Application practice of the most volcanic aluminum

Shandong Aluminum Co., Ltd. (hereinafter referred to as Shandong Aluminum) anode baking system is a supporting project of adding anode baking system to the original anode production system to provide prebaked anode with 200kA and 80kA prebaked electrolysis series. The design scale of the project is 43000 tons of pre baked anode per year, which was put into operation in September, 2003

the anode baking system of Shandong Aluminum Co., Ltd. is designed based on the combustion device and control system technology of French sateram company and Swiss Rd company, combined with the actual situation of domestic pre baking anode baking. The anode baking system adopts the domestic advanced furnace type, with 34 furnace chambers, which are divided into 2 flame systems. Each furnace chamber has 6 material boxes and 7 heating fire channels. The anode is installed vertically, and no filler is added between the anodes. According to different varieties, 120 and 126 anodes can be installed in each furnace chamber. The carbon blocks are grouped and ungrouped by the anode marshalling and ungrouping machine. Adopt multi-function crown block to load and discharge the furnace; The temperature control adopts pulse combustion device and temperature negative pressure automatic control system. The furnace surface equipment is mainly domestic equipment, and 200# heavy oil is used as fuel; Its roasting process system (temperature rise curve) is advanced and reasonable, and the roasting cycle can be adjusted in a wide range: at the initial stage of production, 252h roasting curve (the flame moves to promote the dynamic cycle of the investment project of 36h) is selected for baking; After putting into production, the roasting curve is optimized to 168h (flame moving cycle 28h). After the system is put into operation, the anode baking production is stable, and the physical and chemical indexes of the pre baked anode meet the requirements of national first-class products, meeting the needs of electrolysis. Shandong aluminum anode baking system solves the problems existing in the traditional anode baking furnace, such as unreasonable furnace type, high energy consumption, large pollution, short furnace life, low automation level, low productivity, unstable quality of pre baked anode products, etc

compared with the traditional anode baking system, the new anode baking system has the following characteristics: (1) large material box (5246mm) is used × 53 fixture: drag roller can move up and down metal pressing plate: 100x100mm or Φ 150mm 1 set/2 pieces 70mm × 703mm), and the filling rate of anode carbon block in the material box is as high as 61%. The advanced control algorithm is used to accurately control the temperature rise curve of each fire path heating belt and the blank belt of 2024 and 7075 Aerospace plate and strip that cannot be mass produced during preheating. The maximum horizontal temperature difference between the fire paths in the preheating stage is 18 ℃, the horizontal temperature difference between the fire paths in the heating stage is only ± 2 ℃, and the error between the temperature of each fire path and the target temperature is ± 1 ℃, which can improve the homogeneity of carbon blocks. The p+t control mode is adopted to control the temperature of each flue when bridging the flue, so as to ensure the quality of carbon blocks in the bridging furnace chamber, and solve the problem of large quality fluctuation in the bridging furnace chamber that is common in China. (2) The self-developed new solid thermocouple improves the temperature measurement accuracy and service life. The thermocouple adopts many new technologies such as integral sealing, extra deep blind hole and extra thick wall protective tube, which solves the problems of long life and high stability of the thermocouple used in anode baking furnace. (3) The asphalt volatiles are fully burned, and the tar content of the flue gas at the outlet of the annular flue is very low; After the energy consumption of the furnace is reduced, the emission of flue gas and air pollution are reduced, and the emission of asphalt smoke is only 10mg/m3. (4) The yield, output and asphalt yield of the product are improved. After adopting the new control system, the horizontal and vertical temperature differences of the fire path are reduced, the temperature control is accurate, and the operation cycle of the roaster is shortened to 28h. At the same time, after the fire path temperature is evenly distributed, the volatilization speed and combustion speed of asphalt smoke are well controlled, and the volatilization time of asphalt smoke can reach 20h. (5) The technical and economic benefits are improved. The increase of charging capacity and the shortening of roasting cycle can reduce the capital investment cost per unit product; The energy consumption of the furnace is reduced, and the anode manufacturing cost is reduced; The improvement of anode quality leads to the reduction of anode consumption and a series of related costs in the electrolysis process; Reasonable use of refractory materials improves the service life of the roasting furnace; The process control system avoids overheating of roasting temperature and prolongs the service life of refractory materials

after the new anode baking system of Shandong Aluminum is put into operation, the main technical indicators are as follows: (1) the temperature control accuracy of the fire path of anode baking: preheating stage ± 30 ℃; Heating stage ± 3 ℃; (2) Adopt 28h flame moving cycle and 168h roasting temperature rise curve; (3) 65.2kg heavy oil is consumed per ton of anode; (4) 58.5kg filler is consumed per ton of anode; (5) Asphalt smoke emission 10mg/m3; (6) The qualified rate of roasted carbon block is 98.2%, and the solid yield of carbon block is 94.5%

after the project is put into operation, the annual economic benefit of 25.9736 million yuan can be achieved only in terms of the completion of indicators in production and fuel saving, regardless of the investment, the extension of service life and the benefits brought by electrolytic application