摘要
A clean and efficient route for the utilization of ilmenite concentrates was proposed by direct carbothermic reduction in microwave field.High dosage of Na_(2)CO_(3),which can be recycled,was added to accelerate the reduction reaction of ilmenite concentrates.After microwave heating in the temperature range of 1073−1123 K for 20 min,the main products were Na_(2)TiO_(3)and metallic Fe with the metallization ratios being as high as 92.67%−93.21%.The reduction products were processed by water leaching,ball-milling in CO_(2) atmosphere and magnetic separation in turn.The final products after magnetic separation were Fe-rich materials and Ti-rich materials(90.04 wt.%TiO2),which can be used to produce iron and TiCl4 or TiO2.The optimized heating temperature was 1123 K in terms of metallization ratios,magnetic separation and caking property of the reduction products.Besides,the reduction mechanism of ilmenite concentrates with the addition of Na_(2)CO_(3)in microwave field was also proposed.
提出一种基于直接碳热还原和微波加热的钛铁矿绿色高效利用新工艺。通过添加高剂量的Na_(2)CO_(3)加速还原反应的进行,并且Na_(2)CO_(3)可以循环利用。反应原料(钛铁矿+石墨+Na_(2)CO_(3))在微波场下加热至1073~1123 K,保温20 min后,主要还原产物为Na_(2)TiO_(3)和金属铁,其中铁的金属化率可以达到92.67%~93.21%。还原产物依次经过水洗、CO_(2)气氛中球磨和磁选分离,最终可以得到富铁料和富钛料。其中富钛料中TiO2含量可以达到90.04%(质量分数),并可后续用于生产TiCl4或TiO_(2)。基于金属化率、磁选分离效率和产物结瘤特性等参数,优化得到的还原温度为1123 K。此外,还提出添加Na_(2)CO_(3)后的钛铁矿在微波场下的还原机理。
基金
financially supported by the National Natural Science Foundation of China(Nos.51734002,51474141)
China Postdoctoral Science Foundation(No.2020M671071)
Independent Research and Development Project of State Key Laboratory of Advanced Special Steel,Shanghai Key Laboratory of Advanced Ferrometallurgy,Shanghai University,China(No.SKLASS 2019-Z014)。
