含砷酸性废水无害化处理及渣形态与稳定性分析

Harmless Treatment of Arsenic-bearing Acidic Wastewater and Speciation and Stability Analysis of Slag

含砷难处理金矿石经过加压氧化预工艺处理后产生含砷和铁均较高的酸性废水,采用两段中和法和针铁矿法对其进行无害化处理并对渣中砷的形态进行分析。结果表明,两段中和法和针铁矿法均可高效去除酸性水中的游离态砷和铁,两者的去除率均超过99.9%。与两段中和法相比较,针铁矿法具有处理出水中砷浓度更低、中和浆液的沉降效果好、渣量小、含砷渣的稳定性高等优势。

Acidic wastewater with high arsenic and iron concentrations from pressure oxidation pretreatment of arsenic-bearing refractory gold ore was treated by two stage neutralization and goethite process.As speciation and long term behavior in slag was analyzed.The results show that both methods can effectively remove free state arsenic and iron from aqueous solution with removal rate of both 99.9% above.Compared with two stage neutralization process,goethite process exhibits superior performance of lower As concentration in disposal waste water,better settling performance of settling rate and underflow concentration of neutralized slurry,fewer slag quantity,and higher long term stability of arsenic-bearing slag.