通过柠檬酸湿法工艺处理废旧铅酸蓄电池铅膏,浸出转化得到的前体柠檬酸铅结晶产物粒度较小,不易过滤。通过超声波的方式对柠檬酸铅的结晶过程加以控制,对处理前后的样品进行XRD、TG-DTA和SEM表征,对比超声波处理前后的柠檬酸铅晶体形貌变化。结果表明,经过超声波处理后,柠檬酸铅晶体由薄片状转变为长径比约为8∶1的柱状,柱状晶体长20~50μm,超声波处理前柠檬酸铅晶体的粒度均小于5μm。因此,超声波处理能够有效调控柠檬酸铅晶体的结晶形貌,改善柠檬酸铅前体的过滤性能,提高铅膏湿法转化的效率。
Lead paste from spent lead-acid battery was produced by hydrometallurgy process in citric acid solution.The small size of lead citrate,the precursor of the process made it difficult to be filtered from the liquid mixture.The crystallization process of lead citrate was controlled by ultrasound.The products were characterized by means of XRD,TG-DTA and SEM before and after the treatment of ultrasound.The results indicated that morphology of lead citrate changed from crystal flakes to columnar with draw ratio about 8∶1,and the length of crystal ranged from 20 μm to 50 μm.The crystal size of lead citrate before ultrasound treatment is less than 5 μm.Therefore,ultrasound treatment can efficiently control the crystal morphology of lead citrate resulting in improvement of the filter performance of lead citrate precursor and the conversion ratio of lead paste in hydrometallurgical processes.