel jaw and an anode carbon block are connected mechanically. The anode carbon block is provided with an upper T-shaped connecting protruding head and a lower T-shaped connecting groove. The anode carbon block becomes a used anode carbon block after being consumed partially, the used anode carbon block is taken from the anode steel jaw, and then a new anode carbon block is connected with the anode steel jaw and is in inserting connection with the upper T-shaped connecting protruding head of the used anode carbon block through the lower T-shaped connecting groove, so that a new anode carbon block set is formed. The used anode carbon block is recycled, and no anode scrap is generated in the pre-baked aluminum electrolysis production process. The pre-baked aluminum electrolysis production method has the characteristics that no anode scrap is generated, the utilization rate of the anode carbon block is improved to 100% from original 70-80%, the production cost of electrolytic aluminum can be lowered, the steel jaw is long in service life, the work conditions of an electrolytic cell are stable, and the electrical loss is relatively low.

Description

technical field [0001] The invention relates to a prebaked aluminum electrolytic production method, in particular to a prebaked aluminum electrolytic production method without anode residues. Background technique [0002] In the modern electrolytic aluminum industry, prebaked anodes are used to produce electrolytic aluminum. The prebaked anode is generally a cuboid with a stable geometric shape. It uses stone tar and pitch coke as the aggregate and coal tar pitch as the binder. It has different sizes according to the size of the electrolytic cell current and the process. Its current density Generally at 0.68-0.9A / cm 2 Within the range, the service life of each carbon block is generally 23-30 days. [0003] In the existing prebaked anode electrolytic aluminum production, the anode steel claws and the anode carbon block are all connected by casting of phosphorus pig iron, and there are 2-4 diameters of 160-180mm on the upper surface of the prebaked anode carbon block in the ...

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Problems solved by technology

[0005] At present, the traditional way to deal with the anode residues is to smash and fall off the residues connected to the conductive rods in the anode assembly workshop, and then use the aluminum conductive rods after the broken anode steel bowls cast by phosphorus pig iron to be used in new ones. The carbon block is recycled in this way, which results in time-consuming and laborious replacement process of the carbon block

[0006] And under normal circumstances, the production of anode residues is 10-15% of the output of aluminum ingots, resulting in a great waste. According to the current annual production of 26-27 million tons of electrolytic aluminum in my country, the anode residues are as high as 260-390 tons. 10,000 tons / year, according to the value of anode carbon block 2700 yuan / ton, the value of wasted anode carbon block reaches tens of billions of yuan every year, and the waste in the world is even more. Carbon itself has a porosity of 25-27%, and a large amount of electrolyte is adsorbed in the body of the residual electrode. The main component of the electrolyte is fluoride salt, and the anode residual electrode containing a large amount of fluoride salt is very serious to the environment.

[0007] Cast steel claw-carbon block connection method, the contact voltage drop of the connection surface is large, the temperature of the poured phosphorus pig iron molten iron is about 1600 ℃, after cooling, there must be a gap between the phosphorus pig iron bowl and the carbon bowl, so the steel claw carbon block When the anode group works in the electrolytic cell, a voltage drop of about 150mv occurs between the steel claw and the contact surface of the carbon block, resulting in an electrical loss of about 400-500 degrees / ton of aluminum

[0008] When using the existing cast-type anode carbon block group, in order to reduce the waste of the anode as much as possible, it is necessary to burn the anode as thin as possible. At the end of the life of the anode carbon block, the top surface of the anode carbon block is very close to the electrolyte level, which is affected by the magnetic field and Influenced by the air flow, there are continuous strong waves on the surface of the electrolyte, or due to production control deviations, in the actual production process, the anode steel claws are often corroded by the electrolyte, and the iron of the steel claws dissolves into the electrolyte, and then enters the aluminum water to affect the quality of the aluminum ingots , in actual production, the average service life of the steel claws used in the electrolysis workshop is only about 3 years, which also increases the production cost to a certain extent

And at the end of the life of the anode carbon block, the thickness of the too thin residual electrode will inevitably lead to uneven conduction of the carbon electrode, resulting in fluctuations in the working conditions of the electrolytic cell and increased electrical loss

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