Coal slimes are mainly composed of coal and clay particles.The interaction energies among these particles were calculated using extended DLVO(DERJAGUIN-LANDAU-VERWEY-OVERBEEK)theory and the aggregation mechanisms were...Coal slimes are mainly composed of coal and clay particles.The interaction energies among these particles were calculated using extended DLVO(DERJAGUIN-LANDAU-VERWEY-OVERBEEK)theory and the aggregation mechanisms were analyzed based on the settling experiments for coal-kaolinite and coal-montmorillonite suspensions,respectively,under different conditions of water hardness.The results indicate that for coal-kaolinite suspensions,as the water hardness reaches 10.0mol/L,the coal particles aggregate with each other easily,and then,the coal particles may aggregate with kaolinite particles.However,no aggregation occurs between kaolinite particles.A clay platelet network is formed in coal-montmorillonite suspensions by montmorillonite particles and coal particles are captured into the network.Coal and montmorillonite particles settle completely.展开更多
The flotation of diasporic bauxite is to separate diaspore(valuable mineral)from aluminosilicate minerals(gangue minerals,mainly including kaolinite,illite and pyrophyllite),and the microscopic interaction force betwe...The flotation of diasporic bauxite is to separate diaspore(valuable mineral)from aluminosilicate minerals(gangue minerals,mainly including kaolinite,illite and pyrophyllite),and the microscopic interaction force between the two types of minerals and air bubbles determines the separation efficiency.In this paper,based on the extended Derjaguin-Landau-Verwey-Overbeek(DLVO)theory,the van der Waals,electrostatic and hydrophobic interaction between particles of the four minerals mentioned above and air bubbles in collectorless solution were calculated first,and then diaspore and kaolinite were taken as examples to analyze the influence of various factors such as electrolyte concentration,mineral particle size,air bubble size,collector type(dodecylamine hydrochloride(DAH)and sodium oleate(NaOL))and concentration,and pulp pH on the interactions between the particles of valuable mineral and gangue minerals and air bubbles.The results showed that the total extended DLVO interactions between the four minerals and air bubbles were repulsive in most cases in collectorless solution.The increase in electrolyte concentration reduced the interaction force or even changed the direction of the force under certain circumstances.The addition of DAH and NaOL can reduce the adhesion energy barrier of kaolinitebubble and diaspore-bubble respectively.Each type of minerals exhibited a specific interface interaction response with air bubbles in each collector with different pH values.The research results have theoretical guiding significance for the optimization and directional control of diasporic bauxite flotation conditions.展开更多
The extended DLVO theory was used to analyze the stability of emulsion stabilized by solid particles. It was emphasized that emulsion droplets covered by solid particles behaved as congener solid granules with the sam...The extended DLVO theory was used to analyze the stability of emulsion stabilized by solid particles. It was emphasized that emulsion droplets covered by solid particles behaved as congener solid granules with the same diameter as droplets. The interaction potential energy curves between emulsion droplets stabilized by mica particles in the copper solvent extraction system were calculated. The results show that the effect of hydration repulsive forces are more powerful than that of electrostatic forces on stabilizing droplets for O/W emulsions. The energy barrier between droplets increases dramatically by about 7 × 103 kT when the hydration repulsion is considered.展开更多
Not only the basic principle of the extended DLVO has been expounded, but also all kinds of interaction energies between fine particles in coal slurry suspension have been calculated in this peper. Coal is a natural h...Not only the basic principle of the extended DLVO has been expounded, but also all kinds of interaction energies between fine particles in coal slurry suspension have been calculated in this peper. Coal is a natural hydrophobic mineral, and the hydrophobic attractive power between coal surfaces is a decisive factor to the aggregation of particles in hydrophobic suspensions. The calculation results show that the extended DLVO theory can explain successfully the coagulation or dispersion of fine particle coal.展开更多
In order to alleviate the pressure on the supply of lithium resources, this research proposes the use of binary/ternary collectors with high selectivity and collecting ability to enhance the flotation purification of ...In order to alleviate the pressure on the supply of lithium resources, this research proposes the use of binary/ternary collectors with high selectivity and collecting ability to enhance the flotation purification of low-grade zinnwaldite ore. The binary collector is a mixture of dodecylamine polyoxyethylene ether and DL-2-octanol. A binary collector is added first, followed by sodium oleate, known as a ternary collector. Under acidic conditions, the recovery of Li2O in the concentrate was increased by 8.26% with the binary collector and 13.70% with the ternary collector, compared to the dodecylamine polyoxyethylene ether. The binary collector enhanced the dispersibility of the single collector, while co-adsorption strengthened the hydrophobic nature of the zinnwaldite surface. Consequently, zinnwaldite particles,after the application of binary collector, displayed inter-particle flocculation and attachment to bubbles within 60×10^(-9)m compared to other particles. Ternary collector exhibited the capacity to lower critical micelle concentration and surface tension, subsequently inducing a denser and thicker hydrophobic layer through electrostatic forces, hydrophobic interactions, and chemical reactions. The objective of this research is to facilitate the recovery of lithium resources from low-grade ores in order to meet the needs of sustainable development.展开更多
基金Project(50425168)supported by the National Natural Science Foundation of ChinaProject (0100471413)supported by China Postdoctoral Science FoundationProject (201104547)supported by Pisdoctorcal Science Foundation of Jiangsu Province,China
文摘Coal slimes are mainly composed of coal and clay particles.The interaction energies among these particles were calculated using extended DLVO(DERJAGUIN-LANDAU-VERWEY-OVERBEEK)theory and the aggregation mechanisms were analyzed based on the settling experiments for coal-kaolinite and coal-montmorillonite suspensions,respectively,under different conditions of water hardness.The results indicate that for coal-kaolinite suspensions,as the water hardness reaches 10.0mol/L,the coal particles aggregate with each other easily,and then,the coal particles may aggregate with kaolinite particles.However,no aggregation occurs between kaolinite particles.A clay platelet network is formed in coal-montmorillonite suspensions by montmorillonite particles and coal particles are captured into the network.Coal and montmorillonite particles settle completely.
基金supported by the National Natural Science Foundation of China(No.51904240,51904239,52104268)the Natural Science Foundation of Shaanxi Province(No.2020JQ-752,2021JQ-571)+3 种基金the Postdoctoral Science Foundation of China(No.2019M653877XB)the Outstanding Youth Science Foundation of Xi’an University of Science and Technology(No.2019YQ3-08)the Huo Yingdong Education Foundation(No.171102)the 2019 Merit-based Science and Technology Project Foundation for Shannxi Overseas-educated Scholars(No.14).
文摘The flotation of diasporic bauxite is to separate diaspore(valuable mineral)from aluminosilicate minerals(gangue minerals,mainly including kaolinite,illite and pyrophyllite),and the microscopic interaction force between the two types of minerals and air bubbles determines the separation efficiency.In this paper,based on the extended Derjaguin-Landau-Verwey-Overbeek(DLVO)theory,the van der Waals,electrostatic and hydrophobic interaction between particles of the four minerals mentioned above and air bubbles in collectorless solution were calculated first,and then diaspore and kaolinite were taken as examples to analyze the influence of various factors such as electrolyte concentration,mineral particle size,air bubble size,collector type(dodecylamine hydrochloride(DAH)and sodium oleate(NaOL))and concentration,and pulp pH on the interactions between the particles of valuable mineral and gangue minerals and air bubbles.The results showed that the total extended DLVO interactions between the four minerals and air bubbles were repulsive in most cases in collectorless solution.The increase in electrolyte concentration reduced the interaction force or even changed the direction of the force under certain circumstances.The addition of DAH and NaOL can reduce the adhesion energy barrier of kaolinitebubble and diaspore-bubble respectively.Each type of minerals exhibited a specific interface interaction response with air bubbles in each collector with different pH values.The research results have theoretical guiding significance for the optimization and directional control of diasporic bauxite flotation conditions.
文摘The extended DLVO theory was used to analyze the stability of emulsion stabilized by solid particles. It was emphasized that emulsion droplets covered by solid particles behaved as congener solid granules with the same diameter as droplets. The interaction potential energy curves between emulsion droplets stabilized by mica particles in the copper solvent extraction system were calculated. The results show that the effect of hydration repulsive forces are more powerful than that of electrostatic forces on stabilizing droplets for O/W emulsions. The energy barrier between droplets increases dramatically by about 7 × 103 kT when the hydration repulsion is considered.
文摘Not only the basic principle of the extended DLVO has been expounded, but also all kinds of interaction energies between fine particles in coal slurry suspension have been calculated in this peper. Coal is a natural hydrophobic mineral, and the hydrophobic attractive power between coal surfaces is a decisive factor to the aggregation of particles in hydrophobic suspensions. The calculation results show that the extended DLVO theory can explain successfully the coagulation or dispersion of fine particle coal.
文摘根据Young s方程的推导公式结合接触角的测定结果计算黄铁矿和氧化亚铁硫杆菌的表面能参数。结果表明,氧化亚铁硫杆菌的表面能明显高于黄铁矿的表面能。应用热力学计算氧化亚铁硫杆菌在黄铁矿表面吸附的自由能,发现其吸附自由能为正值,无法解释氧化亚铁硫杆菌在黄铁矿表面的吸附现象,而通过扩展DLVO理论建立的Lifshitz-van der Waals(LW)、Lewis acid-base(AB)和静电(EL)作用自由能与作用距离(d)之间的势能曲线,能够准确的预言氧化亚铁硫杆菌在黄铁矿表面的吸附现象。
基金supported by the National Key Research and Development Program of China(No.2023YFC2811403).
文摘In order to alleviate the pressure on the supply of lithium resources, this research proposes the use of binary/ternary collectors with high selectivity and collecting ability to enhance the flotation purification of low-grade zinnwaldite ore. The binary collector is a mixture of dodecylamine polyoxyethylene ether and DL-2-octanol. A binary collector is added first, followed by sodium oleate, known as a ternary collector. Under acidic conditions, the recovery of Li2O in the concentrate was increased by 8.26% with the binary collector and 13.70% with the ternary collector, compared to the dodecylamine polyoxyethylene ether. The binary collector enhanced the dispersibility of the single collector, while co-adsorption strengthened the hydrophobic nature of the zinnwaldite surface. Consequently, zinnwaldite particles,after the application of binary collector, displayed inter-particle flocculation and attachment to bubbles within 60×10^(-9)m compared to other particles. Ternary collector exhibited the capacity to lower critical micelle concentration and surface tension, subsequently inducing a denser and thicker hydrophobic layer through electrostatic forces, hydrophobic interactions, and chemical reactions. The objective of this research is to facilitate the recovery of lithium resources from low-grade ores in order to meet the needs of sustainable development.
