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公开(公告)号：US20230265541A1
公开(公告)日：2023-08-24
申请号：US18132979
申请日：2023-04-11
Applicant: BEIJING UNIVERSITY OF TECHNOLOGY
Inventor： Qijun Zhang , Yufeng Wu , Minwei Song
Abstract: The invention relates to a method of recovering rare-earth in cerium-based rare-earth polishing powder waste by two-step acid leaching gradient separation, characterized by: firstly, using a one-step acid leaching treatment on cerium-based rare-earth polishing powder waste to obtain a rare-earth leaching liquor which is rich in La; secondly, the leaching residue is then processed through alkali activation and transformation process, water washing and impurity removal process, secondary acid leaching process, filtration, and recovery to obtain high purity CeO2 products; thirdly, the acid leaching liquor obtained through first acid leaching and second acid leaching process is finally precipitated by oxalic acid, filtered and calcined at high temperature to obtain rare-earth oxide mixed products, which achieves the gradient separation and recovery of rare-earths from cerium-based rare-earth polishing powder waste. The total recovery efficiency of rare-earth of this invention reaches 97% or higher, with high efficiency of rare-earth recovery, wide process applicability, and low environmental pollution.
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公开(公告)号：US20230286822A1
公开(公告)日：2023-09-14
申请号：US18139844
申请日：2023-04-26
Applicant: BEIJING UNIVERSITY OF TECHNOLOGY
Inventor： Yufeng Wu , Minwei Song , Qijun Zhang
CPC classification number: C01F17/241 , C09K3/1418 , C09G1/02 , C22B59/00 , C22B7/007 , C22B1/005
Abstract: The invention relates to a method of separating and extracting rare-earths from rare-earth polishing powder waste and regenerating rare-earth polishing powder, which is characterized by: firstly, process the waste powder with first acid leaching, alkali roasting, and second acid leaching to separate and extract rare-earths from rare-earth polishing powder waste to obtain the leaching solution of rare-earth chloride; secondly, precipitate from the leaching solution with ammonia to remove impurities and hydrochloric acid solution to obtain the purified solution of rare-earth chloride; thirdly, co-precipitate from the solution acquired in the second step with hydrofluoric acid, ammonium bicarbonate, and dispersant to obtain the lanthanum cerium fluoro-carbonate; and finally, after drying, two-stage high-temperature calcination, and ball milling, the regenerated rare-earth polishing powder with decent polishing performance can be obtained. The total leaching efficiency of rare-earths in the rare-earth polishing powder waste of the present invention reaches more than 95%, and the total recovery efficiency of rare-earths reaches more than 93%, which realizes the efficient separation, extraction, and regeneration of rare-earths in the rare-earth polishing powder waste.
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公开(公告)号：US11753308B1
公开(公告)日：2023-09-12
申请号：US18139844
申请日：2023-04-26
Applicant: BEIJING UNIVERSITY OF TECHNOLOGY
Inventor： Yufeng Wu , Minwei Song , Qijun Zhang
CPC classification number: C01F17/241 , C09G1/02 , C09K3/1418 , C22B1/005 , C22B7/007 , C22B59/00
Abstract: The invention relates to a method of separating and extracting rare-earths from rare-earth polishing powder waste and regenerating rare-earth polishing powder, which is characterized by: firstly, process the waste powder with first acid leaching, alkali roasting, and second acid leaching to separate and extract rare-earths from rare-earth polishing powder waste to obtain the leaching solution of rare-earth chloride; secondly, precipitate from the leaching solution with ammonia to remove impurities and hydrochloric acid solution to obtain the purified solution of rare-earth chloride; thirdly, co-precipitate from the solution acquired in the second step with hydrofluoric acid, ammonium bicarbonate, and dispersant to obtain the lanthanum cerium fluoro-carbonate; and finally, after drying, two-stage high-temperature calcination, and ball milling, the regenerated rare-earth polishing powder with decent polishing performance can be obtained. The total leaching efficiency of rare-earths in the rare-earth polishing powder waste of the present invention reaches more than 95%, and the total recovery efficiency of rare-earths reaches more than 93%, which realizes the efficient separation, extraction, and regeneration of rare-earths in the rare-earth polishing powder waste.
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