微波碳热还原白云鄂博稀选尾矿试验

为了进一步降低铌精矿选择性还原的能耗,改善工作环境,降低环境污染,及扩大原料范围,本文以白云鄂博稀选尾矿作为原料,以微波加热作为热源,采用正交试验考察还原剂粒度、反应温度、反应时间和料层厚度对微波场下还原产物的影响。结果表明,在微波场下,采用高挥发分含量的焦粉,有利于获得高金属化率的还原稀选尾矿,影响还原稀选尾矿金属化率的主次因素依次为还原温度、还原时间、还原剂粒度和料层厚度,最佳试验条件为:采用挥发分含量12.6%、粒度0~1 mm的焦粉做为还原剂,反应温度950℃、时间3.5 h、料层厚度9 mm。

碳热还原白云鄂博稀选尾矿试验研究

文章采用正交试验考察反应温度、反应时间和料层厚度对碳热还原白云鄂博稀选尾矿的影响。结果表明,采用高挥发分含量的焦粉,有利于获得高金属化率的还原稀选尾矿。影响还原稀选尾矿金属化率的主次因素依次为还原温度、还原时间和料层厚度,最佳试验条件为:采用挥发分含量12.6%、粒度0~2 mm的焦粉做为还原剂,反应温度1 000℃、时间4.5 h、料层厚度10 mm。

Magnetizing roast and magnetic separation of iron in rare-earth tailings

Magnetic separation of iron in rare-earth tailings was achieved by magnetizing roast process with coal as reductant. Effects of the temperature, carbon to oxygen ratio, and cooling type on magnetic susceptibility and composition of rare-earth tailings were investigated. The results show that roast conditions with the temperature of 650℃, carbon to oxygen ratio of 3.85, and holding time of 2.5 h are in favor of reduction of Fe_2O_3 to Fe_3O_4 when the roasted rare-earth tailings is cooled along with furnace. Under these roast conditions, magnetic susceptibility of rare-earth tailings is 2.36 that is very close to theoretical value（2.33）. However, magnetic separation results of iron in rare-earth tailings cooled along with furnace are not satisfactory. Through comparing magnetic separation results of iron in rare-earth tailings cooled by different ways, it is found that water cooling is more favored of magnetic separation of iron in the roasted rare-earth tailings than furnace cooling and air cooling. Grade and recovery of iron in concentrate from rare-earth tailings cooled by water are 45.00%-49.00% and 65.00%-77.50%, respectively.