Open AccessProcess Flowsheet Development for Separation of Sm, Co, Cu, and Fe from Magnet Scrap
Author(s) -
Alok Kumar Nayak,
Binapani Behera,
K. Sarangi,
Malay Kumar Ghosh,
Suddhasatwa Basu
Publication year - 2020
Publication title -
acs omega
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.779
H-Index - 40
ISSN - 2470-1343
DOI - 10.1021/acsomega.0c04132
Subject(s) - scrap , calcination , leaching (pedology) , hydrometallurgy , magnet , chemistry , magnetic separation , materials science , factorial experiment , nuclear chemistry , metallurgy , extraction (chemistry) , separation process , copper , chromatography , mathematics , catalysis , environmental science , biochemistry , physics , statistics , quantum mechanics , soil science , soil water
A complete process flowsheet to recover metal values from Sm 2 Co 17 -type magnet scrap was investigated. The magnet scrap was leached in chloride medium at pulp density of 2% (w/v) under the optimum conditions of 15% (v/v) HCl and 5% (v/v) H 2 O 2 at 70 °C for 3 h, which yielded 98.5% Sm and 99% Co extractions. The full factorial Design of Experiment technique was adopted for the optimization of leaching conditions. Sm was selectively separated from the leach liquor as precipitated double salt using Na 2 SO 4 . The precipitated double sulfate was later converted to Sm-oxalate, which was subsequently calcined to produce pure Sm 2 O 3 . Following Sm separation, Fe was removed through precipitation by raising the pH to 3.0. For Cu and Co recovery, solvent extraction techniques using LIX 84I and Na-CYANEX 272, respectively, were followed. The McCabe-Thiele diagrams for extraction as well as stripping were presented for both Cu and Co.