Daniela Grigorova
@uctm.edu
Faculty of Metallurgy and Materials Science
University of Chemical Technology and Metallurgy
EDUCATION
University of Chemical Technology and Metallurgy
RESEARCH INTERESTS
metallurgy, thermodynamics, kinetics, recycling, agglomeration, sintering, briquetting, steelmaking, properties of the metals,
high temperature processes & heat treatment technology
Scopus Publications
Scholar Citations
Scholar h-index
Scopus Publications
N. Dishovsky, D. Grigorova, VI. Iliev, and S. Borros
SAGE Publications
In the past decade, we have witnessed unprecedented increase in the quantities and variety of the electromagnetic field sources used for domestic, industrial, and military purposes. Of late, the protection from the ultra high frequency (UHF) electromagnetic radiation is gaining importance owing to human health care and quality of life and work improvement. Independently from the variety of produced absorbers, the problem with development of new, more effective, and cheap absorbing materials becomes a question of interest. The mainly used functional fillers in rubber-based composites effectively absorbing UHF electromagnetic radiations are carbonyl iron or magnetite, in same cases in combination with graphite or carbon black. At the same time in sinter plants of the extraction ferrous metallurgy, after gas cleaning equipment (electrostatic precipitators (ESP)) up to thousand tons of waste powder have been generated annually. The X-ray diffraction analysis shows that powder contains mainly magnetite. In the present research on the base of waste sinter powder a filler modified with carbon was obtained. The rubber-based composites with different concentration of modified and nonmodified fillers were produced. The vulcanization, physico-mechanical, electrical, and microwave properties of the obtained rubber-based composites were measured and evaluated. The results show that the modified fillers usage improves microwave characteristics, strength-deformation properties, and aging stability.