Process for producing sodium salts from brines of sodium ores
Patent 5283054 Issued on February 1, 1994. Estimated Expiration Date: March 30, 2013. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.
423/206.2, Alkali carbonate from trona23/302T, Sodium compounds299/5, Dissolving or chemical reaction423/421Alkali metal containing (Li, Na, K, Rb, or Cs)
A process for producing valuable sodium-based chemicals from a brine containing sodium carbonate and sodium bicarbonate, such as those containing from about 8% to about 20% total alkali obtained by contacting water with an underground trona formation by heating the brine at about 100° C. to about 140° C. to evaporate water, convert sodium bicarbonate to sodium carbonate and to drive off resulting carbon dioxide, reacting the brine with reduced sodium bicarbonate with an aqueous sodium hydroxide solution in amounts to convert essentially all of the remaining sodium bicarbonate in the brine to sodium carbonate, cooling to about 5° C. to about 25° C. to precipitate sodium carbonate decahydrate crystals, separating the crystals from their mother liquor, melting the separate crystals to form a sodium carbonate solution, heating the solution to from above about 60° C. to below 110° C. to evaporate water, precipitating sodium carbonate monohydrate crystals, separating the sodium carbonate monohydrate crystals from their mother liquor and calcining them to soda ash which is recovered as a product. The sodium hydroxide used in the above process is formed preferably by causticizing sodium carbonate values with calcium oxide or calcium hydroxide in a separate but parallel operating causticizing circuit.
March 30, 2013. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.
