Experimental Research On Converter Slagging Agent Prepared By Metallurgical Solid Waste

Large amounts of solid wastes are produced in the production process of steel industry,leading to the occupation of land resources and environmental pollution.Therefore,it is of great significance to recycle these solid wastes for reducing the occupation of land resources,protecting the environment and resource utilization.Some solid wastes produced in the process of steelmaking and rolling,such as converter dust removal and iron oxide scale,own higher iron content and less impurities,which are good secondary resource in metallurgical industry and have great value for recycling and reusing.In this paper,recycling and reusing of converter precipitator dust and iron oxide scale in the production of converter slagging agent was studied.The main research contents and results are as follows:The converter slagging agent was prepared using converter precipitator dust and iron oxide scale as raw materials,with bentonite,calcium oxide and soluble glass as binders.The influence of different binders on the strength of converter slagging agent was studied.The results showed that when the bentonite and calcium oxide were used alone,the falling strength of green pellet was high,while the compressive strength of dry pellet could not meet the production index.As soluble glass was used alone,the compressive strength of dry pellet was high,while the falling strength of green pellet was low.All the strength could meet the production index by above 7wt.%addition.When a mixture of three binders was used,the optimal ratio of three binders obtained by orthogonal experiments was 4wt.%bentonite,7wt.%calcium oxide and 3wt.%soluble glass,respectively.The properties of converter slagging agent prepared with above ratio were best.The falling strength of green pellet for each sample was 3.7 times,and the compressive strength of dry pellet could reach 988.72 N·cm^-2.On the basis of the laboratory results,the feasibility of industrial production of converter slagging agent was verified through pilot-plant experiment.Meanwhile,a solution to the possible problems in actual production was raised.Combined with the laboratory preparation of converter slagging agent,the industrial production technology was studied,and production quality target was set.According to the designed production line,a small-scale trial production of converter slagging agent was carried out,and the properties of the product were tested.The results showed that the performance of converter slagging agent in the trial production was fully satisfied with the requirements of converter steelmaking.The converter slagging agent from trial production was used in converter steelmaking.The properties such as smelting indices,slag composition,dephosphorization capacity,desulphurizing capacity,melting point,melting rate and slag viscosity were compared and analyzed before and after using converter slagging agent,and the application effect was evaluated.The results showed that the converter slagging agent from trial production could reduce the consumption of iron and steel material,lime and oxygen,and improve the dephosphorization capacity,desulphurizing capacity of slag and the slagging speed of converter.Meanwhile,the converter slagging agent could reduce the slag viscosity and speed up slag spreading,leading to the loss decrease of metal and heat in the liquid steel and the cycle time reduction of smelting.