Effective flotation separation of scheelite and calcite by applying methylene phosphonic acid sodium as a novel and green depressant

It is known that the flotation separation of scheelite and calcite quite difficult due to their similar surface properites. To slove problem, ethylenediaminetetra (methylene phosphonic acid) sodium (EDTMPS), an environmentally friendly reagent, was employed as efficient depressant for first time. In experiments, it demonstrates EDTMPS could strongly inhibit but barely affect flotaiton behavior scheelite, showing excellent dpress ability selectivity. Based on a series measurements including contact angle analysis, zeta potential, XPS found large amout be absorbed through strong chemical chelation reaction thus inhibiting further adsorption NaOL. On contrary, little owing negatively charged tungstate ions in relative terms. All all, these results exhibit has selective inhibition calcite, which can potentially applied actual process.