Abstract: Fluorite and calcite have similar surface properties,that is,the same active calcium particles,which makes it very difficult to separate the two minerals in the flotation process. In this paper,the environmental protection water-soluble phosphonate sodium ethylenediamine tetramethylene phosphonate (EDTMPS) was proposed for the first time to strengthen the flotation separation of fluorite and calcite,and related flotation tests were carried out. The results show that EDTMPS can effectively inhibit the flotation of calcite,but has little effect on the flotation behavior of fluorite when the pH value of pulp is 7~ 9. The flotation test of artificial mixed ore proves that the separation of calcite and fluorite can be realized by using EDTMPS as an inhibitor. The mechanism of separation of calcite from fluorite by EDTMPS inhibitor was studied and analyzed. It was found that phosphonate ions in EDTMPS molecular structure chemically adsorbed with calcium ions on calcite surface,which hindered the further adsorption of oleate ions. Comparatively speaking,EDTMPS had little adsorption on fluorite surface and little floatability. Generally speaking,EDTMPS inhibitors can selectively inhibit calcite,which has a wide application prospect in the flotation separation of calcite and fluorite.

Key words: fluorite,calcite,ethylenediamine tetra methylene phosphonic acid sodium,phosphonate ion,chemisorption