废锂电池资源化技术及污染控制研究

发布时间：2018-01-27 16:03

本文关键词： 废钴酸锂电池资源再生酸浸出萃取污染控制　出处：《西南交通大学》2017年硕士论文　论文类型：学位论文

【摘要】：钴酸锂电池广泛应用于各类电子产品,是日常生活中必不可少的移动电源,但是锂电池的大量使用使其废弃量也在急剧增长,废锂电池中含有钴、锂、铝、铜、铁等有价值的可回收金属,同时锂电池中还含有电解质、有机粘结剂等有毒成分,锂电池的大量报废不仅造成资源浪费,还造成许多环境问题,因此,废锂电池的资源再生正成为亟需处理和关注的问题;在废锂电池资源再生过程中,课题组不仅关注钴、锂的回收,同时需要降低工艺能耗,提高清洁生产水平,对污染物减量化进行研究,以达到废锂电池回收经济效益最大化和污染物排放最小化。本文通过建立废锂电池再生资源化技术体系,对废锂电池进行资源化处理:首先将废锂电池进行放电处理之后,对其进行手工拆解获取电池正极,采用有机溶剂NMP(N-甲基-2-吡咯烷酮)溶解有机粘结剂PVDF使正极上的活性材料LiCoO_2与铝箔分离,得到含活性物质LiCoO_2的黑色粉末,再用H_2S04+H_2O_2酸体系对LiCoO_2粉末进行酸浸出,使用萃取剂P204对浸提液中Co~(2+)、Li~+进行萃取除杂,得到富Co~(2+)、Li~+的萃余液,再用萃取剂P507对Co~(2+)、Li~+进行萃取分离,Co~(2+)进入有机相,Li~+进入水相,最后使用HC1反萃Co~(2+),得到较纯CoCl_2,用饱和Na2C03沉淀Li~+,得到沉淀Li_2CO_3,从而达到回收Co、Li的目的。废锂电池资源再生过程中的主要工艺包括:废锂电池预处理工艺,H_2S04+H_2O_2酸浸工艺,有机溶剂萃取分离工艺,HC1反萃工艺。经预处理实验得出:饱和食盐水可对废锂电池进行放电完全;有机溶剂NMP能使正极活性物质LiCoO_2与铝箔分离,最佳固液比为1:4。H_2S04+H_2O_2酸体系对含LiCoO_2黑色粉末酸浸实验得出:硫酸浓度、浸提液温度、反应时间、液固比是影响Co~(2+)、Li~+浸出的重要因素,最优浸提Co~(2+)、Li~+条件为:硫酸浓度2mol/L、浸提液温度60℃、反应时间1h、固液比1:15,最优条件下钴、锂的浸出率均达到99%。P_204萃取Co~(2+)、Li~+实验得出:影响P204萃取的主要因素有萃取pH,相比。P204最优萃取除杂条件为:pH=2.58,相比为1:1,此时P204萃取钴、锂的萃取率达到95%以上,杂质离子基本去除,锰、镁、锌的去除率均达到80%以上;P507萃取分离钴、锂实验得出:萃取pH,相比是影响P507萃取分离钴、锂的主要因素,最优萃取分离条件为:pH=5.46,相比为1:1,此时P507对钴的萃取率能达到98%。富钴有机相采用HC1反萃,得到CoCl2溶液,其最优反萃HC1浓度为3mol/L,钴的反萃率达到98%;富锂水相采用饱和碳酸钠进行沉淀回收锂,沉淀率在95%以上。针对废锂电池再生污染物,利用NaOH溶液吸收拆解过程中挥发的电解液从而对其进行无害化处理;计算H_2SO_4+H_2O_2酸体系下不同硫酸浓度浸出钴、锂条件下的酸消耗与剩余酸,控制合适酸量;分析锰、镁、锌三种金属在H_2SO_4+H_2O_2酸体系中的浸出率及萃取剂P204对锰、镁、锌的去除。酸消耗量和剩余量实验得出最优浸提Co~(2+)、Li~+条件下,100ml实验样品合适酸用量为:17.5ml,剩余酸量为6.5ml;通过测定锰、镁、锌三种金属在H_2SO_4+H_2O_2酸体系中的浸出率,得出三种金属均被浸出进入料液,浸出率均达到80%以上;在P204萃取除杂时,Mn~(2+)、Zn~(2+)去除率均能达到95%以上,Mg~(2+)去除率能达到80%,采用NaOH溶液处理含锰、镁、锌离子的废液,使其生成稳定Mn(OH)_2、Mg(OH)_2、Zn(OH)_2沉淀而被去除。
[Abstract]:Cobalt acid lithium is widely used in all kinds of electronic products, mobile power supply is essential in daily life, but the extensive use of lithium battery to its waste is increasing sharply, the waste lithium battery containing lithium, cobalt, aluminum, copper, iron and other valuable metals Recyclable, but also contains the electrolyte of lithium battery, organic binder and other toxic ingredients, a large number of scrapped lithium battery is not only a waste of resources, but also caused many environmental problems, therefore, recycling waste of lithium battery is becoming an urgent and concern; in the process of recycling waste lithium battery, the research group is concerned not only with cobalt, lithium recovery, and the need to reduce the energy consumption of technology and improve the level of clean production, carry out the research on pollution reduction, in order to achieve the maximum economic benefits of lithium battery recycling waste and minimize pollutant emissions. In this paper, through the establishment of waste lithium battery renewable resources technology system, The waste lithium batteries for recycling treatment: after the waste lithium battery discharge process and manual dismantling of the acquisition of the battery cathode, using organic solvent NMP (N- methyl -2- pyrrolidone) dissolved organic binder PVDF to active material LiCoO_2 and aluminum foil anode separation, black powder containing active substance LiCoO_2 then, H_2S04+H_2O_2 acid system for acid leaching of LiCoO_2 powder, the extraction liquid using Co~ extraction agent P204 (2+), Li~+ extraction and impurity removal, get rich Co~ (2+), raffinate Li~+, and extraction agent P507 on Co~ (2+), Li~+ Co~ (2+) extraction. Into the organic phase, Li~+ into the aqueous phase, and finally use the HC1 stripping of Co~ (2+), with pure CoCl_2, Li~+ with saturated Na2C03 precipitation, the precipitation of Li_2CO_3, so as to achieve the recovery of Co, Li. The purpose of waste lithium battery recycling including the main process of waste lithium battery pretreatment Process, H_2S04+H_2O_2 acid leaching process, separation process of organic solvent extraction, HC1 stripping process. The pretreatment experiment showed: saturated salt water of waste lithium batteries discharge completely; organic solvent can make NMP cathode active material LiCoO_2 and the separation of aluminum foil, the best ratio of solid to liquid 1: 4.H_2S04+H_2O_2 acid system on the leaching experiments with black LiCoO_2 powder: acid sulfuric acid concentration, extraction temperature, reaction time, ratio of liquid to solid is Co~ (2+), an important factor of Li~+ leaching, the optimal extraction of Co~ (2+), Li~+ condition: sulfuric acid concentration 2mol/L, extraction temperature 60 C, reaction time 1H, the optimal conditions of solid-liquid ratio at 1:15. Under the cobalt, lithium leaching rate of 99%.P_204 extraction of Co~ (2+), Li~+ tests show that the main factors affecting the extraction of pH P204 extraction,.P204 extraction and impurity removal compared to optimal conditions: pH=2.58, compared to 1:1, the P204 extraction of cobalt, lithium extraction rate reached more than 95% impurities Ion removal, manganese, magnesium, zinc removal rate reached more than 80%; P507 extraction separation of cobalt, lithium extraction experiments show that: pH, is compared with the effect of P507 extraction of cobalt, lithium main factors, the optimal extraction conditions were: pH=5.46, compared to 1:1 P507 on time, the extraction rate of cobalt 98%. cobalt rich organic phase by HC1 stripping, CoCl2 solution, the optimal concentration of HC1 was 3mol/L stripping, the stripping rate of cobalt reached 98%; lithium rich aqueous sodium carbonate by precipitation with saturated lithium recovery, precipitation rate is above 95%. The regeneration of waste lithium battery, using NaOH electrolyte solution absorption of volatile dismantling in the process of harmless treatment of H_2SO_4+H_2O_2 acid; calculation system under different concentration of sulfuric acid leaching of cobalt, acid consumption and residual acid lithium under the condition of proper control of acid; analysis of manganese, magnesium, zinc leaching rate of three kinds of metal in acid system and H_2O_2 H_2SO_4+ The extraction agent P204 on manganese, magnesium, zinc removal. The remaining amount of acid consumption and leaching experiments to obtain the optimal Co~ (2+), Li~+, 100ml experimental samples suitable acid dosage is 17.5ml, residual acid was 6.5ml; the determination of manganese, magnesium, zinc leaching of three kinds of metal in acid system in H_2SO_4+H_2O_2 the rate of three kinds of metals were leached out into the liquid, the leaching rate reached more than 80%; in the P204 extraction and impurity removal, Mn~ (2+), Zn~ (2+) removal rate could reach more than 95%, Mg~ (2+) removal rate can reach 80%, the processing of manganese, magnesium and zinc in NaOH solution. From the waste liquid to produce a stable Mn (OH) _2, Mg (OH) _2, Zn (OH) and removed the precipitation of _2.

【学位授予单位】：西南交通大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：X705

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