Dissolution Patterns of Fe³⁺ and Mg²⁺ from the Surfaces of Specularite and Chlorite and Their Effects on Floatability

During the separation process of specularite/chlorite, the dissolution of metal ions on the mineral surface can affect the floatability of the minerals. Using ICP, conductivity measurements, and single mineral flotation tests, the dissolution patterns of Fe³⁺ and Mg²⁺ ions from the surfaces of specularite and chlorite and their effect on floatability were investigated y. Additionally, by combining Zeta potential measurements and lgc−pH analysis, the inhibition mechanisms of Fe³⁺ and Mg²⁺ on specularite and chlorite were studied. The results showed that Fe³⁺ and Mg²⁺ exhibited a trend of increasing followed by decreasing with dissolution time, and the dissolution amount of Fe³⁺ from the chlorite surface was significantly higher than that of Fe³⁺. In addition, the total ion concentration in the solution decreased continuously as the pH of the solution increased. Both Fe³⁺ and Mg²⁺ had certain inhibitory effect on specularite and chlorite, but Fe³⁺ had a stronger inhibitory effect. Under conditions where the Fe³⁺ concentration was 3.11 mg/L and pH=6, the recovery rates of specularite and chlorite decreased to 10.23% and 13.35%, respectively. Fe³⁺ primarily inhibits minerals through the adsorption of hydrophilic Fe(OH)₃ precipitates, while Mg²⁺ mainly increases the electrostatic repulsion between mineral particles and DDA through adsorption in the form of Mg²⁺, resulting in decreased mineral floatability.