The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Mar. 28, 1989
Filed:
May. 13, 1988
Edward C Rosar, Lakewood, CO (US);
Roger L Day, Rifle, CO (US);
NaTec, Ltd., Houston, TX (US);
Abstract
Nahcolite solution mining process comprising drilling at least one well into a Nahcolite bed, circulating hot barren aqueous liquor in a cavity in said Nahcolite bed for a time sufficient to produce a pregnant liquor having an increase in the concentration of NaHCO.sub.3 in the range of from about 3 to about 20% while maintaining Na.sub.2 CO.sub.3 concentration in the range of about 0.25-4%, preferably less than 2.5%, withdrawing said pregnant liquor, cooling said pregnant liquor to preferentially precipitate NaHCO.sub.3 therefrom and to produce a barren liquor, recovering said NaHCO.sub.3, and reheating and re-injecting said barren liquor in said well. The cavity temperature is maintained below about 250.degree. F. and preferably below about 200.degree. F. The barren liquor is injected at a pressure of below about 150 psig. The pregnant liquor is extracted at a temperature in the range of from about 85.degree. F. to about 200.degree. F., and the cystallization occurs at a temperature of about 25.degree.-120.degree. F. The NaCl concentration is maintained at below about 6% and preferably below about 1.0%. Crystalline sodium bicarbonate of high purity (98+% NaHCO.sub. 3) is produced in the as-crystallized form, and simple washing increases the purity.