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Elimination of Cyanide Compounds from the Flotation Process. Author: Zoran Petkovic Presenter: Ivan Rajevic PETKOM S.A. Chile. The Flotation Process. Collectors Xanthates, ditiophosphates, thionocarbamates Modifiers CaO, NaOH, Na 2 CO 3 Depressants NaCN, Na 2 SO 3 , Na 2 S 2 O 4 , ZnSO 4
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Elimination of Cyanide Compounds from the Flotation Process Author: Zoran Petkovic Presenter: Ivan Rajevic PETKOM S.A. Chile CTWMI 2008, Santiago, Chile
The Flotation Process • CollectorsXanthates, ditiophosphates, thionocarbamates • ModifiersCaO, NaOH, Na2CO3 • DepressantsNaCN, Na2SO3, Na2S2O4, ZnSO4 • ActivatorsCuSO4, H2SO4, FeSO4 • Foaming AgentsPolyalcohols, natural oils CTWMI 2008, Santiago, Chile
Use of NaCN in Flotation • In the flotation of sulfide Cu ores, as a depressant of pyrite (FeS2) • In the flotation of Pb-Zn ores, as a depressant of Zn, so that Pb can be obtained CTWMI 2008, Santiago, Chile
Amount of Effluents Generated by Some Mines CTWMI 2008, Santiago, Chile
How to Reduce the Environmental Impact? • Waiting for NaCN to break up in the tailings pond by exposing to UV light, or... • The best way – eliminate the contaminant! CTWMI 2008, Santiago, Chile
CTWMI 2008, Santiago, Chile Case 2: Sase Pb-Zn mine, Bosnia & Herzegovina Industrial – scale testing Activator: CuSO4 Collector: K – Ethyl Xanthate,K – Amyl Xanthate Foaming agent: D-250 Depressants: NaCN, ZnSO4 Case Studies on PETKOM Reagents Case 1: Medium-size Cu mine, Chile Lab test on standard ore sample pH: 11.5 Cell type:Denver Collectors: AF-238, MC-CIPXS Foaming agents: MIBC, AF-70 Depressant: NaCN
Case 1: Cu Mine, ChileStandard Ore Sample, Standard Flotation Regime CTWMI 2008, Santiago, Chile
Case 1: Cu Mine, ChileStandard Ore Sample, PETKOM-40 CTWMI 2008, Santiago, Chile
CTWMI 2008, Santiago, Chile Case 1: Cu Mine, ChileComparison • The quality of the concentrate after 2 min is 0,12 % better with PETKOM 40 than with NaCN (19,15% vs. 19.03 %); • The quality of the concentrate after 12 min is 0,13 % better with PETKOM 40 than with NaCN (12,0 % vs. 11,87 %); • The cumulative recovery is 0,15 % better with PETKOM 40 than with NaCN (92,93 % vs. 92,78 %); • The corrosion inhibiting properties of PETKOM were not tested.
Case 2: Sase CTWMI 2008, Santiago, Chile
CTWMI 2008, Santiago, Chile Case 2: SaseComparison • SKIK/PETKOM shows 4,15% better Pb recovery even when there is 1,41 % less Pb in the ore • Acceptable non – penalized content of Zn in the Pb concentrate (3,48 %) • Approximately equal content of Zn in the tails at 0,37 % less Zn in the ore.
Conclusion • The SKIK/PETKOM reagent series, due to its selectivity, removes the need for NaCN or other CN salts as depressants in the flotation of pyrite Cu ores and Pb-Zn ores • SKIK/PETKOM replaces the standard collectors CTWMI 2008, Santiago, Chile
Conclusion(Cont.) • Removal of cyanide compounds from flotation is a major environmental gain • Important positive financial effect • Most indicators show equal or better results compared to classic reagent regimes. CTWMI 2008, Santiago, Chile