CMMMech
CMMMech > Primary resource > Eudialyte concentrate

Eudialyte concentrate primary resource

A beneficiated geological feed represented by the TANBREEZ concentrate from southern Greenland characterized by Ma and colleagues (2019). The source describes crushing followed by partly magnetic selection; this is an upgraded mixed mineral concentrate, distinct from the uncharacterized crushed eudialyte ore in Hunter's 2020 thesis, a formal eudialyte mineral species or group, elemental zirconium and recovered rare-earth products. Table I reports 1.60 wt% total rare earth elements and 6.46 wt% Zr in the laboratory feed. QEMSCAN assigns 67.05% of the material to eudialyte, alongside amphibole, nepheline, feldspar and other phases; this classification does not establish a pure species or a universal commercial concentrate specification. The source acknowledges the Geological Survey of Finland as concentrate supplier. No criticality designation is inherited from constituent elements.

Microbial & Biochemical Mechanisms (1)

Chemical digestion and precipitation of a mixed rare-earth product

recovery

Concentrated hydrochloric acid digestion followed by water leaching mobilized rare earths from the mixed concentrate. Calcium carbonate neutralization removed part of the co-leached impurities, followed by sodium carbonate precipitation and a further dissolution and reprecipitation step to obtain a mixed rare-earth-bearing product. This is a chemical process with laboratory optimization and a reported 36 kg pilot test, not microbial extraction or evidence of industrial operation. Zirconium was treated as an impurity in this REE process; the study does not demonstrate isolated zirconium, hafnium or niobium products.

Experimental Context & Analytical Limits:
Laboratory runs used 500 g concentrate and 10 M HCl. The selected HCl:concentrate ratio was 1.25 L/kg with 40 minutes dry digestion, followed by water at 2 L/kg. Digestion had no external heating but reached 70-80 degrees C through an exothermic reaction; only the subsequent water leaching was at approximately 20-25 degrees C. Laboratory parameter comparisons held water leaching at one hour; the pilot selected 30 minutes after a separate time series. Figures 10-14 compare chemical operating conditions, not inoculated and abiotic arms. Replicate numbers and statistical uncertainty are not supplied for these plotted comparisons. The pilot used two 40 L digestion reactors, with 6 kg concentrate per reactor per charge, totaling 36 kg in the described test. Alternating acid and concentrate additions avoided the agglomeration or silica gel observed when either was charged first. Neutralization to about pH 4 with calcium carbonate preceded a single combined filtration in the pilot, whereas the laboratory flow sheet has separate residue separations. Sodium carbonate then raised the enriched liquor to pH 5.7. Details and reagent quantities for the final dissolution and reprecipitation are incomplete, and the final product mass is not reported.
Curated Evidence Points:
Support Source: ma2019
Methods, Table I and Figures 1-4 establish a characterized, beneficiated, multiphase feed. XRF, dissolution followed by ICP-MS and QEMSCAN provide chemical and mineralogical context. The source's generic eudialyte classification does not resolve an IMA species for every grain. Extraction from this mixture is not a phase-specific dissolution fraction.
Support Source: ma2019
Figures 10-13 report about 88.8% solution extraction at the selected laboratory conditions; this is distinct from a final product yield. Figure 14 reports Zr, Al and Fe removal of 99.1%, 90.0% and 53.1% at about pH 4, accompanied by 2.1% REE loss. Increasing neutralization further also increased REE loss. The chemical conditions, co-leaching and losses are retained; there is no matched microbial comparison in this paper.
Partial Source: ma2019
Sections 3.2 and 4.2, Table III and Figures 7-9 and 15-17 document actual pilot equipment and a 36 kg upscaling test. Figure 16 reports principal liquid and residue flows but not a complete element-resolved balance through the final product. Residual eudialyte and operational mixing problems remain; apparatus capacity is not evidence of continuous commercial throughput. The absence of external digestion heating is not an energy or environmental life-cycle assessment.
Partial Source: ma2019
Page 11 reports greater than 98.8% REE precipitation from the enriched liquor and 85.5% overall REE recovery to the final product, on different process denominators. Figure 18 shows the collected product. The approximately 30 wt% REE content is a mixed elemental grade, not 30% or 100% phase purity or an isolated single-element yield. Table IV reports TREE 29.95 wt%, while its individually listed rare-earth values sum to 30.40 wt%; this inconsistency is unresolved. Al and Ca remain at 3.31 and 4.18 wt%, respectively. No product diffraction or complete final-product mass balance is supplied, so the source-assigned carbonate identity and reported overall yield are not independently reconstructed here.
Context_only Source: ma2019
The article explicitly builds on the same group's earlier parameter modeling and digestion work. Those cited studies are not counted as independent replications of this pilot. Proposed subsequent solvent extraction and the Figure 16 residue route toward Nb, Zr and Hf extraction are downstream plans, not demonstrated products in the reviewed experiment.

Sources & References

  1. ma2019: Ma Y, Stopic S and Friedrich B (2019). Hydrometallurgical Treatment of an Eudialyte Concentrate for Preparation of Rare Earth Carbonate. Johnson Matthey Technology Review 63(1):2-13. DOI 10.1595/205651318X15270000571362. Complete original twelve-page article inspected, including Figures 1-18 and Tables I-IV. Feed characterization: pp.3-5; laboratory and pilot procedures: pp.6-10; product and limitations: pp.10-12.
    https://doi.org/10.1595/205651318X15270000571362 (accessed 2026-10-12)
  2. rwth_metadata: RWTH Publications record 758718, institutional bibliographic confirmation of Ma, Stopic and Friedrich's article and repository DOI 10.18154/RWTH-2019-03094. The record reports online availability on 4 December 2018, while the journal issue and publisher date are January 2019; these are not separate experiments. The local original PDF was acquired from an indexed open-article mirror after direct repository and publisher downloads failed content checks.
    https://publications.rwth-aachen.de/record/758718 (accessed 2026-10-12)

Curation History

Timestamp Curator Action Summary
2026-10-12T09:56:19Z codex (GPT-6) CREATE Added a distinct characterized concentrate with chemical laboratory and pilot recovery evidence, preserving feed, temperature, product grade, source-total and mass-balance limitations.

Record source: data/records/eudialyte-concentrate.yaml