A process for the production of alkali metal hypophosphites

High purity alkali metal hypophosphites are produced in high efficiency by a simple step of using no separating agents other than white phosphorus, alkali metal hydroxides and water as reaction raw materials, resulting in no need of a complicated procedure for removing impurities. The process compri...

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Bibliographic Details
Main Authors TAKIKAWA, YOSHIHIRO, KANAYAMA, ATSUSHI, SHIBATA, KATSUTOSHI, ODA, MASAOKI, TAKEUTI, TAKASHI
Format Patent
LanguageEnglish
French
German
Published 12.04.1995
Edition5
Subjects
CHEMISTRY
COMPOUNDS THEREOF
INORGANIC CHEMISTRY
METALLURGY
NON-METALLIC ELEMENTS
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Summary:High purity alkali metal hypophosphites are produced in high efficiency by a simple step of using no separating agents other than white phosphorus, alkali metal hydroxides and water as reaction raw materials, resulting in no need of a complicated procedure for removing impurities. The process comprises reacting white phosphorus and an alkali metal hydroxide in an aqueous medium to prepare a crude solution of an alkali metal hypophosphite containing the phosphite, feeding the crude solution to a desalting compartment of an electrodialytic cell in which cation exchange membranes and univalent anion permeable membranes are alternately arranged between a cathode and an anode to form at least one pair of a desalting compartment and a concentrating compartment, so as to separate the hypophosphite from the crude solution, during which a dilute solution of an alkali hypophosphite is fed to the concentrating compartment, subjecting them to electrodialysis, withdrawing the purified solution of the alkali metal hypophosphite from the concentrating compartment and concentrating and crystallizing the thus purified solution.
Bibliography:Application Number: EP19910304802