铬渣-煤矸石砖中Cr(Ⅵ)的解毒效果研究

Study on Detoxification Effect of Cr(Ⅵ) in Chromium Residue-coal Gangue Brick

利用自养煤矸石砖技术对铬渣进行无害化治理,通过对原料配比不同的铬渣-煤矸石砖进行浸出毒性分析、稳定性试验和X-粉晶衍射物相分析,结果表明:铬渣加入量为6%的铬渣-煤矸石砖中Cr(Ⅵ)的浸出毒性小于国家标准,还原降解率高,可达98%以上;铬渣-煤矸石砖经过酸溶(醋酸,硫酸)、冻融、曝晒等恶劣条件,Cr(Ⅵ)的解毒稳定性良好;X-粉晶衍射物相分析表明砖中Cr(Ⅵ)被还原为Cr(Ⅲ)后以类质同相方式进入尖晶石、铝硅酸盐等稳定物相,使铬渣得到彻底解毒和资源化综合利用。

Cr（Ⅵ） in chromium residue is reduced and detoxified to Cr（Ⅲ ） by method of sintering bricks with materials which include various ratios of chromium residue to coal gangue. Then, the leaching Cr（ Ⅵ ） concentrations of bricks which are marinated in water or acid solution and marinated after frozen and melted for 30 times or insolated in the sun are measured and phase in sintered bricks are studied. The results suggest that percentage of Cr（ Ⅵ ） detoxified to Cr（ Ⅲ ） in bricks with materials including 6% chromium residue can reach above 98% and the leaching Cr（Ⅵ） concentration is much less than the corresponding standard of state. The concentration of Cr（Ⅵ） in bricks is very steady on vitriol conditions such as marinated by acid solution, frozen and melted, insolated in the sun, etc. The results of X - powder diffraction analysis shows that in bricks, there are phases such as picrite, spinelle and aluminium silicate which increases the stabilization of Cr and Cr of this form is difficuhe leachable.