in diethyl ether pptn. of H3PO4*H2O from soln. of H3PO4 in aq. ether;;

in water addition of calculated amount P2O5 to 64 percent H3PO4 soln. there is heating of liquid, hot filtering off and allowing to crystallize in refrigerator over P2O5, crystallization after 2 to 14 days, crystals are pressed off on clay;;