Linking Mineralogical Characteristics to Dense-Medium Separation Performance: A Case Study of the Dahongliutan Spodumene Deposit in Xinjiang
1
Faculty of Land Resource Engineering, Kunming University of Science and Technology, Kunming 650000, China
2
Xinjiang Kunlun Blue Diamond Mining Development Co., Ltd., Hotan 848000, China
*
Authors to whom correspondence should be addressed.
Minerals 2026, 16(4), 408; https://doi.org/10.3390/min16040408
Submission received: 4 February 2026
/
Revised: 26 March 2026
/
Accepted: 12 April 2026
/
Published: 15 April 2026
(This article belongs to the Section Mineral Processing and Extractive Metallurgy)
Abstract
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.
1. Introduction
Lithium, a core strategic metal in the new energy sector, is an essential raw material for lithium-ion battery cathodes, electrolytes, and energy storage systems [1,2,3,4]. As the global markets for new energy vehicles and large-scale energy storage continue to expand, the demand for lithium resources has risen sharply [5,6]. High-grade spodumene ore, the primary feedstock for producing high-purity lithium salts, has therefore become increasingly important [7,8,9,10]. Common separation methods for spodumene include hand sorting, flotation separation, and gravity separation, among which flotation is currently the most widely used technique [11,12,13,14,15]. However, flotation requires fine grinding of the ore, leading to high energy consumption [12,16,17]. In contrast, dense-medium separation is particularly suitable for coarse particles and for minerals with significant density differences relative to gangue minerals [18,19]. Pegmatite-type spodumene ores are typically characterized by coarse crystal size and a high degree of natural liberation, providing favorable mineralogical conditions for dense-medium separation [13,18,19,20]. Therefore, exploring the application of dense-medium separation to coarse-grained pegmatite spodumene ore is of considerable significance.
Dense-medium separation is favored for its advantages, including high sorting accuracy, large processing capacity, and relatively low operating costs. This technique relies on the difference in specific gravity between valuable minerals and gangue minerals, enabling their separation within a well-controlled dense medium suspension [19,21]. In such a system, particles with densities higher than that of the medium sink, whereas those with lower densities float. Therefore, the separation performance depends not only on the density contrast between minerals, but also on factors such as particle size and mineral liberation. The specific gravity of spodumene is approximately 3.1–3.2 g/cm3, which is generally higher than that of major gangue minerals such as quartz and feldspar (approximately 2.6–2.7 g/cm3) [18,22]. This density difference provides a fundamental physical basis for the application of dense-medium separation [18,19,22]. Recently, a great number of researchers have explored the application of dense-medium separation for lithium [18,22,23,24]. Olli et al. [23] investigated a method to enhance lithium separation by combining dense-media separation with heat treatment and selective sieving, thereby achieving a significant improvement in lithium concentrate grade. Daulet et al. [24] investigated the extraction of spodumene using dense-medium separation and reverse flotation as two independent processes. A Li2O concentrate with a grade of 5%–7% was obtained, with a recovery of 85%–90% at a medium density of 2.8 g/cm3. Meanwhile, fine-grained minerals were recovered at pH 10 using a NaOL/DAA collector system. Existing studies have demonstrated that dense-medium separation of spodumene ore can produce lithium concentrates of acceptable grade, although the recovery remains relatively low [18,22,24]. Therefore, further investigation into the dense-medium separation of spodumene ore is of considerable significance.
The Dahongliutan area in Xinjiang hosts an exceptionally large lithium–beryllium–tantalum–niobium polymetallic deposit, with lithium reserves reaching 1.1 million tons [25,26]. In response to the growing need for efficient utilization of low-grade spodumene resources, this study takes the Dahongliutan spodumene ore as the research object [27] and takes process mineralogy as the core starting point to systematically analyze the mineral composition, particle size distribution, monomer dissociation degree, and density characteristics of the ore. On this basis, dense-medium separation experiments are conducted to reveal the mineralogy-controlled density-based separation law of coarse-grained pegmatite spodumene, including the response of separation performance to particle size (dominated by mineral dissociation) and medium density (matching the mineral density difference). Three processes are compared, and one process is recommended. This work not only provides a technical basis for the efficient utilization of Dahongliutan lithium resources but also enriches the theoretical system of mineralogy-controlled density-based separation of non-ferrous metal ores.
2. Materials and Methods
2.1. Materials
The ore sample was obtained from the Dahongliutan area in Xinjiang, China. The chemical multi-element analysis of the samples was conducted, and the results are shown in Table 1 [28,29]. The contents of lithium, sodium, potassium, rubidium, and cesium were determined using an atomic absorption spectrometer (AA-7000, Shimadzu, Kyoto, Japan), whereas the contents of beryllium, iron, aluminum, calcium, and magnesium were determined using a plasma emission spectrometer (Optima 8000, PerkinElmer, Shelton, CT, USA). The block-shaped samples were cut into thin slices measuring approximately 25 mm × 30 mm and examined using an optical microscope. The sand-like crushed composite samples were sieved and classified, and the resulting size fractions were used to prepare SEM mounts with a diameter of 30 mm at room temperature. Grinding and polishing were performed, and a thin layer of carbon was sputter-coated onto the samples as a conductive film for process mineralogical analysis. The water used during sample preparation and grinding was tap water from the plant area, and the adhesives and curing agents applied were inert materials. Grinding and polishing were purely mechanical operations and did not involve any chemical reagents or solvents. Sample screening, preparation, testing, and analysis were all conducted in accordance with the technical requirements for mineral product characterization.
2.2. Mineral Characterization Methods
X-ray diffraction (XRD) analysis: The mineral samples were analyzed for their crystal phases using an X-ray diffractometer (D2 PHASER, Bruker AXS, Karlsruhe, Germany), with a scanning range of 10~70° and a step size of 0.02°. Phase identification was carried out using MDI Jade 6.0 software [30,31]. The results from optical microscopy, SEM-EDS, and XRD were interpreted in a complementary manner for mineralogical characterization.
Scanning electron microscope-energy dispersive spectrometer (SEM-EDS) analysis: Using a scanning electron microscope (QUANTA 600, FEI, Hillsboro, OR, USA) equipped with an energy dispersive spectrometer (GENENSIS2000, EDAX, Mahwah, NJ, USA) to analyze the morphology and composition of the minerals. Typical fields were selected for energy-spectrum scanning to determine the elemental composition of lithium-containing minerals, metallic minerals, and gangue minerals.
Optical microscopy analysis: a microscope (BX51TFR, Olympus, Hachioji, Tokyo, Japan) was used to conduct single-polarization and orthogonal-polarization observations on the mineral sections, analyzing the crystal form and distribution characteristics of the minerals.
Defining the determination method for particle size distribution: The particle size distribution of minerals with a size fraction larger than 0.025 mm was measured using the standard sieve analysis method. The minerals with a size fraction less than 0.025 mm were measured using the Mineral Liberation Analyzer (MLA). The MLA is a comprehensive device composed of a scanning electron microscope (QUANTA 600, FEI), an energy spectrometer (GENENSIS 2000, EDAX), and MLA mineral analysis system software (version 2.7).
Method for determining mineral dissociation degree: The dissociation degree of mineral monomers (area method) was measured using the MLA. Different particle sizes of mineral samples were selected, polished sheets were prepared, and automatic scanning was performed to calculate the proportion of monomer/aggregate areas of the minerals.
2.3. Dense-Medium Separation Tests
Dense medium preparation: Ferrosilicon (with more than 80% of particles smaller than 0.074 mm) was used as the weighting agent and mixed with water to prepare the dense medium suspension. The medium density was adjusted by varying the amount of ferrosilicon added.
Medium-density measurement: The actual density of the suspension was determined using the pycnometer method. Density calibration was performed before each experiment.
Dense-medium separation: The spodumene ore was first crushed using an E-type crusher. Oversized pieces were removed with a coarse screen and sent back for re-crushing, while the undersized material was separated into three particle-size ranges of 0–6 mm, 0–10 mm, and 0–15 mm using a grading screen. The dense-medium experiments were carried out on the beneficiation test platform at Weihai Haiwang Cyclone Co., Ltd. (Weihai, China). The principal process flow chart is shown in Figure 1a. The process flow chart for the two-product DMS process is shown in Figure 1b, and the hydrocyclone was FZJ 500 produced by Weihai Haiwang Cyclone Co., Ltd. The process flow chart of the pressureless three-product DMS process was shown in Figure 1c, and the hydrocyclone was connected in series by FZJ 500 and FZJ 400 produced by Weihai Haiwang Cyclone Co., Ltd. The process flow chart of the two-stage, two-product DMS process was shown in Figure 1d, and the hydrocyclones for the first stage and second stage were FZJ 500 and FZJ 400, respectively, produced by Weihai Haiwang Cyclone Co., Ltd. After separation, the products were dried, weighed, and sampled for grade determination, and the recovery was calculated based on these results.
3. Results Analysis and Discussion
3.1. Research on Process Mineralogy
3.1.1. Mineral Composition Analysis
The mineral composition of the raw ore was characterized by integrated mineralogical analysis, including XRD and EDS. Figure 2 shows the XRD pattern of the raw ore, and Table 2 lists the major crystalline phases identified by XRD, together with their chemical formulas and corresponding PDF card numbers. The relative contents of the major minerals are summarized in Table 3. As shown in Table 3, the ore has a relatively simple mineral composition. Metallic minerals account for less than 1% and mainly include tantalum–niobium iron ore, manganese iron oxide, and manganese iron phosphate. Lithium minerals make up approximately 27% of the sample, with spodumene as the dominant phase, followed by lepidolite, and minor amounts of phosphate lithium aluminate and lithium iron tourmaline. Gangue minerals account for about 73% of the sample and are primarily composed of quartz, plagioclase, and K-feldspar, with trace amounts of cassiterite and other accessory minerals.
The relatively simple mineral composition of the ore and the single density type of gangue minerals (quartz/feldspar, 2.6~2.7 g/cm3) eliminate the interference of multi-density gangue on density-based separation, which is a key mineralogical advantage for dense-medium separation. The low content of metallic minerals prevents density overlap between metallic minerals and spodumene, ensuring the purity of density segregation during dense-medium separation.
3.1.2. Mineralogical Characteristics of Major Minerals
- Lithium-containing minerals
The lithium-bearing minerals in this ore are primarily spodumene and lepidolite, accompanied by minor amounts of phosphate lithium aluminate and lithium iron tourmaline. Among them, spodumene and lepidolite are currently the most widely used lithium minerals in industrial applications. The representative EDS spectra of the lithium-bearing minerals are provided in Figure S1 in the Supplementary Materials. From the perspective of crystal morphology, three main types of spodumene occur in this ore. The first type is a semi-euhedral columnar crystal. These crystals are coarse-grained, reaching up to approximately 3 mm in size, with well-developed cleavage and readily fractured surfaces, as shown in Figure 3a. The second type consists of irregular fine-grained aggregates. These crystals are somewhat smaller, with the largest ones reaching about 1 mm. The grain boundaries often appear corroded, and small tail-like protrusions can be seen extending into the intergranular spaces of the surrounding gangue minerals, as shown in Figure 3b. The third type consists of columnar aggregates with irregular boundaries, formed by several crystals growing together. The internal cracks and voids are small, and the overall appearance is that of a fine-grained, dark-surfaced aggregate, as shown in Figure 3c. Multiple crystal morphologies of spodumene coexist in the ore, and local fragmentation of spodumene can be observed. Small fragments of lithium muscovite commonly occur along grain edges and appear to be associated with microcrystalline K-feldspar aggregates, infilling fractures within the felsic bedrock, as shown in Figure 3d. Lepidolite typically occurs as semi-euhedral to xenomorphic platy crystals or aggregates. Several aggregates are intergrown with elongated quartz grains, as shown in Figure 3e, and exhibit well-developed foliation. The particle-size distribution of lepidolite is uneven, predominantly occurring as individual crystals, with minor fine particles scattered within the gaps between equigranular quartz or feldspar grains.
- 2.
- Metallic minerals
Trace amounts of metallic minerals such as tantalum–niobium, iron ore, manganese–iron oxide, and manganese–iron phosphate are present in the ore. The tantalum–niobium minerals mainly occur as niobium–iron ore and tantalum–iron ore within the same phase series. The results of EDS of the metallic minerals are presented in Figure S2 in the Supplementary Materials. Their elemental compositions are similar, with differences primarily reflected in their relative proportions. The Nb2O5 content ranges from 53% to 72%, while the Ta2O5 content ranges from 9% to 28%. Some of these minerals exhibit euhedral to semi-euhedral needle-like crystals (Figure 4), whereas others appear as granular particles, typically occurring as single mineral grains or aggregates that are sparsely and unevenly distributed within the ore. The grain size of tantalum–niobium iron ore varies significantly. The maximum particle size is approximately 0.15 mm, with most grains concentrated between 0.006 mm and 0.07 mm. Approximately 68% of the grains exceed 0.02 mm, about 17% fall within the range of 0.01–0.02 mm, and around 15% are finer than 0.01 mm. Manganese–iron oxide and manganese–iron phosphate commonly occur as gel-like aggregates, which may represent impurities introduced during the ore-crushing process.
- 3.
- Gangue minerals
The gangue minerals of the ore exhibit a relatively simple composition, dominated by plagioclase, quartz, and K-feldspar, with minor to trace amounts of cassiterite and other accessory minerals. The ore-hosting rock is primarily pegmatite and is characterized by an abundance of light-colored minerals, whereas dark-colored or metallic minerals are scarce. Coarse crystals of feldspar and spodumene are readily visible to the naked eye; however, the ore is intensely fractured and therefore highly susceptible to breakage.
Feldspar in the ore is predominantly plagioclase, with K-feldspar occurring in subordinate amounts. Most feldspar crystals are relatively coarse and occur as subhedral to euhedral tabular grains, with simple and polysynthetic twinning commonly observed; in the slice, feldspar surfaces appear slightly turbid and show dissolution features, and fractures are developed within some coarse crystals, as shown in Figure 5a. In addition, a minor proportion of feldspar occurs as fine-grained particles dispersed among equigranular quartz grains, as shown in Figure 5b. Part of the K-feldspar occurs as microcrystalline aggregates with irregular anhedral shapes, rough surfaces, and a relatively dark appearance, as shown in Figure 3d. These aggregates appear to be locally associated with small amounts of equigranular sericite, and their coarse aggregates enclose fragments of spodumene, lepidolite, and minor quartz, with a limited number of aggregates occurring as narrow vein-like fillings along fractures within the feldspathic–quartzose host rock, as shown in Figure 5b. Quartz mainly occurs as anhedral granular crystals that aggregate into coarse masses intergrown with feldspar grains. Fractures are well developed within the quartz aggregates, and quartz is locally fragmented into fine grains along these fractures, as shown in Figure 5c. Some fractures are filled with microcrystalline K-feldspar aggregates, as shown in Figure 5b.
The coarse columnar crystal morphology and well-developed cleavage of spodumene lead to easy dissociation along the cleavage plane during crushing, forming natural coarse-grained monomer particles without artificial fine grinding. This coarse crystallization characteristic is the core mineralogical basis for the adaptation of dense-medium separation to this ore, which fundamentally determines that the ore can realize efficient density separation via dense-medium separation.
3.1.3. Particle-Size Distribution of Major Minerals
The particle size distribution statistics of selected minor minerals in the ore, namely tantalum–niobium iron ore, phosphate lithium aluminate, and cassiterite, are summarized in Table 4. The particle-size distribution statistics of the main lithium-bearing minerals, including spodumene, lepidolite, and lithium iron tourmaline, are presented in Table 5. The particle-size distribution of the principal gangue minerals, quartz and feldspar (plagioclase and K-feldspar), is shown in Table 6.
According to the results in Table 4, the particle size of the tantalum–niobium iron ore in the sample is relatively fine, with the maximum size not exceeding 0.15 mm and an average particle size of approximately 0.033 mm. The particle size of cassiterite is slightly coarser than that of the tantalum–niobium mineral, with an average size of about 0.133 mm. The average particle size of phosphate lithium aluminate is approximately 0.067 mm. According to the results in Table 5, the average particle size of lithium iron tourmaline is around 0.189 mm. The P50 of the main lithium-bearing mineral spodumene is 421.67 μm, while the P50 of lepidolite is 207.90 μm. The particle size is relatively coarse, with about 85% of spodumene particles and about 71% of lepidolite particles distributed above 0.1 mm. According to Table 6, the P50 values of the main gangue minerals, quartz and feldspar, are 403.54 μm and 360.06 μm, respectively, indicating coarse grain sizes. Approximately 83% of quartz and 82% of feldspar have particle sizes distributed above 0.1 mm.
The consistent coarse-grain distribution characteristics of spodumene (P50 = 421.67 μm) and gangue minerals (quartz P50 = 403.54 μm, feldspar P50 = 360.06 μm) ensure synchronous density segregation of valuable minerals and gangue in the coarse-grain fraction. The high proportion of coarse-grain particles (>0.1 mm; spodumene 85%, quartz 83%, feldspar 82%) prevents fine-grain entrainment and misplacement in dense-medium separation, which is an important mineralogical guarantee for high separation precision.
3.1.4. Monomer Dissociation Degree of Major Mineral Components
The statistical results for the monomer dissociation degree of selected minerals in the ground products are presented in Table 7, and the distribution of monomer dissociation degrees of the major lithium-bearing minerals across different particle-size ranges is shown in Table 8.
According to Table 7, after grinding, the monomer dissociation degrees of the four main lithium-bearing minerals are relatively high. The monomer dissociation degree of spodumene is approximately 94%, that of lepidolite is about 90%, phosphate lithium aluminate is about 89%, and lithium iron tourmaline is approximately 78%.
According to Table 8, due to its relatively coarse particle size, the monomer content of spodumene exhibits little variation across different size fractions after grinding, and its monomer dissociation degree reaches only 97% under the 600-mesh size. Due to its structural characteristics, the monomer dissociation degree of lepidolite increases significantly with decreasing particle size; however, no substantial increase is observed below 600 mesh, which may be related to the inherently fine particle size of a portion of the mica.
3.2. Research on Dense-Medium Separation
Based on the above process mineralogy analysis, the ore has three core mineralogical characteristics that are highly compatible with dense-medium separation. First, there is a distinct density difference between spodumene and gangue minerals, providing the physical basis for density separation. Second, the ore exhibits coarse crystal size and a uniform particle size distribution, ensuring its suitability for coarse-grained, dense-medium separation. Third, a high natural degree of liberation forms well-defined density units and reduces interference from intergrowth during dense-medium separation. In this section, using mineralogical characteristics as the core control factor, we systematically study the mineralogically controlled separation laws for particle size (dominated by the degree of monomer liberation) and medium density (matching the mineral density difference) to reveal the mineralogically controlled density-based separation mechanism of coarse-grained pegmatite spodumene ore.
3.2.1. Influence of Particle Size on the Results of Dense-Medium Separation
After crushing the raw ore into three particle-size ranges of 0~6 mm, 0~10 mm, and 0~15 mm, the particle-size compositions of each feed material are shown in Table 9.
According to Table 9, as the upper particle-size limit increases, the grade of the +0.5 mm size fraction decreases, indicating that after crushing, a large proportion of gangue minerals becomes dissociated and enters the −0.5 mm fine size range. The optimal degree of mineral dissociation occurs when the maximum particle size is 6 mm.
In addition, a two-product dense-medium separation test was conducted by varying the intermediate density, and the results are shown in Figure 6.
As illustrated in Figure 6, considering both grade and recovery, when the selected particle-size range is 0.5~6 mm, and the intermediate density is 2.29 g/cm3, a lithium concentrate with a yield of 35.55%, a grade of 5.50%, and a recovery of 87.08% can be obtained, with a tailings grade of 0.45%. When the selected particle-size range was 0.5–10 mm, and the medium density was 2.29 g/cm3, a lithium concentrate with a yield of 25.71%, a grade of 5.45%, and a recovery of 72.09% was obtained, while the tailings grade was 0.73%. When the selected particle-size range is 0.5~15 mm, and the intermediate density is 2.39 g/cm3, a lithium concentrate with a yield of 15.88%, a grade of 5.48%, and a recovery of 48.01% can be obtained, and the tailings grade is 1.12%.
The separation performance shows a significant negative correlation with the upper limit particle size of the ore, and the 0.5~6 mm size fraction achieves the optimal indexes. This phenomenon is essentially controlled by the monomer dissociation degree of spodumene in different size fractions. As shown in Table 8, when the particle size upper limit changed from 0.5~15 mm to 0.5~6 mm, the spodumene monomer dissociation degree increased further, which increased the proportion of pure spodumene density units, thus effectively improving the concentrate grade and recovery.
In addition, as shown in Table 9, the decrease in spodumene grade in the +0.5 mm fraction with the increase in particle size upper limit is due to the uneven dissociation of coarse-grained gangue minerals. The large particle size ore is insufficiently crushed, and the gangue minerals are easy to form coarse-grain aggregates, leading to the dilution of spodumene grade in the coarse-grain fraction. The 0.5~6 mm size fraction achieves the optimal balance between ore crushing dissociation and a coarse-grained structure. This balance is the core mineralogical reason why the 0.5~6 mm size fraction is the optimal particle size range for DMS.
3.2.2. Influence of Dense Medium Beneficiation Process on the Separation Results
In order to identify a suitable dense-medium separation process for this ore, we compared three approaches: a two-product DMS process, a pressureless three-product DMS process, and a two-stage, two-product DMS process.
Figure 7 shows the lithium recovery and grade obtained at different medium densities during the separation of spodumene using different dense-medium separation processes. According to Figure 7a, when the two-product DMS process is used, the concentrate yields are in the range of 26.68%~32.75%, and grades are in the range of 5.41%~6.17%, the recoveries are in the range of 78.91%~85.97%, and the tailings grades are in the range of 0.43%~0.60%. Overall, the separation performance under these conditions appears fairly good. When the intermediate density is adjusted to 2.49 g/cm3, the lithium concentrate shows a yield of 26.68%, a grade of 6.17%, and a recovery of 78.91%, while the tailings grade is 0.60%. Since the grade of the concentrates is qualified, only the ore with a size fraction of −0.5 mm or both the ore with a size fraction of −0.5 mm and tailings require further grinding. When the requirements for tailings grade are relatively low, only the ore with a size fraction of −0.5 mm is fed into the grinding process, which accounts for 14.34% based on Table 9. The estimated grinding energy consumption is approximately 10 kWh/t. Therefore, 8.57 kWh can be saved per ton of raw ore. The energy conservation rate is 85.67%. When the requirements for tailings grade are relatively high, both the ore with a size fraction of −0.5 mm and tailings need to be further ground, which accounts for 77.14%. Therefore, 2.29 kWh can be saved per ton of raw ore. The energy conservation rate is 22.9%.
Figure 7b summarizes the results from the pressureless three-product DMS process. Under this configuration, the concentrate yields are 25.84%~33.99%, grades are 4.53%~5.47%, the recoveries are 69.28%~77.93%, the middling grades are 1.22%~2.22%, and the tailings grades are 0.20%~0.35%. This process is capable of separating concentrates, intermediate ore, and tailings more distinctly. However, the intermediate product still requires additional treatment, which increases the overall complexity of the flowsheet. When the intermediate density is 2.55 g/cm3, a lithium concentrate with a yield of 25.84%, a grade of 5.47%, and a recovery of 69.28% can be obtained, along with middling with a yield of 19.64%, a grade of 2.22%, and a recovery of 21.37%, and tailings with a grade of 0.35%. The grade of the concentrate and tailings is qualified; thus, only the middling and the ore with a size fraction of −0.5 mm need to be further ground, which together account for 31.17%. The estimated grinding energy consumption is approximately 10 kWh/t. Therefore, 6.88 kWh can be saved per ton of raw ore. The energy conservation rate is 68.8%.
Figure 7c,d show the results of the two-stage, two-product DMS process. Figure 7c shows the results of a single-stage dense-medium separation experiment using a two-stage two-product dense-medium separation process. As shown in Figure 7c, as the intermediate density decreases, the lithium grade in the first-stage concentrate gradually decreases, and the recovery rate gradually increases, while the lithium grade and recovery rate in the first-stage tailings gradually decrease. Figure 7d shows the results of secondary dense medium sorting and waste disposal experiments on a section of tailings at different intermediate densities. The tailings are experimental products from the one-stage two-product DMS process. It can be seen from Figure 7d that when the intermediate density of the first section is 2.3 g/cm3, the sorting effect is best, yielding a concentrate with a grade of 5.38% and a recovery rate of 74.82%. At this time, the middling grade is 1.12%~1.31%, and the tailings grade is 0.29%~0.30%. The grade of the concentrate and tailings is qualified; thus, only the middling and the ore with a size fraction of −0.5 mm require further grinding. which total accounts for approximately 29.98%. Therefore, 7 kWh can be saved for each ton of raw ore. The energy conservation rate is 70%.
This process also achieves the separation of three products: concentrate, middling, and tailings. The tailings have a lower grade but still produce about 20% of the intermediate ore that needs further processing.
From the above results, it can be seen that the dense-medium separation process is simple and can effectively reduce grinding energy. Compared with flotation results reported in the literature, the grade of the concentrate of dense-medium separation is close to or even higher than that of flotation, which confirms the advantages of dense-medium separation for the pre-concentration of spodumene ore. For example, when (E)-octadec-9-enoylglycine was used as the collector, the Li2O grade was 5.03%, and the Li2O recovery was 65.95% [32]. The above three processes each have their own advantages. The two-product dense-medium separation process is simple and has stable separation indicators, but the tailings grade is relatively high. The results of the three-product dense-medium separation process and the two-stage, two-product dense-medium separation process are similar. Both can produce three products: Concentrates, tailings, and middling. Both of them can effectively control the grade of the concentrates and tailings, and the grade of the tailings is relatively low. But the middling produced needs further processing, and the process is relatively complex. Compared with the pressureless three-product dense-medium separation process and the two-stage, two-product dense-medium separation process, the two-stage, two-product dense-medium separation process is easier to control and has more stable separation indicators. Considering the grade of the concentrate, recovery, the grade of the tailings, and grinding energy consumption, it is recommended to adopt the combined process of two-stage, two-product dense-medium separation and flotation. The flow chart is shown in Figure 8.
4. Conclusions
This study takes the Dahongliutan spodumene ore as the research object, uses process mineralogy as the core starting point, systematically analyzes the ore’s mineralogical characteristics, and reveals the mineralogically controlled density-based separation mechanism of coarse-grained pegmatite spodumene ore via dense-medium separation experiments. The main conclusions are as follows:
The ore has typical mineralogical characteristics that are well-suited to dense-medium separation. The mineral composition is simple, with a distinct density difference between spodumene and gangue minerals. Spodumene is coarse with well-developed cleavage, and more than 70% of the spodumene particles in the crushed product already appear as monomers. When the grinding fineness reaches approximately −200 mesh, accounting for 72% of the material, the monomer dissociation degree increases to about 94%. Overall, the ore exhibits coarse crystallization and readily achieves mineral dissociation. The particle size distribution of spodumene and gangue is consistent, with a high proportion of coarse-grain particles (>0.1 mm), avoiding fine-grain entrainment. These characteristics constitute the intrinsic mineralogical basis for the efficient dense-medium separation of this ore.
The dense-medium separation results 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 the balance between ore crushing dissociation and coarse-grain, dense-medium separation adaptation. Furthermore, the ore was tested using three separation flowsheets, and each has its own advantages. The two-product dense-medium separation process is simple and has stable separation indicators, but the tailings grade is relatively high. The three-product dense-medium separation process and the two-stage, two-product dense-medium separation process are similar. Both can produce three products: Concentrate, tailings, and middling. Both of them can effectively control the grade of the concentrates and tailings, and the grade of the tailings is relatively low. But the middling produced needs further processing, and the process is relatively complex. Compared with the pressureless three-product, dense-medium separation process and the two-stage, two-product dense-medium separation process, the two-stage, two-product dense-medium separation process is easier to control and has more stable separation indicators. Considering the grade of the concentrate, recovery, the grade of the tailings, and grinding energy consumption, it is recommended to adopt the combined process of two-stage, two-product dense-medium separation and flotation. This study clarifies the intrinsic link between the mineralogical characteristics and density-based separation behavior of coarse-grained pegmatite spodumene ore and enriches the theoretical system of mineralogically controlled spodumene ore separation. However, due to the absence of float–sink test data, a more quantitative evaluation of separation sharpness, such as partition curve analysis, was beyond the scope of the present study. Future work will therefore focus on collecting such data to further assess the separation performance of the process.
Supplementary Materials
The following supporting information can be downloaded at: https://www.mdpi.com/article/10.3390/min16040408/s1. Figure S1: Representative EDS spectra of lithium-bearing minerals; Figure S2: Representative EDS spectrum of the tantalum–niobium iron ore shown in Figure 4; Figure S3: Representative EDS spectra of cassiterite; Table S1: EDS results for spodumene (%); Table S2: EDS results for lepidolite (%); Table S3: EDS results for phosphate lithium aluminate (%); Table S4: EDS results for lithium iron tourmaline (%); Table S5: EDS results for tantalum–niobium iron ore (%); Table S6: EDS results for cassiterite ore (%).
Author Contributions
Conceptualization, S.W.; Methodology, S.W.; Formal analysis, B.C.; Investigation, B.C.; Resources, J.L.; Data curation, B.C. and J.L.; Writing—original draft, B.C.; Writing—review & editing, A.F.; Funding acquisition, B.C. All authors have read and agreed to the published version of the manuscript.
Funding
This work was funded by Xinjiang Talent Development Fund and the National Key R&D Program of China (No. 2023YFC2909000).
Data Availability Statement
The data presented in this study are available within the article and Supplementary Materials. Additional data are available on request from the corresponding author.
Conflicts of Interest
Author Bao Cui was employed by Xinjiang Kunlun Blue Diamond Mining Development Co., Ltd. The remaining authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.
References
- Zhang, X.; Aldahri, T.; Tan, X.; Liu, W.; Zhang, L.; Tang, S. Efficient co-extraction of lithium, rubidium, cesium and potassium from lepidolite by process intensification of chlorination roasting. Chem. Eng. Process. 2020, 147, 107777. [Google Scholar] [CrossRef]
- Zhang, X.; Tan, X.; Li, C.; Yi, Y.; Liu, W.; Zhang, L. Energy-efficient and simultaneous extraction of lithium, rubidium and cesium from lepidolite concentrate via sulfuric acid baking and water leaching. Hydrometallurgy 2019, 185, 244–249. [Google Scholar] [CrossRef]
- Zhou, W.; Xie, R.; Tong, X.; Xie, X.; Wang, X.; Zhao, Z. A novel approach of synergistically enhancing green and efficient lithium extraction from clay-type lithium ore and its mechanism. Process Saf. Environ. Prot. 2025, 200, 107418. [Google Scholar] [CrossRef]
- Zhang, X.; Chen, Z.; Rohani, S.; He, M.; Tan, X.; Liu, W. Simultaneous extraction of lithium, rubidium, cesium and potassium from lepidolite via roasting with iron(II) sulfate followed by water leaching. Hydrometallurgy 2022, 208, 105820. [Google Scholar] [CrossRef]
- Dessemond, C.; Lajoie-Leroux, F.; Soucy, G.; Laroche, N.; Magnan, J.-F. Spodumene: The Lithium Market, Resources and Processes. Minerals 2019, 9, 334. [Google Scholar] [CrossRef]
- Bowell, R.J.; Lagos, L.; de los Hoyos, C.R.; Declercq, J. Classification and Characteristics of Natural Lithium Resources. Elements 2020, 16, 259–264. [Google Scholar] [CrossRef]
- Roy, T.; Plante, B.; Benzaazoua, M.; Demers, I. Geochemistry and mineralogy of a spodumene-pegmatite lithium ore at various mineral beneficiation stages. Miner. Eng. 2023, 202, 108312. [Google Scholar] [CrossRef]
- Bu, Y.; Yan, W.; Deng, X.; Huang, S.; Sun, A.; Guan, Q.; Zhou, S.; Peng, W.; Wang, W.; Ge, P.; et al. A Review on Lithium Extraction Processes from Spodumene and Resource Utilization of the Generated Lithium Slag. Minerals 2025, 15, 1073. [Google Scholar] [CrossRef]
- Xie, R.; Zhou, W.; Tong, X.; Liu, Y.; Xie, X.; Wang, X. Study on extraction of lithium from clay-type lithium ore with low roasting temperature and water and its mechanism. Sep. Purif. Technol. 2025, 364, 132450. [Google Scholar] [CrossRef]
- Goodenough, K.M.; Shaw, R.A.; Borst, A.M.; Nex, P.A.M.; Kinnaird, J.A.; van Lichtervelde, M.; Essaifi, A.; Koopmans, L.; Deady, E.A. Lithium Pegmatites in Africa: A Review. Econ. Geol. 2025, 120, 513–539. [Google Scholar] [CrossRef]
- Tadesse, B.; Makuei, F.; Albijanic, B.; Dyer, L. The beneficiation of lithium minerals from hard rock ores: A review. Miner. Eng. 2019, 131, 170–184. [Google Scholar] [CrossRef]
- Kundu, T.; Rath, S.S.; Das, S.K.; Parhi, P.K.; Angadi, S.I. Recovery of lithium from spodumene-bearing pegmatites: A comprehensive review on geological reserves, beneficiation, and extraction. Powder Technol. 2023, 415, 118142. [Google Scholar] [CrossRef]
- Petrakis, E.; Alexopoulos, I.; Pantelaki, O.; Karmali, V.; Komnitsas, K. Advances in Mineral Processing of Hard-Rock Lithium Ores: A Comprehensive Review. Min. Metall. Explor. 2025, 42, 1251–1283. [Google Scholar] [CrossRef]
- Opoku, P.A.; Tadesse, B.; Albijanic, B.; Nikoloski, A.N. An overview of coarse particle beneficiation of lithium ores. Sci. Rep. 2025, 15, 29091. [Google Scholar] [CrossRef] [PubMed]
- Sahoo, S.K.; Tripathy, S.K.; Nayak, A.; Hembrom, K.C.; Dey, S.; Rath, R.K.; Mohanta, M.K. Beneficiation of lithium bearing pegmatite rock: A review. Miner. Process. Extr. Metall. Rev. 2024, 45, 1–27. [Google Scholar] [CrossRef]
- Kawenski Cook, B.; Aghamirian, M.; Gibson, C.E. Optimization of spodumene flotation with a fatty acid collector. Miner. Eng. 2023, 204, 108412. [Google Scholar] [CrossRef]
- Cook, B.K.; Gibson, C.E. A Review of Fatty Acid Collectors: Implications for Spodumene Flotation. Minerals 2023, 13, 212. [Google Scholar] [CrossRef]
- Gibson, C.E.; Aghamirian, M.; Grammatikopoulos, T.; Smith, D.L.; Bottomer, L. The Recovery and Concentration of Spodumene Using Dense medium separation. Minerals 2021, 11, 649. [Google Scholar] [CrossRef]
- Napier-Munn, T. The dense medium cyclone—Past, present and future. Miner. Eng. 2018, 116, 107–113. [Google Scholar] [CrossRef]
- Brandt, F.; Haus, R. New concepts for lithium minerals processing. Miner. Eng. 2010, 23, 659–661. [Google Scholar] [CrossRef]
- Lowry, C.S.; le Roux, J.D.; Craig, I.K. Modelling, analysis and validation of a dynamic dense medium separation circuit model for detecting medium losses. Miner. Eng. 2024, 210, 108652. [Google Scholar] [CrossRef]
- Wang, S.; Wang, J.; Qiu, G.; Shen, L.; Liao, R.; Wu, L. Computational and Experimental Research on Dense Medium Separation of Low-Grade Spodumene. Minerals 2025, 15, 434. [Google Scholar] [CrossRef]
- Peltosaari, O.; Tanskanen, P.; Hautala, S.; Heikkinen, E.-P.; Fabritius, T. Mechanical enrichment of converted spodumene by selective sieving. Miner. Eng. 2016, 98, 30–39. [Google Scholar] [CrossRef]
- Sagzhanov, D.; Ito, J.; Altansukh, B.; Godirilwe, L.L.; Haga, K.; Takasaki, Y.; Shibayama, A. Lithium Ore Beneficiation: Sustainable Approaches for Efficient Recovery of Lithium from a Low-Grade Spodumene Ore. J. Sustain. Metall. 2025, 11, 754–772. [Google Scholar] [CrossRef]
- Yan, Q.H.; Wang, H.; Chi, G.; Wang, Q.; Hu, H.; Zhou, K.; Zhang, X.Y. Recognition of a 600-km-long Late Triassic rare metal (Li-Rb-Be-Nb-Ta) pegmatite belt in the Western Kunlun orogenic belt, western China. Econ. Geol. 2022, 117, 213–236. [Google Scholar] [CrossRef]
- Hong, T.; Harlaux, M.; Zhai, M.G.; Wang, Y.J.; Xu, X.W.; Xia, X.P.; Gao, J.; Tang, J.L.; Hu, M.X.; Gao, H.X. Syn-tectonic emplacement of Li-bearing pegmatites related to detachment faulting in the Dahongliutan pegmatite belt, Western Kunlun, NW China. Miner. Deposita 2025. ahead of print. [Google Scholar] [CrossRef]
- Zeng, Z.C.; Fan, J.J.; Wang, Z.L.; Du, B.; Wang, P.; Hong, Z.L. The role of fluid exsolution in the Li enrichment in granitic pegmatites: A case study from the Dahongliutan Li ore field in West Kunlun. Ore Geol. Rev. 2025, 178, 106491. [Google Scholar] [CrossRef]
- Ferreira, S.L.C.; Bezerra, M.A.; Santos, A.S.; dos Santos, W.N.L.; Novaes, C.G.; de Oliveira, O.M.C.; Oliveira, M.L.; Garcia, R.L. Atomic absorption spectrometry—A multi element technique. TrAC Trends Anal. Chem. 2018, 100, 1–6. [Google Scholar] [CrossRef]
- Douvris, C.; Vaughan, T.; Bussan, D.; Bartzas, G.; Thomas, R. How ICP-OES changed the face of trace element analysis: Review of the global application landscape. Sci. Total Environ. 2023, 905, 167242. [Google Scholar] [CrossRef]
- Nicholas, C.L.; Mowat, J.P.S.; Nicholas, C.P. Tutorial review on catalyst characterization and materials preparation for x-ray powder diffraction analysis. Appl. Catal. A Gen. 2025, 692, 120093. [Google Scholar] [CrossRef]
- Simonnet, T.; Grangeon, S.; Claret, F.; Maubec, N.; Fall, M.D.; Harba, R.; Galerne, B. Phase quantification using deep neural network processing of XRD patterns. IUCrJ 2024, 11, 859–870. [Google Scholar] [CrossRef]
- Liu, Y.; Lu, Z.; Wang, J.; Li, W. Froth flotation separation of spodumene ore using (E)-octadec-9-enoylglycine as the flotation collector. Results Eng. 2025, 28, 107439. [Google Scholar] [CrossRef]
Figure 1.
(a) Principal process flow chart; (b) process flow chart of two-product; (c) process flow chart of pressureless three-product; and (d) process flow chart of two-stage, two-product.
Figure 1.
(a) Principal process flow chart; (b) process flow chart of two-product; (c) process flow chart of pressureless three-product; and (d) process flow chart of two-stage, two-product.
Figure 2.
XRD pattern of the raw ore sample.
Figure 3.
Mineralogical characteristics of lithium-containing minerals: (a) semi-euhedral columnar spodumene; (b) fine-grained spodumene aggregate; (c) columnar spodumene aggregate; (d) spodumene associated with lepidolite and microcrystalline K-feldspar; (e) lepidolite intergrown with quartz.
Figure 3.
Mineralogical characteristics of lithium-containing minerals: (a) semi-euhedral columnar spodumene; (b) fine-grained spodumene aggregate; (c) columnar spodumene aggregate; (d) spodumene associated with lepidolite and microcrystalline K-feldspar; (e) lepidolite intergrown with quartz.
Figure 4.
Mineralogical characteristics of metallic minerals.
Figure 5.
Mineralogical characteristics of gangue minerals: (a) coarse feldspar with quartz; (b) fine-grained feldspar among quartz grains; (c) fractured quartz intergrown with feldspar.
Figure 5.
Mineralogical characteristics of gangue minerals: (a) coarse feldspar with quartz; (b) fine-grained feldspar among quartz grains; (c) fractured quartz intergrown with feldspar.
Figure 6.
Two-product dense-medium separation tests: (a) 0.5–6 mm size fraction; (b) 0.5–10 mm size fraction; (c) 0.5–15 mm size fraction.
Figure 6.
Two-product dense-medium separation tests: (a) 0.5–6 mm size fraction; (b) 0.5–10 mm size fraction; (c) 0.5–15 mm size fraction.
Figure 7.
Curves of spodumene recovery and grade varying with medium density in different dense-medium separation processes for spodumene ((a) two-product dense-medium separation process; (b) three-product dense-medium separation process without pressure; (c) first stage of two-stage; two-product dense-medium separation process; (d) second stage of two-stage; two-product dense-medium separation process).
Figure 7.
Curves of spodumene recovery and grade varying with medium density in different dense-medium separation processes for spodumene ((a) two-product dense-medium separation process; (b) three-product dense-medium separation process without pressure; (c) first stage of two-stage; two-product dense-medium separation process; (d) second stage of two-stage; two-product dense-medium separation process).
Figure 8.
The flow chart.
Table 1.
Results of multi-element analysis of the raw ore (%).
| Composition | Li2O | BeO | Ta2O5 | Nb2O5 | Cs2O | Rb2O | K2O | Na2O |
|---|---|---|---|---|---|---|---|---|
| Grade | 1.39 | 0.040 | 0.0031 | 0.0062 | 0.0061 | 0.12 | 2.43 | 4.05 |
| Composition | Fe2O3 | P2O5 | Al2O3 | CaO | MgO | SiO2 | MnO2 | TFe |
| Grade | 0.29 | 0.34 | 16.36 | 0.40 | 0.068 | 71.68 | 0.089 | 0.54 |
Table 2.
Identified mineral phases, chemical formulas, and PDF card numbers of the raw ore sample.
| Mineral Name | Chemical Formula | PDF Card No. |
|---|---|---|
| Spodumene | LiAlSi2O6 | 01-071-1509 |
| Plagioclase | (Ca,Na)(Al,Si)2Si2O8 | 00-009-0465 |
| Quartz | SiO2 | 00-005-0490 |
| K-feldspar | KAlSi3O8 | 00-019-0932 |
Table 3.
Relative content of major minerals in the sample (%).
| Mineral Group | Mineral Name | Relative Content | Subtotal |
|---|---|---|---|
| Metallic Minerals | Tantalum–niobium iron ore | 0.02 | 0.05 |
| Manganese iron oxide | 0.01 | ||
| Manganese iron phosphate | 0.02 | ||
| Lithium Minerals | Spodumene | 21.60 | 27.18 |
| Lepidolite (lithium muscovite) | 4.98 | ||
| Phosphate lithium aluminate | 0.35 | ||
| Lithium iron tourmaline | 0.25 | ||
| Gangue Minerals | Quartz | 28.26 | 72.77 |
| Plagioclase | 33.19 | ||
| K-feldspar | 10.90 | ||
| Cassiterite | 0.05 | ||
| Others | 0.37 |
Table 4.
Particle-size distribution of selected minor minerals (%).
| Particle-Size Range (μm) | Tantalum–Niobium Iron Ore | Phosphate Lithium Aluminate | Cassiterite | |||
|---|---|---|---|---|---|---|
| Discrete | Cumulative | Discrete | Cumulative | Discrete | Cumulative | |
| >250 | / | / | 35.66 | / | 55.80 | / |
| 250~106 | 19.16 | / | 11.11 | 46.77 | 8.86 | 64.66 |
| 106~75 | / | 19.16 | 17.76 | 64.53 | 19.15 | 83.81 |
| 75~38 | 25.33 | 44.49 | 16.64 | 81.17 | 9.43 | 93.24 |
| 38~19 | 23.67 | 68.16 | 11.50 | 92.67 | 4.22 | 97.46 |
| 19~9.6 | 16.52 | 84.68 | 6.96 | 99.63 | 2.42 | 99.88 |
| <9.6 | 15.32 | 100.00 | 0.37 | 100.00 | 0.12 | 100.00 |
| Total | 100.00 | / | 100.00 | / | 100.00 | / |
| Pass, % | μm | |||||
| P20 | 11.12 | 20.15 | 44.52 | |||
| P50 | 33.41 | 67.11 | 133.28 | |||
| P80 | 74.08 | 226.59 | 246.31 | |||
Table 5.
Particle-size distribution of major lithium-bearing minerals (%).
| Particle-Size Range (μm) | Spodumene | Lepidolite (Lithium Muscovite) | Lithium Iron Tourmaline | |||
|---|---|---|---|---|---|---|
| Discrete | Cumulative | Discrete | Cumulative | Discrete | Cumulative | |
| >1000 | 11.11 | / | / | / | / | / |
| 1000~500 | 28.67 | 39.78 | 15.82 | / | / | / |
| 500~250 | 29.34 | 69.12 | 28.99 | 44.81 | 36.65 | / |
| 250~106 | 15.93 | 85.05 | 26.05 | 70.86 | 31.07 | 67.72 |
| 106~75 | 4.00 | 89.05 | 8.23 | 79.09 | 9.28 | 77.00 |
| 75~38 | 5.32 | 94.37 | 10.47 | 89.56 | 12.41 | 89.41 |
| 38~19 | 3.29 | 97.66 | 5.93 | 95.49 | 3.47 | 92.88 |
| 19~9.6 | 1.78 | 99.44 | 3.37 | 98.86 | 5.64 | 98.52 |
| <9.6 | 0.56 | 100.00 | 1.14 | 100.00 | 1.48 | 100.00 |
| Total | 100.00 | / | 100.00 | / | 100.00 | / |
| Pass, % | μm | μm | μm | |||
| P20 | 155.96 | 71.65 | 59.28 | |||
| P50 | 421.67 | 207.90 | 188.57 | |||
| P80 | 793.24 | 417.55 | 331.36 | |||
Table 6.
Particle-size distribution of major gangue minerals (%).
| Particle-Size Range (μm) | Quartz | Feldspar | ||
|---|---|---|---|---|
| Discrete | Cumulative | Discrete | Cumulative | |
| >1000 | 9.94 | / | 7.44 | / |
| 1000~500 | 28.91 | 38.85 | 25.42 | 32.86 |
| 500~250 | 28.23 | 67.08 | 30.6 | 63.46 |
| 250~106 | 16.12 | 83.20 | 18.23 | 81.69 |
| 106~75 | 4.05 | 87.25 | 4.67 | 86.36 |
| 75~38 | 5.99 | 93.24 | 6.48 | 92.84 |
| 38~19 | 3.90 | 97.14 | 4.16 | 97.00 |
| 19~9.6 | 2.22 | 99.36 | 2.33 | 99.33 |
| <9.6 | 0.64 | 100.00 | 0.67 | 100.00 |
| Total | 100.00 | / | 100.00 | / |
| Pass, % | μm | μm | ||
| P20 | 132.14 | 118.65 | ||
| P50 | 403.54 | 360.06 | ||
| P80 | 714.32 | 688.11 | ||
Table 7.
Statistical results of monomer dissociation for selected minerals (Area%).
| Mineral Name | Spodumene | Lepidolite | Phosphate Lithium Aluminate | Lithium Iron Tourmaline | Tantalum–Niobium Iron Ore | |
|---|---|---|---|---|---|---|
| Monomer | 93.95 | 89.85 | 89.49 | 77.59 | 79.62 | |
| Intergrowth | With spodumene | / | 2.30 | 0.24 | 5.01 | 0.30 |
| With lepidolite | 1.23 | 0.00 | 1.15 | 4.52 | 0.53 | |
| With phosphate lithium aluminate | / | 0.03 | 0.00 | 0.07 | / | |
| With lithium iron tourmaline | 0.22 | 0.30 | 0.11 | / | 0.68 | |
| With tantalum–niobium, iron ore, and cassiterite | / | 0.01 | / | 0.17 | / | |
| With quartz | 1.51 | 1.64 | 1.82 | 4.75 | 7.98 | |
| With feldspar | 3.06 | 5.78 | 6.50 | 7.80 | 9.74 | |
| With other minerals | 0.03 | 0.10 | 0.69 | 0.10 | 1.15 | |
| Total | 100.00 | 100.01 | 100.00 | 100.01 | 100.00 | |
Table 8.
Monomer dissociation statistics of major lithium-bearing minerals in different particle-size ranges (Area%).
Table 8.
Monomer dissociation statistics of major lithium-bearing minerals in different particle-size ranges (Area%).
| Mineral Name | >0.074 | 0.074~0.038 | 0.038~0.023 | <0.023 |
|---|---|---|---|---|
| Intergrowth state | Monomer | |||
| Spodumene | 93.97 | 91.65 | 93.74 | 97.05 |
| Lepidolite | 85.93 | 90.24 | 95.51 | 94.70 |
| Phosphate lithium aluminate | 76.07 | 91.12 | 91.44 | 95.47 |
| Lithium iron tourmaline | 74.53 | 89.01 | 76.54 | 69.71 |
| Intergrowth state | Intergrowth with other lithium-bearing minerals | |||
| Spodumene | 1.66 | 0.44 | 0.35 | 0.09 |
| Lepidolite | 3.23 | 1.24 | 0.58 | 0.26 |
| Phosphate lithium aluminate | 0.62 | 3.29 | 9.53 | 4.45 |
| Lithium iron tourmaline | 17.88 | 5.44 | 15.34 | 7.00 |
| Intergrowth state | Intergrowth with metallic and gangue minerals | |||
| Spodumene | 4.37 | 6.91 | 5.29 | 2.17 |
| Lepidolite | 10.84 | 6.73 | 3.24 | 3.81 |
| Phosphate lithium aluminate | 23.31 | 6.12 | 6.23 | 3.78 |
| Lithium iron tourmaline | 7.59 | 5.55 | 8.12 | 23.30 |
| Total | ||||
| Spodumene | 100.00 | 100.01 | 100.00 | 100.00 |
| Lepidolite | 100.00 | 100.00 | 100.00 | 100.00 |
| Phosphate lithium aluminate | 100.00 | 100.01 | 100.00 | 100.00 |
| Lithium iron tourmaline | 100.00 | 100.00 | 100.00 | 100.00 |
Table 9.
Particle-size composition of feed material.
| Sample | Size Fraction (mm) | Yield (%) | Grade (%) |
|---|---|---|---|
| 0.5~15 mm | +0.5 | 94.29% | 1.84 |
| −0.5 | 5.71% | 1.73 | |
| Total | 100.00% | 1.83 | |
| 0.5~10 mm | +0.5 | 91.73% | 1.93 |
| −0.5 | 8.27% | 1.63 | |
| Total | 100.00% | 1.91 | |
| 0.5~6 mm | +0.5 | 85.66 | 2.08 |
| −0.5 | 14.34% | 1.13 | |
| Total | 100.00% | 1.94 |
Disclaimer/Publisher’s Note: The statements, opinions and data contained in all publications are solely those of the individual author(s) and contributor(s) and not of MDPI and/or the editor(s). MDPI and/or the editor(s) disclaim responsibility for any injury to people or property resulting from any ideas, methods, instructions or products referred to in the content. |
© 2026 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license.
Share and Cite
MDPI and ACS Style
Cui, B.; Wen, S.; Liu, J.; Fei, A. Linking Mineralogical Characteristics to Dense-Medium Separation Performance: A Case Study of the Dahongliutan Spodumene Deposit in Xinjiang. Minerals 2026, 16, 408. https://doi.org/10.3390/min16040408
AMA Style
Cui B, Wen S, Liu J, Fei A. Linking Mineralogical Characteristics to Dense-Medium Separation Performance: A Case Study of the Dahongliutan Spodumene Deposit in Xinjiang. Minerals. 2026; 16(4):408. https://doi.org/10.3390/min16040408
Chicago/Turabian StyleCui, Bao, Shuming Wen, Jian Liu, and Aoxiang Fei. 2026. "Linking Mineralogical Characteristics to Dense-Medium Separation Performance: A Case Study of the Dahongliutan Spodumene Deposit in Xinjiang" Minerals 16, no. 4: 408. https://doi.org/10.3390/min16040408
APA StyleCui, B., Wen, S., Liu, J., & Fei, A. (2026). Linking Mineralogical Characteristics to Dense-Medium Separation Performance: A Case Study of the Dahongliutan Spodumene Deposit in Xinjiang. Minerals, 16(4), 408. https://doi.org/10.3390/min16040408
Note that from the first issue of 2016, this journal uses article numbers instead of page numbers. See further details here.
