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

Yaoyang Ruan,Chunqiao Xiao,Zeqiang Zhang,Huihua Luo,Ruan Chi,Fang Zhou

doi:10.3390/min8040141

Abstract

The effects of Ca2+, Mg2+, Al3+, and Fe3+ 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 Ca2+ and Mg2+ can improve the floatability of apatite but had a negligible effect on the flotation performance of dolomite, whereas Al3+, Fe3+, and excessive amounts of Ca2+ 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.

Highlights

Flotation has been widely used for the separation and purification of finely disseminated minerals, and its separation efficiency strongly depends on the selectivity during the flotation process
Fatty acids are commonly used as anionic collectors in phosphate flotation but their use is sensitive to the metal ions [5,11]
The crystal apatite was sorted from Madagascar in South Africa while the pure quartz and dolomite samples were taken from Hubei province in China

Summary

Introduction

Flotation has been widely used for the separation and purification of finely disseminated minerals, and its separation efficiency strongly depends on the selectivity during the flotation process. Due to the water quality, dissolution of minerals and consumption of grinding medium, a certain amount of metal ions, such as Ca2+ , Mg2+ , Al3+ and Fe3+ , are inevitably present in the pulp of the actual flotation system [1,2]. Fatty acids are commonly used as anionic collectors in phosphate flotation but their use is sensitive to the metal ions [5,11]. Santos et al [12] reported that calcium and magnesium ions contributed significantly to the decline of apatite recovery and P2 O5 grade. They identified that the metal ions can react with fatty acid, resulting in reagent consumption. Al-Thyabat and Al-Zoubi [13]

Methods

Results

Conclusion