高铁铝土矿含碳球团的直接还原熔分工艺

Direct reduction and melting process of carbon composite bauxite pellets

采用煤基直接还原熔分技术研究了高铁铝土矿含碳球团的还原熔分工艺,考察了直接还原熔分工艺对粒铁尺寸和粒铁收得率以及熔分渣中Al2O3品位的影响.结果表明:当球团碱度为1.0,还原-熔分温度为1 450℃,配碳比n(C)/n(O)为1.4,外配Ca F2质量分数为2.0%,还原-熔分时间为20 min时,粒铁尺寸最大(15.55 mm),粒铁收得率和熔分渣中的Al2O3品位最高,分别为95.67%和43.96%.高质量的粒铁具有较高的碳含量(w[C]=3.86%)和金属铁含量(w[Fe]=93.46%)以及锰含量(w[Mn]=1.63%),能够满足钢铁工业对铁水品质的要求,同时熔分渣的化学成分也达到了黏土砖熟料的工业指标.

The direct reduction and melting process of carbon composite bauxite pellets were researched by coal-based direct reduction and melting technology. Effects of reduction and melting process on nugget size,nugget recovery ratio and Al2O3 grade in slag were investigated. The results showed that when the reduction temperature is1 450 ℃,the pellet basicity is 1. 0,n（C）/n（O） is 1. 4,the added CaF2 content is 2. 0%,and the reduction time is20 min,the nugget size is biggest（15. 55 mm）,the nugget recovery ratio and Al2O3 grade in slag reach a maximun,the nugget recovery ratio and Al2O3 grade are 95. 67% and 43. 96%,respectively. The nugget with a high quality has a higher carbon content（w[C] = 3. 86%）,iron content（w[Fe] = 93. 46%） and Mn content（w[Mn] =1. 63%）,which can satisfy the requirements of iron and steel industry. Meanwhile,chemical composition of slag also reaches the industrial index of clay brick clinker.