METHOD AND SYSTEM FOR CONTROLLING ADDITION OF POWDERY MATERIALS TO THE BATH OF AN ELECTROLYSIS CELL FOR THE PRODUCTION OF ALUMINIUM

摘要

The invention relates to a method for controlling the provision of powdery materials to an electrolysis cell used to produce aluminium by fused-salt electrolysis and provided with at least one distributor for powdery materials and at least one piercing device (30) comprising an actuator (31) and a hammer chipper (33) wherein at least one opening is formed in the crust of the solidified bath with the aid of the piercing device and the powdery material is introduced via at least one opening according to a normal supply method wherein, at a given moment to, an electric signal is generated in order to cause the hammer chipper to descend with the aid of the actuator (31) and the moment t, when the hammer chipper assumes a given low position, is measured, the value of at least one operational indicator for supply F is calculated from the value of the value to and the value obtained for moment t, abnormal or normal operation is determined from at least one operational criterion and the value of the operational indicator(s); if operation is not deemed to be abnormal, the normal supply procedure is maintained; if the operation is deemed to be abnormal, at least one corrective procedure (regularization, normalization) is initiated in order to bring the supply of powdery material into line with normal operation. The inventive method can be automated easily and enables operation of the supply to be monitored even during anode effects.