| 摘要 |
<p>PURPOSE:To advantageously recover rare earth metallic elements from the remaining water soln. by melting rare earth metal contg. a Co salt into a suitable acid, working a sulfurizing agent thereon to convert the Co salt into CoS and precipitating and separating it. CONSTITUTION:The material such as target scrap wood for a magnetooptical disk consisting of the alloy between rare earth metal such as Dy, Cd and Nd and Co is melted into an acid water soln. of concd. hydrochloric acid, etc., to prepare the water soln. in which the salt of Co is present together with the salt of rare earth metal. A sulfurizing agent such as Na2S is added to the water soln. at the rate of the stoichiometric amounts or above to bring them into reaction with and black color of CoS is precipitated. The precipitation is separated away. The remaining water soln. contg. the rare earth metallic salt is subjected to well-known wet treatment to precipitate and separate the rare earth metal in the form of a compound or a salt; it is thereafter refined into the rare earth elements in the form of metal to recover the rare earth metal.</p> |
