Abstract

single-phase pilot furnace was run with a target load of 160kW for approximately 80 hours of total continuous operation. Coal, coke, charcoal, and woodchips provided the carbon. The furnace was cooled, filled with epoxy, and core drilled. Characterization of the cores allowed for the recreation of the zones and materials found in the Si process. The furnace contained Si and some slag. Si was found in droplets as high as 5cm from the top of the furnace and above the top cavity, likely from condensation reactions. SiC was seen throughout the furnace from both conversion of carbon materials by SiO gas and through gaseous reactions. Slag tended to wet the SiC and was found at almost all levels in the furnace. Brown, SiO2+Si, and white, SiO2+SiC, condensate was found. The condensate contained alumina (18%), K2O (5%), and Na2O (2%). No cavity was seen directly under the electrode. There was however evidence of a metal pool that appeared to have eroded into the lining. No evidence of a large SiC crust was found.

Keywords: Coal; Silicon; Materials; Furnace; Drilling; Quartz