COPPER REFINING CASE STUDY Acid mist generated by electrowinning metals from acidic electrolytes can be dramatically reduced with Euro-Matic Hollow Plastic Balls. PROBLEM   The Copper refining technique of electrowinning generates oxygen gas at the surface of the anodes, which saturates the electrolyte and forms bubbles which rise to the surface and burst into the atmosphere. A fine acid mist is created which is dangerous to human health and damages the building structure. Increased ventilation rates become costly, cause significant electrolyte temperature loss and merely transfer the contamination outside the building.   SOLUTION Although several techniques have attempted to solve these problems, none offer the performance and flexibility of a Euro-Matic floating blanket of 3/4" (19mm) hollow polypropylene balls. Forming a layer up to four balls deep, most of the acid mist particles impact or condense on the ball, then return harmlessly into the liquid. The balls allow unobstructed retrieval of the cathode and fail to become trapped on the copper deposits.   HEAT SAVING The thermal insulation qualities of a Euro-Matic floating ball cover can reduce heat loss by up to 70% depending on the liquid and ambient temperatures. Process liquid temperatures can also be maintained at optimum operating conditions more easily.   SURFACE COVERAGE Typically, three layers of 19mm (3/4") diameter balls are recommended. Approximately 2,900 balls cover one square metre (270/ sq ft) with a single layer. Recent tests have suggested that further improvements can be obtained by mixing 19mm and 10mm balls in a volume ratio of 70/30.