Effect of high-power nanosecond electromagnetic pulses on the structural, chemical, and technological properties of natural dielectric minerals

Abstract

We studied the mechanism of the structural surface modification, and the subsequent changes of microhardness, physical chemical and technological properties of calcium-bearing minerals (calcite, scheelite, and fluorite) and rock-forming minerals of diamond-bearing kimberlites (olivine and serpentine) under the non-thermal effect of high-voltage nanosecond pulses. X-ray photoelectron spectroscopy (XPS), infrared Fourier spectroscopy (FTIR), analytical scanning electron microscopy (SEM–EDX), atomic force microscopy, microhardness measurements (Vickers hardness test, HV), electrophoretic light scattering experiments (ζ-potential), and other methods were employed to examine the structural, chemical, electrical, mechanical and physicochemical changes in the surface properties of natural dielectric minerals as a result of pulsed energy impacts. According to XPS, DRIFTS, SEM-EDX and microhardness testing data, the effect of high-voltage nanosecond pulses leads to damage the surface microstructure of geomaterials with the subsequent formation of traces of surface breakdowns and microcracks, softening of Ca-bearing minerals and rock-forming minerals of kimberlites, and reducing their microhardness by 40–67% overall. Using the adsorption of Hammett indicators from aqueous media, it has been an established fact that the acceptor properties of calcite and scheelite surfaces grow and the electron donor ability of fluorite increases as a result of pulsed electric field treatment during the first 30 s. Preliminary electromagnetic pulse treatment generally enhances Ca-bearing mineral flotation activity by 5–12%.