Direct-current shunt preheating start method for an inert electrode aluminum electrolysis cell

摘要

The invention discloses a direct-current shunt preheating start method for an inert electrode aluminum electrolysis cell, comprising: (1) forming multiple groups of direct-current shunt elements by using conductors with preset resistance values and geometric sizes; (2) laying in a hearth of the electrolysis cell electrical heating element groups of the same number as/a different number from electrode groups; (3) drying the hearth, smelting electrolyte and establishing a thermal balance and a hearth inner profile by using the electrical heating element groups according to a set heating curve or set steps; (4) changing the number of groups/a series or parallel connection state of the direct-current shunt elements; and (5) gradually replacing inert electrodes and gradually adjusting the number of the groups of/the series or parallel connection state of the shunt elements. By means of the present invention, the inert electrode aluminum electrolysis cell can be well preheated and the thermal balance can be established; in the inert electrode replacement process, stability of the cell voltage can further be ensured, so that the current passing through the inert electrodes in the cell is uniform; and series current is not affected by start of a single electrolysis cell, so that non-disturbance start is implemented.

主权项

1. A direct-current shunt preheating start method for an inert electrode aluminum electrolysis cell, comprising:
(1) forming multiple groups of direct-current shunt elements by using conductors with preset resistance values and geometric sizes, wherein the direct-current shunt elements can share all direct current of the electrolysis cell; (2) laying electrical heating element groups of the same number as, or a different number from, electrode groups in a hearth of the electrolysis cell; (3) drying the hearth, smelting electrolyte and establishing a thermal balance and a hearth inner profile by using the electrical heating element groups according to a set heating curve or set steps to provide an operating environment for inert electrodes; (4) changing the number of groups or a series or parallel connection state of the direct-current shunt elements to permit setting of the voltage which resulted from the shunt current to be the same as the cell voltage of the aluminum electrolysis cell when working by electrification after replacement of the inert electrodes; and (5) gradually replacing the shunt elements by the inert electrodes and gradually adjusting the number of the groups or the series or parallel connection state of the shunt elements to keep the cell voltage stable, ensure uniform and stable direct current passing through the inert electrodes and prevent damage to the inert electrodes, wherein the inert electrodes do not bear all of the direct current until all of the shunt elements stop shunting and all of the inert electrodes are replaced.