Hemihydrate type phosphoric acid process

Details Hemihydrate type phosphoric acid process Hemihydrate type phosphoric acid process

C - Chemistry, Metallurgy

01

B

23/384, 23/76

C01B 25/16 (2006.01)

Patent

CA 1114131

ABSTRACT OF THE DISCLOSURE Phosphate rock and sulfuric acid are reacted under conditions which result in the formation of calcium sulfate hemihydrate and phosphoric acid of about 35% to about 55% P205. A two vessel reaction system maybe used in which the reaction slurry undergoes inter and intra- vessel circulation. The solution portion of the slurry in the first vessel (the "dissolver") is preferably maintained at a negative sulfate concentration (i.e. excess Ca+2) and the solution in the second vessel (the "crystallizer") is preferably maintained at a positive sulfate ion concentration. Also preferred is that the second vessel be maintained at a reduced pressure, (e.g. to provide evaporative cooling). Better filtration rates can thus be obtained due to the favorable shape, size and distribution of the hemihydrate crystals. Most preferred is that a crystal modifier (e.g. a sulfonic acid, a sulfonic acid salt, tall oil fatty acids or esterified tall oil fatty acids) be present in crystallizer. Surprisingly, the sulfuric acid used in the process can be less (e.g., 0.5 - 10%) than the stoichiometric amount to convert the calcium in the feed phosphate rock to calcium sulphate.

282947

Affiliated with

Also associated with

Rating

Hemihydrate type phosphoric acid process does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Hemihydrate type phosphoric acid process, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Hemihydrate type phosphoric acid process will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFCA-PAI-O-638239