Abstract: The addition of urease negative bacteria to sodium smectite clay minerals in pet litter inhibits growth of urease positive bacteria for a period of several days, thereby retarding formation of ammonia and other obnoxious odors. Approximately fifty percent sodium bentonite in the litter causes the litter to clump upon wetting, maintaining the urea in contact with the treated clay and also serving as a buffer to favor growth of the urease negative bacteria.

Abstract: A composition for use in producing a foundry mold, a foundry mold of the composition and a method for making the foundry mold from the composition. The composition includes sodium smectite clay and at least one of a metal oxide, hydroxide or salt as a mineral clay component of the composition. This mineral clay component is present in the composition along with water and foundry sand. The metal of the oxide, hydroxide or salt may be aluminum, calcium, iron, potassium, magnesium, boron or zinc. The sodium smectite clay may be at least one of bentonite, hectorite or saponite.