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
Here,the influence of grinding media with different shapes on the flotation performance of spodumene and its potential mechanism from microscale insights was investigated using a single mineral flotation experiment,X-...Here,the influence of grinding media with different shapes on the flotation performance of spodumene and its potential mechanism from microscale insights was investigated using a single mineral flotation experiment,X-ray diffraction(XRD)test,scanning electron microscopy combined with energy dispersive spectrometry(SEM-EDS),atomic force microscope(AFM)and X-ray photoelectron spectroscopy(XPS).The flotation data indicated that under anionic/cationic(sodium oleate(NaOL)/DDA)collectors system,the rod milled spodumene has a higher floatability than ball milled ones.XRD results confirmed that rod medium makes spodumene exposed more{110}and{100}planes,while ball medium makes spodumene exposed more{010}planes.The typical anisotropic surface of spodumene makes the surface of rod milled spodumene possess more Al sites,further confirmed by SEM-EDS and XPS results.Additionally,it was found that the rod milled spodumene presents a larger value of elongation and flatness,which are parameters closely related to bubble adhesion.AFM analysis indicated that rod milled products have a rougher surface,while ball milled products have a smoother surface.Consequently,the rod medium enhanced the adsorption of NaOL/DDA on the spodumene surfaces.This work provides theoretical guidance for optimizing the separation of spodumene from the perspective of grinding.展开更多
A study of the effects of the pulp nature on desulphurization and de-ashing during high-sulfur coal flotation is described in this paper. Highlighted are the use of a solution oxygen gauge, a pH value gauge and a surf...A study of the effects of the pulp nature on desulphurization and de-ashing during high-sulfur coal flotation is described in this paper. Highlighted are the use of a solution oxygen gauge, a pH value gauge and a surface tension gauge to investigate changes in the pulp nature related to changes in the oxygen content, the pH value and the interfacial tension. The temperature be- fore and after ultrasonic conditioning was also investigated. The results showed that ultrasonic conditioning resulted in a decrease in the oxygen content and the interracial tension and an increase in the pH value and the temperature of the pulp. The perfect index of flotation and the perfect index of desulphurization of fine coal increased by 25.19% and 18.03%, respectively, after the pulp was ultrasonically conditioned. This study shows that ultrasonic conditioning can change the pulp nature and enhance the degree of desulphurization during high-sulfur coal flotation.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supported by the National Natural Science Foundation of China(Nos.51922091,51674207,and 52004337)the Sichuan Science and Technology Program(Nos.2019YFS0453,2018JY0148 and SYZ202074).
文摘Here,the influence of grinding media with different shapes on the flotation performance of spodumene and its potential mechanism from microscale insights was investigated using a single mineral flotation experiment,X-ray diffraction(XRD)test,scanning electron microscopy combined with energy dispersive spectrometry(SEM-EDS),atomic force microscope(AFM)and X-ray photoelectron spectroscopy(XPS).The flotation data indicated that under anionic/cationic(sodium oleate(NaOL)/DDA)collectors system,the rod milled spodumene has a higher floatability than ball milled ones.XRD results confirmed that rod medium makes spodumene exposed more{110}and{100}planes,while ball medium makes spodumene exposed more{010}planes.The typical anisotropic surface of spodumene makes the surface of rod milled spodumene possess more Al sites,further confirmed by SEM-EDS and XPS results.Additionally,it was found that the rod milled spodumene presents a larger value of elongation and flatness,which are parameters closely related to bubble adhesion.AFM analysis indicated that rod milled products have a rougher surface,while ball milled products have a smoother surface.Consequently,the rod medium enhanced the adsorption of NaOL/DDA on the spodumene surfaces.This work provides theoretical guidance for optimizing the separation of spodumene from the perspective of grinding.
基金Projects 50274036 supported by the National Natural Science Foundation of China11531Z02 by the Educational Committee of Heilongjiang Province2009RFXXG030 by the Special Foundation of Harbin Bureau of Science and Technology
文摘A study of the effects of the pulp nature on desulphurization and de-ashing during high-sulfur coal flotation is described in this paper. Highlighted are the use of a solution oxygen gauge, a pH value gauge and a surface tension gauge to investigate changes in the pulp nature related to changes in the oxygen content, the pH value and the interfacial tension. The temperature be- fore and after ultrasonic conditioning was also investigated. The results showed that ultrasonic conditioning resulted in a decrease in the oxygen content and the interracial tension and an increase in the pH value and the temperature of the pulp. The perfect index of flotation and the perfect index of desulphurization of fine coal increased by 25.19% and 18.03%, respectively, after the pulp was ultrasonically conditioned. This study shows that ultrasonic conditioning can change the pulp nature and enhance the degree of desulphurization during high-sulfur coal flotation.
