New Insights into the Pre-Concentration of Alunite from a …
Samples were crushed in a jaw crusher, a cone crusher and a roll crusher to produce particles with a size of -2380+841 µm. In the next step, the samples were ground in a laboratory-scale Denver ball mill of 200 mm internal diameter, the volume of 950 cm3, loaded with 6 steel balls with 42 mm diameter, 21 balls with 31 mm