Group separation of trace rare-earth elements by countercurrent chromatography for their determination in high-purity calcium chloride

2001 ◽  
Vol 370 (8) ◽  
pp. 1109-1113 ◽  
Author(s):  
S. N. Ignatova ◽  
T. A. Maryutina ◽  
B. Ya. Spivakov ◽  
V. K. Karandashev
Keyword(s):  
Rare Earth ◽  
Rare Earth Elements ◽  
Calcium Chloride ◽  
High Purity ◽  
Countercurrent Chromatography ◽  
Group Separation

LPE growth of InGaAsP:InP high purity layers using rare earth elements

1990 ◽  
Vol 13 (1-2) ◽  
pp. 37-41
Author(s):  
R K Sarin ◽  
A T Gorelenok ◽  
V I Korolkov
Keyword(s):  
Rare Earth ◽  
Rare Earth Elements ◽  
High Purity

scholarly journals Resource Recovery of Waste Nd–Fe–B Scrap: Effective Separation of Fe as High-Purity Hematite Nanoparticles

2020 ◽  
Vol 12 (7) ◽  
pp. 2624
Author(s):  
Suiyi Zhu ◽  
Ting Su ◽  
Yu Chen ◽  
Zhan Qu ◽  
Xue Lin ◽  
...  
Keyword(s):  
Rare Earth ◽  
Nitric Acid ◽  
Rare Earth Elements ◽  
High Purity ◽  
Hydrothermal Route ◽  
Acid Dissolution ◽  
Hematite Nanoparticles ◽  
Pharmaceutical Ingredients ◽  
Effective Separation ◽  
Fe Impurity

Recycling rare-earth elements from Nd magnet scrap (Nd–Fe–B scrap) is a highly economical process; however, its efficiency is low due to large portions of Fe impurity. In this study, the effective separation of Fe impurity from scrap was performed through an integrated nitric acid dissolution and hydrothermal route with the addition of fructose. Results showed that more than 99% of the scrap was dissolved in nitric acid, and after three dilutions that the Nd, Pr, Dy and Fe concentrations in the diluted acid were 9.01, 2.11, 0.37 and 10.53 g/L, respectively. After the acid was hydrothermally treated in the absence of fructose, only 81.8% Fe was removed as irregular hematite aggregates, whilst more than 98% rare-earth elements were retained. By adding fructose at an Mfructose/Mnitrate ratio of 0.2, 99.94% Fe was precipitated as hematite nanoparticles, and the loss of rare-earth elements was <2%. In the treated acid, the residual Fe was 6.3 mg/L, whilst Nd, Pr and Dy were 8.84, 2.07 and 0.36 g/L, respectively. Such composition was conducive for further recycling of high-purity rare-earth products with low Fe impurity. The generated hematite nanoparticles contained 67.92% Fe with a rare-earth element content of <1%. This value meets the general standard for commercial hematite active pharmaceutical ingredients. In this manner, a green process was developed for separating Fe from Nd–Fe–B scrap without producing secondary waste.

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