Study On Physical And Chemical Properties Of High Phosphorus Manganese Silicon Alloy Dephosphorization And Dephosphorization Final Slag

China’s silicon manganese alloys have large output and a wide range of applications.The manganese ore resources in Chongqing are mainly distributed in Chengkou County and Xiushan County.It is characterized by low grade and high harmful impurity elements such as S and P.The P in the silicon-manganese alloy will contaminate the molten steel,causing the steel to be"cold and brittle"and reducing the quality of the steel.Therefore,exploring the best conditions for reducing the P content in silicon-manganese alloys is an important issue that needs to be resolved urgently.Recycling is an important part of the recycling economy.The country pays more and more attention to resource utilization.Therefore,the high phosphorus silicon manganese alloy dephosphorization final slag is used as a raw material for reuse,while avoiding re-pollution.The physical and chemical properties and environmental properties of the phosphorus final slag are particularly important.This subject first explores the best conditions for removing phosphorus content in the high-phosphorus silicon-manganese alloy.A"silicon-molybdenum furnace"is used to carry out orthogonal experiments of high-temperature dephosphorization.The effect of CaO-SiO₂-Al₂O₃ dephosphorization.And with the help of modern inspection methods:ICP,XRF,XRD,radioactive detection,leaching toxicity test analysis and other experimental methods,the basic physical and chemical characteristics of high phosphorus silicon manganese alloy dephosphorization final slag samples were characterized and analyzed.Based on the study of the environmental characteristics of the dephosphorization final slag,this subject focuses on the study of its leaching toxicity and verifies whether it has the possibility of harm to the soil and water resources environment.The thesis research draws the following conclusions:（1）According to the determined CaO-SiO₂-Al₂O₃ ternary slag system.The effects of slag-to-metal ratio,temperature and holding time on the dephosphorization rate were studied.Through orthogonal experiments,the results show that the dephosphorization effect is best when the horizontal combination is A₄B₄C₄,and the dephosphorization rate reaches 85%.（2）The moisture content of the dephosphorization final residue is extremely low,and the density is 2.0917g/cm³.The p H value of the dephosphorization final leaching solution is about 10.30,which is between 2.00 and 12.50,which does not exceed the corrosive identification standard and is not corrosive.And the dephosphorization final slag after radioactive detection can be used for building main materials and decoration materials.（3）The dephosphorization products mainly exist in the form of（Ca₂（SiO₄））₆（Ca₃（PO₄）₂）,Ca（PO₄）₂SiO₄ and Al PO₄.The phase structure of the final slag is stable and not powdered.（4）The leaching toxicity of the main heavy metals in the dephosphorization final slag is less than the identification standard value in GB 5085.3-2007,and the leaching mass concentration of manganese,phosphorus and sulfur is also within the standard value range in GB 8978-1996.Therefore,the dephosphorization final residue is not a leaching toxic hazardous waste,and will not cause pollution to soil and water resources.