CMC浮选分离萤石与方解石作用机理研究

为了更有效地浮选分离萤石和方解石，通过浮选试验、接触角、Zeta电位、吸附量及微量热分析，研究了羧甲基纤维素（CMC）在萤石、方解石浮选分离中的作用，揭示了CMC对萤石、方解石选择性抑制机理。结果表明：CMC用量为20 mg/L时能够高效抑制方解石，当pH=8时，可最大化实现两者浮选分离。由于CMC优势组分—RCOO—大量吸附于方解石表面，使得方解石表面只能吸附较少油酸根离子，同时造成方解石Zeta电位显著负移，使其亲水增强，这与接触角测试结果一致。吸附模型表明，方解石表面Ca²⁺活性位点大量减少，难以继续吸附油酸根离子，是其被抑制的主要原因，且体系反应级数n=1。

Study on the Reaction Mechanism of Fluorite and Calcite Flotation Separation by Carboxymethyl Cellulose

In order to separate fluorite and calcite more effectively by flotation,the effects of carboxymethyl cellulose (CMC) in the flotation separation of fluorite and calcite was studied by flotation test and various measurements such as contact angle,zeta potential,microcalorimetry,thereby revealing the selective inhibition mechanism for fluorite and calcite by CMC.The results showed that the CMC concentration of 20 mg/L depressed calcite efficiently and maximized the flotation separation at pH=8.Due to the high adsorption of —RCOO— dissociated from the CMC component on the calcite surface,the calcite surface only adsorbed a small quantity of oleate ions.At the same time,an apparent negative shift of calcite zeta potential was observed,leading to a greater hydrophilicity,consistent with the contact angle measurements.The proposed adsorption model indicated that the diminished active Ca²⁺ sites on the calcite surface was the main reason for its depression,with a reaction order of n=1.