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Record W4407384239 · doi:10.1002/cjce.25639

Selective leaching of neodymium from <scp>NdFeB</scp> carbonyl residues using hydrochloric acid

2025· article· en· W4407384239 on OpenAlex
Yida Li, Liping Dong, Bo Li, Pei Shi, Yun Li, Hao Yang, Zhongqi Ren, Zhiyong Zhou

Why this work is in the frame

A frame that forgets how it found something cannot be audited. These are the routes that admitted this work.

venuePublished in a venue whose home country is Canada.
no affNo Canadian affiliation: this work is invisible to an affiliation-only frame.
No Canadian affiliation. An affiliation-only frame, the usual design, would never have seen this work. It is one of the works that make the case for inverting the frame.

Bibliographic record

VenueThe Canadian Journal of Chemical Engineering · 2025
Typearticle
Languageen
FieldEngineering
TopicExtraction and Separation Processes
Canadian institutionsnot available
FundersNational Natural Science Foundation of China
KeywordsHydrochloric acidLeaching (pedology)Oxalic acidChemistryNeodymium magnetNeodymiumNuclear chemistryInorganic chemistry

Abstract

fetched live from OpenAlex

Abstract An efficient recovery method of valuable metals from NdFeB carbonyl residues with ultra‐low rare earth content was developed. Selective leaching of NdFeB carbonyl residues was carried out using hydrochloric acid, and the leaching conditions were investigated and optimized. The experimental results showed that the optimum operating conditions for hydrochloric acid leaching were as follows: concentration of 2.5 mol/L, leaching temperature of 60°C, leaching time of 0.5 h, leaching solid–liquid ratio of 1:2 (g/mL), and rotational speed of 600 rpm during the leaching process. At this time, the leaching rate of neodymium in the carbonyl residues of NdFeB was 46.67%, and the leaching rate of iron was around 0.01%. The use of hydrochloric acid leaching had a high selectivity for Nd and Fe in the carbonyl residues. Neutralization and removal of impurities from the leach solution was carried out using NaOH and the pH of the leach solution was set to 4.0, at which time the removal of Fe was 76.52%. The neodymium in the leach solution was directly recovered by oxalic acid precipitation method, and the dosage of oxalic acid was 1.2 times of the theoretical dosage of oxalic acid, at which the recovery rate of neodymium was 96.38%, and the purity of the rare earth oxides obtained was 99.95%.

Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.

Full frame distilled prediction

Teacher imitation

Not calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.

metaresearch head score (Codex)0.000
metaresearch head score (Gemma)0.000
Version: codex-gemma-dda1882f352aValidation status: machine_predicted_unvalidated
Candidate categoriesnone
Consensus categoriesnone
DomainCandidate signal: none · Consensus signal: none
Study designCandidate signal: Bench or experimental · Consensus signal: Bench or experimental
GenreCandidate signal: Empirical · Consensus signal: Empirical
Teacher disagreement score0.185
Threshold uncertainty score0.527

Codex and Gemma teacher scores by category

CategoryCodexGemma
Metaresearch0.0000.000
Meta-epidemiology (narrow)0.0000.000
Meta-epidemiology (broad)0.0000.000
Bibliometrics0.0000.000
Science and technology studies0.0000.000
Scholarly communication0.0000.000
Open science0.0000.000
Research integrity0.0000.001
Insufficient payload (model declined to judge)0.0000.000

Machine scores (provisional)

The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.

Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.

Opus teacher head0.008
GPT teacher head0.209
Teacher spread0.201 · how far apart the two teachers sit on this one work
Validation statusscore_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from it