Trona calcination
Patent 4021525 Issued on May 3, 1977. Estimated Expiration Date: 
May 3, 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 3, 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 3838189 3870780 InventorAssigneeApplicationNo. 05/587577 filed on 06/17/1975US Classes:423/184, Forming insoluble substance in liquid423/206.2, 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 silicates is reduced by the improvement which comprises calcining the crushed trona at temperature of 200° C. to 600° C. in the presence of an additive selected from the group consisting of aluminum oxide and bauxite. When the trona is calcined in the presence of aluminum oxide or bauxite at temperatures of 350° to 600° C., then the sodium carbonate solution is low in both soluble silicate as well as carbonaceous matter. |
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