The effects of acid surface dissolution on the flotation kinetics of ilmenite(IL)and its common accompanied gangue minerals including olivine-pyroxene(Ol-Px),tremolite-clinochlore(Tr-Cch)and quartz were investigated.T...The effects of acid surface dissolution on the flotation kinetics of ilmenite(IL)and its common accompanied gangue minerals including olivine-pyroxene(Ol-Px),tremolite-clinochlore(Tr-Cch)and quartz were investigated.The results show that through the surface dissolution the adsorption rate constant for ilmenite increases from 5.272 to 8.441 mol/(g·min)while it decreases for Ol-Px,Tr-Cch and quartz from 6.332,7.309 and 7.774 mol/(g·min)to 5.034,6.223 and 7.371 mol/(g·min),respectively.Also,the flotation experiments on a binary mixture of minerals indicate that after surface dissolution the values of modified rate constant for ilmenite flotation from Ol-Px,Tr-Cch and quartz are enhanced from 36.15,36.52 and 47.86 min-1 to 41.72,45.78 and 56.24 min-1,respectively.This results in the improvement of kinetic selectivity index(SI)in the separation of treated ilmenite from gangue minerals.As evidenced by ICP-MS analysis,the decrease of kinetic parameters for gangue minerals can be due to the removal of Fe^2+,Ca^2+and Mg^2+ions from their surfaces,which results in the lack of enough active sites to interact with collector species.As confirmed by contact angle measurements,this prevents the formation of a stable hydrophobic layer on the minerals surfaces for creating stable attachments between minerals and bubbles.Generally,the improvement of ilmenite flotation kinetics has a negative correlation with the iron content in its accompanied gangue minerals.展开更多
Surface roughness has a significant influence on mineral flotation.The assisting effect of surface roughness on minerals flotation is extensively investigated from its physical properties(e.g.,the existing form of asp...Surface roughness has a significant influence on mineral flotation.The assisting effect of surface roughness on minerals flotation is extensively investigated from its physical properties(e.g.,the existing form of asperity and its size),however,the associated effect on mineral flotation based on the differences in surface chemical property caused by surface roughness has been rarely touched.With such a question in mind,in this study,we investigated the flotation recoveries of two batches of magnesite particles with varying degree of surface roughness produced by two different mills,and associated the flotation performances to their surface chemical properties(amount of adsorption sites for the collector)via a series of detections,including Scanning Electron Microscope-Energy Dispersive Spectrometry(SEM-EDS)observations,X-ray photoelectron spectroscopy(XPS)analysis,adsorption capacity tests,and contact angle measurements.Finally,we concluded that rougher magnesite particles could provide more active sites(Mg^(2+))for a larger capacity of sodium oleate(NaOL),thereby improving the hydrophobicity and floatability.展开更多
文摘The effects of acid surface dissolution on the flotation kinetics of ilmenite(IL)and its common accompanied gangue minerals including olivine-pyroxene(Ol-Px),tremolite-clinochlore(Tr-Cch)and quartz were investigated.The results show that through the surface dissolution the adsorption rate constant for ilmenite increases from 5.272 to 8.441 mol/(g·min)while it decreases for Ol-Px,Tr-Cch and quartz from 6.332,7.309 and 7.774 mol/(g·min)to 5.034,6.223 and 7.371 mol/(g·min),respectively.Also,the flotation experiments on a binary mixture of minerals indicate that after surface dissolution the values of modified rate constant for ilmenite flotation from Ol-Px,Tr-Cch and quartz are enhanced from 36.15,36.52 and 47.86 min-1 to 41.72,45.78 and 56.24 min-1,respectively.This results in the improvement of kinetic selectivity index(SI)in the separation of treated ilmenite from gangue minerals.As evidenced by ICP-MS analysis,the decrease of kinetic parameters for gangue minerals can be due to the removal of Fe^2+,Ca^2+and Mg^2+ions from their surfaces,which results in the lack of enough active sites to interact with collector species.As confirmed by contact angle measurements,this prevents the formation of a stable hydrophobic layer on the minerals surfaces for creating stable attachments between minerals and bubbles.Generally,the improvement of ilmenite flotation kinetics has a negative correlation with the iron content in its accompanied gangue minerals.
基金This work was financially supported from the National Natural Science Foundation of China(grant nos.51874072 and 51974064).
文摘Surface roughness has a significant influence on mineral flotation.The assisting effect of surface roughness on minerals flotation is extensively investigated from its physical properties(e.g.,the existing form of asperity and its size),however,the associated effect on mineral flotation based on the differences in surface chemical property caused by surface roughness has been rarely touched.With such a question in mind,in this study,we investigated the flotation recoveries of two batches of magnesite particles with varying degree of surface roughness produced by two different mills,and associated the flotation performances to their surface chemical properties(amount of adsorption sites for the collector)via a series of detections,including Scanning Electron Microscope-Energy Dispersive Spectrometry(SEM-EDS)observations,X-ray photoelectron spectroscopy(XPS)analysis,adsorption capacity tests,and contact angle measurements.Finally,we concluded that rougher magnesite particles could provide more active sites(Mg^(2+))for a larger capacity of sodium oleate(NaOL),thereby improving the hydrophobicity and floatability.
