Liquid purification or separation – Processes – Liquid/liquid solvent or colloidal extraction or diffusing...
Patent
1998-02-12
2000-09-26
Walker, W. L.
Liquid purification or separation
Processes
Liquid/liquid solvent or colloidal extraction or diffusing...
210650, 210739, 210744, 210746, 2101952, B01D 6114, B01D 6122
Patent
active
061238481
DESCRIPTION:
BRIEF SUMMARY
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention pertains to methods and apparatus for removing water-soluble impurities from water-insoluble particles. More particularly, this invention pertains to methods and apparatus that use filtration for purifying a fluid aqueous suspension may be containing water-soluble impurities.
2. Description of the Relevant Art
Water-insoluble particles sometimes have-uses which require the removal of water-soluble impurities. Such uses include use as a mordant in dyeing, an ion-exchanger, a filtering medium, a chromatography substrate, a printing ink, an antiperspirant, a dentifrice, a tablet filler, and others. For example, aluminum hydrate, also known as aluminum hydroxide, hydrated alumina, or aluminum trihydrate, may be used as a mordant in dyeing, an adsorbent, an emulsifier, an ion-exchanger, a filtering medium, an antacid, and an antihyperphosphatemic. Aluminum hydrate is also used in chromatography; in the manufacture of glass, fire clay, paper, pottery, printing inks, lubricating compositions, and detergents; for waterproofing fabrics; and in antiperspirants and dentifrices, among other applications.
Alumina hydrate and aluminum chloride are useful for making "lakes". "Lakes" are color additives prepared by combining a soluble dye with an insoluble substrate. Lakes made from aluminum compounds are generally thought to be coordination compounds of the aluminum compound with the dye. An aluminum lake is conventionally prepared by adding a base such as sodium carbonate or sodium hydroxide to a solution of aluminum sulfate to precipitate aluminum hydrate. That process generates sodium sulfate as a water-soluble byproduct, which is removed by pressing a filter cake and washing the filter cake in the filter press. A solution of colorant is added to the resulting slurry, which is acidified with hydrochloric acid to convert the colorant to an aluminum salt, which then absorbs onto the surface of the aluminum hydrate to form a lake. In that step, sodium chloride is formed as a water-soluble byproduct.
A lake may also be formed by adding a dye to an aluminum hydrate formed by adding aluminum chloride to a solution of sodium bicarbonate as described in U.S. Pat. No. 3,909,284, incorporated herein by reference. According to that patent, a dye dissolved in water is added to the resulting aluminum hydrate suspension and then a thin stream of aluminum chloride solution is added until the pH is between 4.1 to 4.3 to effect laking. An advantage of this process is-that it does not generate sulfate salts, but it still generates chloride salts as an intermediate byproduct.
The slurry formed by either lake making process is filtered and the filter cake is then washed, dried and ground to the appropriate fineness. The product is marketed as is, mixed with other lakes, mixed with approved diluents, or dispersed in edible vehicles or other media that make the mixtures appropriate for printing food wrappings, marking capsules, coloring health and beauty products that come in contact with the skin, coloring products intended for human consumption, etc.
When the colorants used to make lakes are intended for human contact or consumption, they are generally required to be "certified" by an appropriate government agency. In the U.S., that agency is the U.S. Food & Drug Administration (the FDA). U.S. certified colorants are generally referred to as FD&C (Foods, Drugs and Cosmetics) and D&C (Drugs and Cosmetics) colorants. Other entities which certify colorants include the European Economic Community (E.E.C), the World. Health Organization (W.H.O.), and most developed countries. Alternative substrates for making "lakes" approved in some countries, include blanc fixe, gloss white, clay, titanium dioxide, zinc oxide, talc, rosin, aluminum benzoate, calcium carbonate, and combinations thereof.
The need for removal of the water-soluble salts generated at each step of the "lake" manufacturing process is a serious problem, because copious amounts of water has been required to wash s
REFERENCES:
patent: Re28940 (1976-08-01), Komline, Sr. et al.
patent: 3524756 (1970-08-01), Signorino et al.
patent: 3576663 (1971-04-01), Signorino et al.
patent: 3622508 (1971-11-01), Komline
patent: 3667614 (1972-06-01), Komline
patent: 3694237 (1972-09-01), Piotrowski
patent: 3701432 (1972-10-01), Schlegel
patent: 3723712 (1973-03-01), Komline, Sr. et al.
patent: 3799532 (1974-03-01), Schlegel
patent: 3803806 (1974-04-01), Komline, Sr. et al.
patent: 3918821 (1975-11-01), Schlegel et al.
patent: 4009103 (1977-02-01), Burke
patent: 4276176 (1981-06-01), Shorr
patent: 4336244 (1982-06-01), Woznicki et al.
patent: 4366129 (1982-12-01), Czegledi et al.
patent: 4670150 (1987-06-01), Hsuing et al.
patent: 4676959 (1987-06-01), The et al.
patent: 4786482 (1988-11-01), The et al.
patent: 4801381 (1989-01-01), Niesen
patent: 4895653 (1990-01-01), Cherochak
patent: 4952317 (1990-08-01), Culkin
patent: 4986911 (1991-01-01), Goron et al.
patent: 5014564 (1991-05-01), Culkin
patent: 5049233 (1991-09-01), Davis
patent: 5141610 (1992-08-01), Vaughan
patent: 5198085 (1993-03-01), Vaughan
patent: 5244583 (1993-09-01), Goron et al.
patent: 5338457 (1994-08-01), Capozzola et al.
patent: 5455019 (1995-10-01), Inui et al.
Jantosik, Jr. Edward Charles
Lauff Danny Thomas
Mitchell John David
Quepons Dominguez Rosa Isabel
Solter Lance Eugene
Walker W. L.
Ward Richard W.
Warner-Jenkinson Company, Inc.
LandOfFree
Ultrafiltration method for purifying water-insoluble aluminum hy does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Ultrafiltration method for purifying water-insoluble aluminum hy, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Ultrafiltration method for purifying water-insoluble aluminum hy will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2096974