Mechanism of the Effect of High-Voltage Nanosecond Pulses on the Structural, Chemical, and Technological Properties of Natural Dielectric Minerals

Resumo

The mechanism behind the modification of the surface chemical structure and technological and physicochemical properties of Ca-bearing minerals (calcite, scheelite, and fluorite) under the effects of highvoltage nanosecond pulses is investigated by means of XPS, FTIR, X-ray luminescence spectroscopy, electrophoretic light scattering (ζ-potential), atomic-force microscopy (Kelvin probe force microscopy), microhardness measurements, and an approach based on the adsorption of acid–base indicators with different intrinsic pK_α parameters. The acceptor properties of calcite and scheelite surfaces grow and the electron donor ability of fluorite increases as a result of pulsed electric field processing (t_treat ~ 30 s, N_imp ~ 3 × 10³). The impact of energy pulses results in the formation of structural defects, surface softening (a 50–67% reduction in microhardness), and a directional change in mineral electric properties. Preliminary electropulse treatment generally enhances mineral flotation activity by 5–12%.