Prussian blue prodn by oxidn of berlin white - obtd by simultaneous mixing of ferrocyanide, ferrous salt and potassium salt

摘要

In the prodn of Prussi n blue by reacting Ca2Fe(CN)6 or Na4Fe(CN)6 with a Fe(II) salt at pH 7; converting the resultant acid Fe salt of H4Fe(CN)6 into Berlin white with org. or inorg. K salt at pH 1-6; and oxidn of the Berlin white to Prussian blue, as in DT 2308122, the Ca2Fe(CN)6 or Na4Fe(CN)6; Fe(II) salt and K salt are present simultaneous in the reactor and reaction to Berlin white takes place initially at 20-60, pref. ca 40 degrees C and can then be completed rapidly by heating to boiling. It is pref. to use a 1-10 mole % escess of the ferrocyanide and/or Fe(II) salt or 2-6 mole % excess of the Fe(II) salt over the stoichmetric amt.