SELECTIVE EXTRACTION OF SALTS FROM MIXED BRINE

摘要

FIELD: chemistry.SUBSTANCE: invention can be used in chemical industry. A method of extracting sodium chloride and sodium carbonate decahydrate from concentrated brine, which contains sodium chloride and sodium carbonate, includes feeding concentrated brine into an evaporative crystalliser, heating to 50°C or higher and further concentration of the brine to obtain sodium chloride crystals. The starting concentrated brine is formed from product water which is separated from coal bed gas during gas extraction and subjected to preliminary concentration. Sodium chloride crystals are separated from the brine. The obtained concentrated brine is fed into a cooling crystalliser and the brine is cooled to temperature of 30°C or lower. The brine is then concentrated to obtain sodium carbonate decahydrate crystals which are separated from the brine.EFFECT: invention reduces the amount of reagents and wastes when producing sodium chloride and sodium carbonate decahydrate from mixed brine and avoids the use of evaporation ponds.26 cl, 7 dwg