Abstract: A method for enhancing the recovery of dense soda ash from Na.sub.2 SO.sub.4 - and NaCl-containing aqueous sodium carbonate solutions by first co-crystallizing anhydrous sodium carbonate and burkeite and next introducing the co-crystallized solids to an aqueous medium at elevated temperature to dissolve the burkeite and cause reversion of the anhydrous sodium carbonate solids to crystalline sodium carbonate monohydrate, which is then separated from the dissolved sulfate and recovered as product.
Type:
Grant
Filed:
November 26, 1982
Date of Patent:
May 28, 1985
Assignee:
Intermountain Research & Development Corp.
Inventors:
William C. Copenhafer, Michael L. Pinsky
Abstract: Separate deposits of trona or nahcolite ore are solution mined with two solvents, aqueous sodium hydroxide and aqueous hydrogen chloride. Aqueous sodium carbonate solution is withdrawn from the region of the NaOH-treated ore deposit, for recovery of soda ash. Aqueous sodium chloride brine is withdrawn from the region of the HCl-treated ore deposit and introduced to an electrodialysis cell to regenerate the two solvents and thereby continue the solution mining cycle.
Type:
Grant
Filed:
August 15, 1983
Date of Patent:
February 12, 1985
Assignee:
Intermountain Research & Development Corp.
Abstract: Alkali values are recovered in a cyclic method from mechanically mined trona ore or from trona deposits by a solution mining technique utilizing a solvent comprising an aqueous solution of sodium sulfide. The ore is solubilized as sodium carbonate which is precipitated as sodium sesquicarbonate and/or sodium bicarbonate by treating the solution with hydrogen sulfide and the precipitated salt separated from the mother liquor. In the process, sodium sulfide and hydrogen sulfide become converted into sodium hydrosulfide which is contained in the mother liquor. Heat treatment of the mother liquor converts the sodium hydrosulfide into sodium sulfide thereby regenerating a solution of sodium sulfide which is recycled to the trona ore and into hydrogen sulfide which is evolved and recycled to the sodium carbonate solution.
Type:
Grant
Filed:
April 23, 1980
Date of Patent:
August 25, 1981
Assignee:
Intermountain Research and Development Corp.