Search Results (128)

Lithium extraction from ores is the main source of lithium salts in China, and the development of green and efficient extraction technologies is an inevitable trend in the country’s lithium industry. Due to the limited availability of domestic lithium ore resources, the efficient utilization of low-grade ores and the development of extraction processes from non-traditional lithium resources will be essential for reducing costs and improving efficiency. This review summarizes the resource characteristics and mineral structures of typical lithium-bearing ores, examines recent advances in extraction processes for representative lithium deposits (spodumene, lepidolite) and discusses strategies for the efficient utilization of low-grade lithium ores (zinnwaldite, petalite, amblygonite, clay-type lithium ore, and jadarite). Finally, the research gap in life cycle assessment of lithium extraction processes from multiple types of lithium ores is addressed by providing a useful reference framework for the development and optimization of lithium extraction technologies from ores. Full article

Pegmatite-related rare-metal exploration in high-altitude mountainous regions is commonly limited by rugged terrain, complex structural frameworks, and uneven bedrock exposure. This study presents a multi-source remote-sensing workflow for regional-scale rare-metal prospectivity assessment in the Pusharong area of western Sichuan, China, by integrating GF-5A Advanced Hyperspectral Imager (AHSI) data, ASTER thermal infrared (TIR) data, and structural interpretation. GF-5A hyperspectral data were used as the primary source for extracting mineral-related anomaly responses associated with muscovite, tourmaline, cookeite, and spodumene. Mixture Tuned Matched Filtering (MTMF) was applied to enhance weak target-related spectral responses, whereas Spectral Angle Mapper (SAM) provided an independent spectral-consistency constraint to reduce potential over-identification. ASTER TIR-derived Quartz Index (QI) and Feldspar Ratio Index (FRI) responses were used as supplementary lithological and differentiation-related background constraints rather than as continuous quartz–feldspar mineral-distribution maps. Structural interpretation was further integrated to evaluate the spatial relationship between mineral-related anomalies and favourable fault settings. Preliminary point-based validation shows a high degree of consistency between the mapped anomaly zones and available field or geochemical observations, with an overall consistency of 92.86% and a Kappa coefficient of 0.91. The integrated workflow delineated four prospective target zones for follow-up verification, with T1 showing the strongest multi-source support, followed by T2 and T3, whereas T4 is regarded as a lower-priority verification target. These results demonstrate the usefulness of the workflow for first-pass regional target prioritisation in complex mountainous terrain, but the delineated targets require further field, mineralogical, geochemical, and drilling verification before any deposit-scale interpretation can be made. Full article

This study investigated the production of spodumene concentrate and lithium carbonate from a low-grade pegmatite ore containing approximately 0.26 wt.% Li₂O. The ore consisted predominantly of a quartz–feldspar aluminosilicate matrix with dispersed spodumene mineralization, which complicates conventional processing approaches. Preliminary lithium concentration was performed by dense media separation (DMS) using an industrially applicable ferrosilicon-based suspension. The highest separation efficiency was achieved for the −4.0/+2.8 mm fraction, producing a DMS concentrate containing 5.77 wt.% Li₂O with 98% lithium recovery. The obtained spodumene concentrate was subjected to decrepitation at 1000–1100 °C to convert α-spodumene into the more reactive β-modification, followed by sulfation roasting with concentrated sulfuric acid at 250–270 °C. The productive leach solution obtained after water leaching contained up to 12.1 g/L Li₂O. After purification from iron-bearing impurities and precipitation with sodium carbonate, a lithium carbonate product containing at least 98.8 wt.% Li₂CO₃ was obtained. Approximately 53% of the lithium contained in the original ore was recovered into the DMS feed fraction, whereas the overall lithium recovery into lithium carbonate reached about 45% relative to the ore and approximately 70% relative to the concentrate. Full article

Five pH- and light-switchable punicine derivatives were investigated as collectors in the flotation of spodumene and quartz. At the natural pH of the minerals, the punicine substituted with a C17 alkyl residue showed the best recovery under daylight (>5000 lux), with values up to 65.0% and 97.8%, and also the highest absolute recovery difference between the two minerals. For pH values of 2 and 12, the punicine collector with a viologen moiety and a C9 alkyl residue shows the best absolute recovery difference, with values of 32.45% and 32.88%, respectively. Studies on the influence of pH, particle size distribution, UV light and darkness, ζ-potential measurements, and IR spectroscopic measurements were carried out to gain insight into the mechanisms. Full article

The potassium-rich mother liquor generated from the sulfuric acid process for lithium extraction from spodumene cannot be directly used for the production of battery-grade lithium salts, resulting in lithium resource loss. To address the issues of slow reaction rate and high seed crystal dosage in the traditional jarosite process for potassium removal, this paper systematically optimizes the type, dosage, and particle size of seed crystals based on the mechanisms of crystal nucleation and growth, ion occupancy competition, and interfacial crystallization-driven behavior. Results show that potassium jarosite seed offers high crystallographic compatibility, ease of preparation, and the best overall performance. Seed particle size must balance specific surface area and dispersibility; either too large or too small is detrimental to uniform crystal growth. Thermodynamic and kinetic analyses confirm that jarosite precipitation is strongly spontaneous and chemically controlled. Under the optimal process conditions (pH = 1.5, n(Fe³⁺)/n(K⁺) = 3.5:1, 1 g of potassium jarosite seed, 95 °C, 1 h), the potassium removal rate reaches (92.60 ± 0.48)%, and the lithium recovery rate is (95.20 ± 0.34)%. Lithium loss mainly arises from precipitate entrainment and insufficient washing; enhanced washing can further improve recovery. This study elucidates seed-mediated crystallization regulation and provides both theoretical guidance and technical reference for efficient potassium removal and high-value lithium recovery from potassium-rich mother liquor. Full article

The rapid growth of battery energy storage and electric vehicles has increased lithium demand and intensified the attention given to the environmental performance of alternative extraction pathways. Conventional life cycle assessments (LCA) of lithium production typically report midpoint indicators in physical units, which limits cross-category comparison and reduces their usefulness for economic and policy analysis. This study presents a comparative monetized LCA of lithium carbonate equivalent (LCE) production from three pathways: solar brine evaporation, hard-rock spodumene mining, and geothermal brine recovery. Using the TRACI 2.1 midpoint results reported in a prior LCA, six impact categories—global warming, smog formation, acidification, respiratory effects, carcinogenic toxicity, and non-carcinogenic toxicity—are converted into monetary values through a benefit-transfer, damage-cost approach. Total environmental external costs are estimated at USD 11.85/kg LCE for solar brine evaporation, USD 9.45/kg LCE for spodumene mining, and USD 4.11/kg LCE for geothermal brine recovery (all USD amounts are expressed in $2025 unless otherwise mentioned). Smog formation contributes more than 80% of the total monetized damages across all pathways, while toxicity-related impacts account for a smaller share than implied by the normalized midpoint results. Monetization changes the relative ranking of the solar brine and spodumene pathways, while indicating that geothermal brine recovery has the lowest monetized external cost among the impact categories evaluated. These findings show that monetized LCA can complement conventional midpoint assessment and provide more decision-relevant insights for policy and economic evaluation. Full article

The critical metal lithium (Li) is increasingly sourced from spodumene and petalite pegmatite deposits due to their relatively high grades, lower mining environmental impacts and widespread global distribution. However, there are numerous gaps in our understanding of their genesis and the formation of unzoned or poorly zoned Li pegmatites is particularly difficult to explain. To investigate this, both spodumene-bearing and non-mineralized pegmatites and aplites are studied in the Moylisha segment of the Leinster pegmatite belt of SE Ireland, which were emplaced within the East Carlow Deformation Zone (ECDZ). Trace element modeling suggests that granite melts can achieve Li concentrations high enough (~5000 ppm) to crystallize spodumene. However, once crystallization begins, Li levels will drop rapidly below this threshold. While Li could be replenished by incoming melts, there is no supporting textural evidence for this, such as internal magmatic contacts, crosscutting relationships, or mingling. We test the hypothesis that low viscosity, Li-rich fluids from underlying reservoirs, most likely almost fully crystallized granite magmas or mush, continuously migrate through the heterogeneously crystallizing pegmatite-forming melts by percolative reactive flow, refertilizing interstitial melt by diffusion under favorable geochemical gradients. The flow of fluids is likely maintained due to their low relative density and periodic shearing within the ECDZ. Fluids with >10,000 ppm Li, derived by >95% crystallization (Rayleigh fractionation) of a granite magma, are shown to be capable of refertilizing a pegmatitic crystal mush after its emplacement. Supporting evidence includes macro- and micro-textures indicative of paragenetically late spodumene crystallization along apparent fluid flow pathways in mineralized pegmatites and aplites. Similar features are common in spodumene pegmatites worldwide and suggest that Li upgrading by fluid flow through crystallizing spodumene pegmatites may be a key process in enhancing Li grades and in some cases in producing economically favored low-Fe spodumene. Full article

The lithium resource reserves in Xinjiang’s Dahongliutan reach 1.1 million tons, making it one of the most representative spodumene deposits in China. Through process mineralogy analysis, the ore was identified as having inherent characteristics that control density-based separation: Coarse crystallization, a high monomer dissociation degree, and a density contrast. Based on these mineralogical characteristics, dense-medium separation experiments were conducted to investigate the mineralogically controlled separation behavior as a function of particle size and medium density. Three process flows (two-product, pressureless three-product, and two-stage, two-product) were further designed and comparatively evaluated. It indicated that the dense-medium separation efficiency is positively correlated with the monomer dissociation degree of spodumene, and the 0.5~6 mm size fraction is the optimal particle size range because it achieves a balance between ore crushing dissociation and coarse-grain dense-medium separation adaptation. Furthermore, all three dense media processes can save grinding energy, and each of them has its own advantages and disadvantages. Comprehensively considering the grade of the concentrate, recovery, the grade of the tailings, and grinding energy consumption, it is recommended to adopt a combined process of two-stage, two-product dense-medium separation and flotation. Full article

The Himalayan metallogenic belt is a globally significant province for leucogranites and pegmatites. Recent exploration has yielded major breakthroughs in the exploration of pegmatite-type Li-Be-Nb-Ta rare-metal deposits within its eastern segment. Discoveries such as the Qiongjiagang and Lhozhag deposits underscore the region’s substantial mineralization potential. In contrast, the western Himalayan segment remains comparatively underexplored. This study presents the geology and geochronology of the newly identified Zhaguopu Li-Be-Nb-Ta deposit in the Gyirong area, providing critical new insights. The deposit is centered on the Gyirong granite dome, which features a core of tourmaline-bearing leucogranite surrounded by a peripheral zone of beryl-bearing pegmatites and vein- to lens-shaped spodumene pegmatites, all hosted within metamorphosed sandstone, slate, and marble. The largest individual spodumene pegmatite vein exceeds 400 m in length, with thicknesses ranging from 0.5 to 4 m and a cumulative thickness surpassing 50 m. Principal ore minerals include spodumene, beryl, and columbite-group minerals. U-Pb geochronology of zircon, monazite, and columbite-group minerals from the leucogranite and pegmatite units constrains the rare-metal mineralization to a tight interval of 25–23 Ma, contemporaneous with the Qiongjiagang and Lhozhag deposits. Whole-rock geochemical data define a coherent fractional crystallization sequence from tourmaline granite through beryl pegmatite to spodumene pegmatite, characterized by increasing SiO₂ and peraluminosity, and extreme depletion in Ba, Sr, Eu and Nb/Ta ratios. This geochemical trend underscores the critical role of extreme magmatic differentiation in rare-metal enrichment. Field relationships and these coeval ages strongly support a genetic model in which the mineralized pegmatites originated from the extreme fractional crystallization of a common, cogenetic magmatic suite. The timing of this mineralization event correlates precisely with the post-collisional extension of the Himalayan orogen and the activity of the Southern Tibet Detachment System. We conclude that the interplay between this large-scale tectonism and magmatic differentiation is the fundamental driver for rare-metal enrichment. The discovery of the Zhaguopu deposit highlights the significant and previously underestimated potential for major pegmatite-type rare-metal deposits in the western Himalayan belt. Full article

The rapid development of the lithium battery industry resulted in a large accumulation of spodumene mining residue (SMR). This paper explored the feasibility of using SMR as mineral admixtures in cement mortar. The properties of cement mortar, including flexural strength, compressive strength, fluidity, hydration characteristics, and durability, were studied. The interaction mechanism between SMR and cement mortar had been explored using the Dinger–Funk model, isothermal calorimetry, X-Ray Diffraction (XRD), fourier Transform Infrared Spectroscopy (FTIR), and thermogravimetry (TG) methods. Additionally, the environmental impact of cement mortar was quantitatively evaluated by the life cycle assessment method. The results showed that, while the dosage of SMR was no more than 20 wt.% replaced cement, the flexural strength, compressive strength, and anti-carbonation and sulfate corrosion resistance properties of S2 and S3 cement mortar were similar to that of the blank group. After curing for 28 d, the compressive strength of S1, S2, and S3 were 44.2 MPa, 43.15 MPa, and 40.32 MPa, respectively. SMR powder could improve the workability and reduce the cumulative hydration heat of cement mortar, which confirmed its application potential in large-volume concrete projects. The appropriate content of SMR incorporation into cement mortar could improve the structure and properties of cement-based materials through particle filling, the induced nucleation effect, and the pozzolanic effect. In addition, the utilization of SMR reduced the environmental emissions and resource consumption of cement-based materials. Using 1 m³ cement mortar as an example, for every 10 wt.% increase in SMR powder replacing cement, the energy consumption, the emissions of CO₂, CO, C_xH_y, NO_x, SO₂, dust, and resource consumption of cement mortar were decreased by approximately 342 MJ, 40 kg, 8.1 g, 5.55 g, 88.3 g, 5.24 g, 1.80 kg, and 74.3 kg, respectively. The research findings of this paper are expected to promote the resource utilization of SMR and reduce the carbon emissions of the building materials industry. Full article

This study investigates the trace-element geochemistry of rare-metal pegmatites from the Kalba–Narym Batholith, Eastern Kazakhstan, to establish geochemical indicators of zonation and subtype differentiation within pegmatite fields. Detailed ICP-MS analyses of muscovite and K-feldspar reveal systematic variations in Li, Cs, Rb, Ta, Nb, P, and Ga contents that reflect progressive melt fractionation during the evolution of granitic magmas. These data allow the identification of four main pegmatite subtypes, including barren, beryl, albite–spodumene, and albite, representing successive stages of LCT (Li-Cs-Ta) pegmatite evolution. Both vertical and lateral geochemical zonation are recognized across the Kalba–Narym Batholith, controlled by magmatic differentiation and volatile enrichment. The results highlight the diagnostic value of trace-element systematics in rock-forming minerals as reliable indicators of fractionation and ore potential, and they provide quantitative criteria for the classification and exploration of rare-metal pegmatites within the Kalba–Narym Batholith. Full article

This study investigates the geological, mineralogical, and geochemical features of the Alday ore occurrence (Central Kalba, East Kazakhstan) and aims to identify indicators of rare-metal mineralization, with lithium considered to be one of its principal components. In this study, the structural–stratigraphic position of the occurrence is refined; three series of albite–spodumene pegmatites are identified; the compositions of the ore-bearing schists and the granitoids of the Kunush and Kalba complexes are compared; and the role of metasomatic alteration in the concentration of Li, Ta, Nb, Be, and Sn is established. The plagiogranites and dikes of the Kunush complex are characterized by Li anomalies (up to 306 g/t), Ta (up to 64 g/t), and a fractionated REE spectrum (La/Yb up to 108). In addition, the following predictive criteria are formulated: the presence of tectonically disrupted dikes in the Kunush complex with Na₂O/K₂O > 4, the presence of albite and muscovite alteration zones, and the presence of ladder-type spodumene-bearing pegmatites controlled by northwest-trending faults. The ⁴⁰Ar/³⁹Ar muscovite age of the Alday pegmatites (~292 Ma) aligns with the age range of the Kalba granite complex. Based on the main principles of rare-metal pegmatite generation, it is determined that the Tochka pegmatites were formed during the fluid–magmatic fractionation of magma in large granitic reservoirs of the Kalba complex. The Karagoin–Saryozek zone—located between several large granite massifs of the Kalba complex, where host rocks function as a roof—may be promising for investigating rare-metal pegmatite mineralization. Full article

Routine chemical assays, which are more readily available than direct mineralogical analyses, offer a rapid and cost-efficient approach of estimating mineral grades for geometallurgical modelling. This paper addresses the prediction of ore minerology from chemical assays for lithium-bearing pegmatites by implementing and comparing two element-to-mineral conversion (EMC) approaches: (1) mass balance techniques using two calculation variants and (2) machine learning methods (MLM). Both routines of the mass balance approach achieved satisfactory R² values exceeding 0.8, although calculation routine 1 was unable to automatically differentiate between the two lithium-bearing phases (spodumene and cookeite). Of the eight algorithms applied for the MLM approach, the top three performing models achieved R² values greater than 0.6 for both training and testing datasets, with slightly lower error evaluation metrics compared to the mass balance approach. Based on data accuracy requirements across the Mine Value Chain, the mass balance approach is suitable for the feasibility and operational stages, while the MLM approach meets the minimum data accuracy requirements of the scoping and pre-feasibility stages. However, it should be noted that the mass balance approach is limited to deposits with simple mineral assemblages while the MLM approach can handle deposits with greater elemental overlap among minerals. Full article

Rapid and reliable analytical methods are required to support quality control and decision-making in lithium-bearing mineral processing. In this study, the application of Fourier Transform Infrared (FTIR) spectroscopy combined with Partial Least Squares (PLS) chemometric modeling is evaluated for the simultaneous prediction of lithium oxide (Li₂O) and spodumene contents in pegmatitic samples. Two independent PLS models were developed using FTIR spectra preprocessed with first derivative and/or Standard Normal Variate (SNV). Spectral regions were selected based on the vibrational response of Al–O, Si–O, and OH⁻ groups, which are indirectly influenced by lithium-bearing phases. The spectral datasets were divided into calibration and independent external test sets, and model performance was assessed using statistical metrics and Principal Component Analysis (PCA). The Li₂O model achieved an R² of 0.9934 and an RMSEP of 0.185 in external validation, with a mean absolute error below 0.15%. The spodumene model achieved an R² of 0.9961, an RMSEP of 1.79, and a mean absolute error of 2.80%. These results demonstrate that the FTIR-PLS approach enables efficient quantitative estimation of lithium-bearing minerals, with reduced analytical time, good predictive accuracy, and suitability for application in process control and mineralogical sorting environments. PCA confirmed the statistical representativeness of the test sets, with no evidence of spectral extrapolation. Full article

Lithium is an essential material for lightweight batteries. Traditional mining of soluble salts expanded to include the extraction of hard rocks, which requires their solubilization through roasting. Among hard lithium rocks, spodumene has recently received attention from the scientific community. Its metallurgical processing can be classified according to the type of reagents, as well as the operating temperature and pressure. The use of calcium carbonate as a natural alkali avoids aggressive chemicals such as sulfuric acid or caustic soda. In this article, 0.5 g of jewelry-grade spodumene was loaded into a ceramic crucible with 2.5 g of reducing agent in a tandem of roasting at 1050 °C-1 bar-30 min and leaching with neutral water at 90 °C-1 bar-20 min at a water/clinker mass ratio of 25. Measurements by XRD, ICP-OES, and SEM-EDX suggest a pathway of spodumene cracking because of poor contact with the reductant. Potassium present in the crucible acts as a flux and encapsulates spodumene crystals, causing lithium to end up bound to silica. While lithium metasilicate is barely soluble in water, leaching potassium aluminate hoards in the liquid. The empirical observations were supported with thermodynamic spontaneity studies, which required compiling the mineral properties based on open reference tabulations. Full article