Design and study of protective properties of electromagnetic screens based on iron ore dust

Abstract

The study of the chemical composition and dispersion of iron ore dust, which forms during the enrichment of iron ore, proved its suitability to be used as a screening filler in the production of metal-polymer electromagnetic screens of large areas. We developed the technology of production of protective screening material in the form of a foam-latex with different content of iron-ore dust of different dispersion. We determined the dependence of the coefficient of screening of material and contribution of the reflection coefficient of ultrahigh frequency electromagnetic waves to it on the weight content of iron ore dust. The study showed that an increase in dispersion of metal and metal-containing particles by 10‒20 times increases the overall screening coefficient by 6‒8 times. At the same time, the reflection coefficient decreases from 0.25 to 0.10. We established that the guaranteed screening coefficient of the magnetic field of the industrial frequency is 1.8‒2.2 even for screening particles of 50‒100 µm sizes. We determined that a sharp increase in protective properties of materials occurs at the content of iron-ore dust of 11‒12 % in the polymer matrix. We investigated electrophysical properties (specific conductivity and dielectric permeability) of developed materials with different contents of metal and metal-containing substance. The obtained data are sufficient for calculational forecasting of protective properties of the electromagnetic screen based on the amplitude-frequency characteristics of the electromagnetic field, which needs to be screened.