Heat balance control method for aluminum electrolysis cell in low-voltage operation

Abstract

The invention provides a heat balance control method for an aluminum electrolysis cell in low-voltage operation, which comprises the following steps of: judging the heat and cold trend of the cell condition and determining extruded aluminum yield by controlling cell temperature, electrolyte, aluminum level, feeding amount and a burst effect coefficient and observing the electrolyte viscosity, carbon residue separation condition and burner blocking condition of the electrolysis cell, wherein the extruded aluminum yield is increased or reduced; determining that the aluminum yield of a single cell is 2,200 to 2,500kg; finely adjusting voltage according to the heat and cold trend of the cell condition, namely raising the voltage of an electrolysis cell tending to the cold trend by 10 to 50mv and reducing the voltage of the electrolysis cell tending to the heat trend by 10 to 20mv; and controlling the extrusion period of extruded aluminum to 7 to 10 days, so that the heat and cold amplitude of the cell condition is prevented from being changed due to overlong extrusion period of the extruded aluminum. The method has the advantages of keeping good heat balance of the electrolysis cell, improving current efficiency, reducing the direct current power consumption of each ton of aluminum, and increasing economic benefit.

Description

technical field [0001] The invention relates to a low-voltage aluminum electrolytic production method, in particular to a heat balance (balance of heat income and heat expenditure of the electrolytic cell) control method for the low-voltage operation of the aluminum electrolytic cell. Background technique [0002] In recent years, due to the high price of electricity, the reduction of power consumption in aluminum electrolysis production has become the goal pursued by many manufacturers. Due to the generally low quality of domestic raw materials, a substantial increase in current efficiency has become a luxury, and low voltage has become a more common choice. It is one of the fastest and most effective means to reduce DC power consumption per ton of aluminum. . [0003] Production practice has proved that low-voltage aluminum electrolysis production can effectively reduce power consumption and improve power efficiency. However, the thermal equilibrium state of the electrol...

AI Technical Summary

Problems solved by technology

However, due to the limitation of objective conditions, it is difficult for many manufacturers to greatly increase the current

Some are limited by the height of the anode; some are limited by the age of the tank; some power supply equipment or lines cannot meet the requirements, etc.

[0004] Therefore, various characteristics of insufficient heat input appear in low-voltage operation: ① When the temperature of the tank is low, the electrolyte is low, the effect coefficient increases, and there is a lack of alumina in the electrolytic tank, sudden effects are prone to occur. Shell blanking, insert the effect rod into the aluminum water of the electrolytic cell, so that the aluminum water splashes on the anode to cause a short circuit in time, and the effect is extinguished; ②The electrolyte is sticky, and the carbon slag is not easy to separate; ③The electrolyte shrinks, and the surface shell sticks to the electrolyte phenomenon Obviously; ④The tank temperature tends to hover at a low level, and it is difficult to increase; ⑤The content of iron and silicon is easy to get out of control. In the production of electrolytic cells, the raw materials contain a small amount of iron and silicon, which are generally melted in aluminum water and shrunk on the side of the furnace In the process, once the electrolytic cell tends to the hot stroke, the side of the furnace melts, and the iron and silicon come out, it will be dissolved in the aluminum water, causing the quality of the primary aluminum to decline; ⑥The phenomenon of jamming hammer heads increases. The ability to viscous and dissolve alumina is reduced, and the hammer head of the shelling and feeding port is prone to jamming; ⑦The feeding volume remains high, and when the tank is cold, the alumina cannot be dissolved. When the tank tends to heat, the side of the furnace melts, the amount of material to be fed decreases, and the current efficiency drops significantly

[0005] Through long-term practice, we found that: in the low-voltage operation state, the aluminum output and voltage adjustment are unreasonable, which can easily make the electrolytic cell tend to be in a cold and hot state, and adjust to a good heat balance state, and the cycle is longer

Images