Abstract: The effects of heat on the behavior of sodium and calcium bentonite in bonding foundry sands were studied.
Tests such as differential thermal analysis, viscosity, and melting or vitrification temperatures do not indicate the suitability of a bentonite for foundry use.
The deterioration temperatures of sodium and calcium bentonite are 1180° and 600°F respectively.
Reactivities of bentonites with cereal as affected by temperature and mulling were also studied. Flowability of sands, defined as mold densification in this paper, is better with heated calcium than sodium bentonite.
Heating bentonites alone does not simulate the conditions encountered in heating bentonite-sand mixtures in a mold.