Roasting-starting method of aluminium reduction cell with bulge-structure cathode

Abstract

The invention discloses a roasting-starting method of an aluminium reduction cell with a bulge-structure cathode. The bulged upper surface of the cathode carbon block is laid with a layer of coke grains, or a layer of mixed paste of coke grains and binder above the layer of coke grains; and a carbon anode is placed on the upper surface of the coke grains or the paste. When the coke grain resistor of the reduction cell is roasted to 500-800 DEG C, aluminium water is poured through an aluminium outlet, when the coke grain resistor is roasted to 950 DEG C by continuous energization, the aluminium outlet is opened, liquid electrolyte is poured, and the anode is lifted to execute wet starting of the reduction cell; or the coke grain resistor is roasted to 960-980 DEG C continuously, the liquid electrolyte is poured through the aluminium outlet, and simultaneously, the anode is lifted, the cell voltage is increased, and the reduction cell is started in a wet method directly. In the method, the used coke grains are less, the current and the temperature distribution on the surface of the cathode carbon block are uniform, thus avoiding cracking on the surface of the cathode carbon block owning to partial overheat.

Description

technical field [0001] The invention belongs to the technical field of electrolytic aluminum, and in particular relates to a method for starting the firing of an aluminum electrolytic cell. Background technique [0002] Invention patent 200810013029.8 proposes a method for starting the firing of an aluminum electrolytic cell with a new type of cathode structure with protrusions on the cathode surface. This method first uses flame roasting technology to make the temperature of the electrolytic cell reach above 700°C, and then pours aluminum liquid into it to implement Flame-aluminum liquid two-stage roasting technology. This roasting method can ensure the roasting quality of the electrolytic cell, and has been widely used in the roasting start-up of the electrolytic cell with a new cathode structure. However, this method also has the disadvantages that the flame equipment used in the flame roasting stage is expensive, complicated, and troublesome to operate. In addition to t...

AI Technical Summary

Problems solved by technology

This roasting method can ensure the roasting quality of the electrolytic cell, and has been widely used in the roasting start-up of the electrolytic cell with a new cathode structure, but this method also has the disadvantages of expensive flame equipment used in the flame roasting stage, complex equipment, and troublesome operation

In addition to the flame-aluminum liquid two-stage roasting method, some aluminum plants also use carbon particle roasting technology. The biggest disadvantage of this method is that the amount of carbon powder coke particles embedded in the electrolytic cell is large, and the coke particles are not only placed on the cathode. The raised upper surface layer, and the coke particles need to be buried in the groove between the raised structure and the raised structure. As a result, after the electrolytic cell is started, a large amount of electrolyte carbon residue in the cell needs to be fished out

In this way, not only the labor volume and labor intensity of the electrolysis workers are greatly increased, but also a large amount of electrolyte loss is caused, the power consumption is also large, and the pollution to the environment is also serious.