Selective activation of new regulator SMP in reverse flotation separation of brucite and calcite

This study used dodecylamine (DDA) as a collector to explore the role and adsorption mechanism of a new regulator sodium monododecyl phosphate (SMP) on the flotation separation of brucite and calcite. A microflotation test revealed that only 2 mg/L of SMP could considerably increase the flotation recovery of calcite and achieve a difference in flotation recovery of up to 75.85 % between brucite and calcite. The adsorption capacity measurements indicated that SMP selectively increase the adsorption capacity of calcite for DDA. Contact angle measurements showed that the presence of SMP greatly increased the contact angle of calcite while slightly decreasing the contact angle of brucite. Infrared spectrum analysis, zeta potential detection and X-ray photoelectron spectroscopy revealed that the adsorption of SMP onto the brucite surface is not conducive to the adsorption of DDA onto the brucite surface; meanwhile, the adsorption of SMP onto the calcite surface promoted the adsorption of DDA onto the calcite surface and activated the flotation of calcite.