皂素在含硫铁矿采选固废生物氧化中的作用

EFFECT OF SAPONIN ON BIOLOGICAL OXIDATION OF PYRITE-CONTAINING SOLID WASTE FROM MINING AND DRESSING

为提升含硫铁矿采选固废生物氧化分解效率,以皂素-微生物-含硫铁矿采选固废为反应体系,研究皂素对含硫铁矿采选固废生物氧化过程中H+、Fe及S释放的影响,并探讨其作用机制。结果表明:添加30 mg/L皂素,生物氧化38 d后,含硫铁矿采选固废释放H+0.55 mmol/g、总Fe 111.4 mg/g和SO_(4)^(2-)359.3 mg/g,相比未添加皂素的空白对照组,释放量分别提升了175%、82.9%和39.2%。皂素的添加,促进了矿物表面沉淀层(黄钾铁矾、S0)的氧化溶解,并抑制了次生矿物黄钾铁矾生成,从而减缓了钝化作用;可显著减小溶液与矿物表面的接触角、表面张力,增强溶浸液Fe3+在矿物微孔裂隙中的渗透作用,从而加速了含硫铁矿采选固废的氧化与溶解。研究结果可为皂素在含硫铁矿采选固废生物氧化的应用提供理论支撑。

In order to improve the efficiency of biological oxidative decomposition of pyrite-containing solid waste from mining and dressing,this paper investigated the effect of saponin on the release of H+,Fe and S in the biological oxidation process of pyrite-containing solid waste from mining and dressing,by using saponin-microorganism-sulfurous iron ore mining solid waste as a reaction system,and its mechanism was discussed.The results showed that it could release 0.55 mmol/g of H+,and 111.4 mg/g of total Fe,as well as 359.3 mg/g of SO_(4)^(2-)by adding 30 mg/L saponin and bio-oxidizing for 38 days from the pyrite-containing solid waste of mining and dressing,which were increased by 175%,82.9%and 39.2%,respectively compared with the blank control group.Firstly,the addition of saponins accelerated the oxidative dissolution of the sendiment layer(jarosite,S0)on the mineral surface,and inhibited the formation of secondary mineral jarosite,thus slowed down the passivation effect.Secondly,it could significantly reduce the contact angle and surface tension between the solution and the mineral surface,and enhance the penetration of Fe3+in the mineral microporous cracks,so as to accelerate the oxidation and dissolution of pyrite-containing solid waste from mining and dressing.The research results can provide theoretical support for application of saponin in the biological oxidation of pyrite-containing solid waste from mining and dressing.