METHOD FOR ISOLATION OF TECHNICAL SODIUM FORMATE Russian patent published in 2004 - IPC

FIELD: organic chemistry, chemical technology. SUBSTANCE: invention relates to the improved method for preparing technical sodium formate from sodium formate and sodium chloride an aqueous solution formed in the process of producing chloroform by cleaving method of technical formal with sodium hydroxide an aqueous solution. Method involves evaporation, crystallization and drying being evaporation of sodium formate and sodium chloride an aqueous solution is carried out at least for two stages. The first evaporation stage is combined with sodium chloride crystallization stage that is carried out up to content of sodium formate in solution 50-60 wt.-%. Then sodium chloride crystals are separated from sodium formate crystals by settling and the following washing out precipitate of sodium chloride crystals with the parent an aqueous solution containing sodium formate and sodium chloride and recovering washing out solution to the first stage of evaporation. Then evaporation and drying are finished to obtain the solid product. Method provides the enhancement of quality of the end product, for example, by sodium chloride content in it from 20-30% to 7.3-8.6%. Prepared sodium formate can be used as an accelerating agent for concrete hardening. EFFECT: improved isolation method. 1 tbl, 1 dwg