Effect and Mechanism of Depressant Disodium Carboxymethyl Trithiocarbonate on Flotation Separation of Stibnite and Pyrite

Disodium carboxymethyl trithiocarbonate (D8) is an effective depressant for the flotation separation of stibnite and pyrite, but its inhibitory mechanism is still unclear. Hence, in this study, the flotation separation performance and inhibition mechanism of D8 were investigated through micro-flotation experiment, contact angle, infrared spectroscopy, adsorption capacity, and zeta potential measurement. The flotation experiment results showed that the D8 had a strong inhibitory ability on pyrite, while its inhibitory ability on stibnite was weak. Infrared and adsorption capacity experiment results indicated that D8 adsorbed onto the surface of pyrite and stibnite through physical adsorption; D8 and sodium diethyldithiocarbamate competitively adsorbed onto the surface of pyrite, which reduced the adsorption amount of sodium diethyldithiocarbamate. The measurement results of contact angle and zeta potential showed that the contact angle and zeta potential of pyrite were significantly reduced with the D8 adsorption, while after D8 acted on the surface of stibnite, the contact angle barely changed. Therefore, D8 enhanced the hydrophilicity of the pyrite surface and the pyrite was effectively depressed.