Experimental Study On Magnetized Roasting Variable Diameter Rotary Kiln For Refractory Iron Ore

In recent years,the iron and steel industry is in the condition of small profit or at a loss,many enterprises face a survival test,the only way to survive is reducing costs through technology innovation,and one way to reduce the cost is to improve the utilization efficiency of self-made iron ore.Now,restricted by the magnetizing roasting equipment,billions of tons domestic refractory iron ore can't be effectively used,and it is urgent to develop a rotary kiln equipment suitable for magnetizing roasting process of domestic refractory iron ore.The paper mainly takes rotary kiln equipment for magnetizing roasting as the research object,makes the experimental study on the kiln ring forming mechanism and prevention measures,studies the feasibility of inhabiting ring forming by changing the structure of kiln body,according to the principle of mass conservation in the gas flowing process and the preheating,drying,heating,reduction time of the material and the length of the kiln,determines the radius ratio and length to diameter ratio of kiln body of rotary kiln structure,and optimizes the rotary kiln structure parameters;and conducts the contrast verification test on ring forming of variable diameter rotary kiln and size rotary kiln to magnetizing roast 1~5mm powder ores classified from JISCO 0~15mm powder ores to verify the effect of kiln body radius variation optimization on inhabiting the ring forming.According the test results,the putting-in-service rotary kiln body structure is designed.First of all,the paper studies the ring forming mechanism of rotary kiln magnetization roasting refractory iron ore,analyzes the ring forming position,kiln body ring forming mechanism of solid phase and liquid phase and the factors of kiln body ring forming,puts forward the view point that the reasons of the kiln ring forming are the feeding of the fine and low melting material and local high temperature in the rotary kiln.The size grading can be applied to prevent the feeding of the fine material,and the local high temperature can be solved by kiln body structure optimization design.According to the principle of mass conservation in the gas flowing process and the preheating,drying,heating,reduction time of the material and the length of the kiln,determines the radius ratio (?) times and length to diameter ratio between 13~17 times of kiln body of rotary kiln structure,and optimally designs the kiln body structure of the laboratory ? 0.45×6m size gas rotary kiln.Secondly,the ring forming verification test is carried out on the magnetizing roasting of JISCO 1~5mm powder ore by using the? 0.65~0.45×9m gas variable diameter rotary kiln and? 0.45×6m.The verification test result shows that under the same condition of the magnetizing roasting temperature and other parameters,comparing the size rotary kiln,the capacity of variable diameter rotary kiln is improved by 50%,the energy consumption is reduced by 20%,and the effect of inhabiting ring forming is obvious,also optimally designs the body structures of three kinds of rotary kilns for industrial use and determines the rotary kiln technological parameters and operating parameters.After the completion of the project,the difficulty can be solved that the rotary kiln is restricted by kiln body ring forming,can't be widely used to the magnetizing roasting of refractory iron ore,providing the magnetizing roasting equipment of high capacity and low energy consumption for domestic billions tons of refractory iron ore,and has bright market prospects.