| 摘要 |
PURPOSE:To precipitate Mo as calcium molybdate and to separate it by heating a Glauber's salt aq. soln. contg. Mo and regulating the aq. soln. to the specified pH value and thereafter adding Ca salt thereto. CONSTITUTION:Alkali such as NaOH is added to a Glauber's salt (Na2SO4) aq. soln. contg. Mo as the impurities and the pH value is regulated to >=7.0 preferably 8-9. After heating this aq. soln. at >=40 deg.C, at least one kind of Ca salt such as Ca(OH)2, CaCO3, CaCl2, Ca(NO3)2 and CaSO4 is added so that Ca/Mo is regulated to >=1 molar ratio. Mo contained in the liquid is deposited and precipitated as calcium molybdate, and high-purity Na2SO4 can be easily and inexpensively recovered by filtering and removing calcium molybdate.
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