Fundamental Study On Recycling Use Of Steel Slags

Steel slags is the main solid waste of metallurgical industry. 0.6×10~8 ton steel slags is produced every year, but the general utilization ratio is low. How can we use these slags will influence our steel industry's development. According to the demand of environmental protection and decline production costs, recycling use of steel slags in the steel industry is an ideal way.Use of steel slags is a system engineering, this paper is mainly focused on the use of converter slag in hot metal pretreatment and hot LF slag use in the LF refinement. Converter slag is a kind of slag with high basicity and high oxidizability, it can be used to replace part of lime and oxidizing agent in the desiliconization flux and dephosphorization flux, it can also be returned to hot metal pretreatment. After LF refinement, LF slag is still of certain sulphide capacity and recovery value, it can be recycled in LF refinement.Melting temperature is an important index mark to the physical property of the flux. The converter slag's melting temperature is higher than the temperature of hot metal pretreatment, so it can not be used in hot metal pretreatment directly, and further treatment is needed. That is adding flux to reduce the slag's melting temperature. In this paper, quadratic regression orthogonal design is used, the converter slag's melting temperature measurement is carried out in the laboratory, and then melting temperature regression equation is obtained. Through this regression equation, various composition converter slag's melting temperature can be calculated, the influence of each composition to the converter slag's melting temperature are analyzed. This can provides theories basis for the use of converter slag in hot metal pretreatment. Many actual problems will occur in the use and re-use of steel slags, including to choose a suitable method to treatment steel slags, choosing a suitable craft arrangement, etc.. This paper carried on some researches in these aspect, can provide some references to steel industry in the utilization of steel slags.