| 摘要 |
PROBLEM TO BE SOLVED: To provide a harmful material adsorbent to be for improving soil and water quality by satisfactorily utilizing the features of a rare earth compound and suppressing elution of lead from the rare earth compound even though the compound of the rare earth metal is used as a main agent, and a method for preparing the same. SOLUTION: In this method for preparing the harmful material adsorbent, the harmful material adsorbent comprising, as a main agent, grain and powder of a rare earth compound having a lead content of not more than 0.08 wt%, and a naturally occurring mineral containing the rare earth compound and lead are ground, and the resultant powder is washed with water containing sulfuric acid ions to separate and remove lead, whereby a purified rare earth compound having a lead content of not more than 0.08 wt% is obtained. COPYRIGHT: (C)2004,JPO
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