Abstract: Processes are described for the extraction and recovery of alkali metal from the char that results from catalytic gasification of a carbonaceous material. Among other steps, the processes of the invention include a hydrothermal leaching step in which a slurry of insoluble particulate comprising insoluble alkali metal compounds is treated with carbon dioxide and steam at elevated temperatures and pressures to effect the conversion of insoluble alkali metal compounds to soluble alkali metal compounds. Further, processes are described for the catalytic gasification of a carbonaceous material where a substantial portion of alkali metal is extracted and recovered from the char that results from the catalytic gasification process.

Abstract: Processes are described for the extraction and recovery of alkali metal from the char that results from catalytic gasification of a carbonaceous material. Among other steps, the processes of the invention include a hydrothermal leaching step in which a slurry of insoluble particulate comprising insoluble alkali metal compounds is treated with carbon dioxide and steam at elevated temperatures and pressures to effect the conversion of insoluble alkali metal compounds to soluble alkali metal compounds. Further, processes are described for the catalytic gasification of a carbonaceous material where a substantial portion of alkali metal is extracted and recovered from the char that results from the catalytic gasification process.

Abstract: The present invention concerns a high vacuum in-situ refining method for high-purity and superhigh-purity materials and the apparatus thereof, characterized in heating the upper part and lower part of crucible separately using double-heating-wires diffusion furnace under vacuum, thereby forming the temperature profile which is high at upper part and low at lower part of crucible, or in reverse during different stages; then heating the crucible in two steps to remove impurities with high saturation vapor pressure and low saturation vapor pressure respectively in efficiency; and obtaining high-purity materials eventually. The whole procedure is isolated from atmosphere, reducing contamination upon stuff remarkably. The present invention could provide products with high-quality and high production capacity, which are stable in performance, therefore is reliable and free from contamination.

Abstract: Processes are described for the extraction and recovery of alkali metal from the char that results from catalytic gasification of a carbonaceous material. Among other steps, the processes of the invention include a hydrothermal leaching step in which a slurry of insoluble particulate comprising insoluble alkali metal compounds is treated with carbon dioxide and steam at elevated temperatures and pressures to effect the conversion of insoluble alkali metal compounds to soluble alkali metal compounds. Further, processes are described for the catalytic gasification of a carbonaceous material where a substantial portion of alkali metal is extracted and recovered from the char that results from the catalytic gasification process.

Abstract: A method for producing sodium bicarbonate from a nahcolite deposit comprising injecting water or other aqueous solution at a temperature of at least 250° F. into the deposit, dissolving sodium bicarbonate in the hot water to form a production solution and subjecting the production solution to multiple stages of crystallization. The sodium bicarbonate crystals may be dewatered and dried to form a commercial sodium bicarbonate product.

Abstract: Cooking liquors of significantly different sulphidity (e.g. one having a sulphidity about 30-40% and the other a sulphidity of above 40%, e.g. about 60-70%) may be produced in a simple energy-efficient manner. Black liquor is treated to recover chemicals, and the chemicals are dissolved to produce green liquor, which is clarified, as is conventional. The temperature of a first portion of the green liquor is decreased to effect crystallization of sodium carbonate in the green liquor by expanding the green liquor in at least two (and typically more than three) stages with vapor being produced during expansion. The sodium carbonate crystals produced are separated from the first portion of green liquor to produce a green liquor with high sulphidity (greater than about 40%) and this high sulphidity liquor may be heated by bringing it into direct heat exchange relationship with at least part of the expansion vapor (in a number of different stages).

Abstract: A process for disaggregating boronatrocalcite ore (Ulexite) in an alkaline aqueous medium for the production of sodium borate and calcium borate, characterized in that boronatrocalcite is dispersed in alkaline mother liquor having a H.sub.3 BO.sub.3 /Na.sub.2 O weight ratio ranging from 1.8 to 2.7, at a temperature of 120.degree.-200.degree. C. under autogenous pressure of 2-16 bars, under intense stirring.

Abstract: A method for enhancing recovery of sodium carbonate from sodium carbonate solutions which contain sodium chloride. Anhydrous sodium carbonate is recovered in good yields from aqueous sodium carbonate solutions containing sodium chloride by evaporative crystallization at superatmospheric pressure and at a temperature of at least about 120.degree. C.

Abstract: A thick suspension of sodium carbonate anhydride is obtained by countercurrent contacting of a high pressure steam and a suspension of sodium bicarbonate or sodium sesquicarbonate in a concentrated solution of sodium carbonate. The decomposition reaction is promoted to near completion by maintaining the reaction temperature above 150.degree. C. to realize a high HCO.sub.3.sup.- ion concentration in the solution. The sodium carbonate anhydride suspension is cooled to cause transition of the anhydride to the monohydrate, followed by the separation of the crystalline monohydrate from the mother liquor. Calcination of this monohydrate gives a dense soda ash featuring a high purity and a uniform particle size, while the mother liquor is recycled for the preparation of the sodium bicarbonate suspension.

Abstract: A process for separating and recovering metal values and salts from brine, such as brine produced from a subterranean geothermal reservoir, in which the brine is pressurized to above the bubble point pressure and thereafter a precipitating agent, such as a soluble sulfide, is added to the brine to form insoluble metal sulfide precipitates. The precipitates are separated from the brine while maintaining the brine at a pressure above the bubble point pressure, and the hot brine is subsequently utilized to derive energy therefrom. The brine effluent after such energy derivation and the precipitate are optionally processed to primarily recover saleable salts and metal values, respectively.

Abstract: A process for preparing from aqueous NaCl brine containing appreciable quantities of dissolved calcium sulfate high purity dendritic salt, characterized by an exceptionally low calcium sulfate content. The process is carried out by a "feed and bleed" procedure comprising admixing an alkali metal polyphosphate with said brine to increase the supersaturation of calcium sulfate therein, feeding the brine containing this additive into an evaporating and crystallizing chamber, evaporating the brine at an elevated temperature and reduced pressure to cause crystallization of pure salt and concomitantly bleeding brine from the chamber, the rate of feed of the brine to the chamber and the rate of bleed of brine from the chamber being such as to maintain the calcium sulfate in the dissolved state and prevent its precipitation with the salt.

Abstract: A method for the reprocessing of cell liquor from diaphragm cell electrolysis plants that operate on potassium chloride brine. The cell liquor is contacted with an SO.sub.2 -bearing gas, and the effluent solution is oxidized with an oxygen-bearing gas, then a definite quantity of KCl is added to said oxidized solution, and this solution is subjected to a filtration and precipitation step, and finally it is then recycled as make-up brine to the electrolysis cell plant.