The inventive developments disclosed in this application include the following features and combinations thereof: extracting oil from spent bleaching earths for
animal feed; using earths and
acid water as soil amendment /
fertilizer; efficient extraction of substances valuable to plants, animals, and humans from
plant, animal, and
fish oil soapstock, especially using the “
interphase”
emulsion from soapstock acidulation; use of “black paste” from oil refining as
fertilizer component (
nutrient source); use of
interphase from agricultural oil refining, especially refining of non-degummed oils, as
animal feed; use of “oil refining by-products to fertilizers” process and / or KOH refining in conjunction with “Miscella”-type
hexane refining or “
Zenith” process refining; fertilizers containing silica / silicates from by-products of agricultural oil refining; use of higher-
sodium oil refining by-products as
fertilizer for
sodium-tolerant plants; using by-products of
sugar beet refining as
nutrient source; agriculturally useful
potassium soaps from oil refining; products of the refining of non-degummed agricultural oils having useful biocidal or other biological properties; the use, as a
feed additive, of
potassium soapstock from the caustic refining of agricultural oils using a
potassium caustic (KOH), especially with non-degummed oils, which has unexpected advantages over the use of soapstock from
sodium caustic (NaOH) refining, especially from degummed oils.