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.

Abstract: A cyclic method for recovering alkali values from subterranean trona deposits. The ore is contacted via solution mining with an aqueous mining solvent containing sodium hydroxide, the resulting Na.sub.2 CO.sub.3 -containing solution is withdrawn and carbonated, and sodium sesquicarbonate and/or sodium bicarbonate is crystallized and separated from the solution. The crystallized solids are calcined in a direct coal-fired calciner, and the resultant anhydrous soda ash is recrystallized in water to form sodium carbonate monohydrate or anhydrous sodium carbonate, which is recovered as a dense alkali product. Aqueous mining solvent is regenerated by causticization of one or more of the various liquor streams, and the recovery cycle is repeated.

Abstract: Sodium carbonate peroxide stabilized against loss of its active oxygen content is prepared by incorporating into sodium carbonate peroxide an ethylene oxide-derivative stabilizing agent selected from the group consisting of polyethylene glycol, polyethoxy fatty acid tertiary amines, diamines and quaternary ammonium salts thereof, N,N-polyethoxy fatty acid amides and polyethoxy fatty acid esters and recovering the sodium carbonate peroxide as a dry, free-flowing solid.

Abstract: A method for recovering alkali value from sodium bicarbonate-containing ore by utilizing an aqueous solvent containing ammonia. The aqueous ammonia solvent is contacted with the ore to solubilize the sodium bicarbonate-containing ore. The alkali values in the resulting solution are crystallized, preferably as sodium carbonate monohydrate or as sodium sesquicarbonate, which may be processed to recover soda ash. Aqueous ammonia solvent is preferably regenerated from the mother liquor remaining after recovery of the solids, the ammonia solvent then being employed in a cyclic method to recover additional alkali values from the ore.

Abstract: An electrode that is specific for the isocyanurate ion, and capable of rapid determination of the free isocyanurate ion activity directly in solution uses as its sensing element a platinum wire covered with a polyvinyl chloride membrane. The membrane is plasticized with a solution of a quaternary ammonium salt of isocyanuric acid. When this electrode and a commercial reference electrode are immersed in a solution containing the isocyanurate ion, a differential voltage proportional to the isocyanurate ion concentration is generated which is detected by a pH meter.