Alkali roasting secondary recovery process for rare earth waste residues

The invention discloses a rare earth waste residue alkali roasting secondary recovery process which comprises the following steps: S1, mixing and roasting rare earth waste residue and excessive sodium hydroxide solid, so that rare earth elements exist in the form of rare earth oxide; s2, washing a product obtained by roasting for multiple times under an alkaline condition to remove phosphorus and fluorine, so as to obtain an insoluble substance and a washing solution; s3, the insoluble substances are subjected to acid leaching treatment, solid residues are filtered out, and rare earth feed liquid is obtained; and S4, the rare earth feed liquid serves as rare earth ore to be subjected to secondary extraction. According to the method, the rare earth metal in the rare earth waste residues can be effectively subjected to secondary recovery, and full utilization of resources is achieved. 本发明公开了一种稀土废渣碱焙烧二次回收工艺，包括以下步骤：S1、将稀土废渣与过量氢氧化钠固体混合焙烧，使稀土元素以稀土氧化物的形式存在；S2、将焙烧获得的产物在碱性条件下多次水洗，以除磷、除氟，得到不溶物及水洗液；S3、将不溶物进行酸浸处理，过滤掉固体渣，