Flotation separation of magnesite and its calcium-containing carbonate minerals is a difficult problem.Recently,new regulat-ors have been proposed for magnesite flotation decalcification,although traditional regulator...Flotation separation of magnesite and its calcium-containing carbonate minerals is a difficult problem.Recently,new regulat-ors have been proposed for magnesite flotation decalcification,although traditional regulators such as tannin,water glass,sodium carbon-ate,and sodium hexametaphosphate are more widely used in industry.However,they are rarely used as the main regulators in research because they perform poorly in magnesite and dolomite single-mineral flotation tests.Inspired by the limonite presedimentation method and the addition of a regulator to magnesite slurry mixing,we used a tannin pretreatment method for separating magnesite and dolomite.Microflotation experiments confirmed that the tannin pretreatment method selectively and largely reduces the flotation recovery rate of dolomite without affecting the flotation recovery rate of magnesite.Moreover,the contact angles of the tannin-pretreated magnesite and dolomite increased and decreased,respectively,in the presence of NaOl.Zeta potential and Fourier transform infrared analyses showed that the tannin pretreatment method efficiently hinders NaOl adsorption on the dolomite surface but does not affect NaOl adsorption on the magnesite surface.X-ray photoelectron spectroscopy and density functional theory calculations confirmed that tannin interacts more strongly with dolomite than with magnesite.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
基金supported by the National Natural Science Foundation of China (Nos.51974064,52174239,and 52374259)the Open Project of the Key Laboratory of Solid Waste Treatment and Resource Utiliza-tion of the Ministry of Education,China (No.23kfgk02).
文摘Flotation separation of magnesite and its calcium-containing carbonate minerals is a difficult problem.Recently,new regulat-ors have been proposed for magnesite flotation decalcification,although traditional regulators such as tannin,water glass,sodium carbon-ate,and sodium hexametaphosphate are more widely used in industry.However,they are rarely used as the main regulators in research because they perform poorly in magnesite and dolomite single-mineral flotation tests.Inspired by the limonite presedimentation method and the addition of a regulator to magnesite slurry mixing,we used a tannin pretreatment method for separating magnesite and dolomite.Microflotation experiments confirmed that the tannin pretreatment method selectively and largely reduces the flotation recovery rate of dolomite without affecting the flotation recovery rate of magnesite.Moreover,the contact angles of the tannin-pretreated magnesite and dolomite increased and decreased,respectively,in the presence of NaOl.Zeta potential and Fourier transform infrared analyses showed that the tannin pretreatment method efficiently hinders NaOl adsorption on the dolomite surface but does not affect NaOl adsorption on the magnesite surface.X-ray photoelectron spectroscopy and density functional theory calculations confirmed that tannin interacts more strongly with dolomite than with magnesite.
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.
