SYNTHESIS OF A SILICON CARBIDE FROM NATURAL RAW MATERIAL IN A SOLAR FURNACE
Annotatsiya
In this study, the processes involved in synthesis of silicon carbide (SiC) from a natural mineral raw material (diatomite mixed with coke) were investigated. The initial material mixture was placed in a graphite crucible installed on the focal zone of a large solar furnace. High-temperature heating was carried out using a stream of concentrated high-density solar radiation (200-300 W/cm<sup>2</sup>). After irradiating the material sample with the concentrated solar radiation, the crucible was cooled arbitrarily for 30 minutes. The synthesized material contained three phases: &beta;-SiC with a cubic crystalline lattice and lattice parameter of 0.436 nm; &alpha;-SiC with a hexagonal crystalline lattice and lattice parameters of a &#61; 0.307 nm and c &#61; 1.511nm; and graphite with a hexagonal crystalline lattice. The SiC material obtained in the solar furnace in a freshly sintered state showed high refractoriness (up to 1650&deg;C), while the material fired at 1550&deg;C showed refractoriness up to 1580&deg;C.