Anisotropic CMS adsorption on talc and molybdenite basal and edge surfaces and interaction mechanism with magnesium ion

Due to the limitations of existing flotation technologies, the resource development of talc-containing molybdenum ores remains an urgent issue that must be addressed. The development of effective talc depressants has become a significant research focus. Studies indicate that the combination of sodium carboxymethyl starch (CMS) and magnesium ion (Mg²⁺) can effectively inhibit talc, achieving high selective flotation of molybdenite. However, the interaction mechanism between CMS and Mg²⁺, as well as its depressing mechanism on the anisotropic surface of talc, remains unclear. To address this issue, this study employed multiple testing methods and combined micro-flotation tests to systematically compare the differences in adsorption and bonding mechanisms between the mixed dosing system and the sequential dosing system on various crystal surfaces of talc and molybdenite, while also exploring their impact on flotation behavior. The research results indicate that in the mixed dosing system, CMS and Mg²⁺ interact with the surface of talc through complex formation, which enhances its hydrophilicity. When the concentration of CMS is 1 × 10^-3 mol/L, the average recovery rate of talc decreases to 14.82 %, while the recovery rate of molybdenite reaches 84.85 %, thereby facilitating the selective separation of talc and molybdenite.