Flotation Characteristics And Mechanism Of Phenylallyl Hydroxamic Acid Collector On Lead-zinc Oxide Ore

In order to improve the recovery of low-grade lead-zinc oxide minerals and improve the comprehensive utilization level of mineral resources,this paper takes two typical lead-zinc oxide minerals(cerussite and smithsonite)and three kinds of gangue(dolomite,quartz and calcite)as the research object.A series of experiments were systematically carried out to investigates the flotation characteristics of phenylallyl hydroxamic acid(PHA)on cerussite and smithsonite.The interaction mechanism between PHA and lead-zinc oxide minerals was studied through infrared spectroscopy,Zeta potential measurement,adsorption capacity and X-ray photoelectron spectroscopy(XPS).In this paper,the Density functional theory(DFT)calculation and adsorption energy calculation were applied to describe the differences between the molecular structure parameters and theoretical flotation performance precisely of PHA,Benzo hydroxamic acid(BHA)and sodium oleate(Na OL).The calculation results were employed to compare the different adsorption energy between PHA and different minerals,so as to further explain that why PHA can form the stability of adsorption structure than other collectors.The main research results were exhibited as follows:(1)The flotation test results of single mineral and artificial mixed ore showed that PHA had good flotation selectivity and collecting capacity for cerussite and smithsonite.When the pulp pH value was 7 and the dosage of collector was 50mg/L,the flotation recoveries of cerussite and smithsonite were 93% and 93.5% respectively,and the flotation recoveries of calcite,quartz and dolomite were only 20%,5% and 22.5%.In the flotation test of artificial mixed ore,the lead concentrate with Pb grade was 46.08%and recovery was 74.3%,the zinc concentrate with Zn grade was 21.11% and recovery was 47.75%,while the feed grade of Pb(38.76%)and Zn(16.58%)after one-time flotation test.Through the comparison of direct flotation(PHA,BHA,Na OL were applied as collector)and sulfurization flotation,the flotation test results showed that the collecting capacity of PHA is obviously better than that of conventional hydroxamic acid collectors,and the selectivity capacity is stronger than that of Na OL and sulfurization flotation.(2)The results of infrared spectrum analysis,Zeta potential measurement,adsorption capacity measurement and XPS analysis showed that PHA could forms a stable chelating structure by combining with the lead atom on the surface of cerussite and the zinc atom on the surface of smithsonite,firmly adsorbs on the surface of cerussite and smithsonite,which significantly improved the surface properties of minerals.The adsorb structure also improved the surface hydrophobicity of cerussite and smithsonite,and realizes the selective and efficient recovery of cerussite and smithsonite.(3)DFT calculation results showed that compared with BHA and Na OL,PHA had more ideal parameters such as frontier orbital energy,dipole moment and Clog P value.The simulation results of adsorption energy between collector and mineral surface showed that the adsorption structure of PHA on the surface of cerussite and smithsonite was more stable than that of gangue,which explains the reason why PHA had better collecting capacity and selectivity capacity.