选择性还原法分离高炉粉尘中锌和铁的研究

采用兰炭作还原剂,对高炉粉尘进行还原焙烧,再对焙砂进行磁选,然后浸出磁选尾矿中的锌,实现锌、铁分离。在热力学计算的基础上,研究了焙烧条件对锌、铁浸出率的影响,结果表明:加碳焙烧可使高炉粉尘中的铁酸锌选择性还原为磁性氧化铁和氧化锌,较优的焙烧工艺参数为:焙烧温度800 ℃,焙烧时间2 h,配炭量50%。磁选可分离出焙砂中的磁性氧化铁。采用1 mol/L的硫酸在室温下浸出磁选尾矿1 h,锌、铁浸出率分别为75.39%和27.46%。

Separation of Zinc and Iron from Blast Furnace Dust by Selective Reduction

The blast furnace (BF) dust was treated by reduction roasting with blue carbon as the reductant and the obtained calcine was then subjected to magnetic separation for removing Fe₃O₄. The tailings after magnetic separation were finally leached by sulfuric acid in order to effectively separate zinc from iron. Based on the thermodynamic calculation, the influences of roasting parameters on zinc and iron leaching rate were studied. The results showed that by adding blue carbon, the zinc ferrite in the BF dust was selectively reduced to zinc oxide and ferriferous oxide. With the optimized roasting parameters, including the roasting temperature about 800 ℃, the roasting time of 2 h and carbon addition in quantities of 50% by weight of BF dust, the magnetic iron oxide was separated from the calcine by magnetic separation. After that, the tailings of magnetic concentration were leached with a 1 mol/L solution of sulfuric acid for 1 h at the room temperature, and the leaching rates of zinc and iron reached 75.39% and 27.46%, respectively.