Device and method for balancing alumina concentration of aluminium electrolysis tank

Abstract

The invention discloses a device and a method for balancing the alumina concentration of an aluminium electrolysis tank, wherein an anodic current density monitoring module M1 monitors anodic current density in real time and reports monitored anodic current density data to a CPU (Central Processing Unit) of an electrolysis tank control system; and, after receiving the anodic current density data sent by the anodic current density monitoring module M1, the CPU of the electrolysis tank control system starts an alumina concentration estimating module M2 to carry out alumina concentration estimation at positions with higher and lower anodic current densities, and increases or decreases baiting according to the estimation result till the anodic alumina concentration at the Ai position returns to the normal control range. The existing electrolytic process is unnecessary to change, so that the device and the method disclosed by the invention are easy to industrially implement; the problems of having lower alumina concentration at corner regions in the electrolysis tank or higher alumina concentration of a newly changed anodic region can be effectively avoided; anode side effects, scintillation effects and PFC (Polymerization Ferric Chloride) emission can be obviously reduced; and the device and the method disclosed by the invention are conductive to operating the electrolysis tank stably at high efficiency.

Description

technical field [0001] The invention belongs to the technical field of electrolytic aluminum, and in particular relates to a device and a method for equalizing the concentration of alumina in an aluminum electrolytic cell. Background technique [0002] In the process of producing metal aluminum using the Hall-Elut aluminum electrolysis process, carbon anode is used to reduce aluminum oxide to produce metal aluminum, and the normal anode reaction product is CO 2 . The following problems will occur in the electrolysis process: (1) Since the carbon anode is not made of homogeneous materials, the anode reaction is always accompanied by side reactions; (2) Due to the limited service life of the carbon anode, generally 26-30 (3) Due to various reasons, the anode current of the newly replaced carbon anode temporarily cannot reach the normal level, which will cause the anodes around it to carry a large current, resulting in uneven distribution of current among all anodes; (4) Unev...

AI Technical Summary

Problems solved by technology

The following problems will occur in the electrolysis process: (1) Since the carbon anode is not made of homogeneous materials, the anode reaction is always accompanied by side reactions; (2) Due to the limited service life of the carbon anode, generally 26-30 (3) Due to various reasons, the anode current of the newly replaced carbon anode temporarily cannot reach the normal level, which will cause the anodes around it to carry a large current, resulting in uneven distribution of current among all anodes; (4) Uneven anode current distribution will lead to differences in anode current density, resulting in unbalanced anode reactions and differences in alumina consumption; (5) With the continuous increase of the current capacity of the electrolytic cell, the size of the cell shell The larger the size, the farther the distance between the alumina feeder installed in the center of the electrolytic cell and the sides and corners of the electrolytic cell is, and the alumina cannot quickly diffuse to the sides and corners, resulting in uneven alumina concentration at the lower part of the anode, which intensifies the Anode side reactions occur

Since the anode reaction of aluminum electrolysis is carried out in a high-temperature molten electrolyte, the consumption of alumina in the electrolytic cell cannot be observed with the naked eye; and due to the strong corrosiveness of the fluoride electrolyte, there is no solution that can be directly inserted into the electrolyte for long-term measurement. Aluminum Oxide Concentration Materials

Therefore, the lack of alumina in the tank cannot be found in time, which has caused difficulties in replenishing alumina in time, which needs to be resolved

Images