Aluminum electrolysis carbon pre-baking anode pre-heating method

Abstract

The present invention discloses an aluminum electrolysis carbon pre-baking anode pre-heating method. According to the method, aluminum carbon calcination rotary kiln high temperature flue gas is adopted as a heat source, and the loaded carbon pre-baking anode is pre-heated in a pre-heating furnace, such that the average temperature of the anode can achieve more than or equal to 300 DEG C within 24 h; according to the requirement of the electrolysis bath electrode replacing period, the heated anode is taken out from the pre-heating furnace, is loaded into a special thermal insulation device for conveying the pre-heated anode, is conveyed to an electrolysis workshop, and is loaded into the electrolysis bath to replace the old anode so as to be used; and with the pre-heating, the thermal shock influence on the anode can be reduced, the carbon consumption of the anode is reduced, the fluctuation of the stability and the thermal balance of the electrolysis bath can be reduced, the current efficiency is increased, the current conduction time of the anode is shortened, the furnace bottom precipitate is reduced, the anode effect and the noise generated during the electrode replacing are reduced, and the disordered and harsh conditions of the anode current distribution are reduced so as to provide great benefits for the normal operation of the electrolysis bath.

Description

technical field [0001] The invention belongs to the field of aluminum electrolysis production, in particular to a heating method for aluminum electrolysis carbon prebaked anodes. Background technique [0002] The carbon prebaked anode used in the current industrial aluminum electrolysis production, as the electrochemical reaction proceeds, the anode is continuously consumed and needs to be replaced regularly. [0003] When changing poles, serious thermal shock problems will occur because the anode is a brittle material: since the new anode is not preheated, the initial temperature of the new anode is equal to the ambient temperature. When the new anode enters the molten electrolyte at 950-960°C, There is a high heat flow to penetrate into the anode body, and the anode begins to thermally expand under the action of high temperature, resulting in thermal stress; the greater the temperature difference between the anode temperature and the electrolyte temperature, the greater th...

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Problems solved by technology

[0003] When changing poles, serious thermal shock problems will occur because the anode is a brittle material: since the new anode is not preheated, the initial temperature of the new anode is equal to the ambient temperature. When the new anode enters the molten electrolyte at 950-960°C, There is a high heat flow to penetrate into the anode body, and the anode begins to thermally expand under the action of high temperature, resulting in thermal stress; the greater the temperature difference between the anode temperature and the electrolyte temperature, the greater the thermal stress, and the greater the impact of thermal shock on the anode, resulting in cracks , breakage, and slag drop, which affect the normal operation of the electrolytic cell, reduce the current efficiency of the cell, and increase the consumption of the anode

[0006] 1. The amount of steam used in general enterprises is limited. When heating is not available in summer and autumn, the water vapor will be emptied due to the abundance, resulting in energy waste;

[0007] 2. The temperature of the high-temperature flue gas entering the waste heat boiler is still high when it is discharged after heat exchange, the heat energy of the flue gas has not been effectively utilized, and the thermal efficiency is very low

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