| 摘要 |
<p>PROBLEM TO BE SOLVED: To economically dissolve Sc in an acid in a short time without requiring special conditions by using a concentrated material including Sc as a hydroxide or carbonate. SOLUTION: The production process of high purity scandium oxide from a concentrated material including Sc consists of 7 steps. The first step to dissolve the material makes the whole process easy. Namely, in the step to dissolve the concentrated material in an acid soln. to prepare a soln. containing Sc, no special conditions for dissolution is required but the step can be carried out at normal temp. and normal pressure, or a higher dissolution efficiency can be obtd. at about 60 deg.C. The acid used can dissolve the Sc compd. as a sulfate, chloride or nitrate according to the kind of the acid in a short time. About one hour is enough as the dissolution time. The amt. of the acid used is controlled to obtain about 1.5 pH of the soln. Thus, >=90% of Sc can be easily dissolved under the conditions described above without causing filtering failure of the soln. and the residue, and liquid-solid separation can be easily performed.</p> |
