METHOD OF AGGLOMERATING SILICON/SILICON CARBIDE FROM WIRESAWING WASTE AND PRODUCT THEREFROM

摘要

The process of the present invention begins with a source of silicon and silicon carbide from wafer production. The silicon/silicon carbide waste material is dewatered as need be and passed to a mixer where the waste material is agglomerated. A binder is applied to the waste material either during agglomeration or during pelletizing. A variety of organic binders may be used such as polyvinyl alcohol, molasses, sodium silicate and polyethylene glycol; however, the preferred binder is a lignosulsulfonate. The amount of binder used will depend upon the particular binder and the feed material used. The silicon/silicon carbide-containing waste material is pelletized. The invention also provided silicon/silicon carbide-containing pellets that may be used as reduction material in smelting furnaces for the production of metals and alloys.

主权项

1. A method for making silicon/silicon carbide pellets from the waste material of silicon wafer manufacturing comprising:
providing silicon/silicon carbide-containing waste material at a moisture content below about 25% by weight solids; forming an agglomerate of silicon/silicon carbide-containing having particles of a predetermined size; feeding a controlled amount of said silicon/silicon carbide-containing agglomerate into a pelletizer; adding from about 2% to about 8% by weight of a binder selected from the group consisting of polyvinyl alcohol, sodium silicate, polyethylene glycol, and lignin while pelletizing to bind said silicon/silicon carbide-containing particles in said agglomerate; pelletizing to compact said bound silicon/silicon carbide-containing agglomerate in said pelletizer to form a silicon/carbide-containing pellet having a predetermined particle size; and discharging said pellet from said pelletizer.