Inhibition effect and mechanism of actinolite dissolution characteristics on quartz flotation

• With the increase of actinolite content, the recovery rate of quartz in concentrate product decreases. • The Ca 2+ , Mg 2+ , and Fe 2+ ions, which are dissolved from actinolite, can inhibit the adsorption of DDA on the quartz surface. • Actinolite surface can dissolve and hydroxyl, forming a large number of hydrogen bond. • The strong competitive adsorption of DDA on actinolite surface inhibits the flotation of quartz. • A schematic model of actinolite inhibiting flotation of quartz is proposed. The dissolution of complex silicate minerals has a significant influence on the flotation of quartz, but its effect and mechanism have not been clarified. In this work, the inhibition effect and mechanism of actinolite on quartz flotation using dodecylamine (DDA) as a collector were investigated via micro-flotation, mineral dissolution, adsorption tests, wrapping angle tests, Atomic Force Microscope (AFM) measurement, Fourier Transform Infrared Spectroscopy (FTIR), zeta potential characterization, contact angle tests, X-ray Photoelectron Spectroscopy (XPS) analyses, and solution chemistry calculation. Micro-flotation tests showed that actinolite adversely affected the flotation of quartz and the unfavorable effect increases with decreasing particle size and increasing content. The results of the surface analysis showed that the dissolved metal ions (i.e., Ca 2+ , Mg 2+ , and Fe 3+ ) from actinolite can be adsorbed on the quartz surface, hindering the adsorption of DDA on the quartz surface, reducing the hydrophobicity of the quartz surface, and thus decreasing the recovery of quartz. In addition, in the system of actinolite-quartz, the adsorption of DDA on actinolite and quartz is competitive, and the adsorption of more DDA on the surface of actinolite, which has a larger specific surface area, will weaken the adsorption of DDA on the surface of quartz and hinder the attachment of quartz particles on the surface of bubbles, thus inhibiting the flotation of quartz. In summary, the inhibition of quartz flotation by actinolite arises from a combination of metal ions dissolved in actinolite adsorbed on the quartz surface and competition between actinolite and quartz for adsorbed DDA.