Fundamental Research On Flotation Separation Of Chalcopyrite And Galena

Under more than one hundred year, of research and development, flotation separation of Cu-Pb is not satisfying yet. On a basis of systematic literature search, this paper summarized flowsheet structure, reagent, electrochemistry property and mechanics of Cu-Pb separation. Via flotation tests, instrument detecting and calculation, extensively explored mechanics of collector and depressor's effect on sulphide floatability:With the aid of advanced modern physical and chemical analysis technique such as XRD, XPS and FTIR, surveyed property variation of precipitates formed on chalcopyrite and galena surface processed by various reagents;Systematically tested selective collectors, regular depressors such as Na2SO3 and ZnSO4 and newly developed depressors effect on single sulphide mineral's floatability, separation of two type of single minerals and production minerals;Kept trace of pulp potential variation trend in the course of sulphide minerals flotation by using on-line pulp potential measurement technique;Made calculation of molecular mechanics and quanta chemistry by using Materials Studio software.In comparison, selective collectors, typically, (CH3)2CHOC(S)NHC2H5, (C4H9O)2PSSNa and C2H5OSCSK, were tested to make the difference of chalcopyrite and galena flotation result, it was indicated that,In the case of 5.7≤pH≤7.2,10mV≤ECu≤50mV,-30mV≤EPb≤30mV, 160≤EPt≤470mVOr,9.0≤pH≤11.5,-50mV≤ECu≤-10mV,-10mV≤ECu≤-50mV,0mV≤EPt≤100mV(CH3)2CHOC(S)NHC2H5 can be of effective selective collector for chalcopyrite and galena separation, moreover, along with higher concentrates of (CH3)2CHOC(S)NHC2H5, the floatability difference of chalcopyrite and galena is almost fixed. The mechanism is such that (CH3)2CHOC(S)NHC2H5 makes reaction with Cu or Fe atom in surface of chalcopyrite to produce new resultant. The study on "hard to avoid cations" which might be present in pulp indicates that after ore was soaped in ion-removing water, ions in upper water, including Ca2+, Mg2+, Na+, Mn2+, Fe2+, Fe3+, K+, Cu2+, Zn2+, Al3+ and Li+ etc, make evident change. And results from further study on chalcopyrite and galena floatability which is affected by dissoluble saline solution of the above ions are:The above ions have no impact on chalcopyrite flotation;But the effect on galena flotation falls into three categories:activating factor such as Cu+; depressing factor such as Al3+, Fe3+ and Fe2+, typically when using (CH3)2CHOC(S)NHC2H5 to float galena, high valence ions like Al3+, Fe3+ are strongly depressing; non-influence factor such as Mg2+ and Ca2+.The investigation to influence of compound like ZnSO4, Na2SO3, NaHSO3, Na2S2O3 and Na2SO4 on single mineral flotation of chalcopyrite and galena reveals that ZnSO4, Na2SO3 and NaHSO3 can be used as depressor of galena to separate Cu from Pb when floating single mineral by using (CH3)2CHOC(S)NHC2H5 as collector. Test on man-made mixture of two type of minerals and production ore by using ZnSO4, Na2SO3 indicates that:ZnSO4 solely, not at low concentrate but high concentrate, is depressing to galena;Na2SO3 solely, is depressing to galena at low concentrate, but depressing to both galena and chalcopyrite at high concentrate.The mechanism lies in the fact that SO32- from Na2SO3 makes reaction with Pb2+ in surface of galena to produce hydrophilic thin membrane of PbSO3 which covers surface of galena to prevent collector from making action with galena.Three new depressors, PPD,DDT and PDA have been found out based on pulp electrochemistry property, which are depressing to galena and activating to chalcopyrite. Test on single mineral of chalcopyrite and galena, man-made mixture of chalcopyrite and galena and production ore conclude that possibly the three reagents will be effective depressors to separation of Cu-Pb, but response to different depressing mechanism.