某钒钛磁铁矿精矿深度还原铁颗粒长大特性研究

深度还原过程中铁颗粒粒度特征对后续分选指标有重要影响，以攀西地区某钒钛磁铁矿精矿为对象，通过单因素条件试验重点考察还原温度、还原时间、Na2CO3质量分数对铁颗粒长大特性的影响规律。结 果表明：随着还原温度的升高、还原时间的延长及Na2CO3质量分数的增大，试样中还原铁含量增加，金属化率不断提高，铁颗粒大小不断增大。当还原温度为1 000 ℃、还原时间为2 h、Na2CO3质量分数为15%时，还 原铁含量为44.28%、金属化率为86.84%；在此还原条件下还原产品中+19 μm粒级含量为53.29%，+53 μm粒级含量达到了13.35%，进一步磨矿和磁选后金属铁的回收率可达93%以上。深度还原过程中铁颗粒长大经历了 形核、长大、冷却三个阶段，最终还原形成的铁颗粒50%以上形成单体，剩余大量铁颗粒存在于矿物边缘或内部孔洞边缘，少量存在于矿物颗粒内部。

Study on Iron Particles Growth Characteristic in the Processing of Deep Reduction for a Vanadium-titanium Magnetite Concentrate

In the process of deep reduction， the particle size characteristics of iron particles have an important influence on subsequent sorting indexes. A vanadium-titanium magnetite concentrate in Panxi Area was regarded as object， and the influence of reduction temperature， reduction time and the amount of Na2CO3 mass ratio on the growth characteristics of iron particles were investigated through single factor condition test. The results showed that the amount of reduction iron in the samples increases， the metallization rate increases， and the size of iron particles increases with the increase of reduction temperature， reduction time and the mass ratio of Na2CO3. The reduction iron contents is 44.28% and the metallization rate is 86.84% with the reduction temperature of 1 000 ℃， the reduction time of 2 h and the mass ratio of Na2CO3 of 15%. The contents of particle over 19 μm is 53.29% and the contents of particle over 53 μm is 13.35% in the reduction condition. The recovery rate of metallic iron could reach more than 93% after further grinding and magnetic separation. Iron particles grow up through three stages of nucleation， growth and cooling in the process of deep reduction. In the end， more than 50% of iron particles formed by reduction form monomer， and a large amount of iron particles exist in the edge of mineral or the edge of internal pores， and a small amount of iron particles exist in the interior of mineral particles.