摘要
A new method of producing tungstic acid with a yield over 98% at room temperature and low acidity is advanced and referred to as Complcx -Homogeneous Precipitation Method. If combined with the treatment of activated charcoal in recovering the remnant tungsten left in the filter liquor, a perfect closed technological process can be obtained. The key to this method is to prevent the formation of pseudo-metatungstatc during scdium rungstate being acidified directly with the aid of the complexing-protecting agent H2O2, The perexo-mtermediate, which was prepated and identified as dipcroxytetratnngstate by IR and Raman analysis by comparison with diperorytetramolybdate, can be decomposed by SO2 tapidly and quantitatively. The tungstic acid precipitate can be filtered and washed easily. The related mechanisin is studied.
A new method of producing tungstic acid with a yield over 98% at room temperature and low acidity is advanced and referred to as Complcx -Homogeneous Precipitation Method. If combined with the treatment of activated charcoal in recovering the remnant tungsten left in the filter liquor, a perfect closed technological process can be obtained. The key to this method is to prevent the formation of pseudo-metatungstatc during scdium rungstate being acidified directly with the aid of the complexing-protecting agent H2O2, The perexo-mtermediate, which was prepated and identified as dipcroxytetratnngstate by IR and Raman analysis by comparison with diperorytetramolybdate, can be decomposed by SO2 tapidly and quantitatively. The tungstic acid precipitate can be filtered and washed easily. The related mechanisin is studied.
