Abstract: An aqueous sodium hypochlorite solution (3) is added, in a quantity which is deficient relative to that required to decompose the entire amount of calcium chloride, to an aqueous calcium chloride solution (2), the sodium chloride which precipitates (6) is separated and the remaining amount (9) of the sodium hypochlorite solution is then added to the resulting mother-liquor (7). Single FIGURE.

Abstract: Process and plant for the preparation of concentrated aqueous solutions of alkali metal hypochlorite, in which a suspension of crystals of alkali metal chloride in an aqueous solution of alkali metal hypochlorite is circulated from bottom to top in a tubular reaction chamber located in an enclosure, chlorine and an aqueous solution of alkali metal hydroxide are reacted in this suspension in the chamber, a fraction of the resulting suspension leaving the open upper part of the chamber, overflows out of the enclosure and is filtered to separate the crystals, and the remaining fraction of the suspension is kept in the enclosure where it is recycled to the base of the reaction chamber.

Abstract: Method for the manufacture of crystals of sodium carbonate monohydrate, comprises crystallizing sodium carbonate monohydrate from a carbonated aqueous liquor of sodium hydroxide above 35.degree. C. and separating the crystals of sodium carbonate monohydrate and a mother liquor. The sodium carbonate monohydrate is crystallized on crystalline seeds of sodium carbonate monohydrate obtained by evaporation, between 35.degree. and 107.5.degree. C., of a solution of sodium carbonate free from sodium hydroxide.

Abstract: A method for the recovery of ammonia from liquor from the filters of ammonia-soda plants, which contains free ammonia and ammonium chloride. In this method the liquor is heated to release the free ammonia, and the remaining liquor is then treated successively in a prelimer with lime in an amount insufficient to decompose the whole part of the ammonium chloride and in a still with steam and an alkali metal hydroxide in an amount sufficient to decompose the remaining part of ammonium chloride.

Abstract: Manufacture of chlorine and sodium carbonate using a combination of electrolysis of an aqueous solution of sodium chloride in a diaphragm cell, carbonation of the caustic brine leaving the cell, and the ammonia-soda method of making sodium carbonate. An aqueous solution of sodium chloride is electrolyzed in at least one diaphragm cell to form a caustic brine. The caustic brine leaving the cell is carbonated and further treated. This is first done in a soda plant without ammonia by treating the caustic brine in at least one monocarbonation scrubber by reacting the caustic brine with a gas having a low carbon dioxide content without causing bicarbonate precipitation in the monocarbonation scrubber to form a monocarbonated caustic brine, and treating the monocarbonated caustic brine in at least one bicarbonation column by reacting at least part of it with gas rich in carbon dioxide to precipitate sodium bicarbonate in the bicarbonation column and to form a mother liquor.