


The starting material contained 27.37% copper, 0.52% silver, 0.06% gold and 0.04% palladium. This material was crushed with a Retsch heavy-duty cutting mill, and the crushed matter was separated into four groups with particle size as: +1.168 mm, −1.168 + 0.6 mm, −0.6 + 0.3 mm, and −0.3 mm. The smallest size portion was researched by a ...