焙烧制度对煤泥-浸锌渣冷固结球团还原行为的影响

Effect of Roasting System on Reduction Behavior of Cold Bond Pellets Made of Coal Slime-Zinc Leaching Residue

基于直接还原法探讨了焙烧制度对煤泥-浸锌渣冷固结球团中锌、铅挥发率和铁金属化率的影响,分析了焙烧制度对球团中含锌、铅、铁化合物相变的影响,试验确定了焙砂磨矿—弱磁选回收其中铁的工艺和效果。结果表明:在1 250℃焙烧90 min,可使球团中锌、铅的挥发率分别达到98.87%、95.39%,铁的金属化率达到98.66%;焙砂中未见锌、铅单质及其化合物,只存在大量的金属铁,且金属铁颗粒多数大于30μm;焙砂采用2段磨矿、2段弱磁选流程处理,可同时获得含铁91.20%、回收率为30.32%的金属铁粉和铁品位为61.58%、回收率为50.01%的铁精矿,铁总回收率达80.33%。

The effect of roasting system on lead and zinc evaporation rate, iron metallization rate of cold bond pellets made of coal slime-zinc leaching residue was investigated based on direct reduction. The influence of roasting system on phase change of Zn,Pb and Fe compounds in the pellets was analyzed. The process of grinding-low intensity magnetic separation for i-ron recovering is determined according experiments. Results show that calcined at 1 250 ℃for 90 min,the evaporation rate of lead 95. 39% and zinc 98. 87%,iron metallization rate of 98. 66% were obtained. In the roasting products,diffraction peak of Zn,Pb monomer metals and its compounds disappeared,while more iron emerged,and majority of which are greater than 30μm in particle size. Metallic iron powder with iron grade of 91. 20% and recovery of 30. 32%,and iron concentrate with iron grade of 61. 58% and recovery of 50. 01% were obtained through two stage grinding,two stage low intensity magnetic separation process,and the total iron recovery reaches 80. 33%.