Optimizing the Charge Pelletizing Parameters for Silicon Smelting Based on Technogenic Materials

Abstract

The pelletizing parameters for fine technogenic raw materials generated in the production of metallurgical silicon (Simet) are optimized. The technogenic waste of Simet production in ore-smelting furnaces (OSF) is barely used in other industries. Silica-containing waste (gas-treatment dust and sludge) containing 86.3 to 95.8% SiO2 is proposed to use as a charge component. The other charge components (fine waste) are petcoke screenings, charcoal fines, and silicon screenings (Siscr). Liquid glass laced with dust from aluminum-production precipitators is used as a binder. To be transported and loaded in an OSF, the pelletized charge must have sufficient mechanical strength. This is why the drop resistance coefficient (Rdr) is used as an optimization parameter in mathematical processing of experimental data on charge pelletizing. A model equation that describes the effects of the following three factors is derived: pelletizing duration, binder content of the charge, and Siscr particle size. For the optimal pelletizing parameters, Rdr is equal to 82.5%. Based on the study results, a process flow diagram for the production of Simet using an additional facility for pelletizing technogenic materials is proposed.