Effects of massive electromagnetic pulses on the structural and chemical properties and leaching efficiency of eudialyte concentrate

Effect of high-power electromagnetic pulses and dielectric barrier discharges on physicochemical and flotation properties of perovskite

“…Testing using procedures [11,[14][15][16][17][18] involved samples of perovskite (formula CaTiO 3 ) in the form of grains extracted from hand specimens of Afrikanda perovskite (Kola Peninsula, Russia) and specially manufactured polished plates approximately 4.5 mm thick. The samples are courtesy of the museum staff members M. Yu.…”

“…Sidorov, E. A. Selivanova and V. N. Yakovenchuk at the Geological Institute of the Kola Science Center of the Russian Academy of Sciences. The chemical composition and the content of impurities of the samples was determined by the X-ray fluorescence analysis using spectrometer ARL Advant'X (Thermo Fisher Scientific Inc), mass percentage: 48.0 TiO The details of the electrophysical parameters of electromagnetic treatment (HPEMP and DBD) and the treatment conditions of perovskite samples are given in [14][15][16][17]; the treatment duration range is t treat t t = 10÷150 s. In case of high-power EMP, the front, duration and amplitude of out voltage pulse were ~3-8 ns, 30-50 ns and 70 kV, respectively; the electromagnetic field strength and current in the electrode gap 7 mm long were 10 7 V·m -1 and ~10 11 A·m -2 , respectively [14,15], the frequency of nanosecond pulses was 375 Hz. For preventing fragmentation of the polished sections and to eliminate dispersion of particles -50 μm in size under high-voltage pulses, the HPEMP treatment conditions for perovskite samples before testing their microhardness, structure and physicochemical properties (electrokinetic potential and contact angle) included the front, duration, out voltage pulse amplitude and pulse repetition rate of 2-5 ns, 4-10 ns, 25-30 kV and 100 Hz, respectively.…”

“…The electrode voltage in DBD generator cell was 20 kV, the pulse duration was 8 μs, the pulse-leading edge duration was 300 ns, the pulse repetition rate was 16 kHz, and the electrode gap was 5 mm long [14][15][16][17]. In the conditions of cold nonequilibrium plasma of DBD in the air, the gas temperature in the work zone of the discharge cell was not higher than the dielectric barrier temperature and was at the level of the room temperature for t treat.…”

“…Application of high-energy effects [11,[14][15][16][17] in processing of rebellious minerals enables efficient selective disintegration of finely dissemination mineral aggregates, enhances contrast between the physicochemical and flotation properties of mi nerals, and improves the further separation thanks to formation of hydrophobic and hydrophilic micro and nano phases on the mineral surface. Pioneering experimental research made it possible to substantiate the mechanism of effect exerted by γ-ray and β-particles on flotation of semiconducting minerals-rutile, ilmenite, ilmenorutile, zircon, chalcopyrite, galenite, perovskite, pyrolusite and antimonite [11].…”

“…Tests proved the intensifying effect of high-power electromagnetic pulses (HPEMP) and dielectric barrier discharge (DBD) cold plasma on acid leaching [14] and flotation [15] of Lovozero eudialyte concentrate, as well as the modifying effect of electromagnetic pulses on the surface structure and physicochemical properties of Juine ilmenite [16] and sulfide minerals and quartz from different deposits [17].…”