CONTINUOUS SODIUM PERCARBONATE PRODUCTION PROCESS, INSTALLATION FOR SODIUM PERCARBONATE PRODUCTION, AND DRY SODIUM PERCARBONATE

摘要

FIELD: inorganic compounds technology. SUBSTANCE: hydrogen peroxide, sodium carbonate, and aqueous medium are loaded into reaction vessel, at least part of sodium carbonate being loaded in solid state and at least part of sodium carbonate dissolved in mother solution. Sodium carbonate can be dissolved in mother solution so that concentration of sodium carbonate in solution were not higher than 95% of the saturation concentration. Prior to be loaded into dissolution reservoir, mother solution is cooled to temperature by at least 5 C lower than temperature in dissolution reservoir, which is varied between 15 and 35 C. Molar ratio H₂O₂/Na₂CO₃ is (0.8-1.2):1. Mother solution may further contain at least one hydrogen peroxide stabilizer, in particular sodium silicate, and polycarboxylate and/or polyphosphonate complexing agent. Reaction can be conducted in presence of crystalline-nature modifier, in particular alkali metal or ammonium salts, (meth)acrylic acid homo- or copolymer, and alkali metal phosphate. Installation contains reaction vessel provided with hydrogen peroxide-supply means and double sodium carbonate device intended for (i) preliminary dissolution of sodium carbonate in recycled mother solution and (ii) direct introduction of solid sodium carbonate. Dry sodium percarbonate shows average particle size 500-1200 mcm, moisture absorption no higher than 30 g/kg on storage for 24 h at 32 C and relative humidity 80%, apparent bulk density 800-1100 g/kg, and heat emission 3 mcW/h during 16 h at 40 C after 7- day storage. Product can be used for production of detergents, cleansing means, and bleachers. EFFECT: optimized process parameters. 33 cl, 2 dwg, 13 ex