湿法炼锌厂针铁矿渣的表征

Characterization analysis of goethite residue from zinc hydrometallurgy plants

针对湿法炼锌厂针铁矿渣中铁和锌质量分数波动大、过滤性不佳的问题,通过采集不同锌厂的针铁矿渣样,对其展开系统的表征分析,研究铁、锌在针铁矿渣样中的赋存特征以及形成原因。研究结果表明:尽管不同厂家的针铁矿渣成分相差较大,但颗粒粒径及铁、锌分布特征相似;铁渣样品中粒径小于38μm的颗粒占多数,且这部分颗粒渣中铁质量分数较高,锌质量分数较低,而对于粒径大于80μm的颗粒,锌质量分数约为30%,铁质量分数仅为15%左右,这说明除酸洗外还可采用分级的方法降低针铁矿渣中锌质量分数;在针铁矿样品中,大部分铁存在明显的富集相,而锌除了存在富集相外,还有一部分呈分散分布;因此,为了获得理想的针铁矿渣、除调控沉铁工艺条件外,还需严格控制中和剂品质。

Considering the great variation of iron and zinc mass fraction and poor filtration performance in the goethite residue from zinc hydrometallurgy plants,the goethite residue samples from different zinc plants were collected and characterized systematically.The occurrence characteristics of zinc and iron in goethite residue and its formation causes were revealed.The results show that although there is great difference in the mass fractions of zinc and iron in these samples,the characterization of particle size and distribution of Fe and Zn are similar.Particles smaller than 38μm in diameter in the sample account for vast majority,and contain high mass fraction of iron and low mass fraction of zinc.While particles of greater than 80μm in diameter contain up to 30%zinc,but only 15%iron.In other words,besides acid washing process,size classification can also reduce the mass fraction of zinc in the goethite residue.Most of the iron in the goethite samples exists as enrichment phase.For zinc,in addition to zinc rich phase,some zinc is widely scattered in the sample.For obtaining ideal iron removed goethite residue,the quality of neutralizer also need to be strictly controlled in addition to improvement of iron precipitation parameters.