Study On Quality Control Of Lime For Steel-making

In recent years,the concept of green is gradually accepted by human,and the national has stepped up its control in the steel industry.In order to promote transformation and upgrading of steel industry,towards to be quality,functionalization and diversification.At the same time,with the competition of the steel market,the development of new varieties,more stringent standards were put forward to the process and raw materials.One of the best in the world's steel industry-China,most of it is rough steel,only can be used as a foundation for construction,and can not meet the requirements of modern industry.High quality steel still needs a large number of imports.Therefore,it is urgent to intensify the production of high quality steel products.Lime,as the main slag making agent in iron and steel smelting,plays a vital role in the quality of steel.The fine quality lime can not only improve the speed of slag making,the impurity removal and the quality of molten steel,but also reduce consumption.At the same time,the lime also can improve the smelting conditions,shorten the smelting time,and stabilize the operation.As an important auxiliary material in steel-making process,the different uses of steel need different indexes of lime.The lime produced in lime plant is directly used for steel-making.However,due to the quality of lime,some batch of lime has been returned every month,which directly brings economic loss and material waste to the unit.The quality of the lime not only affects the quality of the steel directly,but also the profit and long-term development of the enterprise are also affected by the lime quality.Therefore,aiming at the quality problem of calcined lime in a lime sleeve shaft kiln,the SPC theory,orthogonal test and 5M1 E method were applied to study the quality of lime.First of all,Several widely used kiln types are analyzed,include Rotary kiln,MAERZ kiln,Double beam kiln and the annular sleeve kiln.From the three aspects of the function of lime in steel-making,the performance requirements of the lime in steel-making and the process of the lime production and the setting of the parameters,the related production parameters are collected and recorded.Secondly,aiming at the existing problems of lime plant,the collected data were analyzed by SPC theoretical knowledge,and seek the improvements;Then,the process parameters on the quality of limewere analyzed,the content of CaO,the rate of raw and over burning and activity degree were improved through the research,the best parameters were found;At last,the corresponding quality control plan is set up according to the 5M1 E method,and its economic analysis and effect verification are carried out.Through the research in this paper,the quality of lime has been improved to a certain extent,reducing unnecessary losses,and providing references for other lime enterprises.