Abstract: A process for recovery of alkali values from trona in which trona is dissolved, the sodium carbonate in the feed solution is converted to sodium bicarbonate by introducing carbon dioxide, sodium bicarbonate is crystallized and separated from a mother liquor, and sodium bicarbonate in the mother liquor is converted to sodium carbonate by introducing air to form a recirculating dissolving solution which is used to dissolve the trona.

Abstract: Sulfur dioxide is introduced into a solution of sodium sulfite and sodium bisulfite to form sodium bisulfite in a solution having dissolved sulfur dioxide present with a pH between 3.5 and 4.2. The solution is drawn to a cooling crystallizer where an alkali such as soda ash, caustic soda, sodium sulfite, and mixtures thereof is added to produce additional sodium metabisulfite that increases the yield of sodium metabisulfite crystallizing per pass. The mother liquor is recycled.

Abstract: Sulfur dioxide is introduced into a solution of sodium sulfite and sodium bisulfite to form sodium bisulfite in a solution having dissolved sulfur dioxide present with a pH between 3.5 and 4.2. The solution is drawn to a cooling crystallizer where sodium hydroxide is added to produce additional sodium metabisulfite that increases the yield of sodium metabisulfite crystallizing per pass. The mother liquor is recycled.

Abstract: A process for recovering alkali values from trona ore by partially dissolving trona in a first dissolving solution to form a first feed liquor and undissolved trona. The first feed liquor is cooled and sodium carbonate decahydrate is precipitated. The sodium carbonate decahydrate is recovered from the resultant first mother liquor that is returned as the first dissolving solution. The undissolved trona is further dissolved in a second dissolving solution to form a second feed liquor. The second feed liquor is preferably carbonated to convert sodium carbonate into sodium bicarbonate, and cooled to precipitate sodium bicarbonate. The sodium bicarbonate is recovered from the resultant second mother liquor that is returned as the second dissolving solution.

Abstract: A process for recovery of alkali values from trona ore comprising (a) dissolving the trona ore, (b) separating the insoluble material to obtain an alkali containing feed liquor, (c) cooling the feed liquor and crystallizing sodium bicarbonate and separating the bicarbonate crystals from the resulting mother liquor, (d) cooling the mother liquor and crystallizing sodium carbonate decahydrate and separating the decahydrate crystals from a weak liquor, and (e) treating the sodium carbonate decahydrate crystals to recover the alkali values therein.

Abstract: Disclosed is a method of producing sodium hydroxide comprising the steps of: (a contacting trona ore and sodium hydroxide under conditions suitable to form sodium carbonate; (b) removing essentially all solids larger than 32 mesh from the sodium carbonate product of step (a); (c) contacting the sodium carbonate product of step (b) and calcium hydroxide in the presence of a suitable amount of seed crystal calcium carbonate with crystal size in the range of about 1 to about 10 microns, and under conditions suitable to form aqueous sodium hydroxide and calcium carbonate crystals with crystal size in the range of about 30 to about 50 microns; and (d) recovering aqueous NaOH from the reaction product of step (c). The seed crystals may be introduced from an external source, or made insitu in the lime slaker by the addition of a small amount of sodium carbonate into the lime slaker.