Study On Leaching Lead Paste With R4NOH-R4NX Conjugated Solution And Recovering PbO

Since the French Prandt invented lead-acid batteries in 1859,the application of lead-acid batteries has been developing rapidly in the electric car and automotive applications and it has become the world's largest battery production,the most widely used one.In recent years lead-acid batteries occupies about 80%of the world's total lead consumption.The greater the yield of lead-acid batteries,the more the lead-acid batteries will be renewed.From the environmental point of view,lead-acid batteries are hazardous on the environment and human's health.If the discarded lead-acid batteries are not recycled,not only will cause pollution to the environment,but also a waste of non-renewable lead resources.This paper aims to overcome the technical shortcomings of the existing technology,such as high cost of recycled lead oxide and low purity of the products.We propose the wet recovery method of lead paste with high desulfurization rate,simple process,environment friendly and low cost.The main research contents are as follows:?1?In this paper,the main components and contents of the raw materials were measured by chemical titration.The contents of PbSO₄,PbO₂,PbO and Pb in the lead paste are 33%27%,28%,10%,respectively.The rest 2%is lead free,mainly introduced during the process of preparing and cracking of the battery.The organic additive is removed by roasting.The PbO₂ and Pb was changed to PbO at high temperature to facilitate the subsequent recovery.The results show that the conversion of PbO₂ and Pb is above 99%when the calcination temperature is 600?,the calcination time is 1h and the thickness of lead paste is 2cm.Acidification is converted to roasted lead paste and the purpose is to lead the composition of lead into PbSO₄ to facilitate the subsequent leaching of carbonation.The effects of sulfuric acid concentration,acidification temperature,acidification time,solid-liquid ratio and catalyst dosage on the acidification conversion process were studied in the process of acidification.?2?The lead paste has been converted to PbSO₄ after the calcination and acidification steps.The leaching carbonization step is based on the good solubility of the lead sulfate in the conjugated solution.The specific reaction is as follows:PbSO₄ + NH3 + H2O = NH4?Pb?OH?SO₄?.The effects of single factor such as quaternary ammonium hydroxide concentration,ammonium sulfate concentration,reaction temperature and reaction time on the leaching process were studied during the leaching and carbonization.process.The results showed that the concentration of R4NOH 10 mol L-1,R4NX 3.5 mol L-1,the leaching temperature 40?,the leaching time 10 min,and the carbonization temperature 30?,CO₂ ventilation twice the amount of lead material are the best leaching carbonation conditions.?3?The ?-Pb0,?-PbO and Pb₃O₄ can be prepared by baking lead carbonate by thermogravimetric analysis of lead carbonate.The results show that ?-PbO is obtained by calcination of lead carbonate at 450? in the inert gas atmosphere.In the air atmosphere,lead carbonate is calcined at 560? to obtain ?-PbO.Pb₃O₄ is obtained by calcination of lead carbonate in air atmosphere at 480?.