Selective flotation of apatite from calcite using 2-phosphonobutane-1,2,4-tricarboxylic acid as depressant

In this study, 2-phosphonobutane-1,2,4-tricarboxylic acid (PBTCA) was introduced as a depressant for the flotation separation of apatite from calcite. The micro-flotation test results showed that good floatability of both apatite and calcite were obtained at around pH 8.5 when using sodium oleate (NaOl) as collector. Mixed minerals flotation test results showed that an efficient separation of apatite from calcite was achieved using PBTCA as depressant, which presented a selective depression for the calcite. Zeta potential measurements indicated that the addition of PBTCA prior to NaOl did not interfere the interaction between NaOl and apatite while it decreased NaOl adsorption on calcite surface.