Mechanism of Selective Alkaline Dissolution of Spodumene Surfaces AITranslate
Abstract AITranslate
For the nation, lithium is a vital resource. The process of extracting lithium from ores is now the main way to obtain lithium metal. Flotation is the method most frequently used to extract lithium from lithium spodumene. During flotation, surface qualities are typically regulated by mechanical, ultrasonic, acidic, or alkaline treatments in order to enhance the difference in surface properties between spodumene and gangue minerals. In particular, sodium hydroxide's weak alkaline treatment is the most practical and efficient. This article began with the crystal structure of spodumene. Using Materials Studio (MS) software, a crystal model of spodumene was built based on density functional theory. To start, a convergence test was run to figure out what value of plane wave truncation energy (Ecut) and k-point sampling density (k-point) is right. Second, using the CASTEP module in MS software, appropriate parameters were chosen to optimize the shape of the crystal model. Next, the usual spodumene cleavage planes (110) and (001) should be removed, and their respective surface energies should be ascertained. Ultimately, the most stable crystal plane model was chosen as a depiction of the spodumene surface by comparing the surface energies of the two crystal planes. With the use of the GGA-PBE basis set of the DMol3 module, the adsorption energy of the hydroxide ion adsorption model at the Li, Al, and Si atomic sites on the crystal plane was determined. In parallel, the mechanism of selective alkali corrosion on the surface of spodumene was found and examined using X-ray photoelectron spectroscopy (XPS) and atomic force microscopy (AFM) methods. According to the MS calculation results, it was discovered through convergence testing that the energy of the spodumene crystal model first fell and then progressively approached equilibrium when Ecut and k-point rise. When optimizing the shape of spodumene crystals, the estimated energy difference indicated that 662 eV was the appropriate Ecut value, with a k-point of 3×3×3. Out of the two primary cleavage planes of spodumene, the (110) surface was more likely to occur, as indicated by the computed surface energies of the spodumene (110) and (001) surfaces, which were 0.65 and 1.42 J·m−2. In addition, the (110) plane was more stable than the (001) plane since it required less energy to create. Consequently, it was shown that the (110) plane was the most frequent cleavage plane for spodumene when grinding or natural conditions were met. The values of the adsorption energies were determined to be –1.61, –1.98, and –3.18 kJ·mol−1 by creating an adsorption model for hydroxide ions on the top sites of Li, Al, and Si atoms on the (110) crystal plane of spodumene. As a result, it was determined that hydroxide ions could spontaneously adsorb at Li, Al, and Si atomic sites and encourage the dissolution of atoms' bonds on the surface. The relative stability of their adsorption structures was Si>Al>Li, but overall stability was poor and desorption phenomena was likely to occur. According to the results of the AFM investigation, selective dissolving caused dissolution pits to form in some parts of the lithium spodumene surface, and weak alkaline treatment considerably increased the surface roughness of the material. There were numerous large or little projecting particles in the range of height variation, which had grown from –3.9~2.6 to –318.7~274.1 nm. It might be concluded that the distribution and composition of atomic sites on the surface of spodumene were changed by the selective dissolving of sodium hydroxide, based on the results of the quantum chemical calculation discussed previously in the article. Spodumene's surface was weakly alkaline treated, as revealed by XPS technology, which resulted in changes to the binding energies of Li 1s (56.57 and 64.38 eV to 55.73 and 63.12 eV), Al 2p (75.06 to 74.49 eV), and Si 2p (102.90 to 102.75 and 101.95 eV). This reduced the binding energies of Li, Al, and Si atoms collectively. Parallel to this, the median binding energies of related compounds in the 1s orbitals of Li atoms, the 2p orbitals of Al atoms, and the 2p orbitals of Si atoms were compared via the National Institute of Standards and Technology (NIST) website. It could be observed from this that certain Li–O, Al–O, and Si–O bonds on the surface were selectively dissolved by sodium hydroxide. On the surface of spodumene, it resulted in modifications to the relative atomic contents of Li, Al, and Si. In addition, it adsorbed some hydroxide ions concurrently, revealing more Li, Al, and Si atomic sites on the surface of spodumene. As a result, this would enable the activation of metal ions and the adsorption of traps. It was demonstrated that a specific quantity of hydroxide ions can be adsorbed on the surface of spodumene while also encouraging the surface corrosion of some Li–O, Al–O, and Si–O bonds, etc. This resulted in the selectivity of alkali corrosion for Li, Si, and Al, exposing one or more new Li, Al, and Si atomic sites, which was advantageous for the following metal ion activation and collector's adsorption.
KeyWords AITranslate
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Basic Information:
DOI：10.13373/j.cnki.cjrm.XY24010002
Chinese Library Classification Number:TD954
Citation Information:
For the nation, lithium is a vital resource. The process of extracting lithium from ores is now the main way to obtain lithium metal. Flotation is the method most frequently used to extract lithium from lithium spodumene. During flotation, surface qualities are typically regulated by mechanical, ultrasonic, acidic, or alkaline treatments in order to enhance the difference in surface properties between spodumene and gangue minerals. In particular, sodium hydroxide's weak alkaline treatment is the most practical and efficient. This article began with the crystal structure of spodumene. Using Materials Studio (MS) software, a crystal model of spodumene was built based on density functional theory. To start, a convergence test was run to figure out what value of plane wave truncation energy (Ecut) and k-point sampling density (k-point) is right. Second, using the CASTEP module in MS software, appropriate parameters were chosen to optimize the shape of the crystal model. Next, the usual spodumene cleavage planes (110) and (001) should be removed, and their respective surface energies should be ascertained. Ultimately, the most stable crystal plane model was chosen as a depiction of the spodumene surface by comparing the surface energies of the two crystal planes. With the use of the GGA-PBE basis set of the DMol3 module, the adsorption energy of the hydroxide ion adsorption model at the Li, Al, and Si atomic sites on the crystal plane was determined. In parallel, the mechanism of selective alkali corrosion on the surface of spodumene was found and examined using X-ray photoelectron spectroscopy (XPS) and atomic force microscopy (AFM) methods. According to the MS calculation results, it was discovered through convergence testing that the energy of the spodumene crystal model first fell and then progressively approached equilibrium when Ecut and k-point rise. When optimizing the shape of spodumene crystals, the estimated energy difference indicated that 662 eV was the appropriate Ecut value, with a k-point of 3×3×3. Out of the two primary cleavage planes of spodumene, the (110) surface was more likely to occur, as indicated by the computed surface energies of the spodumene (110) and (001) surfaces, which were 0.65 and 1.42 J·m−2. In addition, the (110) plane was more stable than the (001) plane since it required less energy to create. Consequently, it was shown that the (110) plane was the most frequent cleavage plane for spodumene when grinding or natural conditions were met. The values of the adsorption energies were determined to be –1.61, –1.98, and –3.18 kJ·mol−1 by creating an adsorption model for hydroxide ions on the top sites of Li, Al, and Si atoms on the (110) crystal plane of spodumene. As a result, it was determined that hydroxide ions could spontaneously adsorb at Li, Al, and Si atomic sites and encourage the dissolution of atoms' bonds on the surface. The relative stability of their adsorption structures was Si>Al>Li, but overall stability was poor and desorption phenomena was likely to occur. According to the results of the AFM investigation, selective dissolving caused dissolution pits to form in some parts of the lithium spodumene surface, and weak alkaline treatment considerably increased the surface roughness of the material. There were numerous large or little projecting particles in the range of height variation, which had grown from –3.9~2.6 to –318.7~274.1 nm. It might be concluded that the distribution and composition of atomic sites on the surface of spodumene were changed by the selective dissolving of sodium hydroxide, based on the results of the quantum chemical calculation discussed previously in the article. Spodumene's surface was weakly alkaline treated, as revealed by XPS technology, which resulted in changes to the binding energies of Li 1s (56.57 and 64.38 eV to 55.73 and 63.12 eV), Al 2p (75.06 to 74.49 eV), and Si 2p (102.90 to 102.75 and 101.95 eV). This reduced the binding energies of Li, Al, and Si atoms collectively. Parallel to this, the median binding energies of related compounds in the 1s orbitals of Li atoms, the 2p orbitals of Al atoms, and the 2p orbitals of Si atoms were compared via the National Institute of Standards and Technology (NIST) website. It could be observed from this that certain Li–O, Al–O, and Si–O bonds on the surface were selectively dissolved by sodium hydroxide. On the surface of spodumene, it resulted in modifications to the relative atomic contents of Li, Al, and Si. In addition, it adsorbed some hydroxide ions concurrently, revealing more Li, Al, and Si atomic sites on the surface of spodumene. As a result, this would enable the activation of metal ions and the adsorption of traps. It was demonstrated that a specific quantity of hydroxide ions can be adsorbed on the surface of spodumene while also encouraging the surface corrosion of some Li–O, Al–O, and Si–O bonds, etc. This resulted in the selectivity of alkali corrosion for Li, Si, and Al, exposing one or more new Li, Al, and Si atomic sites, which was advantageous for the following metal ion activation and collector's adsorption.
quote
| GB/T 7714-2015 | [1] Zhenkun Cui, Tai Wang, Dianwen Liu, et al. Mechanism of Selective Alkaline Dissolution of Spodumene Surfaces[J]. Chinese Journal of Rare Metals, 2025, 49(12): 1920-1930. DOI:10.13373/j.cnki.cjrm.XY24010002. |
| MLA | [1] Zhenkun Cui, et al., "Mechanism of Selective Alkaline Dissolution of Spodumene Surfaces." Chinese Journal of Rare Metals, vol. 49, no. 12, 2025, pp. 1920-1930, https://doi.org/10.13373/j.cnki.cjrm.XY24010002. |
| APA | [1] Zhenkun Cui, Tai Wang, Dianwen Liu, Fen Jiao, Kaizhi Yang, & Peilun Li. (2025). Mechanism of Selective Alkaline Dissolution of Spodumene Surfaces. Chinese Journal of Rare Metals, 49(12), 1920-1930. https://doi.org/10.13373/j.cnki.cjrm.XY24010002 |
| IEEE | [1] Zhenkun Cui, Tai Wang, Dianwen Liu, Fen Jiao, Kaizhi Yang, and Peilun Li, "Mechanism of Selective Alkaline Dissolution of Spodumene Surfaces," Chinese Journal of Rare Metals, vol. 49, no. 12, pp. 1920-1930, 2025, doi: 10.13373/j.cnki.cjrm.XY24010002. keywords: {spodumene surface;quantum chemistry;selective alkali dissolution;hydroxide ion;adsorption} |