PHYSICAL AND CHEMICAL TRANSFORMATIONS OF COAL SUBSTANCE IN WEAK ELECTROMAGNETIC FIELDS

Abstract

The results of experimental studies of physicochemical transformations in fossil coal under the influence of electric and magnetic fields of low intensity are analyzed in a brief review. The processing temperature in all experiments did not exceed the range of 290-315 K; the pressure was (1-2)×10⁵ Pa. The results of exposure of coal samples to electric and magnetic fields differ fundamentally in many parameters. It has been shown that after electric treatment, coal acquired an electret potential with ultra-long charge relaxation, the size of microparticles decreased by 15-29 %, gas production was activated, coal went into a more metastable state, and the heat of combustion decreased. After the magnetic field treatment, the size of microparticles increased by 11-210 %, the heat of combustion increased, and the properties of the coal approached the next in the carbonization series.