Trona calcination
Patent 4022868 Issued on May 10, 1977. Estimated Expiration Date: 
May 10, 1994. 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.
May 10, 1994. 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.Patent References 3689218 3838189 3870780 InventorAssigneeApplicationNo. 05/587576 filed on 06/17/1975US Classes:423/184, Forming insoluble substance in liquid23/302T, Sodium compounds423/206.2, Alkali carbonate from trona423/421Alkali metal containing (Li, Na, K, Rb, or Cs)ExaminersPrimary: Vertiz, O. R.Assistant: Langel, Wayne A. Attorney, Agent or FirmAbstractIn the process of making sodium carbonate from trona involving the steps of crushing the trona, calcining the crushed trona, dissolving the calcined trona to obtain a solution comprising sodium carbonate and insoluble impurities contaminated by soluble silicates and soluble carbonaceous matter, contamination of the sodium carbonate solution with soluble carbonaceous matter is reduced by the improvement which comprises calcining the crushed trona at temperature of 300° C. to 600° C. in the presence of magnesium oxide. When the trona is calcined in the presence of magnesium oxide at temperature of 350° to 600° C., then the sodium carbonate solution is low in both soluble carbonaceous matter as well as insoluble silicates. |
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