| After flotability studies on Cu-Zn-Fe sulphides in an ore which is contaminated by the acidic wastewater in an underground mine from time to time, and in which the content of secondary copper sulphides is about 40% of the total copper content, it is proved that separation of sulphides in this ore is very difficult. It is also discovered that the copper sulphides in this ore are possibly divided into two groups of different natural flotability, the sphalerite also has two groups of different flotability whether they can be suppressed by non-cyanide depressants. Therefore, a new concept of two-step flotation process to treat this refractory Cu-Zn-Fe sulphide ore is formulated. Characteristics of the two-step flotation process are described in detail. The two-step Cu-Zn flotation process has successfully been tested both in laboratory and in production. This process could produce a final total copper concentrate (grade of 19.3% Cu and 2.5% Zn recovery of 84.6% for Cu), a zinc concentrate (grade of 51.7%Zn, recovery of 80.7% for Zn) and a iron sulphide concentrate (grade of 34.8% S, recovery of 80.2% for S) in industry.
A new effective method for separating the Cu-Zn-Fe sulphide bulk concentrate is also introduced. |