ORGANIC REAGENT AS ALTERNATIVE FOR PYRITE DEPRESSION IN SEAWATER
FLOTATION.
Ricardo I. Jeldres 1 , Luis A. Cisternas 2 .
1 CSIRO-Chile International Center of Excellence, Chile.
2 Mineral Process and Chemical Engineering Department, Universidad de Antofagasta, Chile.
Using seawater in flotation of copper ores leads to certain difficulties. One of them can appear if ores contain molybdenite because the operation is usually performed at high pH, i.e. pH>10.5, promoting pyrite depression. Then a strong reduction of Mo floatability take place mainly due to Ca and Mg precipitation.
Further the buffer effect of seawater leads to need excessive amount of lime increasing reagent cost.
Therefore, direct use of lime to depress pyrite is not convenient in seawater and new pyrite depressants that can be used at low pH (pH<9.5) are needed. The goal of this paper is to analyze the impact of organic pyrite depressant on flotation of different copper sulphides in seawater at low pH. These reagents are Results show that organic reagents are a promised alternative for pyrite depression in chalcopyritic copper ores where results are comparable with metabisulphite. However these can be detrimental if ore contain Mo because its floatability is reduced.
KEYWORDS
Seawater flotation, Organic pyrite depressant, Cu-Mo sulphide ores.