Processing of South Dakota Shale for Ceramic Production — 67p — Ann Sheehy, Stephen Gebes, Brandon Stuber, Jacob Petersen Ph.D., Jon Kellar Ph.D.

Belle Fourche Shale (BFS) is a bentonite-rich shale that is prevalent in the central portion of the United States. In addition to smectite clays, BFS also contains small-grained quartz and mica as predominant mineral components. The presence of the swelling bentonite makes subsequent processing of the shale into a ceramic problematic as it can cause cracking/bloating. This research focused on the effect of mixing time on the brick clay and the addition of cellulose additives to prevent cracking or bloating in fired bricks. Raw BFS was removed from the edge of the South Dakota Mines campus, air dried, and comminuted (hammer mill). Dry shale was combined with a paper-water slurry, and mixed in a laboratory blender for various mixing times. In addition to BFS the mixture contained 30 wt% added water content and 1 wt% cellulose (tissue paper). Next, the mixture was pressed into a brick mold and dried overnight in an oven at 93°C. Finally, the dried material was fired to 1152°C (cone 3). The research showed that the addition of tissue paper significantly decreased cracking in fired bricks, with minor cracking in bricks with added tissue paper but significant cracking in bricks without tissue paper addition. Additionally, when fired bricks were cut in half, bricks with longer mixing times were visibly less porous. This research demonstrated a viable process for manufacturing bricks from local shale. There are no apparent brick manufacturers in South Dakota currently; and the processing showed a possible pathway for economically processing bricks from shale derived from South Dakota.

South Dakota Mines
Jon Kellar