Well-ordered aluminosilicates(MAs)were prepared by in-situ assembly of pre-crystallized units of zeolite Y precursors at a commercial scale,and applied in an industrial fluid catalytic cracking unit for the first time...Well-ordered aluminosilicates(MAs)were prepared by in-situ assembly of pre-crystallized units of zeolite Y precursors at a commercial scale,and applied in an industrial fluid catalytic cracking unit for the first time.Compared with incumbent equilibrium catalyst,the surface area of trial equilibrium catalysts(30%inventory ratio)increased from 110 m^(2)g^(-1)to 120m^(2)g^(-1).Moreover,a significant increase of the mesoporous surfaceareaof trial equlibrium catalysts(30%inventoryrati)from 33 m g/to 40magi(22%increase).Furthermore,the equilibrium catalyst that contain 80%LPC-65 yields significantly lower heavy oil(0.23%)and higher total liquids(0.53%)compared with LDO-70.The industrial results demonstrated excellent hydrothermal stability and superior catalytic cracking properties,showing the promising futurein the industrial units.展开更多
The thermodynamic stability of sulfate ions on synthesized calcium aluminosilicate hydrate (C-A-S-H) microstructure with different Ca/Si ratios and Al/Si ratios was investigated by XRD, SEM-EDS, 29Si and 27A1 nuclear ...The thermodynamic stability of sulfate ions on synthesized calcium aluminosilicate hydrate (C-A-S-H) microstructure with different Ca/Si ratios and Al/Si ratios was investigated by XRD, SEM-EDS, 29Si and 27A1 nuclear magnetic resonance (NMR) and thermodynamic modeling. The results indicate that sulfate attack leads to both decalcification and dealumination for C-A-S-H gels, and the amount of corrosion products (gypsum and ettringite) decreased gradually with decreasing Ca/Si ratios of C-A-S-H. Sulfate ions can also promote the polymerization degree of C-A-S-H gels, improving its resistance to sulfate attack. Moreover, the 4-coordination aluminum (Al[4]) in C-A-S-H, 5-coordination aluminum (Al[5]), 6-ccordination aluminum (A1[6J) in TAH (third aluminum hydrate) and Al[6] in monosulfate or C-A-H (calcium aluminate hydrate) can be transformed into Al[6] in ettringite by sulfate attack. Furthermore, through thermodynamic calculation, the decrease of Ca/Si ratios and increase of Al/Si ratios can improve the thermodynamic stability of C-A-S-H gels under sulfate attack, which agrees well with the experiment results.展开更多
In this study the characterization of an aluminosilicate synthesized from commercial Al2(SO4)3 and colloidal SiO2 is presented, as well as its capacity for the removal of copper from aqueous solution. Characterization...In this study the characterization of an aluminosilicate synthesized from commercial Al2(SO4)3 and colloidal SiO2 is presented, as well as its capacity for the removal of copper from aqueous solution. Characterization of the synthesized material was performed using X-ray diffraction, BET nitrogen adsorption-desorption, mass titration and the Boehm method. In order to obtain stable agglomeration and enhance its surface area (165 - 243 m2/g) and solid adsorbing capabilities, the molar ratio SiO2:Al2O3 (1:3, 1:1 and 3:1) was studied, the solubility of the preparation material, synthesis-procedure time and solution pH function were also examined. The maximum capacity to remove copper ions from an aqueous solution by synthesized aluminosilicate was 16 mg/g at pH 4 and 25℃. The Langmuir model fitted better to the copper adsorption experimental data.展开更多
In pyrometallurgical process, Al-and Si-bearing minerals in iron and aluminum ores are easily transformed into sodium aluminosilicates in the presence of Na_2O constituents, which alters the leaching behaviors of Al_2...In pyrometallurgical process, Al-and Si-bearing minerals in iron and aluminum ores are easily transformed into sodium aluminosilicates in the presence of Na_2O constituents, which alters the leaching behaviors of Al_2O_3 and SiO_2. It was confirmed that sodium aluminosilicates with different phase compositions synthesized at various roasting conditions were effectively digested in the alkaline digestion process. Under the optimum conditions at temperature of 100–120°C, liquid-to-solid ratio(L/S) of 10:2 mL/g, caustic ratio of 4, and Na_2O concentration of 240 g/L, the actual and relative digestion ratio of Al_2O_3 from the synthesized sodium aluminosilicates reached maximums of about 65% and 95%, respectively, while SiO_2 was barely leached out. To validate the superior digestion property of sodium aluminosilicate generated via an actual process, the Bayer digestion of an Al_2O_3-rich material derived from reductive roasting of bauxite and comprising Na_(1.75) Al_(1.75) Si_(0.25)O_4 was conducted; the relative digestion ratio of Al_2O_3 attained 90% at 200°C.展开更多
Molecular dynamics simulation was utilized to investigate the transport and adsorption of chloride in the nanopore of calcium aluminosilicate hydrate(C-A-S-H)with associated cation types of Ca,Mg,Na and K.The local io...Molecular dynamics simulation was utilized to investigate the transport and adsorption of chloride in the nanopore of calcium aluminosilicate hydrate(C-A-S-H)with associated cation types of Ca,Mg,Na and K.The local ionic structure,atomic dynamics and bond stability were analyzed to elucidate the interaction between cations and chloride ions.The results show that interfacial chloride is absorbed through the ion pairing formation in the vicinity of C-A-S-H substrate.Interfacial cations can simultaneously interact aluminosilicate chains,water molecules and Cl^(-)ions,which restrict the motion of interfacial Cl^(-)ions.Pore solution chloride can be immobilized through the solvation effect of cations.Cations along with their hydration shell can connect to neighboring Cl^(-)ions to decrease their mobility.Owing to the varied ionic chemistry,cations show different interaction strength with neighboring water molecules and anions,which determines the chloride transport behavior in the nanopore of C-A-S-H.The chloride immobilization capacity of C-A-S-H nanopore with different associated cations is listed in following order:Mg^(2+)Ca^(2+)<Na^(+)≈K^(+),which agrees reasonably with previous experiments.展开更多
Wood-based panels containing urea-formaldehyde resin result in the long-term release of formaldehyde and threaten human health.In this study,inorganic aluminosilicate coatings prepared by combining metakaolin,silica f...Wood-based panels containing urea-formaldehyde resin result in the long-term release of formaldehyde and threaten human health.In this study,inorganic aluminosilicate coatings prepared by combining metakaolin,silica fume,NaOH,and H_(2)O were applied to the surfaces of wood-based panels to obstruct formaldehyde release.The Si/Al,Na/Al,and H_(2)O/Na_(2)O molar ratios of the coatings were regulated to investigate their effects on the structure and formaldehyde-resistant barrier properties of coatings.Results showed that the cracks in the coatings gradually disappeared and the formaldehyde resistance rates of the barrier increased as the Si/Al molar ratio was increased from 1.6 to 2.2.This value also increased as the Na/Al molar ratio was increased from 0.9 to 1.2 because of the improvement of the degree of polymerization.As the H_(2)O/Na_(2)O molar ratio was increased from 12 to 15,the thickness of the dry film decreased gradually and led to the reduction in the formaldehyde resistance rate.When the Si/Al,Na/Al,and H_(2)O/Na_(2)O molar ratios were 2.2,1.2,and 12,respectively,the inorganic aluminosilicate coating showed good performance as a formaldehyde-resistant barrier and its formaldehyde resistance rate could reach up to 83.2%.展开更多
A novel aluminosilicate With well-defined bimodal mesopore distribution has beenSynthesized directly, in which one mesopore is distributed at around 3.8nm and the other at 2.
Manganese is ubiquitous in terrestrial environments and most studies have focused on dissolution of Mn oxides,but aluminosilicates also release Mn.Here,we evaluated oxic Mn dissolution from six rocks and minerals(amph...Manganese is ubiquitous in terrestrial environments and most studies have focused on dissolution of Mn oxides,but aluminosilicates also release Mn.Here,we evaluated oxic Mn dissolution from six rocks and minerals(amphibolite,anorthosite,kaolinite,kyanite,muscovite,orthoclase feldspar) and soils from four Critical Zone Observatories(CZOs) under four LMWOLs treatments(catechol,citric acid,oxalic acid,control).Overall rock and mineral Mn mass-normalized release was 1.4 ± 0.5 nM μM^(-1) 14 d^(-1) and dissolution rate was 2403 ± 935 nM m^(-2) d^(-1) x 10^(3).Overall CZO soil Mn release was 16.7±5.1 nM μM^(-1) 14 d^(-1) and dissolution rate was 7010 ± 2570 nM m^(-2) d^(-1) × 10^(3).Anorthosite and kyanite had the highest Mn dissolution rates but kaolinite and kyanite had the highest Mn mass-normalized release rates.We hypothesize the structural location of Mn,surface area,and potential inclusions of highly-weatherable-phases control Mn dissolution for rocks and minerals.CZO soils with the highest solid phase Mn had the highest Mn release and dissolution rates.Citric acid and catechol had higher Mn release and dissolution rates than the control while oxalic acid did not.For rocks and minerals,we found pH 4 had higher Mn release and dissolution rates than pH6,but not for control treatments without LMWOL.Our study highlights that the abundance of Mn drove Mn release in soils but not rocks and minerals.Moreover,LMWOLs are important for Mn dissolution,even under acidic pH conditions.展开更多
In this study,the effect of the addition of various amounts of ZnO(0,1,2,and 3 wt.%)to aluminosilicate bioactive glass(BGs)network(SiO_(2)-Al_(2)O_(3)-P_(2)O_(5)-CaF_(2)-CaO-K_(2)O-Na_(2)O)on the mechanical properties...In this study,the effect of the addition of various amounts of ZnO(0,1,2,and 3 wt.%)to aluminosilicate bioactive glass(BGs)network(SiO_(2)-Al_(2)O_(3)-P_(2)O_(5)-CaF_(2)-CaO-K_(2)O-Na_(2)O)on the mechanical properties of the fabricated glass ionomer cement(GIC)samples was studied.The GIC samples were fabricated by mixing the synthesized aluminosilicate BGs with Riva-self cure liquid.The synthesized aluminosilicate glass was characterized using differential thermal analysis(DTA),X-Ray diffraction(XRD),Fourier-transform infrared spectroscopy(FTIR),and scanning electron microscopy(SEM).Besides,the mechanical properties of GICs were evaluated using Vickers microhardness and Diametral tensile strength(DTS)test.According to DTA analysis,the glass transition temperature(Tg)of aluminosilicate BGs was decreased from 575 to 525°C.According to the results,the aluminosilicate BGs with an amorphous state(~90%)and the grain size of 36μm were synthesized.Doping of the ZnO to glass network up to 3 wt.%could increase the amorphous phase up to 95%and decrease the grain size of the particles up to 28μm.The microhardness and DTS of the GIC samples containing the aluminosilicate BGs were about 677 Hv and 8.5 MPa,respectively.Doping of ZnO to the glass network increased the mentioned values up to 816 Hv and 12.1 MPa,respectively.展开更多
In this work,the structure,viscosity and ion-exchange process of Na_(2)O-MgO-Al_(2)O_(3)-SiO_(2) glasses with different Al_(2)O_(3)/SiO_(2) molar ratios were investigated.The results showed that,with increasing Al_(2)...In this work,the structure,viscosity and ion-exchange process of Na_(2)O-MgO-Al_(2)O_(3)-SiO_(2) glasses with different Al_(2)O_(3)/SiO_(2) molar ratios were investigated.The results showed that,with increasing Al_(2)O_(3)/SiO_(2) ratio,the simple structural units Q_(1) and Q_(2) transformed into highly aggregated structural units Q_(3) and Q_(4),indicating the increase of polymerization degree of glass network.Meanwhile,the coefficient of thermal expansion decreased from 9.23×10^(-6)℃^(-1) to 8.88×10^(-6)℃^(-1).The characteristic temperatures such as melting,forming,softening and glass transition temperatures increased with the increase of Al_(2)O_(3)/SiO_(2) ratio,while the glasses working temperature range became narrow.The increasing Al_(2)O_(3)/SiO_(2) ratio and prolonging ion-exchange time enhanced the surface compressive stress(CS)and depth of stress layer(DOL).However,the increase of ion exchange temperature increased the DOL and decreased the CS affected by stress relaxation.There was a good linear relationship between stress relaxation and surface compressive stress.Chemical strengthening significantly improved the hardness of glasses,which reached the maximum value of(622.1±10)MPa for sample with Al_(2)O_(3)/SiO_(2) ratio of 0.27 after heat treated at 410℃for 2 h.展开更多
It has been shown that the major clay minerals of the biothermocatalytic transitional zone source rock are montmorillonite, illite/montmorillonite (I/M) interlayer mineral, illite, kaolinite and chlorite. Within the d...It has been shown that the major clay minerals of the biothermocatalytic transitional zone source rock are montmorillonite, illite/montmorillonite (I/M) interlayer mineral, illite, kaolinite and chlorite. Within the depth of the transitional zone, montmorillonite could convert to the I/M ordered interlayer mineral via the I/M disordered one, i.e. in the intercrystalline layer of montmorillonite, Al3+ replaces Si4+ abundantly, resulting in a surface charge imbalance and the occurrence of a surface acidity. By means of the pyridine analytic method, the surface acidity of these aluminosilicate clay minerals is measured. The catalysis of aluminosilicate clay minerals, such as montmorillonite, illite and kaolinite to the thermo-degraded gas formation of the transitional zone is simulated in the differential thermal analysis-gas chromatography system and the alcohol dehydration catalyzed by clay minerals is employed to discuss this catalytic mechanism. Experiments have shown that montmorillonite is the展开更多
Aluminosilicate clay mineral(ACM)is a kind of typical raw materials that used widely in manufacturing industry owing to the abundant reserve and low-cost exploring.In past two decades,in-depth understanding on unique ...Aluminosilicate clay mineral(ACM)is a kind of typical raw materials that used widely in manufacturing industry owing to the abundant reserve and low-cost exploring.In past two decades,in-depth understanding on unique layered structure and abundant surface proper-ties endows ACM in the emerging research and application fields.In field of solar-chemical energy conversion,ACM has been widely used to support various semiconductor photocata-lysts,forming the composites and achieving efficient conversion of reactants under sunlight irradiation.To date,classic ACM such as kaolinite and montmorillonite,loaded with semi-conductor photocatalysts has been widely applied in photocatalysis.This review summaries the recent works on ACM-based composites in photocatalysis.Focusing on the properties of surface and layered structure,we elucidate the different features in the composition with various functional photocatalysts on two typical kinds of ACM,i.e.,type 1∶1 and type 2∶1.Not only large surface area and active surface hydroxyl group assist the substrate adsorption,but also the layered structure provides more space to enlarge the application of ACM-based photocatalysts.Besides,we overview the modifications on ACM from both external surface and the inter-layer space that make the formation of composites more efficiently and boost the photo-chemical process.This review could inspire more upcoming design and synthesis for ACM-based photocatalysts,leading this kind of economic and eco-friendly materials for more practical application in the future.展开更多
A rapid and environmentally friendly approach to synthesize hierarchical sodalite from natural aluminosilicate mineral without the involvement of any mesoporogen or post-synthesis treatment was developed.This strategy...A rapid and environmentally friendly approach to synthesize hierarchical sodalite from natural aluminosilicate mineral without the involvement of any mesoporogen or post-synthesis treatment was developed.This strategy involves three important steps:the first is the depolymerization of an aluminosilicate mineral into highly reactive silicon and aluminum species with ideal meso-scale structures through activation of a sub-molten salt.The second step is the hydrolysis and condensation of the activated aluminosilicate mineral into zeolitic precursors that also have a meso-scale structure.The third is the rapid zeolitization of the zeolitic precursors through the reversed crystal growth route at room temperature and ambient pressure to form hierarchical sodalite.The physicochemical properties of the as-synthesized sodalite were systematically characterized,and the formation mechanism of the hierarchical pore structure was discussed.When used as a solid base catalyst for Knoevenagel condensation,the as-synthesized sodalite and its potassium ion-exchanged product with hierarchical micro-meso-macroporous structure both exhibited high catalytic activity and product selectivity.展开更多
Magnetic assembly at the nanoscale level brings potential possibilities in obtaining novel delicate nanostructures with unique physical, photonic or electronic properties. Interface surfactant micelle-directed assembl...Magnetic assembly at the nanoscale level brings potential possibilities in obtaining novel delicate nanostructures with unique physical, photonic or electronic properties. Interface surfactant micelle-directed assembly strategy holds great promising in fabricating ordered mesoporous materials with multifunctionality and pore parameter tunability. Combing these, herein, one-dimensional (1D) nanochains with well-aligned silica-coated magnetic particles as core and mesoporous aluminosilicate as shell are rational fabricated for the first time through magnetic field induced interface coassembly in biliquid system followed by the incorporation of Al species via in-situ chemical modification and transformation strategy. The obtained magnetic mesoporous aluminosilicate nanochains (MMAS-NCs) possess well-defined core-shell-shell sandwich nanostructure, tunable perpendicular mesopore channels in the shell (2.7–7.6 nm), high surface area (359 m^(2)·g^(-1)), abundant acidic sites, and superparamagnetism with a magnetization saturation of 13.8 emu·g^(-1). Thanks to the unique properties, the MMAS-NCs exhibit excellent performance in acting as magnetically recyclable superior solid acid catalysts and nanostirrers with high conversion of over 96.8%, selectivity of 95.0% in the deprotection reaction of benzaldehyde dimethylacetal to benzaldehyde. Moreover, MMAS-NCs exhibit an interesting pore size effect on the catalytic activity, namely, in the pore size range of 2–8 nm, the catalysts with larger pores show significantly enhanced catalytic activity due to the balanced mass transport and density of surface active sites.展开更多
Mesoporous aluminosilicates (MAS) bearing microporous zeolite units and mesoporous structures were synthesized by the hydrothermal method. Adsorptive desulfurization ability of model oil and hy-drotreated diesel was s...Mesoporous aluminosilicates (MAS) bearing microporous zeolite units and mesoporous structures were synthesized by the hydrothermal method. Adsorptive desulfurization ability of model oil and hy-drotreated diesel was studied. The effects of template concentration, crystalization time and calcination time were investigated. The desulfurization ability of adsorbents was improved by transitional metal ion-exchanging. The adsorptive desulfurization of diesel was carried out on a fixed-bed system. The results show that the adsorptive capacity is MAS>MCM-41>NaY. The improvement of desulfurization ability of MAS by Cu+ is more significant than that of Ag+.展开更多
The effect of substitution La_(2)O_(3)and YF_(3)as network modifiers respectively for Y_(2)O_(3),and ZnO as intermediate oxide for Al_(2)O_(3)on crystallization and viscous behavior of Y_(2)O_(3)-Al_(2)O_(3)-SiO_(2)gl...The effect of substitution La_(2)O_(3)and YF_(3)as network modifiers respectively for Y_(2)O_(3),and ZnO as intermediate oxide for Al_(2)O_(3)on crystallization and viscous behavior of Y_(2)O_(3)-Al_(2)O_(3)-SiO_(2)glass was studied.La_(2)O_(3)and YF_(3)substitution for Y_(2)O_(3)decreases the melting temperature of studied glass from 1402 to 1346 and 1379℃,and the activation energy of viscous flow decreases from 340 to 250 and 265 kJ/mol.Meanwhile,ZnO substitution for Al_(2)O_(3)decreases the melting temperature to 1379℃while increases the activation energy of viscous flow to 542 kJ/mol,due to their different role in glass structure.Substitution ZnO for Al_(2)O_(3)refines and homogenizes the crystals size and lowers crystallinity because the nucleation and crystal growth are depressed by higher activation energy of crystallization and change of crystallization mechanism from bulk crystallization to surface crystallization.Replacement of Y_(2)O_(3)by La_(2)O_(3)and YF_(3)respectively also decreases the crystallinity of Y_(2)O_(3)-Al_(2)O_(3)-SiO_(2)glass ceramic due to competitive and hindering effect on the rearranged atoms,structural units and groups required by precipitated two crystals.Besides,y-Y2Si2O7,precipitation of Y4.67(SiO4)3O,ZnAl_(2)O_(4),and Y3Si3O10F were observed respectively due to incorporation of La_(2)O_(3),ZnO,and YF_(3).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
Strong, tough, and almost fully dense C fiber reinforced celsian matrix composites have been fabricated by impregnation of the fiber tows with the matrix slurry, winding on a drum, drying, stacking the prepreg tapes i...Strong, tough, and almost fully dense C fiber reinforced celsian matrix composites have been fabricated by impregnation of the fiber tows with the matrix slurry, winding on a drum, drying, stacking the prepreg tapes in the desired orientation, and hot pressing. The monoclinic celsian phase in the matrix was produced in situ, during hot pressing, from amphosous BAS. The unidirectional composites having ≈20 vol% of fibers exhibited graceful failure with extensive fiber pullout in three point bend tests at room temperature. Values of ultimate flexural strength and fracture toughness were 379MPa and 8 3MPa·m 1/2 , respectively.展开更多
基金support through the research programs(Grant Nos.DQzX-KY-21-008,KYWX-21-023,and KYWX-21-022).
文摘Well-ordered aluminosilicates(MAs)were prepared by in-situ assembly of pre-crystallized units of zeolite Y precursors at a commercial scale,and applied in an industrial fluid catalytic cracking unit for the first time.Compared with incumbent equilibrium catalyst,the surface area of trial equilibrium catalysts(30%inventory ratio)increased from 110 m^(2)g^(-1)to 120m^(2)g^(-1).Moreover,a significant increase of the mesoporous surfaceareaof trial equlibrium catalysts(30%inventoryrati)from 33 m g/to 40magi(22%increase).Furthermore,the equilibrium catalyst that contain 80%LPC-65 yields significantly lower heavy oil(0.23%)and higher total liquids(0.53%)compared with LDO-70.The industrial results demonstrated excellent hydrothermal stability and superior catalytic cracking properties,showing the promising futurein the industrial units.
基金Funded by Anhui Key Laboratory of Advanced Building Materials,Anhui Jianzhu University(No.JZCL201602KF)Major State Basic Research Development Program of China(973 Program)(No.2015CB655101)+2 种基金State Key Laboratory of High Performance Civil Engineering Materials(No.2015CEM005)Natural Science Foundation of Hebei Province(No.E2016209283)Hubei Key Laboratory of Roadway Bridge and Structure Engineering(Wuhan University of Technology)(No.DQZDJJ201504)
文摘The thermodynamic stability of sulfate ions on synthesized calcium aluminosilicate hydrate (C-A-S-H) microstructure with different Ca/Si ratios and Al/Si ratios was investigated by XRD, SEM-EDS, 29Si and 27A1 nuclear magnetic resonance (NMR) and thermodynamic modeling. The results indicate that sulfate attack leads to both decalcification and dealumination for C-A-S-H gels, and the amount of corrosion products (gypsum and ettringite) decreased gradually with decreasing Ca/Si ratios of C-A-S-H. Sulfate ions can also promote the polymerization degree of C-A-S-H gels, improving its resistance to sulfate attack. Moreover, the 4-coordination aluminum (Al[4]) in C-A-S-H, 5-coordination aluminum (Al[5]), 6-ccordination aluminum (A1[6J) in TAH (third aluminum hydrate) and Al[6] in monosulfate or C-A-H (calcium aluminate hydrate) can be transformed into Al[6] in ettringite by sulfate attack. Furthermore, through thermodynamic calculation, the decrease of Ca/Si ratios and increase of Al/Si ratios can improve the thermodynamic stability of C-A-S-H gels under sulfate attack, which agrees well with the experiment results.
文摘In this study the characterization of an aluminosilicate synthesized from commercial Al2(SO4)3 and colloidal SiO2 is presented, as well as its capacity for the removal of copper from aqueous solution. Characterization of the synthesized material was performed using X-ray diffraction, BET nitrogen adsorption-desorption, mass titration and the Boehm method. In order to obtain stable agglomeration and enhance its surface area (165 - 243 m2/g) and solid adsorbing capabilities, the molar ratio SiO2:Al2O3 (1:3, 1:1 and 3:1) was studied, the solubility of the preparation material, synthesis-procedure time and solution pH function were also examined. The maximum capacity to remove copper ions from an aqueous solution by synthesized aluminosilicate was 16 mg/g at pH 4 and 25℃. The Langmuir model fitted better to the copper adsorption experimental data.
基金financially supported by the National Natural Science foundation of China (Nos. 51234008 and 51174230)the Program for New Century Excellent Talents in University of Ministry of Education of China (No. NCET-11-0515)
文摘In pyrometallurgical process, Al-and Si-bearing minerals in iron and aluminum ores are easily transformed into sodium aluminosilicates in the presence of Na_2O constituents, which alters the leaching behaviors of Al_2O_3 and SiO_2. It was confirmed that sodium aluminosilicates with different phase compositions synthesized at various roasting conditions were effectively digested in the alkaline digestion process. Under the optimum conditions at temperature of 100–120°C, liquid-to-solid ratio(L/S) of 10:2 mL/g, caustic ratio of 4, and Na_2O concentration of 240 g/L, the actual and relative digestion ratio of Al_2O_3 from the synthesized sodium aluminosilicates reached maximums of about 65% and 95%, respectively, while SiO_2 was barely leached out. To validate the superior digestion property of sodium aluminosilicate generated via an actual process, the Bayer digestion of an Al_2O_3-rich material derived from reductive roasting of bauxite and comprising Na_(1.75) Al_(1.75) Si_(0.25)O_4 was conducted; the relative digestion ratio of Al_2O_3 attained 90% at 200°C.
基金Funded by the National Natural Science Foundation of China(Nos.52008002,U21A20149,U2006224 and 51978352)the Open Foundation of the State Key Laboratory of Silicate Materials for Architectures(Wuhan University of Technology)(No.SYSJJ2022-22)Anhui Province Engineering Laboratory of Advanced Building Materials(No.JZCL2202ZR)。
文摘Molecular dynamics simulation was utilized to investigate the transport and adsorption of chloride in the nanopore of calcium aluminosilicate hydrate(C-A-S-H)with associated cation types of Ca,Mg,Na and K.The local ionic structure,atomic dynamics and bond stability were analyzed to elucidate the interaction between cations and chloride ions.The results show that interfacial chloride is absorbed through the ion pairing formation in the vicinity of C-A-S-H substrate.Interfacial cations can simultaneously interact aluminosilicate chains,water molecules and Cl^(-)ions,which restrict the motion of interfacial Cl^(-)ions.Pore solution chloride can be immobilized through the solvation effect of cations.Cations along with their hydration shell can connect to neighboring Cl^(-)ions to decrease their mobility.Owing to the varied ionic chemistry,cations show different interaction strength with neighboring water molecules and anions,which determines the chloride transport behavior in the nanopore of C-A-S-H.The chloride immobilization capacity of C-A-S-H nanopore with different associated cations is listed in following order:Mg^(2+)Ca^(2+)<Na^(+)≈K^(+),which agrees reasonably with previous experiments.
基金financially supported by the National Key Research and Development Program of China(Nos.2016 YFC0700607,2017YFB0304305,and 2016YFC0700901)the Fundamental Research Funds for the Central Universities of China(No.FRF-TP-20-006A3).
文摘Wood-based panels containing urea-formaldehyde resin result in the long-term release of formaldehyde and threaten human health.In this study,inorganic aluminosilicate coatings prepared by combining metakaolin,silica fume,NaOH,and H_(2)O were applied to the surfaces of wood-based panels to obstruct formaldehyde release.The Si/Al,Na/Al,and H_(2)O/Na_(2)O molar ratios of the coatings were regulated to investigate their effects on the structure and formaldehyde-resistant barrier properties of coatings.Results showed that the cracks in the coatings gradually disappeared and the formaldehyde resistance rates of the barrier increased as the Si/Al molar ratio was increased from 1.6 to 2.2.This value also increased as the Na/Al molar ratio was increased from 0.9 to 1.2 because of the improvement of the degree of polymerization.As the H_(2)O/Na_(2)O molar ratio was increased from 12 to 15,the thickness of the dry film decreased gradually and led to the reduction in the formaldehyde resistance rate.When the Si/Al,Na/Al,and H_(2)O/Na_(2)O molar ratios were 2.2,1.2,and 12,respectively,the inorganic aluminosilicate coating showed good performance as a formaldehyde-resistant barrier and its formaldehyde resistance rate could reach up to 83.2%.
文摘A novel aluminosilicate With well-defined bimodal mesopore distribution has beenSynthesized directly, in which one mesopore is distributed at around 3.8nm and the other at 2.
基金the National Science Foundation Grants (NSF-1360760) to the Critical Zone Observatory Network National Office and NSF-1660923 to Dr.Louis A.Derry through a subaward to Dr.Justin B.Richardson。
文摘Manganese is ubiquitous in terrestrial environments and most studies have focused on dissolution of Mn oxides,but aluminosilicates also release Mn.Here,we evaluated oxic Mn dissolution from six rocks and minerals(amphibolite,anorthosite,kaolinite,kyanite,muscovite,orthoclase feldspar) and soils from four Critical Zone Observatories(CZOs) under four LMWOLs treatments(catechol,citric acid,oxalic acid,control).Overall rock and mineral Mn mass-normalized release was 1.4 ± 0.5 nM μM^(-1) 14 d^(-1) and dissolution rate was 2403 ± 935 nM m^(-2) d^(-1) x 10^(3).Overall CZO soil Mn release was 16.7±5.1 nM μM^(-1) 14 d^(-1) and dissolution rate was 7010 ± 2570 nM m^(-2) d^(-1) × 10^(3).Anorthosite and kyanite had the highest Mn dissolution rates but kaolinite and kyanite had the highest Mn mass-normalized release rates.We hypothesize the structural location of Mn,surface area,and potential inclusions of highly-weatherable-phases control Mn dissolution for rocks and minerals.CZO soils with the highest solid phase Mn had the highest Mn release and dissolution rates.Citric acid and catechol had higher Mn release and dissolution rates than the control while oxalic acid did not.For rocks and minerals,we found pH 4 had higher Mn release and dissolution rates than pH6,but not for control treatments without LMWOL.Our study highlights that the abundance of Mn drove Mn release in soils but not rocks and minerals.Moreover,LMWOLs are important for Mn dissolution,even under acidic pH conditions.
文摘In this study,the effect of the addition of various amounts of ZnO(0,1,2,and 3 wt.%)to aluminosilicate bioactive glass(BGs)network(SiO_(2)-Al_(2)O_(3)-P_(2)O_(5)-CaF_(2)-CaO-K_(2)O-Na_(2)O)on the mechanical properties of the fabricated glass ionomer cement(GIC)samples was studied.The GIC samples were fabricated by mixing the synthesized aluminosilicate BGs with Riva-self cure liquid.The synthesized aluminosilicate glass was characterized using differential thermal analysis(DTA),X-Ray diffraction(XRD),Fourier-transform infrared spectroscopy(FTIR),and scanning electron microscopy(SEM).Besides,the mechanical properties of GICs were evaluated using Vickers microhardness and Diametral tensile strength(DTS)test.According to DTA analysis,the glass transition temperature(Tg)of aluminosilicate BGs was decreased from 575 to 525°C.According to the results,the aluminosilicate BGs with an amorphous state(~90%)and the grain size of 36μm were synthesized.Doping of the ZnO to glass network up to 3 wt.%could increase the amorphous phase up to 95%and decrease the grain size of the particles up to 28μm.The microhardness and DTS of the GIC samples containing the aluminosilicate BGs were about 677 Hv and 8.5 MPa,respectively.Doping of ZnO to the glass network increased the mentioned values up to 816 Hv and 12.1 MPa,respectively.
基金Funded by National Natural Science Foundation of China(Nos.52172019 and 52072148)Shandong Provincial Youth Innovation Team Development Plan of Colleges and Universities(No.2022K1100)。
文摘In this work,the structure,viscosity and ion-exchange process of Na_(2)O-MgO-Al_(2)O_(3)-SiO_(2) glasses with different Al_(2)O_(3)/SiO_(2) molar ratios were investigated.The results showed that,with increasing Al_(2)O_(3)/SiO_(2) ratio,the simple structural units Q_(1) and Q_(2) transformed into highly aggregated structural units Q_(3) and Q_(4),indicating the increase of polymerization degree of glass network.Meanwhile,the coefficient of thermal expansion decreased from 9.23×10^(-6)℃^(-1) to 8.88×10^(-6)℃^(-1).The characteristic temperatures such as melting,forming,softening and glass transition temperatures increased with the increase of Al_(2)O_(3)/SiO_(2) ratio,while the glasses working temperature range became narrow.The increasing Al_(2)O_(3)/SiO_(2) ratio and prolonging ion-exchange time enhanced the surface compressive stress(CS)and depth of stress layer(DOL).However,the increase of ion exchange temperature increased the DOL and decreased the CS affected by stress relaxation.There was a good linear relationship between stress relaxation and surface compressive stress.Chemical strengthening significantly improved the hardness of glasses,which reached the maximum value of(622.1±10)MPa for sample with Al_(2)O_(3)/SiO_(2) ratio of 0.27 after heat treated at 410℃for 2 h.
基金Project supported by the National Natural Science Foundation of China
文摘It has been shown that the major clay minerals of the biothermocatalytic transitional zone source rock are montmorillonite, illite/montmorillonite (I/M) interlayer mineral, illite, kaolinite and chlorite. Within the depth of the transitional zone, montmorillonite could convert to the I/M ordered interlayer mineral via the I/M disordered one, i.e. in the intercrystalline layer of montmorillonite, Al3+ replaces Si4+ abundantly, resulting in a surface charge imbalance and the occurrence of a surface acidity. By means of the pyridine analytic method, the surface acidity of these aluminosilicate clay minerals is measured. The catalysis of aluminosilicate clay minerals, such as montmorillonite, illite and kaolinite to the thermo-degraded gas formation of the transitional zone is simulated in the differential thermal analysis-gas chromatography system and the alcohol dehydration catalyzed by clay minerals is employed to discuss this catalytic mechanism. Experiments have shown that montmorillonite is the
基金This work was supported by the National Natural Science Foundation of China(21976054)the National Key Research and Development Program of China(2017YFA0207002)Beijing Outstanding Young Scientist Program.
文摘Aluminosilicate clay mineral(ACM)is a kind of typical raw materials that used widely in manufacturing industry owing to the abundant reserve and low-cost exploring.In past two decades,in-depth understanding on unique layered structure and abundant surface proper-ties endows ACM in the emerging research and application fields.In field of solar-chemical energy conversion,ACM has been widely used to support various semiconductor photocata-lysts,forming the composites and achieving efficient conversion of reactants under sunlight irradiation.To date,classic ACM such as kaolinite and montmorillonite,loaded with semi-conductor photocatalysts has been widely applied in photocatalysis.This review summaries the recent works on ACM-based composites in photocatalysis.Focusing on the properties of surface and layered structure,we elucidate the different features in the composition with various functional photocatalysts on two typical kinds of ACM,i.e.,type 1∶1 and type 2∶1.Not only large surface area and active surface hydroxyl group assist the substrate adsorption,but also the layered structure provides more space to enlarge the application of ACM-based photocatalysts.Besides,we overview the modifications on ACM from both external surface and the inter-layer space that make the formation of composites more efficiently and boost the photo-chemical process.This review could inspire more upcoming design and synthesis for ACM-based photocatalysts,leading this kind of economic and eco-friendly materials for more practical application in the future.
基金The authors gratefully acknowledge the financial support from the National Natural Science Foundation of China(grant Nos.91434206,21506034,and 21276270).
文摘A rapid and environmentally friendly approach to synthesize hierarchical sodalite from natural aluminosilicate mineral without the involvement of any mesoporogen or post-synthesis treatment was developed.This strategy involves three important steps:the first is the depolymerization of an aluminosilicate mineral into highly reactive silicon and aluminum species with ideal meso-scale structures through activation of a sub-molten salt.The second step is the hydrolysis and condensation of the activated aluminosilicate mineral into zeolitic precursors that also have a meso-scale structure.The third is the rapid zeolitization of the zeolitic precursors through the reversed crystal growth route at room temperature and ambient pressure to form hierarchical sodalite.The physicochemical properties of the as-synthesized sodalite were systematically characterized,and the formation mechanism of the hierarchical pore structure was discussed.When used as a solid base catalyst for Knoevenagel condensation,the as-synthesized sodalite and its potassium ion-exchanged product with hierarchical micro-meso-macroporous structure both exhibited high catalytic activity and product selectivity.
基金This work was supported by the National Natural Science Foundation of China(Nos.21701153,21875044,52073064,22005058,and 22005057)the National Key R&D Program of China(No.2020YFB2008600)+4 种基金Program of Shanghai Academic Research Leader(No.19XD1420300)the State Key Laboratory of Transducer Technology of China(No.SKT1904)China Postdoctoral Science Foundation(Nos.2020M670973 and BX20200085)Sichuan Science and Technology Program(No.2020YJ0243)The authors extend their appreciation to the International Scientific Partnership Program ISPP at King Saud University for funding this research work through ISPP-17-94(2).
文摘Magnetic assembly at the nanoscale level brings potential possibilities in obtaining novel delicate nanostructures with unique physical, photonic or electronic properties. Interface surfactant micelle-directed assembly strategy holds great promising in fabricating ordered mesoporous materials with multifunctionality and pore parameter tunability. Combing these, herein, one-dimensional (1D) nanochains with well-aligned silica-coated magnetic particles as core and mesoporous aluminosilicate as shell are rational fabricated for the first time through magnetic field induced interface coassembly in biliquid system followed by the incorporation of Al species via in-situ chemical modification and transformation strategy. The obtained magnetic mesoporous aluminosilicate nanochains (MMAS-NCs) possess well-defined core-shell-shell sandwich nanostructure, tunable perpendicular mesopore channels in the shell (2.7–7.6 nm), high surface area (359 m^(2)·g^(-1)), abundant acidic sites, and superparamagnetism with a magnetization saturation of 13.8 emu·g^(-1). Thanks to the unique properties, the MMAS-NCs exhibit excellent performance in acting as magnetically recyclable superior solid acid catalysts and nanostirrers with high conversion of over 96.8%, selectivity of 95.0% in the deprotection reaction of benzaldehyde dimethylacetal to benzaldehyde. Moreover, MMAS-NCs exhibit an interesting pore size effect on the catalytic activity, namely, in the pore size range of 2–8 nm, the catalysts with larger pores show significantly enhanced catalytic activity due to the balanced mass transport and density of surface active sites.
基金Supported by National Basic Research Program of China (Grant No. 2006CB202507)National High-tech R&D Program (Grant No. 2006AA02Z209)the National Natural Science Foundation of China (Grant No. 20806086)
文摘Mesoporous aluminosilicates (MAS) bearing microporous zeolite units and mesoporous structures were synthesized by the hydrothermal method. Adsorptive desulfurization ability of model oil and hy-drotreated diesel was studied. The effects of template concentration, crystalization time and calcination time were investigated. The desulfurization ability of adsorbents was improved by transitional metal ion-exchanging. The adsorptive desulfurization of diesel was carried out on a fixed-bed system. The results show that the adsorptive capacity is MAS>MCM-41>NaY. The improvement of desulfurization ability of MAS by Cu+ is more significant than that of Ag+.
基金the National Natural Science Foundation of China(No.51974168)the Science and Technology Major Project of Inner Mongolia Autonomous Region in China(Nos.2019ZD023 and 2021ZD0028)the State Key Laboratory of Silicate Materials for Architectures(Wuhan University of Technology)(No.SYSJJ2020-08)。
文摘The effect of substitution La_(2)O_(3)and YF_(3)as network modifiers respectively for Y_(2)O_(3),and ZnO as intermediate oxide for Al_(2)O_(3)on crystallization and viscous behavior of Y_(2)O_(3)-Al_(2)O_(3)-SiO_(2)glass was studied.La_(2)O_(3)and YF_(3)substitution for Y_(2)O_(3)decreases the melting temperature of studied glass from 1402 to 1346 and 1379℃,and the activation energy of viscous flow decreases from 340 to 250 and 265 kJ/mol.Meanwhile,ZnO substitution for Al_(2)O_(3)decreases the melting temperature to 1379℃while increases the activation energy of viscous flow to 542 kJ/mol,due to their different role in glass structure.Substitution ZnO for Al_(2)O_(3)refines and homogenizes the crystals size and lowers crystallinity because the nucleation and crystal growth are depressed by higher activation energy of crystallization and change of crystallization mechanism from bulk crystallization to surface crystallization.Replacement of Y_(2)O_(3)by La_(2)O_(3)and YF_(3)respectively also decreases the crystallinity of Y_(2)O_(3)-Al_(2)O_(3)-SiO_(2)glass ceramic due to competitive and hindering effect on the rearranged atoms,structural units and groups required by precipitated two crystals.Besides,y-Y2Si2O7,precipitation of Y4.67(SiO4)3O,ZnAl_(2)O_(4),and Y3Si3O10F were observed respectively due to incorporation of La_(2)O_(3),ZnO,and YF_(3).
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Strong, tough, and almost fully dense C fiber reinforced celsian matrix composites have been fabricated by impregnation of the fiber tows with the matrix slurry, winding on a drum, drying, stacking the prepreg tapes in the desired orientation, and hot pressing. The monoclinic celsian phase in the matrix was produced in situ, during hot pressing, from amphosous BAS. The unidirectional composites having ≈20 vol% of fibers exhibited graceful failure with extensive fiber pullout in three point bend tests at room temperature. Values of ultimate flexural strength and fracture toughness were 379MPa and 8 3MPa·m 1/2 , respectively.