Study On The Fire Treatment Of Waste Cathode Carbon Blocks In Electrolytic Aluminum Production

An annual output of 300,000 tons of electrolytic aluminum plant,each year will produce about 7,000 tons of hazardous solid waste-waste cathode carbon,if not processed in time can not be the existing production.The literature mentioned in the method,have not been used in industrial reports.In this paper,"combustion aluminum electrolysis waste cathode carbon block-condensed recovery of fluoride-alumina absorption and purification of exhaust gas" method,is expected to be used in industry.The calorific value of Waste cathode carbon block is low,The heat of the waste cathode with a carbon content of 68.11%is 12.14 MJ/Kg,it is difficult to burn with the general means.The volatility of the fluorinated salt is highest at a temperature of 1030 ?(transformation point).Comparative cryolite molten salt corrosion rate of stainless steel 304 and 310S of the two common,experimental results equipment selection device 310S steel.Thermodynamic calculation and analysis:the time when the waste cathode block 800 ?-1000 ? combustion temperature pyrometallurgical processing waste cathode blocks feasibleStudy on the reaction rate and influencing factors of combustion of waste cathode carbon.The first proposed and used a waste cathode carbon block slag model:(?),the effect of different carbon contents on the reaction rate was studied.It was found that the reaction order of carbon in the reaction process was 0.46 in the reaction process.Carbon content of 98%,89%,82%,72%of the activation energy were 1392.60 Kj/mol.,1652.16 Kj/mol.,1812.12 Kj/mol.,2263.15Kj/mol.The control of the reaction is that the slag accumulation at the reaction interface affects the introduction of oxygen and the volatilization of fluoride.Experimental study on three Combustion processes of Muffle Furnace,RotaryKiln Combustion and Suspended Combustion.In the muffle furnace electrostatic treatment of waste cathode carbon block,burning 3h when the burning rate was only 21.8%.The height of the suspended combustion reactor is about 54.6 m and the residence time is 15.6s.In the rotary kiln mechanical agitator optimization experiment,so that the best treatment of waste cathode carbon block:The optimum conditions were as follows:air flow rate 1.5 m3/h,combustion temperature 900?,particle size 1?3 mm,burning time 1.5h,combustion rate can reach 92.5%.The slag in the experiment can meet the national solid waste emission standards.