电镀污泥中重金属酸浸条件试验

OPTIMAL CONDITIONS FOR ACID-LEACHING OF HEAVY METALS FROM ELECTROPLATING SLUDGE

酸浸条件的选择是资源化利用和安全处置电镀污泥中重金属元素的关键。以盐城市某企业含铜镍电镀污泥为研究对象,考察了酸浸条件对重金属铜镍的浸出率的影响。结果发现:硫酸浸出效果优于盐酸和硝酸,其最佳浓度为1.5 mol/L;污泥粒径越小,其重金属浸出率越高;升高浸取温度可以显著提高浸出率。正交实验结果表明:固液比为1∶15及45℃条件下,1.5 mol/L的硫酸溶液对粒径为100目的电镀污泥中铜、镍2 h后的浸出率分别达到97.59%和91.60%。

Acid-leaching method has become the main precursor technology for the recovery of heavy metals in electroplating sludge and its safety disposal. Using the electroplating sludge containing copper and nickel from a company in Yancheng City as the research object, the effects of acid, concentration, ratio of solid to liquid, sludge particle size, leaching time and temperature on the leaching rate were studied in detail. It was found that the leaching rate was higher in using sulfuric acid as the leaching acid than that of hydrochloric acid and nitric acid, and the most suitable concentration should be controlled at 1.5 mol/L; Smaller of the sludge particle size, higher the heavy metal leaching rate. A certain degree increase of leaching temperature can remarkably increase the leaching rate. In a solid-liquid ratio 1：15 and the leaching temperature 45℃, the leaching rate of copper and nickel reached 97.59% and 91.60% seperately after 2 h of leaching by 1.5 mol/L sulfuric acid solution on the particle size of 100 mesh.