Abstract

Using seawater in flotation of copper-molybdenum ores leads to certain difficulties. One of them is that at pH operated to depress pyrite, ie pH >11, a strong Mo depression take place which is mainly due to Mg precipitation. Further the buffer effect of seawater leads to need excessive amount of lime but Ca ions also have a detrimental effect in the quality of concentrated. 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 operate flotation in seawater at low pH to avoid the problems induced by Ca and Mg ions and different reagents to depress pyrite in seawater are used. The ore used, from a local mining, has as one of the main challenges to improve the performance of molybdenite flotation with major depression of pyrite.