Basic Reactions and Mechanism of Processes Related to the Direct Synthesis

The complex reaction system of direct synthesis had been investigated on the basis of thermodynamic calculations. As a result, the product distributions during induction and stationary period are reproduced with a high agreement to experimental studies. It follows, that many of the reaction products are thermodynamically determined. Dimethyldichlorosilane was found as the most stable reaction product compared to the other methylchlorosilanes. Among the discussed reactions, the classical route of contact mass activation by reaction of silicon with CuCl was experimentally studied with respect to the initial stage of reaction. The role of ZnCl2 is discussed in light of local melt formation based on experimental results and by means of the calculated CuClZnCl2 phase diagram.