南非铬铁矿高温碳热还原机制

以南非铬铁矿为原料,采用内配碳方式,系统研究了配碳比及还原温度对还原过程的影响,并借助光学显微镜(OM)、扫描电子显微镜-能谱仪(SEM-EDS)、X-射线衍射仪(XRD)等分析检测设备,结合FactSage热力学计算结果,分析了铬铁矿还原过程微观形貌变化及物相转变行为。结果表明:在还原温度1 300℃、配碳比1.2的条件下,铬铁矿金属化率可达75.8%,还原产物主要物相为残余碳、金属铁、铬铁碳化物及硅铝酸盐脉石相等;随着还原反应进行,硅酸盐、铝酸盐等高温难还原组分逐渐在未还原铬铁矿颗粒表面聚集,抑制还原进行。

High temperature carbothermal reduction mechanism of South Africa chromite

South Africa chromite was used as raw material. The effect of mixing ratio of carbon and reduction temperature on the reduction process was systematically studied by way of mixing carbon in the South Africa chromite. Optical microscope (OM), scanning electron microscope-energy dispersive spectrometer (SEM-EDS), X-ray diffraction (XRD), and FactSage thermodynamic calculation software were used to reveal the changes of micro-morphology and phase transformation of chromite. The results show that the chromite metallization rate is 75.8% when the reduction temperature is 1300 °C and the mixing ratio of carbon is 1.2. The main phase of the reduction product is residual carbon, iron, ferrochrome carbide and aluminosilicate gangue. The silicate and aluminate phases coated on the surface of the unreduced chromite particles to inhibit the reduction.