The effect of 2-phosphonobutane-1,2,4-tricarboxylic acid on the flotation separation of pyrite from lizardite

To remove lizardite slimes from pyrite surface in pyrite-lizardite system, 2-phosphonobutane-1,2,4-tricarboxylic acid (PBTCA) was introduced as a possible depressant for lizardite slimes. Micro-flotation test results showed that PBTCA can remove lizardite slimes from pyrite surface and the floatability of pyrite was restored. Zeta potential measurements indicated that the surface charge of lizardite transformed from positive to strongly negative values by the addition of PBTCA because of the adsorption of PBTCA at lizardite surface. As a result, the interaction of pyrite and lizardite converted from electrosteric attraction to electrosteric repulsion, and therefore the SBX adsorption at pyrite surface was promoted and the floatability of pyrite was restored.