In this study, citric acid was used as a dispersant to improve the flotation performance of hematite fines. The effect and mechanism of citric acid on the reverse flotation of hematite fines were investigated by flota...In this study, citric acid was used as a dispersant to improve the flotation performance of hematite fines. The effect and mechanism of citric acid on the reverse flotation of hematite fines were investigated by flotation tests, sedimentation experiments, scanning electron microscopy(SEM), zeta-potential measurements, and X-ray photoelectron spectroscopy(XPS). The results of SEM analysis and flotation tests reveal that a strong heterocoagulation in the form of slime coating or coagulation in hematite fine slurry affects the beneficiation of hematite ores by froth flotation. The addition of a small amount of citric acid(less than 300 g/t) favorably affects the reverse flotation of hematite fines by improving particle dispersion. The results of sedimentation experiments, zeta-potential measurements, and XPS measurements demonstrate that citric acid adsorbs onto hematite and quartz surfaces via hydrogen bonding, thereby reducing the zeta potentials of mineral surfaces, strengthening the electrical double-layer repulsion between mineral particles, and dispersing the pulp particles.展开更多
The flotation and surface interaction of rutile with nonyl hydroxamic acid were investigated in this work. The results show that the adsorption density and flotation recovery of rutile have similar tendency, especiall...The flotation and surface interaction of rutile with nonyl hydroxamic acid were investigated in this work. The results show that the adsorption density and flotation recovery of rutile have similar tendency, especially the maximum recovery and adsorption occur at pH about 7.5. In terms of Fourier transform infrared(FTIR) spectroscopic analysis, chemical adsorption is identified on the surface of rutile, where a chelate of O,O-five-membered rings with Ti^4+ on the surface of rutile may form. Adsorption measurements, Zeta potential test, IR spectrum analyses, and solution chemistry calculations illustrate that the adsorption on the rutile surface involves both physical and chemical adsorption, while chemical adsorption is dominant.展开更多
基金financially supported by the National Natural Science Foundation of China(Nos.51374079 and 51604130)the Talent Cultivation Foundation of Kunming University of Science and Technology(No.KKSY201521031)the Foundation of Yunnan Educational Committee,China(No.2015Y067)
文摘In this study, citric acid was used as a dispersant to improve the flotation performance of hematite fines. The effect and mechanism of citric acid on the reverse flotation of hematite fines were investigated by flotation tests, sedimentation experiments, scanning electron microscopy(SEM), zeta-potential measurements, and X-ray photoelectron spectroscopy(XPS). The results of SEM analysis and flotation tests reveal that a strong heterocoagulation in the form of slime coating or coagulation in hematite fine slurry affects the beneficiation of hematite ores by froth flotation. The addition of a small amount of citric acid(less than 300 g/t) favorably affects the reverse flotation of hematite fines by improving particle dispersion. The results of sedimentation experiments, zeta-potential measurements, and XPS measurements demonstrate that citric acid adsorbs onto hematite and quartz surfaces via hydrogen bonding, thereby reducing the zeta potentials of mineral surfaces, strengthening the electrical double-layer repulsion between mineral particles, and dispersing the pulp particles.
基金financially supported by the National Natural Science Foundation of China (No. 51474254)the Ph.D. Programs Foundation of Ministry of Education of China (No. 20120162110008)+2 种基金China Postdoctoral Science Foundation (No. 2013M531813)the Planned Science and Technology Project of Hunan Province, China (No. 2012SK3233)the Independent Exploration and Innovation Projects of Master of Central South University (No. 2014zzts275)
文摘The flotation and surface interaction of rutile with nonyl hydroxamic acid were investigated in this work. The results show that the adsorption density and flotation recovery of rutile have similar tendency, especially the maximum recovery and adsorption occur at pH about 7.5. In terms of Fourier transform infrared(FTIR) spectroscopic analysis, chemical adsorption is identified on the surface of rutile, where a chelate of O,O-five-membered rings with Ti^4+ on the surface of rutile may form. Adsorption measurements, Zeta potential test, IR spectrum analyses, and solution chemistry calculations illustrate that the adsorption on the rutile surface involves both physical and chemical adsorption, while chemical adsorption is dominant.