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:
Dec. 09, 2003
Filed:
Oct. 31, 1996
Roger L. Day, Rifle, CO (US);
Natural Soda AALA, Inc., Rifle, CO (US);
Abstract
Process of crystallization of sodium bicarbonate from solution mined Nahcolite pregnant liquor comprising the use of from about 2 to 100 parts per million of lecithin, introduced full strength, made miscible in water with a soap or detergent, saponified with NaOH at a pH of 10-12, or preferably as a mixture of lecithin in pregnant or barren liquor containing HCO /CO ions at a pH in the range of from about 8 to 12, preferaby 8-10. The lecithin functions as a crystal growth modifier, producing improved crystal yields, product size classification, improved crystal shape including reduction in dendritic, branched and twinned forms, very significant scale reduction, reduction in wet cake moisture, increase in product bulk density, reduction in both oversize and undersize fractions (the classification phenomenon) and less breakage during drying and handling. The aqueous lecithin premix is preferably added to a pregnant liquor tank, and may also be added in one or more crystallizers in the circuit in batch (timed aliquots) or continuously metered in proportion to throughput. The process may also be applied to crystallization of carbonates, bicarbonates, phosphates, nitrates, sulfates, hydroxides and borates of Na, Li, K, Ca and Mg from aqueous solutions including brines. For commercial scale bicarbonate production the presently preferred range is 2-30 ppm, and for product −425 &mgr;m+45 &mgr;m the range is about 5-15 ppm. Coarse product (+425 &mgr;m) is preferably produced in the range of about 12-30 ppm.