METHOD FOR SEPARATING RARE EARTH ELEMENTS FROM OPTICAL GLASS WASTE

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The present invention addresses the problem of separating with good efficiency the rare earths of La and Gd from optical glass waste. Carbon is added to pulverized optical glass waste and the mixture is subjected to reduction roasting in a nonoxidizing atmosphere in order to reduce the zinc oxide to zinc, and the zinc is selectively evaporated and removed. After the rare earth elements remaining in the roasting residue are eluted with hydrochloric acid or nitric acid, the Gd is extracted into the organic phase under acidic conditions at a pH of 2 or less using the extractant PC-88A (Daihachi Chemical Industry Co., Ltd., brand name). The La remaining in the aqueous phase is extracted into the organic phase under acidic conditions at a pH of 3 to 4 using the extractant PC-88A (Daihachi Chemical Industry Co., Ltd., brand name).