FACTORS AFFECTING THE PYROPHORISITY OF SPENT BLEACHING CLAY

Artificial cakes of bleaching clay/vegetable oil have been studied for their pyrophoric character using both Differential Scanning Calorimetry and a constant-temperature, fixed-interval, spontaneous heating (CaTFISH) test developed in this laboratory. It was determined that this is a two-step process involving a first-stage low-temperature spontaneous heating reaaction followed by a second-stage high-temperature spontaneous heating reaction. The latter is characterized by charring and, in some cases, flaming combustion. A study of relevant variables has established that clay type, filter cake age, oil retention, moisture, and the presence of antioxidant significantly affect the spontaneous heating characteristics of clay/oil masses. Oil type was not found to be a significant variable in these studies. © 1990 AOCS Press.