GB729898A - Improved process for the recovery of wool wax from wool scour liquor froths - Google Patents

Abstract

Wool wax is recovered from froth produced from wool scour liquor by treating the froth with one or more sodium or potassium phosphates as a dispersing agent and then separating the wool wax from the dispersion. The pH of the dispersion may be adjusted, unless it is raised sufficiently by the phosphates, according to the nature of the detergent used in the wool scouring and according to the desired acid number of the wax, by adding also sodium carbonate or other alkaline material. The froth may be produced by flotation processes. The wool scour liquors may be liquors wherein the detergent comprises soap or a synthetic detergent, particularly a non-ionic detergent of the condensed ethylene oxide type, e.g. "Lissapol N" (R.T.M.), or an anionic detergent of the sulphated long chain alcohol type, e.g. "Teepol" (R.T.M.). The phosphates specified comprise disodium hydrogen phosphate, sodium dihydrogen phosphate, tetrasodium pyrophosphate, and the sodium polyphosphate known as "Calgon" (R.T.M.). The wool wax is preferably separated from the dispersion by centrifuging. Various solutions of a phosphate and an alkali, particularly sodium carbonate, of specified proportions are exemplified to enable wool waxes of particular acid numbers, e.g. 0.5 or less or about 1, to be obtained, which acid numbers correspond to particular pH values of the solutions. In some cases the alkali is not required. For higher acid numbers the phosphate solutions may have their pH adjusted by adding sulphuric or phosphoric acid or sodium dihydrogen phosphate. The froth, after addition of the phosphate solution and alkali solution if desired, may be heated before centrifuging. A second centrifuging may be used to reduce the water content of the wax, preferably after cooling and reheating the wax.