解胶剂对含铬铝泥中铬的分离效率影响

Effect of Dispergators on the Separation of Chromium from Aluminum Residue

无钙焙烧生产铬盐工艺中产生的副产物铝泥中含有重金属铬,严重影响了铝泥后续的资源化利用。为了高效去除含铬铝泥中的铬,通过开展4种不同解胶剂对铬的分离效果实验,采用单一变量法系统性探索了固液比、解胶剂添加量和反应温度等因素对铝泥脱铬效率的影响。结果表明:当解胶剂Na_(2)CO_(3)、NaHCO_(3)和聚丙烯酰胺(PAM)的固液比1∶5、聚乙二醇(PEG-400)为1∶15时,铬的去除效率最佳,同时升高反应温度有利于铝泥中铬的分离。无机和有机解胶剂联合作用后,Na_(2)CO_(3)∶PEG-400在4∶1的比例下除铬效率可达95.27%。X射线衍射分析(X-ray diffraction,XRD)结果显示,风干后的铝泥呈无定型胶体态,铝泥中铬主要以CrO_(4)^(2-)形式附着在铝泥表面,而经过解胶后的铝泥胶体由无定型态转变为具有晶体结构的拟薄水铝石γ-AlOOH。研究结果将对含铬铝泥中铬的分离工艺优化提供技术参考。

The by-product aluminum residue produced from the calcium-free roasting process contains amount of chromium,which seriously affects its reutilization.In order to remove chromium from aluminum residue,four kinds of dispergators were selected to investigate their effects on the chromium removal.A single variable method was used to systematically study the effects of solid-liquid ratio,dispergator addition and reaction temperature on the chromium removal efficiency.Results indicate that the optimal solid-liquid ratios of Na_(2)CO_(3),NaHCO_(3)and polyacrylamide(PAM)are 1∶5 and polyethylene glycol 400(PEG-400)is 1∶15.The rising reaction temperature can improve the chromium removal efficiency,and it can reach 95.27% by Na_(2)CO_(3) and PEG-400 mixture at the ratio of 4∶1.X-rays diffraction(XRD)analysis shows that the chromium in the dried aluminum residue mainly in the form of CrO_(4)^(2-),and the debonded aluminum residue changes from amorphous to pseudo-boehmite γ-AlOOH with crystalline structure.Results of this research will provide technical reference for the optimization of the chromium separation from chromium-containing aluminum residue.