Claims
- 1. A method for purifying kaolin clay which consists essentially of the steps of:
- (a) providing degritted impure kaolin clay containing particles of a colored iron-contaminated titania impurity, said degritted impure kaolin clay being in the form of a fluid dispersed alkaline aqueous pulp and the dispersant being selected from the group consisting of alum-silica hydrosol, sodium silicate, sodium carbonate, sodium polyacrylate and mixtures thereof, said pulp being free from a phosphate dispersant;
- (b) conditioning said pulp from step (a) by agitating it in a squirrel cage mixer with calcium chloride and an anionic collector reagent comprising oleic acid capable of selectively collector-coating said iron-contaminated titania impurity;
- (c) subjecting the entirety of the conditioned pulp from step (b) to centrifugation or hydrocloning to sediment selectively collector-coated iron-contaminated impurity; and
- (d) separating said sediment from the remainder of the pulp which is a dispersed concentrate of purified kaolin.
- 2. The method of claim 1 wherein said dispersant is sodium silicate or an alum-silica hydrosol.
- 3. The process of claim 1 wherein said collector comprises oleic acid and rosin acids.
- 4. The process of claim 1 wherein said collector comprises oleic acid and said dispersant consists of sodium polyacrylate.
- 5. The process of claim 1 wherein the particle size of the purified kaolin recovered after hydrocloning or centrifugation is substantially the same as the particle size of the clay in said degritted fraction of impure kaolin before it is conditioned in said mixer.
Parent Case Info
This is a continuation application under 37 CRF 160, of pending prior application Ser. No. 988,393 filed on Dec. 9, 1992 now U.S. Pat. No. 5,311,997, which is a continuation of Ser. No. 725,713 filed on Jul. 3, 1991, now abn. ADDITION OF SELECTIVE COLLECTOR REAGENT AND CENTRIFUGATION
US Referenced Citations (24)
Foreign Referenced Citations (1)
Number |
Date |
Country |
104099 |
Mar 1984 |
EPX |
Continuations (2)
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Number |
Date |
Country |
Parent |
988393 |
Dec 1992 |
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Parent |
725713 |
Jul 1991 |
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