不锈钢粉尘内配煤团块高温自还原过程中金属铁的聚集

用不锈钢生产中的高碱度二次粉尘制备内配煤团块,在高温下自还原获得含铬、镍的金属铁粒.研究影响铁粒聚集长大的因素.研究表明：（1）内配煤团块的渣相碱度（w（CaO）/w（SiO2））小于2.8时,还原产物冷却过程中渣相与金属铁粒才能自然分离.碱度越低,渣量越大,越不利于金属铁聚集长大;（2）提高内配碳比,渣相残碳量明显升高,渣中过量的碳阻碍金属相聚集长大;（3）提高还原温度,直接还原铁的海绵状结构解体,逐渐聚集成颗粒状金属铁.还原温度越高,越有利于金属铁的聚集长大

Aggregation of metallic iron during high temperature self-reduction of stainless steel dust coal mixed briquettes

Iron nuggets containing chromium and nickel were obtained by self-reduction of high basicity stainless steel dust coal mixed briquettes at high temperature.The factors influencing aggregation and growth of the iron nuggets were researched.Results show that：（1） When the basicity（w（CaO）/w（SiO2）） of slag phase of the briquettes is less than 2.8,the slag phase of self-reduced product could be separated from the iron nuggets naturally during the product cooling.But when the basicity of the slag phase is lower,more difficultly the iron granules grow up,because of the bigger quantity of slag.（2） Raised the C/O mole ratio,the amount of residual carbon in the slag increases obviously and the excessive carbon in the slag would prevent the metallic phase diffused and aggregating growth;（3） As the temperature increases,the sponge structure of the direct reduction iron disintegrates and the iron nuggets easily form.The higher the reducing temperature is,the more easily to aggregate and grow the iron nuggets.