葡聚糖对酸性矿山废水中次生铁矿物形成的影响

Effects of Dextran on Formation of Secondary Iron Minerals in AMD

采用H2O2氧化Fe2+并供应4种不同浓度葡聚糖的方法,探讨在H2O2氧化体系中葡聚糖对次生铁矿物形成的影响。结果表明:葡聚糖对次生矿物的形成具有明显的抑制作用;随着葡聚糖浓度的提高,次生矿物内的Fe含量降低,而S含量没有显著变化,且所有处理的K含量均较低;没有葡聚糖处理的次生矿物XRD特征峰与黄钾铁矾吻合,而添加葡聚糖后形成的次生矿物的特征峰与施氏矿物吻合,但是所有处理的次生矿物的结晶度都不高;随着葡聚糖浓度的提高,次生矿物的颗粒尺寸降低,比表面积增加。因此,葡聚糖能够抑制次生矿物的合成,并且阻止次生矿物由施氏矿物向黄钾铁矾的转变。

In order to study the effects of different dextran concentrations on the formation of secondary iron minerals, ferrous iron was oxidized by adding H2 O2 under four different dextran concentrations. The results obtained were list as follows ： （ 1 ） dextran restrained the formation of secondary minerals ; （2） with increasing dextran concentrations, Fe concentrations in secondary minerals decreased, while S concentration did not vary significantly. K concentrations in all treatments were extremely low; （3） XRD patterns of secondary minerals formed without dextran were well coincide with that of jarosite, while those formed with dextran were coincide with that of schwertmannite. But the crystalliza- tion of secondary minerals in all treatments was not very good; and （4） with increasing dextran concentrations, the particle sizes of secondary minerals decreased, while specific surface area increased. Therefore, dextran depresses the formation of secondary minerals, and restrains the transformation of schwertmannite to jarosite.