| 摘要 |
<p>PROBLEM TO BE SOLVED: To produce aluminum sulfate while reducing the water content of amorphous aluminum hydroxide sludge without changing its properties. SOLUTION: In this production, amorphous aluminum hydroxide is finely pulverized, and thereafter, the pulverized aluminum hydroxide is dispersed into a hot air stream to instantaneously evaporate water in the pulverized aluminum hydroxide. At this time, the temp. rise of the aluminum hydroxide is controlled so as to be within the range of 40 to 100 deg.C to reduce its water content to the same level as that of crystalline aluminum hydroxide while retaining the pulverized aluminum hydroxide in the amorphous state. Then, the fine-powdery dry amorphous aluminum hydroxide is allowed to react with sulfuric acid of an amount smaller than its neutralization equivalent to the amount of aluminum component in the amorphous aluminum hydroxide, to produce the objective aluminum sulfate.</p> |
