Study On The Recycle Treatment Of Electroplating Sludge

A new technology is developed, described as leaching-precipitating step by sep — innoxious disposal. It is used to treat the electroplating sludge in which the primary heavy metals are copper and Stannum. The mechanisms of leaching , precipitating and purifying of this technology are investigated. The results have shown that the copper and Stannum can be leached mostly, and the waste water and the solid waste produced in leaching and precipitating process do not have adverse effects on the environment.Different acids are used to leach the electroplating sludge, and the results have shown that hydrochloric acid is the best leaching reagent. The optimum conditions of acid leaching are: the fineness of raw material is 100, the ratio of water/solid is 3, acid dosage is 2mL per gram dry sludge, leaching time is lh, the room temperature is used. Copper and Stannum can be effectively leached from the electroplating sludge.Copper and Stannum are separated by precipitating under different pH values from the leaching solution. The impurities are also removed by precipitating. The high-quality products of Sn(OH)4 and Cu(OH)2 are made .The waste water and the solid waste produced in the leaching and precipitating process can meet the standard of safe disposal. So, the wastes have no bad impact to the environment.Through economical analysis, it can be concluded that it is profitable to treat the electroplating sludge using the new method. In our investigation, there are innovations in technology, and the parameters are suitable, so the technology has guidable meaning to the plant application.