| 摘要 |
PURPOSE:To obtain uniform iron hydroxides being preferable for the raw material of ferrite and having high-purity by adding urea to the aq. soln. of iron salts of make a mixture, then by heating said mixture to carrying out the hydroxylation reaction of iron salts by means of ammonium hydroxide which is generated by hydrolysing urea. CONSTITUTION:Urea is added into the aq. soln. of iron salts such as iron chlo ride, iron sulfate, etc., dissolved, heated and stirred. The desired iron hydroxides are obtained by carrying out the hydroxylation reaction of iron salts by means of ammonium hydroxide generated by hydrolyzing urea as shown by the chemi cal equations I and II. Since the reactions shown by the chemical equations I and II are carried out gradually and uniformly in the whole reaction soln., iron hydroxides having uniform shape and dimension can be produced with good reproducibility by controlling the concentration of the iron salts, coexisting impurities, pH in case of forming iron hydroxides, heating temp., heating period, etc.
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