The effect of calcium ions on the flotation behavior of fluorapatite

ABSTRACT

The flotation behavior of apatite, a main mineral source of phosphorus, is strongly affected by the dissolved ionic species from gangue minerals. In this study, the effect of calcium ions on the fluorapatite flotation using the extracted sodium alginate E.SA depressant was investigated through microflotation tests, adsorption experiments, zeta potential measurements, and FTIR analyses. Although the amount of NaOL collector adsorbed on fluorapatite increased with increasing calcium concentrations, microflotation results reveal that adding calcium ions could deteriorate the fluorapatite recovery. More significant depression of fluorapatite could be achieved when Ca²⁺ and E.SA co-existed in the system. Zeta potential measurements and FTIR analyses showed that the addition of Ca²⁺ hardly affected the adsorption of E.SA onto fluorapatite surface, which can be due to the formation and precipitation of calcium alginate. In contrast, NaOL remained weakly adsorbed on the fluorapatite surface even the presence of Ca²⁺ and E.SA.

KEYWORDS:

• Flotation separation
• fluorapatite
• depressant
• calcium ions
• extracted alginate

Acknowledgments

The Authors would like to acknowledge the support through the R&D Initiative APPHOS projects – sponsored by OCP (OCP Foundation, R&D OCP, Mohammed VI Polytechnic University, National Center of Scientific and technical Research CNRST, Ministry of Higher Education, Scientific Research and Professional Training of Morocco MESRSFC) under the project entitled ‘Direct flotation of low-grade Moroccan phosphates,’ project ID*TRT-BAC-01/2017*.

We thank our sponsors who provided insight, expertise, and follow-up that greatly assisted this research.

Disclosure statement

No potential conflict of interest was reported by the author(s).