废旧锂电池废料除铝及回收铝工艺研究

锂离子电池作为电池市场的主要产品，产量不计其数，同时每年废弃的锂离子电池数目也非常巨大，这些锂离子电池废料中含有丰富的金属元素，为了能够有效地提取废旧锂离子电池中宝贵的金属，对其进行除铝和回收铝研究.实验使用NaOH为浸出剂、二级逆流碱浸法为工艺，探究了从锂离子电池废料中除铝的较优条件，并且利用XRF、扫描电镜对锂离子废料元素和氢氧化铝沉淀表面进行形貌分析，初步探究了不同pH值对浸出液中回收氢氧化铝能力的影响.结果表明，除铝较为适宜工艺条件为加碱量为Al的化学计量比的1.5倍，反应温度为80 ℃、反应时间为1 h、一级碱浸固液比为1:12（g/L）、二级碱浸浓度为5 %、一二级碱浸碱配比为6:4，加料方式为一级碱浸先加碱溶液再加固体废料、二级碱浸先加固体废料再加碱溶液的方式.此条件下，铝的浸出率达到12.32 %以上，废料中超过90 %铝被浸出.沉淀氢氧化铝的较优pH值为7~8. 

Study on the process of aluminum removal and recovery from waste lithium ion batteries

As the main products of battery market, lithium ion batteries enjoy a high production, yet each year, the number of spent lithium ion batteries, though still rich in metal elements, is frightening. In order to effectively extract valuable metal elements from waste lithium ion batteries, this paper studies aluminium removal and recovery. In this experiment, NaOH was used as the leaching reagent and the secondary counter-current alkali dissolution method was also employed to explore optimal conditions for removing aluminium from these waste batteries. Besides, their elements and the surface morphology of aluminium hydroxide precipitation were analyzed by XRF and scanning electron microscopy, respectively. The effects of different pH on the recovery of aluminium hydroxide in the leachate were preliminarily investigated. The results show that appropriate conditions for removing aluminium include: the amount of alkali 1.5 times the stoichiometric ratio of Al, reaction temperature of 80 ℃, reaction time of 1h, primary solid-to-liquid ratio of 1:12, 5 % of alkali concentration in the secondary alkali leaching, the distribution ratio of alkali amount in primary and secondary alkali leaching of 6:4. In addition, feeding method is first adding alkali solution and then solid scrap in the first alkali leaching yet the feeding process is opposite to the second alkali leaching. Under these conditions, the dissolution rate of aluminium is above 12.32 %, with more than 90 % of it dissolved in the waste so that the optimum pH for the precipitation of aluminium hydroxide is 7~8.