Study On Resource Technology And Pollution Control Of Waste Lithium Battery

Lithium cobalt oxide batteries are widely used in various types of electronic products,which is essential for daily life mobile power,but the large use of lithium batteries to make its waste is also a sharp increase.in lithium batteries containing cobalt,lithium,aluminum,copper,iron and other valuable recyclable metal.In addition,lithium batteries also contain electrolyte,organic binders and other toxic ingredients,a large number of lithium batteries scrapped not only caused waste of resources,but also caused many environmental problems.Therefore,the recycling of waste lithium battery resources is becoming an urgent need to deal with and concerns.In the process of waste lithium battery recycling,researchers not only concern about the recovery of cobalt and lithium,but also need to reduce the energy consumption,improve the level of clean production,reduce the pollutants,in order to achieve the maximum benefit of waste lithium battery recycling and minimize emissions of pollutants.In this paper,by establishing waste lithium battery recycling technology recovery system,recycling of waste lithium batteries:firstly discharge treatment the waste lithium battery,then manual dismantling of the battery to obtain the positive,the active material LiCoO₂ separated from the aluminum foil by organic solvent NMP?N-methyl-2-pyrrolidone?dissolveing organic binder PVDF,to obtain the black powder containing active material LiCoO₂.The LiCoO₂ powder is leached by H₂SO₄+H₂O₂ acid system,the Co²⁺and Li⁺extracted and removed by extraction P204,obtaining enriched Co²⁺ and Li⁺ in the extract remaining liquid,and then,the Co²⁺ and Li⁺ were separated by extraction agent P507.Co²⁺was introduced into the organic phase and Li⁺ enters the aqueous phase,Finally,the crude CoCl2 was extracted with HCl,and Li⁺ was precipitated with saturated Na2CO3 to obtain Li2CO3,so as to achieve the purpose of recycling Co and Li.The main technical processes in the process of waste lithium battery resource regeneration include:waste lithium battery pretreatment process,H₂SO₄+H₂O₂ acid leaching process,organic solvent extraction and separation process,HCl stripping process.The pretreatment experiment shows that saturated brine can cause waste lithium battery to fully discharge.the organic solvent NMP separates the positive material LiCoO₂ from aluminum foil,and the best solid-liquid ratio is 1:4.The H₂SO₄+H₂O₂ acid system leaching on LiCoO₂ black powder experiment shows:sulfuric acid concentration,extraction temperature,reaction time,solid-liquid ratio are important factor of Co²⁺,Li⁺ acid leaching.The optimum extraction conditions of Co²⁺ and Li⁺ are as follows:2mol/L sulfuric acid concentration,reaction temperature 60?,1h reaction time,solid-liquid ratio 1:15,and the leaching rate of cobalt and lithium is 99%under the optimal conditions.The experiment of Co²⁺,Li⁺ extracted by P204 shows:the main factors affecting P204 extraction are extraction pH and compare.The optimum extraction conditions of P204 are pH=2.58:,compared with 1:1,and the extraction rate of cobalt and lithium in P204 is above 95%.Impurity ions are basically removed,the removal rate of Manganese,Magnesium,Zinc over 80%.The experiment of extracting separated cobalt,lithium by P507 shows:pH and compare are the main factor affecting the extraction of cobalt and lithium by P507 extraction,the optimum extraction conditions:pH=5.46,compared with 1:1,the extraction rate of cobalt on P507 reached 98%,cobalt-rich organic phase stripped by HCl to obtain CoCl2 solution,the optimal stripping concentration of HCl is 3mol/L,cobalt recovery rate of 98%,lithium-rich water phase using saturated sodium carbonate solution precipitation and recovery of lithium,precipitation rate over 95%.For the regeneration pollutants of waste lithium battery,the use of NaOH solution to absorb the process of dismantling volatiled electrolyte to treat harmlessly.Calculate the acid consumption and residual acid under the conditions of H₂SO₄+H₂O₂ acid system and different sulfuric acid concentration to control the proper acid.Analysis of manganese,magnesium and zinc removal in H₂SO₄+H₂O₂ acid system and removal of manganese,magnesium and zinc from extraction agent P204.In H₂SO₄+H₂O₂ acid system and under the experiment conditions of best leaching Co²⁺,Li⁺,100ml experiuental sample of the appropriate amount of acid is 17.5ml,the remaining amount of acid 6.5ml;by measuring the leaching rate of manganese,magnesium and zinc in H₂SO₄ + H₂O₂ acid system,the three metals are leached into the acid liquid,and the leaching rate is over 80%.The removal rate of Mn²⁺ and Zn²⁺ in the extraction P204 can reach more than 90%,and Mg²⁺ can reach 80%.The waste solution containing Mn²⁺,Mg²⁺ and Zn²⁺ are treated with NaOH solution,which are removed by forming stable precipitation.