Separation and recovery of rare earth elements from raw materials containing rare earth elements and iron

摘要

PURPOSE:To easily separate rare earth elements from a raw material contg. rare earth elements and iron at a high yield by dissolving the raw material into the aqueous soln. of sulfuric acid with nitric acid, adding alcohol to the soln. and selectively crystallizing out the sulfate of rare earth elements. CONSTITUTION:At the time of separating Nd, e.g. from Nd-Fe-B magnetic alloy powder, the powder is dissolved into the aqueous soln. of sulfuric acid and is thereafter admixed with the aqueous soln. of nitric acid while heating is executed to about 100 to 120 deg.C to convert Fe2+ into Fe3+. Next, the soln. is admixed with alcohol (having a relatively low b.p. such as ethanol and methanol) by 25 to 40wt.% of the weight of the soln. to crystallize out the sulfate of Nd in the temp. range of about 20 to 60 deg.C, which is then separated and recovered. In this way, rare earth elements can surely be separated and recovered with good operability by using an inexpensive reagent.