Continuous crystallization process of sodium hypophosphite

• Main Authors: CHENG ZHONGYUAN, KONG HONGYU, SONG YUCHEN, TONG HUANGHAI, FU XIULIN, ZHANG YUANYUAN
• Format: Patent
• Language: Chinese; English
• Published: 19.09.2023
• Subjects: CHEMISTRY; COMPOUNDS THEREOF; INORGANIC CHEMISTRY; METALLURGY; NON-METALLIC ELEMENTS

The invention relates to the technical field of chemical raw material preparation, in particular to a sodium hypophosphite continuous crystallization process. The method comprises the following steps: adding sodium carbonate, calcium oxide and water into a reaction kettle, preheating, collecting gas, cooling, and adding white phosphorus into the reaction kettle; adding an auxiliary agent into the reaction kettle, introducing the collected gas into the reaction kettle, and filtering the solution in the reaction kettle to obtain a crude solution; carrying out primary concentration on the crude liquid, filtering out precipitates again, concentrating again, crystallizing, and carrying out centrifugal filtration to obtain crude crystals; and washing the crude crystal with deionized water, dissolving the crude crystal in double distilled water, filtering through a membrane, and recrystallizing to obtain the sodium hypophosphite crystal. The discharged carbon dioxide gas is utilized to ensure that residual calcium h