Effects of Metal Ions on the Flotation of Apatite, Dolomite and Quartz

Abstract

Abstract:The effects of Ca 2+ , Mg 2+ , Al 3+ , and Fe 3+ on the flotation behaviors of apatite, dolomite and quartz were investigated through a micro-flotation test, and the influence of calcium ions on the flotation of these minerals was further elucidated by solution chemistry study, zeta potential measurement, and X-ray photoelectron spectroscopy (XPS) analyses. The results indicate that an appropriate amount of Ca 2+ and Mg 2+ can improve the floatability of apatite but had a negligible effect on the flotation performance of dolomite, whereas Al 3+ , Fe 3+ , and excessive amounts of Ca 2+ decreased the recovery of apatite and dolomite. The studied metal cations can activate quartz at a particular pH. It can be inferred from solution chemistry and zeta potential measurement that the influence of metal ions on the flotation of different minerals should be attributed to the adsorption of various hydrolysis species on the mineral surfaces. XPS analyses reveal that calcium ions can enhance the adsorption of anionic collector on apatite and quartz surfaces, and there are no apparent changes to be observed on the surface of dolomite in the absence and presence of calcium ions at a concentration of 2.5 × 10 −3 M, which was in good agreement with the micro-flotation results.

Review on Beneficiation Techniques and Reagents Used for Phosphate Ores

“…It is seen that the appropriate amount of Ca 2+ and Mg 2+ can improve the floatability of apatite but had a negligible effect on the flotation performance of dolomite, whereas Al 3+ , Fe 3+ and excessive amounts of Ca 2+ decreased the recovery of apatite in anionic flotation. The apparent decline of the apatite recovery caused by Al 3+ and Fe 3+ was attributed to the preferential precipitation of Al(OH) 3 and Fe(OH) 3 on the apatite surface, and the hydrophilicity of apatite was enhanced [5].…”

“…The depression of apatite can be achieved by adjusting the pH of pulp because the flotation behavior barely occurred at pH below 4.5 in an anionic flotation of apatite without the addition of any other phosphate depressant [5]. It is evident that the species of Ca 2+ , CaH 2 PO 4…”

“…To figure out how various anions and cations affect the flotation performance of minerals, extensive efforts have been taken by many researchers. The effect of metal ions on the floatability of apatite was investigated by Ruan et al [5], and the micro-flotation results were showed in Figure 6. It is seen that the appropriate amount of Ca 2+ and Mg 2+ can improve the floatability of apatite but had a negligible effect on the flotation performance of dolomite, whereas Al 3+ , Fe 3+ and excessive amounts of Ca 2+ decreased the recovery of apatite in anionic flotation.…”

“…For the reverse flotation process, silica was floated using cationic surfactants in a weak acidic or neutral pH, and the phosphate minerals (dominantly apatite) were obtained from the underflow product. The superior adsorption of cationic surfactants on silica rather than apatite probably can be attributed to the more negatively charged surfaces of silica [5]. The conventional "Crago" double float process is used to remove silica twice from phosphate ore in Florida.…”

A Review of Flotation Separation of Mg Carbonates (Dolomite and Magnesite)

“…pH and mineral dissolution are cardinal for their selective separation, and using dissolve air flotation can enhance the separation efficiency when slime is apparent [12,15,53,60,61]. In the absence of modifiers, dolomite and magnesite recoveries were around 80% and 45%, respectively.…”