The Efficient And Environment-friendly Agents HQ77 And D82: Characterization, Mechanism, And Practical Application In Flotation Of Lead-Zinc Separation

In the flotation process of Lead-Zinc sulfide ore, it is difficult to depress sphalerite and pyrites that are activated by copper sulfate. And in the preferential flotation of lead, the xylenol dithiophosphate (No.25 DTP) is often used as a collector which leads to severe environmental problems. Through tests of monomineral andreal mineral, this paper had conducted a study on a new reagent D82 as sphalerite depressant and a new nontoxic reagent HQ77 as galena collector, In addition, mechanisms of interaction between depressant D82 and sphalerite and collector HQ77 and galena were studied by infrared spectrometric test and cyclic voltammetry test. An industrial technology of "HQ77+D82" under the low alkaline condition was tested. The main results are as follows:The flotation behavior of both single and mixed ore of galena, sphalerite and pyrites were studied under different conditions. The results show that collector HQ77 has a good collecting powerfor galena which is equivalent to that of No.25 DTP. Considering the strong collecting power and environmental friendly character of HQ77, the performance of HQ77 is better than No.25 DTP. The depressant D82 produces a strong depressing effect for the Cu-activated sphalerite and pyrite but won’t affect the flotation of galena.Interaction mechanisms of HQ77 with galena and D82 with sphalerite have been studied by adopting infrared spectroscopy and cyclic voltammetry testing. The results indicate that the selectivitiy of HQ77 is better than that of No.25 DTP. The depressant D82 can effectively prevent the the adsorption of No.25 DTP and HQ77 on the surface of sphalerite and pyrites and leads a hydrophobic mineral surfaces.Based on the Lead-Zinc ores from Hunan province, the two processing technologies of high-alkalinity "No.25 DTP + ZnSO4 + lime" and low-alkalinity "HQ77+ D82" have been compared. The closed-circuit test results show that a Pb concentrate with Pb grade of 58.22% and Zn grade of 4.72% can be obtained by adopting low-alkalinity "HQ77+ D82" technology. Compared with the high-alkalinity "No.25 DTP + ZnSO4 + lime" technology, the Pb grade increased by 6.97% and Zn grade decreased by 0.87 for the similar Pb recovery.Based on the lab experimental rusults, the industrial testing of low-alkalinity "HQ77+ D82" technology has been performed at Kang Jiawan plant in Shui Koushan. The results indicate that this new technology can not only obtain stable recovery index for Pb but can also improve the recovery of Ag and Au metals. Compared with the high-alkalinity "No.25 DTP + ZnSO4 +lime" technology, the recoveries of Au and Ag increased by 6.19% and 4.23%, respectively. Meanwhile, the low-alkalinity "HQ77+ D82"technology can meet the requirement for the "clean production".