An environment-friendly and highly effective inhibitor for flotation separation of brucite and dolomite in SDS system

Brucite is a type of mineral resource containing structural water and high contents of Mg, and is popular in refractory and flame-retardant materials. Dolomite is a common mineral associated with brucite, and its presence reduces the purity of brucite and utilization efficiency of resources. Therefore, in the flotation system of sodium dodecyl sulfonate, the selective inhibition characteristic and inhibition mechanism of environment-friendly and highly effective inhibitor sodium alginate (SA) on dolomite in the flotation separation of brucite and dolomite were investigated. The flotation test shows that an SA dosage of 8 mg/L can achieve 77.92% difference in floatability between brucite and dolomite, and the flotation effect was verified using the selectivity index. The measurement of contact angle shows the stability of the SA effect, thereby demonstrating significant SA effect on dolomite and a small effect on brucite. Zeta potential detection and infrared spectrum analysis show that the adsorption capacity between SA and dolomite is considerably stronger than that between SA and brucite, which is another critical reason for the inhibition of SA on dolomite flotation. In addition, the interaction of SA with the two minerals and the reasons for its selective interaction with dolomite were analyzed using X-ray photoelectron spectroscopic detection. SA shows strong interaction with Ca sites and the O in the carboxyl group of the SA structure can chelate Ca.