In present systems for treating used cooking oil or fat, the frying system is shut down periodically in order to remove the oil or fat from the fryer to a batch treatment tank where a purifying material is mixed for a specified time and then removed by filtration.
U. S. Pat. No. 4,112,129, issued to Duensing, et al., discloses a composition comprised of diatomite, synthetic calcium silicate hydrate, and synthetic magnesium silicate hydrate may be employed for reclaiming used fats and oil.
U. S. Pat. No. 4,681,768, issued to Mulflur, et al., discloses a process for treating used cooking oil or fat by contacting used cooking oil or fat with a high surface area amorphous synthetic magnesium silicate having a surface area of at least 300 square meters per gram.
U. S. Patent No. 5,597,600, issued to Munson, et al., discloses the treatment of cooking oil or fat with magnesium silicate and at least one alkali material to reduce the content of free fatty acids in the oil or fat.