Study On Separation Behavior And Mechanism Of Chalcopyrite From Pyrrhotite

Copper ores with high sulfur are typically refractory ones, especially those containing high degree of pyrrhotite are even more complex for dressing. The way to improve the separation effect is to use higher effective Cu collector and valid means to depress pyrite. By now xanthate is the mostly industrial used Cu collector, which has no enough selectivity for Cu in lean impurities fine copper ores.The chalcopyrite and pyrrhotite monomineral tests are done in this article, to find out the influences of collectors, metal ions and depressors etc. on their flotation behaviors; by cyclic voltammetry(CV), ultraviolet spectrum(UV), and contact angle tests, to study the mechanism of mineral surface hydrophobization.The monomineral tests show that chalcopyrite has a higher recovery than pyrrhotie during pH=2-11in non-collector flotation, and the flotation pH range of pyrrhotite is between5to10; there is no distinguish difference of floatability between Chalcopyrite and pyrrhotite in butyl xanthate collector system, and chalcopyrite has better floatability than pyrrhotite in DY collector system; The unavoidably ions like Cu2+and Fe3+etc. will affect the mineral floatability, that the Cu2+activates pyrrhotite, improving the floatability, widening its flotation pH interval, increasing the difficulty of depressing. When the Fe3+keeps a certain concentration in pulp and pH value is relatively high, the floatability of chalcopyrite and pyrrhotite reduced notably. Lime as pyrrhotite depressor consumed largely, getting certain effects till pH>12; air agitation before flotation provides some help to the depression on pyrrhotite.According to the CV tests, chalcopyrite and pyrrhotite have different oxidation and reduction product at different electric potential. The hydrophobic products that enabling chalcopyrite self-induced flotation are CuS and S0, and that enabling pyrrhotite self-induced flotation is S0. The Cu-S sulfides studied in this article are low grade, high oxidization, with uneven and fine-grain chalcopyrite, and complexly co-exist with S-Fe sulfides and gangue; this ore contains21%of pyrite and marcasite, and13.25%of pyrrhotite, so it is a kind of refractory Cu-S sulfide. The industrial site operates in preferential flotation technology with butyl xanthate as Cu collector, results in Cu concentrates grade19.18%, recovery57.13%, which is unsatisfactory. The selective flotation tests are done in this article, with a new type Cu collector DY-1, which produced by Guangzhou non-ferrous metal research institute, and the Cu concentrates recovery increases16.43%compared to site technology. The magnetic separation-flotation tests with collector DY-1, gets better Cu concentrates grade and recovery, and less agents consumption, more operating stability.