采用“打浆水洗除Cr（Ⅵ）—电渗析除Cr（Ⅵ）—碱浸提铝—碳酸化分解法精制Al2O3”的新工艺处理含铬铝泥（以下简称铝泥），并回收Al2O3。实验结果表明：铝泥在70℃下经3次打浆水洗后，w（Na2CrO4）（以干铝泥计）降至5.0%；采用电渗析除Cr（Ⅵ）工艺可有效去除铝泥中以结合态和结晶态形式存在的Na2CrO4，在55 V直流电压下电渗析6 h后铝泥中的w（Na2CrO4）降至0.98%；在碱浸温度为100℃、碱浸时间为3 h、NaOH质量浓度为150 g/L的优化碱浸条件下，铝浸出率（以Al2O3计）高达90.0%；经3次碳酸化分解处理后，Al2O3产品的纯度达98.65%，满足GB/T 24487—2009《氧化铝》中的一级标准，Al2O3回收率为96.37%。%The chromium-containing aluminum residue was treated to recover Al2O3 by a new process of beating and water-washing for Cr(Ⅵ)removal-electrodialysis for further Cr(Ⅵ)removal-alkali leaching for aluminum removal-carbonation decomposition for Al2O3 refinement. The experimental results show that:After beating and water-washing for 3 times at 70℃,w(Na2CrO4)(based on dried aluminum residue)of the residue can be reduced to 5.0%;The binding state and crystalline state Na2CrO4 in the residue can be effectively removed by electrodialysis,and w(Na2CrO4)of the residue can be reduced to 0.98%in 55 V DC voltage after electrodialysis for 6 h;Under the optimum alkali leaching conditions of alkali leaching temperature 100℃,alkali leaching time 3 h and NaOH mass concentration 150 g/L,the leaching rate of aluminum (calculate by Al2O3)is up to 90.0%;After 3 times of carbonation decomposition,the purity of Al2O3 product reaches 98.65%,which meets the first grade standard of GB/T 24487-2009,and the recovery rate of Al2O3 is 96.37%.
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