Study On Flotation Separation Of Copper-lead Sulfide Ores

Cyanide and dichromate have long been found as effective depressants for the flotation separation of chalcopyrite and galena, but their use have caused environmental problems. Non-toxic and environmentally friendly reagents with lower price are used, meanwhile the possible interaction mechanisms were proposed by using different measurements.The Micro-flotation tests show that sodium pyrophosphate(SPH) can selectively depress galena by using O-isopropyl-N-ethyl thionocarbamate (Z-200) as collector whithin mildly acidic pH range; In the flowsheet of bulk copper/lead flotation-reagent removal, sodium sulfide(Na2S) was used to remove the excess residual reagents at minerals surfaces; And in the next flowsheet of bulk copper/lead separating flotation, depressing effect of dextrin on galena was strong when Z-200was used as collector;The possible mechanism of depressing action towarda galena was discussed by Zeta potential tests, Infrared spectroscopic analysis, Ion disolution tests and Adsorption measurements. Results show that the existance of SPH promotes the dissolution of lead ions and decreases the active adsorption sites, thus declines the adsorption density of Z-200onto minerals surfaces, and the depressing action towards galena occurs; Possible reagent removal mechanism can be divided into two parts:HS", which competitively adsorb onto minerals surfaces with BX-, is the main hydrolytic component of sodium sulfide within the pH range from8.5to9.0, on the other hand, sodium sulfide has desorbed Cu(BX)2and Pb(BX)2on minerals surfaces; In alkline solution, Hydrox in the structure of dextrin chemical interacts with lead hydroxide both at galena surface and in solution, declining the adsorption density of Z-200onto galena surface, thus the flotation recovery of galena decreases.In the flotation separation of real ores, the bulk flotation of copper-lead was carried out by using MA and sodium diethyldithiocarbamate as collector, and active carbon was using as collector removal reagent, and the separating flotation was achieved using starch, sodium thiosulfate and sodium silicate as mixed depressant.