Methods of Fugitive Emission Reduction in Metallurgical Silicon Production at Kazsilicon Metallurgical Combine

KazSilicon Metallurgical Combine is the first enterprise in the Republic of Kazakhstan to produce highpurity metallurgical silicon. The silicon is produced in a 6.7 MW electric furnace from quartz, obtained from the Sarykul’skoe deposit, and charcoal by the method of vertical directional crystallization. As a result of large fugitive emissions of process gases, the operation of the open-type electric furnace creates very difficult conditions for maintenance work. The presence of leaks and a large number of access windows promotes atmospheric air indraft into the working region of the furnace, which causes the electrodes to break down. To solve these problens, we propose using the thermal pressure head of the process gases and extracting these gases through the furnace roof by means of three gas flues, each with capacity ~25000 m³/h. To extract the process gases fl owing from the furnace through the gasket of the electrode opening, we propose using a slotted hood covering the location of the electrode entry into the furnace. A number of recommendations are also made for improving the design of the electric furnace in order to reduce heat losses and fugitive atmospheric-air indraft into the furnace, eliminate the gas release into the atmosphere in the shop and residential zone, and simplify the operation of the electrode and current-cable holders.