Influence of Thermal Stability of Quartz and the Particle Size distribution of Burden Materials on the Process of Electrothermal Smelting of Metallurgical Silicon

The article studies the thermal stability of quartz deposits in Kazakhstan - Aktas and Sarykul. It is established that the quartz of the Aktas deposit is a raw material with low thermal stability, and quartz is of medium-durability at Sarykul deposit. The complex influence of the thermal stability of this raw material on the technological parameters of smelting of technical silicon under experimental industrial conditions of electrothermal melting in a furnace with a capacity of 30 MVA was studied at LLP "Tau-Ken-Temir" (Kazakhstan). A new method for optimizing the smelting of commercial silicon has been developed, even when using raw materials with low thermal stability. The main idea of ​​the method is that the less thermally stable quartz is used, the more the initial size of its pieces should be. Optimum values ​​of the average size of pieces of quartz - Aktas - (85-95 mm) and Sarykul - (30-40 mm) are obtained.