Causes of insufficient recovery of zirconium during acidic processing of lovozero eudialyte concentrate

Захаров, В. И.; Maiorov, D. V.; Alishkin, A. R.; Матвеев, В. А.

doi:10.3103/s1067821211050129

Cited by 26 publications

(19 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…A significant reduction in grain size (<10 µm) and different physical properties for the secondary Zr, Nb and REE phases may complicate liberation or chemical separation of the metals from the rock. The latter was observed during dissolution studies of EGM concentrates from the Lovozero complex (Russia), where the presence of secondary Na-Zr silicates resulted in low Zr recovery (Zakharov et al, 2011). As such, further studies on the mineralogical and physical properties of EGM alteration assemblages will be of great value for optimal beneficiation of the kakortokites and other EGM occurrences, and enhance their potential value as future ore deposits.…”

Section: Conclusion and Economic Implicationsmentioning

confidence: 93%

“…The latter account for most of the exploitable Zr, Nb and REE mineralization within the kakortokites, and can readily be extracted by magnetic separation (e.g. Bohse et al, 1971;Sørensen, 1992;Zakharov et al, 2011). Wide-spread alteration of EGM, however, led to the formation of complex pseudomorphic aggregates of secondary zirconosilicates, aluminosilicates and various Nb and REE phases.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Zirconosilicates in the kakortokites of the Ilímaussaq complex, South Greenland: Implications for fluid evolution and high-field-strength and rare-earth element mineralization in agpaitic systems

et al. 2016

View full text Add to dashboard Cite

The layered agpaitic nepheline syenites (kakortokites) of the Ilímaussaq complex, South Greenland, host voluminous accumulations of eudialyte-group minerals (EGM). These complex Na-Ca-zirconosilicates contain economically attractive levels of Zr, Nb and rare-earth elements (REE), but have commonly undergone extensive autometasomatic/hydrothermal alteration to a variety of secondary mineral assemblages. Three EGM alteration assemblages are recognized, characterized by the secondary zirconosilicates catapleiite, zircon and gittinsite. Theoretical petrogenetic grid models are constructed to assess mineral stabilities in terms of component activities in the late-stage melts and fluids. Widespread alteration of EGM to catapleiite records an overall increase in water activity, and reflects interaction of EGM with late-magmatic Na-, Cl- and F-rich aqueous fluids at the final stages of kakortokite crystallization. Localized alteration of EGM and catapleiite to the rare Ca-Zr silicate gittinsite, previously unidentified at Ilímaussaq, requires an increase in CaO activity and suggests post-magmatic interaction with Ca-Sr bearing aqueous fluids. The pseudomorphic replacement of EGM in the kakortokites was not found to be associated with significant remobilization of the primary Zr, Nb and REE mineralization, regardless of the high concentrations of potential transporting ligands such as F and Cl. We infer that the immobile behaviour essentially reflects the neutral to basic character of the late-magmatic fluids, in which REE-F compounds are insoluble and remobilization of REE as Cl complexes is inhibited by precipitation of nacareniobsite-(Ce) and various Ca-REE silicates. A subsequent decrease in F– activity would furthermore restrict the mobility of Zr as hydroxyl-fluoride complexes, and promote precipitation of the secondary zirconosilicates within the confines of the replaced EGM domains.

show abstract

Section: Conclusion and Economic Implicationsmentioning

confidence: 93%

Section: Introductionmentioning

confidence: 99%

Zirconosilicates in the kakortokites of the Ilímaussaq complex, South Greenland: Implications for fluid evolution and high-field-strength and rare-earth element mineralization in agpaitic systems

et al. 2016

View full text Add to dashboard Cite

show abstract

“…To date, acid decomposition of eudialyte has been extensively studied [7,8,[12][13][14]. Sulfuric acid (H 2 SO 4 ) is considered to be the best candidate for Zr leaching from the eudialyte or eudialyte residue after REE extraction.…”

Section: Introductionmentioning

confidence: 99%

Basic Sulfate Precipitation of Zirconium from Sulfuric Acid Leach Solution

Stopić

Wang

et al. 2020

Metals

View full text Add to dashboard Cite

H2SO4 was ensured to be the best candidate for Zr leaching from the eudialyte. The resulting sulfuric leach solution consisted of Zr(IV), Nb(V), Hf(IV), Al(III), and Fe(III). It was found that ordinary metal hydroxide precipitation was not feasible for obtaining a relatively pure product due to the co-precipitation of Al(III) and Fe(III). In this reported study, a basic zirconium sulfate precipitation method was investigated to recover Zr from a sulfuric acid leach solution of a eudialyte residue after rare earth elements extraction. Nb precipitated preferentially by adjusting the pH of the solution to around 1.0. After partial removal of SO42− by adding 120 g of CaCl2 per 1L solution, a basic zirconium sulfate precipitate was obtained by adjusting the pH to ~1.6 and maintaining the solution at 75 °C for 60 min. Under the optimum conditions, the loss of Zr during the SO42− removal step was only 0.11%, and the yield in the basic zirconium sulfate precipitation step was 96.18%. The precipitate contained 33.77% Zr and 0.59% Hf with low concentrations of Fe and Al. It was found that a high-quality product of ZrO2 could be obtained from the basic sulfate precipitate.

show abstract

“…It tends to be rich in zirconium, beryllium, cerium, niobium, barium, yttrium, and other rare earth elements [18,19]. The typical chemical formula of Eudialyte is Na 4 (Ca, Ce, Fe) 2 ZrSi 6 O 17 (OH, Cl) 2 , but the component of the mineral may be sometimes different because of the zeolite crystal structure, which possesses ion-exchange properties of eudialyte [20,21].…”

Section: Introductionmentioning

confidence: 99%

Neural Network Modeling for the Extraction of Rare Earth Elements from Eudialyte Concentrate by Dry Digestion and Leaching

Stopić

Gronen

et al. 2018

Metals

View full text Add to dashboard Cite

Eudialyte is a promising mineral for rare earth elements (REE) extraction due to its good solubility in acid, low radioactive, and relatively high content of REE. In this paper, a two stage hydrometallurgical treatment of eudialyte concentrate was studied: dry digestion with hydrochloric acid and leaching with water. The hydrochloric acid for dry digestion to eudialyte concentrate ratio, mass of water for leaching to mass of eudialyte concentrate ratio, leaching temperature and leaching time as the predictor variables, and the total rare earth elements (TREE) extraction efficiency as the response were considered. After experimental work in laboratory conditions, according to design of experiment theory (DoE), the modeling process was performed using Multiple Linear Regression (MLR), Stepwise Regression (SWR), and Artificial Neural Network (ANN). The ANN model of REE extraction was adopted. Additional tests showed that values predicted by the neural network model were in very good agreement with the experimental results. Finally, the experiments were performed on a scaled up system under optimal conditions that were predicted by the adopted ANN model. Results at the scale-up plant confirmed the results that were obtained in the laboratory.

show abstract

Causes of insufficient recovery of zirconium during acidic processing of lovozero eudialyte concentrate

Cited by 26 publications

References 0 publications

Zirconosilicates in the kakortokites of the Ilímaussaq complex, South Greenland: Implications for fluid evolution and high-field-strength and rare-earth element mineralization in agpaitic systems

Zirconosilicates in the kakortokites of the Ilímaussaq complex, South Greenland: Implications for fluid evolution and high-field-strength and rare-earth element mineralization in agpaitic systems

Basic Sulfate Precipitation of Zirconium from Sulfuric Acid Leach Solution

Neural Network Modeling for the Extraction of Rare Earth Elements from Eudialyte Concentrate by Dry Digestion and Leaching

Contact Info

Product

Resources

About