Improved flotation performance of hematite fines using citric acid as a dispersant

Xi-mei Luo^1,2，Wan-zhong Yin^3,4，Chuan-yao Sun⁵，Nai-ling Wang⁴，Ying-qiang Ma³，Yun-fan Wang⁶

1. State Key Laboratory of Complex Nonferrous Metal Resources Clean Utilization, Kunming University of Science and Technology2. Faculty of Land and Resource Engineering, Kunming University of Science and Technology3. College of Zijin Mining, Fuzhou University4. College of Resources and Civil Engineering, Northeastern University5. Beijing General Research Institute of Mining and Metallurgy6. Faculty of Minerals Processing and Bioengineering, Central South University

摘 要：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.

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