Method for increasing true density of calcined coke for prebaked anode for aluminum electrolysis

Abstract

The invention relates to a method for increasing the true density of calcined coke for a prebaked anode for aluminum electrolysis. The method is characterized by comprising the following steps: quantitatively feeding petroleum coke from a storage bin of materials to be calcined into a rotary kiln by means of a weighing system; gradually heating the raw petroleum coke in the rotary kiln to 1300-1500 DEG C, calcining for 70-100 minutes to effectively dewater;thoroughly separating out volatile constituents, introducing the calcined coke into a cooling machine;and directly spraying water to cool the calcined coke in the cooling machine so as to obtain the calcined coke for a prebaked anode for aluminum electrolysis. The invention increases the calcining temperature to 1300-1500 DEG C, while the temperature in the traditional process is 1250 DEG C; the desulfurization rate is increased to 20% or so; the calcining zone is shortened, burning loss of the petroleum coke is reduced, the extraction yield is increased by 1.5%, and 4630 tons of petroleum coke can be saved every year; the preheating time of the petroleum coke in the kiln can be greatly prolonged, so that the volatile constituents can be separated out sufficiently; and the volume density, the compression strength, the thermal shock resistance and the conductibility of the prebaked anode can be obviously improved.

Description

technical field [0001] The invention relates to the technical field of production of prebaked anodes for aluminum electrolysis, in particular to a method for increasing the calcined coke density of prebaked anodes for aluminum electrolysis. Background technique [0002] As the "heart" material of aluminum electrolysis, the prebaked anode is the key factor affecting the energy consumption of electrolysis. Its function is to introduce current into the electrolytic cell and participate in the electrochemical reaction. The carbon anode is installed on the upper part of the electrolytic cell, and the powerful direct current is introduced into the electrolytic cell through the carbon anode. The upper part of the carbon anode is covered with thermal insulation alumina and electrolyte block, the middle part is surrounded by the electrolyte shell, and the lower part is immersed in the molten fluoride salt electrolyte. In a high temperature environment around 950°C, the bottom of the ...

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Problems solved by technology

[0004] In the calcination process, the calcination time is insufficient, the calcination temperature is not enough, and the volatilization analysis of petroleum coke is insufficient, which will cause the true coke density after calcination to be ≤2.0g / cm 3 , resulting in low compressive strength and poor thermal shock resistance of the prebaked anode produced in the subsequent process, resulting in the slag falling off of the prebaked anode during electrolysis, which will not only increase the carbon consumption, but also increase the cell voltage and power consumption. The carbon slag fragments in the electrolyte will destroy the normal technical conditions of electrolytic aluminum production, seriously endanger the production of electrolytic aluminum, and even lead to accidental shutdown

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