Special Bentonite for Foundry used in foundry industry for molding. Bentonite is the main part of the glue, which holds the grain of the molding sand together. Type of packaging : Paper bag 25kg & 100lbs Blue Absorption Value (mmol) 96. min Electric Conductivity (QS/cm) 350 - 750 Swelling Volume (ml) 18. min Standard Sieve 200 (%) 80. min Moisture content (%) 12. max pH 8 - 10.5 Apparent Specific Gravity (gr/ml) 0.6 - 0.8