Hpw/Fe-Bentonite Catalyst Preparated By Mechanochemical Activation And Its Visible-Light Fenton Reaction Degradates Xanthate

In mineral flotation operation, xanthate is widely used as a flotation agent, but it is harmful to the balance of water environment and the health of human beings because of its refractory. HPW/Fe-bentonite is a kind of high catalytic activity composite catalyst, and it has a wide application prospect in the field of visible-light Fenton reaction. This article explored the method of the preparation of HPW/Fe-bentonite composite catalyst by mechanical activation and probed the catalytic performance. The degradation of xanthate by catalyst was studied. It provided theoretical basis for water treatment of xanthate flotation agent waste.Mechanochemical activation ’all-in’ was used in the preparation of HPW/Fe-bentonite composite catalyst, the best preparation technology was determined. The composite catalyst were characterized by XRD, SEM, FT-IR and EDS, for investigating its structure characteristics. HPW/Fe-bentonite composite catalyst was used for visible-light Fenton reaction catalytic degradation of xanthate, ascertaining the optimum process conditions and establishing the corresponding dynamic model. In addition, considering the complex composition of flotation wastewater, the influence of the coexistent element were explored. The results of the study were as follows:The best preparation technology of HPW/Fe-bentonite composite catalyst are as follows:in the medium condition of 20 mL stainless steel ball(φ= 20mm) mix with 10 mL stainless steel ball(φ=6mm),lg bentonite and 0.14g FeSO4·7H2O start to mechanical activate in frequency of 10 Hz in 15 min, then add 0.11 g CTMAB activate 15 mins in frequency of 40 Hz, add 0.5 g HPW activate in frequency of 20 Hz in 25 mins The composite catalyst were characterized by XRD, SEM, FT-IR, and EDS, and through analysis obtained it was found that the interlayer spacing of bentonite grows wider, the interstitial structure shows a platy, the functional component of HPW and CTMAB were successfully loaded, and under the assist of CTMAB,the capacity of W reached nearly 19%.The optimum process conditions of catalytic degradation of xanthate is:the dosage of catalyst is 0.8 g-L-1, the dosage H2O2 is 4mmol-L-1, reaction time is 50 mins. It proved that mechanism of visible-light Fenton reaction is the function of·OH, and experiments also conformed the catalytic kinetic model of composite catalyst catalytic degradation of xanthate was the first order kinetics model.Unavoidably ion have little influence on degradation of xanthate; heavy metal ion can stimulates the reaction; 2#oil and dithiophosphate have no influence on degradation of xanthate; S2- influences the degradation a lot, and this problem can be resolved by increase dosage of H2O2, experiment found the liner relation of H2O2 dosage and S2-concentration, which is Y= 43.8214 + 18.21429 X (X:concentration of S2-, Y:dosage of H2O2).