Chemistry of inorganic compounds – Treating mixture to obtain metal containing compound – Alkaline earth metal
Patent
1988-05-23
1991-05-14
Straub, Gary P.
Chemistry of inorganic compounds
Treating mixture to obtain metal containing compound
Alkaline earth metal
156 43, 264333, 423170, 423171, 106772, C04B 1102, C04B 11024
Patent
active
050154494
ABSTRACT:
The process makes calcium sulfate alpha-hemihydrate or essentially plaster of paris from finely divided gypsum made by desulfurizing flue gas obtain from a power plant fired by brown coal by transforming the calcium sulfate dihydrate in the presence of saturated steam. A molded body is formed from the calcium sulfate dihydrate which has a plurality of pores. The pore volume amounts to 15 to 60% by volume of the total volume of the entire molded body. More than 5% by volume of the pore volume contains air. The molded body is fed to an autoclave. In the presence of a sufficient water quantity in the pores, the crystal habit and the crystal growth of the calcium sulfate alpha-hemihydrate crystals which grow in an aqueous solution phase are controlled by a process temperature in the range between 110.degree. to 180.degree. C. by the pressure of the treatment atmosphere in the autoclave. The molded body is removed from the autoclave after recrystallization transformation and delivered for use. Key products of this process and their derivatives are also described.
REFERENCES:
patent: 1901051 (1933-03-01), Randel et al.
patent: 3410655 (1968-11-01), Ruter
patent: 4309391 (1982-01-01), O'Neill
patent: 4540555 (1985-09-01), Franke et al.
patent: 4604141 (1986-08-01), Natori et al.
Browning, Chemical Engineering, Dec. 4, 1967, pp. 147-170.
Ullmanns Encyklopadie der Technischen Chemie, Fungizide bis Holzwerkstoffe, erlag Chemie, Weinheim-New York, 1976, Band 12, pp. 301, 303, 304.
Baugipse, DIN 1168-Teil 1, Jan. 1986, Preisgr. 4, pp. 1-3, Normenausschuss Bauwesen (NABau) im DIN Deutsches Institut fur Normung e. V.
Baugipse, DIN 1168-Teil 2, Jul. 1975, Preisgr. 6, Fachnormenausschuss Bauwesen (FNBau) im Deutschen Normenausschuss (DNA).
Dubno Herbert
Kalinchail Stephen G.
ProMineral Gesellschaft Zur Verwendung von Mineralstoffen mbH
Sicowa Verfahrenstechnik fur Baustoffe GmbH & Co. K.G.
Straub Gary P.
LandOfFree
Process for making construction grade calcium sulfate alpha-hemi does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Process for making construction grade calcium sulfate alpha-hemi, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Process for making construction grade calcium sulfate alpha-hemi will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1647046