Abstract

The reaction rate for the reaction 2SiO₂+SiC=3SiO+CO has been measured for various polymorphs of SiO₂, for various gas atmospheres and in a temperature area from 1923-2273K (1650-2000 °C). It has previously been theorized that cristobalite has a higher reaction rate compared to quartz, but it was found that there was no difference between the polymorphs quartz or cristobalite. The activation energy was found to be between 424-464kJ/mole and the reaction rate was found to be expressed by the equation where α is the fraction of the sample reacted, varying from 0 to 1. The term 1.9·10⁸ represent the reaction area times the reaction constant. if the area of SiO₂ determines the reaction rate or if the SiC determines the reaction area. In some of the experiments the SiO₂:SiC ratio was measured after the experiment and it was seen that some side reactions, like elemental silicon formation, would also take place.

Keywords: Polymorphs; Silicon; Conductivity; Raw materials; Temperature