Production of gypsum hemihydrate with waste heat, aqueous H.sub.

Details Production of gypsum hemihydrate with waste heat, aqueous H.sub. Production of gypsum hemihydrate with waste heat, aqueous H.sub.

1981-07-13

1984-02-21

Straub, Gary P.

Chemistry of inorganic compounds

Treating mixture to obtain metal containing compound

Alkaline earth metal

423555, 106110, C04B 1100, C04B 1102, C01F 1146

Patent

active

044329547

ABSTRACT:
Alpha gypsum hemihydrate is obtained by calcining calcium sulfate dihydrate, generated with flue-gas desulfurization of power plants or by chemical process, e.g. in the production of phosphoric acid. The calcining process comprises producing initially a dispersion from calcium sulfate dihydrate and diluted, sulfuric acid solution and heating same at a predetermined rate to about 373 K with industrial, dust-free waste heat, whereupon the solid components are separated from the aqueous sulfuric acid and are dried. An alpha gypsum hemihydrate practically free from anhydrite II is obtained from a solution of sulfuric salts in the diluted sulfuric acid. An addition of magnesium oxide yields a hemihydrate with a high degree of fineness and avoids blooming effects.

REFERENCES:
patent: 2216402 (1940-10-01), Muller
patent: 3437330 (1948-03-01), Worner
patent: 3855391 (1974-12-01), Selmeczi et al.
patent: 4091080 (1978-05-01), Kosuigi et al.
patent: 4136998 (1979-01-01), Bassier et al.
patent: 4156712 (1979-05-01), Kanai et al.
patent: 4210626 (1980-07-01), Berrie et al.
Olsen, John C. Unit processes and Principles of Chemical Engineering, D. Van Nostrand Co. New York, NY 1932 pp. 1-3.

Affiliated with

Also associated with

Rating

Production of gypsum hemihydrate with waste heat, aqueous H.sub. does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Production of gypsum hemihydrate with waste heat, aqueous H.sub., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Production of gypsum hemihydrate with waste heat, aqueous H.sub. will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-1035304