铁矾渣还原焙烧制备磁铁矿的研究

Research on Magnetite Preparation by Reductive Baking of Jarosite Residue

对某锌冶炼厂的铁矾渣进行了粉煤还原焙烧-磁选试验研究,考查了焙烧过程中Zn、Fe、S等主要元素的行为。研究结果表明,在900℃时还原焙烧可以产出磁性很强的磁铁矿,Zn转化为铁酸锌。超过900℃时会有有碱性硫化物生成。粉煤还原焙烧铁矾的最佳条件是:温度900℃,粉煤用量为45g/kg,焙烧时间75min。此时烧渣含S3.07%,含Fe55.94%,烧渣水浸后含S降低到1.47%。在最佳条件下进行焙烧—磁选,精矿含Fe在58.99%～58.72%之间,精矿中Zn含量均比尾矿高约1%,烧渣中大部分S与磁性产物在一起,磁选精矿含S在2.5%～3%之间。

Powder coal was adopted for the reductive baking-magnetic separation research of jarosite residue from a zinc plant. The behavior of main elements in jarosite residue, such as Zn, Fe and S, has been studied. Results show that Fe3O4 formed during the process of reductive baking jarosite residue at 900℃, and Zn is turned into ZnO·Fe2O3. When temperature rises over 900℃, alkali -metals sulfide will be formed. The optimal baking condition is： temperature 900℃, powder coal addition 45g/kg, 75 minutes. At this condition, baked residue will contain 3.07% S and 55.94% Fe,and the content of S can be decreased to 1.47% by water wash- ing. Through reduetive baking - magnetic separation at the optimal condition, the content of Fe in concentrate changes between 58.99% and 58.72%, and the Zn content in concentrate is higher than that in tailings by about 1%. Majority of S in baked residue coexists with the magnetic constituent, so the concentrate obtained contains about 2.5% - 3 % S.