【摘要】 针对废旧铝电解质酸化焙烧过程中产生的焙烧渣中有价元素回收问题，本文采用氢氧化钠溶液浸出-晶种分解相结合的方法，实现铝资源的高效回收。首先，考察了氢氧化钠浓度和液固比对焙烧渣中硫酸铝及硫酸铝钠浸出行为的影响。结果表明，在氢氧化钠浓度为3 mol/L、液固比为7 mL/g、浸出温度50℃、浸出时间40 min的条件下，铝组分可最大程度进入溶液，实现与硫酸钙等杂质的一步分离。随后，对浸出滤液进行晶种分解回收铝元素，系统研究了晶种系数、反应温度及时间对分解过程的影响。在晶种系数为0.2、反应温度50℃、反应时间48 h条件下，铝酸钠分解率达到86.21%,获得氢氧化铝固体产物，同时生成可循环利用的种分母液。研究表明，该工艺流程短、操作简便，无污染性气体产生，且母液可循环利用，具有良好的环境与经济效益，为废旧铝电解质焙烧渣的资源化利用提供了有效途径。更多还原

【Abstract】 This study focuses on the recovery of valuable elements from baking slag generated during the acid baking of spent aluminum electrolyte. A combined process of sodium hydroxide leaching and seed precipitation was employed to efficiently recover aluminum. Firstly, the effects of NaOH concentration and liquid to solid ratio on the leaching behavior of aluminum sulfate and sodium aluminum sulfate in the baking slag were systematically investigated. The results indicate that under optimal conditions(NaOH concentration of 3 mol/L, liquid to solid ratio of 7 mL/g, leaching temperature of 50℃ and leaching time of 40 min), aluminum was efficiently leached into the solution, enabling its effective separation from calcium sulfate and other impurities. Subsequently, aluminum was recovered from the leachate via seed precipitation. The effects of seed addition ratio, reaction temperature and reaction time on the precipitation process were further analyzed. Under conditions of a seed addition ratio of 0.2, reaction temperature of 50℃ and reaction time of 48 h, the precipitation rate of sodium aluminate reached 86.21%, resulting in the formation of aluminum hydroxide and recyclable mother liquor. The proposed process features a short flow sheet, simple operation, absence of harmful gas emissions and recyclability of the mother liquor, demonstrating significant environmental and economic benefits. This study provides a promising route for the efficient and sustainable utilization of baking slag from spent aluminum electrolyte.更多还原