During the last few years we have been doing considerable experimenting on methods of precipitating copper. The first patent on precipitating from sulphate solutions by heating with SO2 under pressure was taken out by us (U. S. Pat. 723,949). This reaction, CuSO4 + SO2 + 2H2O = Cu + 2H2SO4, is interesting, but there are … Continue reading Method of Precipitating Copper