Study On Characteristics Of Desulphurization Slag By Pure Magnesium For Hot Metal And Slag Conglomeration Agent In FJSG

With increment of steel variety and improvement of quality requirements,the hot metal desulfurization has become incapable of shortness procedure for steel production,Which realizes prerequisite of economic steelmaking and was one of most effective technology of perfect steel production precess.Desulfurization rate was higher by Magnesium for hot metal of Sanming Iron & Steelmaking Co.Ltd.Throughout the desulfurization process is less sensitive to temperature drop and higher desulfurization. However, the post-desulphurization slag has an exceptionally high melting temperature and is widespread on the hot metal surface in granular forms, unable to form a sintered massive state, difficult to slag-off, high resulfurization rate is causing the higher rate of desulfurization and other issues.Seriously affected process after the process and the high-quality steel production.According to analysis production data and phase analysis of the industry post-desulphurization slag, but also with CaO-Al2O3-SiO2-MgO phase diagram,it was found that increasing the SiO2 or CaO content,can change in the flow characteristics and aggregation effect,can reduce the time of slag-off and improve slag-off effect. Therefore, through the theory analysis and experimental study to optimize the industry post-desulphurization slag in the laboratory, in order to improve performance of desulfurization slag and reduce Fe in the post-desulphurization slag. According to analysis the proportion of desulphurization slag and conglomeration agent contained, can determine parameters of conglomeration agent such as content composition and adding process.①The average desulphurization ratio was about 87% of Sanming Iron & Steelmaking Co.Ltd.The sulfur content of after the hot metal desulfurization was very low, the average periodic heat drop of desulphurization was stable.Flowing characteristics of magnesium desulfurization is had the worse of the CaO desulfurization slag, cause taking a long time to slag-off,The average periodic time of desulphurization was approximately 31min,slag-off used was 32%prosess in the course of time.②The main component is SiO2 and MgO, also contains a small amount of CaO,Al2O3,NaO and FeO of the industry post-desulphurization slag. The main phases is forsterite (2MgO·SiO2) of the industry post-desulphurization slag, the olivine phase between 2MgO·SiO2 and MgO·SiO, its melting point is 1557 ~ 1888℃.③By the CaO-Al2O3-SiO2-MgO phase diagram,slag conglomeration agent recipe is determined with SiO2 content-based and with CaO content-based.④According to theory and relative experiment and industrial trial,modifying slag conglomeration agent contained SiO2 45.0%,Al2O3 2.0%,Na2O19.0%,CaF217.0%,CaO 5.0%, the consumption was two fifths of weight.