China Nonferrous Metallurgy

There are a lot of physical impurities (plastic, lead grid/powder and fiber) in the lead paste of spent lead battery, which have strong adhesion to the lead paste particles and are difficult to separate, which has an important impact on smelting-free recovery process of lead paste. In this paper, alkyl phenol polyoxyethylene polyoxypropylene ether (APEP) is used as dispersant to disperse the waste lead paste particles, and a double-cyclone forced dispersion device and a hybrid power fine screening device are designed to carry out fine separation of physical impurities. The effects of APEP addition, pH value and device parameters on the separation effect were investigated, and the results showed when the APEP dosage was 0.1mg/L and pH was 5.0, the emulsification and dispersion effect was better; the Zeta potential of the waste lead paste reached 22.5mV, and the average particle size was only 3.2μm; the equipment parameters were further optimized under these conditions, and when the mixture inlet flow rate and gas content rate were 8m/s and 15%, and the gyration frequency and compressed air volume were 50 times/min and 2.5m3/h, the removal rates of plastic, lead grid/powder and fiber could reach 99.75%, 82.54% and 99.65%, respectively, the entrainment rates to lead paste were also only 0.17%, 0.06% and 0.36%. The paper provides a stable, reliable and efficient method for producing pure lead paste for the regenerated lead industry, and provides favorable conditions for the application of lead-paste smelting free recovery technology.