We aim in this research at synthesizing high-purity aluminium titanate with sludge from the aluminium profile factory by shock cooling method, and mainly discuss the effect of calcining reaction temperature and holdin...We aim in this research at synthesizing high-purity aluminium titanate with sludge from the aluminium profile factory by shock cooling method, and mainly discuss the effect of calcining reaction temperature and holding time on crystalline, microstructure and content of aluminum titanate materials to determine the preferred calcining temperature and holding time. XRD and SEM methods were utilized to characterize the crystalline and microstructure of each specimen, Rietveld Quantification software was used for the determination of different crystalline contents of specimens, and Philips plus software was applied to determine the cell parameters of aluminium titanate in different specimens. According to the experimental results, preferred calcining temperature is determined as 1400℃ and preferred holding time is 2 h, at which the grains of aluminum titanate grow completely and the purity of aluminum titanate is 97.2wt%.展开更多
Energy saving has been an important concept in modern industry especially to the countries and regions with energy shortage such as China and Japan. Utilization of Coal-Water Slurry （CWS） can improve the burning eff...Energy saving has been an important concept in modern industry especially to the countries and regions with energy shortage such as China and Japan. Utilization of Coal-Water Slurry （CWS） can improve the burning efficiency of coal and reduce the pollutions of soot, sulfide and the nitride by burning lump coal directly. The CWS is a promising energy saving technique and the effectual substitute of oil. The study on the preparation and application of the CWS has made progresses in many aspects. The present paper studied the basal problems for applying the CWS on the rotary kilns during the calcining-dolomite process in the magnesium factory, summarized the key points for the application process of the CWS and gave the corresponding solutions.展开更多
The effects of microwave sintering and conventional H2 sintering on the microstructure and properties of W-15Cu alloy using ultrafine W-15Cu composite powder fabricated by spray drying ＆ calcining-continuous reductio...The effects of microwave sintering and conventional H2 sintering on the microstructure and properties of W-15Cu alloy using ultrafine W-15Cu composite powder fabricated by spray drying ＆ calcining-continuous reduction technology were investigated. In comparison to the conventional HE sintering processing, microwave sintering to W-15Cu can be achieved at lower sintering temperature and shorter sintering time. Furthermore, higher performances in microwave sintered compacts were obtained, but high microwave sintering temperature or long microwave sintering time could result in coarser microstructures.展开更多
The application of high-sulfur petroleum coke after desulfurization in aluminum electrolysis anodes is an important development trend. However, removing sulfur from high-sulfur petroleum coke is still a significant ch...The application of high-sulfur petroleum coke after desulfurization in aluminum electrolysis anodes is an important development trend. However, removing sulfur from high-sulfur petroleum coke is still a significant challenge.This study proposes alkali calcining and reflux washing to examine the impacts of temperature, particle size, the mass ratio of Na_(2)CO_(3) to NaOH, and total sodium addition on the desulfurization efficiency and mechanism. The results show that the desulfurization rate increases with increasing temperature, increasing total sodium content, and decreasing particle size. The addition of alkali can significantly reduce the opening-ring reaction temperature of thiophene and convert organic sulfur into inorganic sulfur(Na_(2)S). Three washing methods were compared, and reflux washing was selected to separate inorganic sulfur(Na_(2)S) from calcined petroleum coke. The sulfur content in petroleum coke decreased from 7.29% to 1.90%, with a desulfurization rate of 80.13% under optimal conditions. The petroleum coke was analyzed before and after desulfurization using X-Ray diffraction(XRD), Scanning Electron Microscopy(SEM), Infrared Spectroscopy(IR), Thermogravimetric Analysis and Differential Scanning Calorimetry(TG-DSC), Gaschromatography-mass Spectrometry(GC-MS). The results show that thiophene and benzothiophene in petroleum coke are decomposed and converted into octane and ethyl cyclohexane. These new observations are expected to provide further understanding and guidance for the utilization of highsulfur petroleum coke.展开更多
The swung gel fibers were hea, ted to 400 ℃ at 0. .5 ,1, 1.5,2,2.5,3and4 ℃ min^-1 of heating rate, respectivel, and soaked.for 1 h ; then heated to 600 ℃ at 3 ℃ min ^-1 of.heating rate amt soaked for 1 h at last ...The swung gel fibers were hea, ted to 400 ℃ at 0. .5 ,1, 1.5,2,2.5,3and4 ℃ min^-1 of heating rate, respectivel, and soaked.for 1 h ; then heated to 600 ℃ at 3 ℃ min ^-1 of.heating rate amt soaked for 1 h at last calcined m 1 000, 1 100, 1 200, 1 300, and 1 400 ℃.for 1 h, respectively.展开更多
Single-crystal alpha alumina （α-Al2O3） platelets were synthesized by calcining a powder mixture of bayerite （α-AI（OH）3） and potassium sulfate （K2SO4） at 900℃. The crystalline phase evolutions and morphologi...Single-crystal alpha alumina （α-Al2O3） platelets were synthesized by calcining a powder mixture of bayerite （α-AI（OH）3） and potassium sulfate （K2SO4） at 900℃. The crystalline phase evolutions and morphologies of the samples were characterized by X-ray diffraction （XRD）, scanning electron microscopy （SEM）, and transmission electron microscopy （TEM）. The synthesized samples mainly consisted of single-crystal α-Al2O3 platelets with a diameter of 0.5-1.5 μm and a thickness of 50-150 nm. Moreover, with 3, 5, and 8 wt% （referred to the obtained alumina） α-Al2O3 seeds adding into the powder mixture of bayerite and potassium sulfate, the average diameter of α-Al2O3 platelets can be reduced to 450, 240, and 220 nm, respectively. It is found that the sequence of the phase transformation is the bayerite （α-Al（OH）3） → boehmite （γ-AIOOH） →γ-Al2O3 → α-Al2O3. Further analysis indicated that K2SO4 can promote the phase transformation from α-Al2O3 to α-Al2O3 and the formation of single-crystal α-Al2O3 platelets might be attributed to the liquid phase K3AI（SO4）3.展开更多
In this work,a novel process consisting of calcining-slaking followed by gravity separation for the enrichment of niobium(Nb)and titanium(Ti)from carbonatite pyrochlore ore was proposed,validated and compared with the...In this work,a novel process consisting of calcining-slaking followed by gravity separation for the enrichment of niobium(Nb)and titanium(Ti)from carbonatite pyrochlore ore was proposed,validated and compared with the current mainstream flotation method.During calcining of the pyrochlore ore,within which the carbonates were transformed into lime.Subsequently,when the calcined ore was slaked,lime was transformed into hydroxide with fine particles which were amenable to gravity separation.After calcining at 900℃for 60 min,slaking at 90℃for 10 min with a liquid–solid ratio of 3:1(mL/g),approximately 40%of tailings can be removed by gravity separation,the recoveries of Nb and Ti were 94.7%and 91.0%,and the enrichment ratios of Nb and Ti were 1.61 and 1.43,respectively.The new approach exhibits high separation efficiency of carbonate gangue minerals and valuable minerals,satisfactory recoveries of niobium as well as titanium can be achieved.展开更多
The incremental improved Back-Propagation （BP） neural network prediction model using the Levenberg-Marquardt algorithm based on optimizing theory is put forward, which can solve the problems existing in the process ...The incremental improved Back-Propagation （BP） neural network prediction model using the Levenberg-Marquardt algorithm based on optimizing theory is put forward, which can solve the problems existing in the process of calcinations for ammonium diuranate （ADU） by microwave heating, such as long testing cycle, high testing quan- tity, difficulty of optimization for process parameters. Many training data probably were offered by the way of increment batch and the limitation of the system mem- ory could make the training data infeasible when the sample scale was large. The prediction model of the nonlinear system is built, which can effectively predict the experiment of microwave calcining of ADU, and the incremental improved BP neural network is very useful in overeoining the local minimum problem, finding the global optimal solution and accelerating the convergence speed.展开更多
To improve separation efficiency of the photogenerated electron-hole pairs,constructing a heterojunction is considered to be a promising strategy.However,the fabrication of heterojunction via a facile route to achieve...To improve separation efficiency of the photogenerated electron-hole pairs,constructing a heterojunction is considered to be a promising strategy.However,the fabrication of heterojunction via a facile route to achieve a substantial improvement in photocatalytic performance is still challenging.In this work,a well-designed nanosheet-based rodlike step-scheme(S-scheme)heterojunction Bi_(4)O_(5)I_(2)/Bi_(4)O_(5)Br_(2) with rich oxygen vacancies(OVs)(Bi_(4)O_(5)I_(2)/Bi_(4)O_(5)Br_(2)-OV)was easily synthesized by calcining BiOAc0.6Br0.2I0.2(Ac-=CH3 COO-)precursor.The as-prepared Bi4O5I2/Bi4O5Br2-OV exhibited excellent visible light photocatalytic performance towards antibiotic tetracycline(TC)and dye rhodamine B(Rh B)degradation and removal rate reached 90.2% and 97.0%within 120 min,respectively,which was higher than those of Bi4O5I2-OV(56.8% and 71.8%),Bi4O5Br2-OV(47.4%and 68.4%),solid solution BiOAc0.6Br0.2I0.2(67.0% and 84.0%)and Bi_(4)O_(5)I_(2)/Bi_(4)O_(5)Br_(2) with poor oxygen vacancies(Bi4O5I2/Bi4O5Br2-P)(30.6%and 40.4%).Owing to the release of heat and generation of reducing carbon during calcining the precursor with Ac-,it could not only reduce the generation temperature of Bi-rich bismuth oxyhalides,which thus decreased particle size and increased surface areas,but also introduce surface OVs,which could trap photoelectrons and inhibit the recombination of carriers.In addition,the calcination of single solid solution precursor benefited to the formation of well-alloyed interfaces with larger contact areas between 2D/2D nanosheet-like materials,which facilitates charge carriers transfer at the interfaces.The Bi4O5I2/Bi4O5Br2-OV also shows the desirable removal rate for TC and Rh B in actual wastewater or in the presence of some electrolytes.This study provides an effective and simple strategy for designing OVs modified Bi-rich oxyhalides heterojunctions.展开更多
Dye wastewater poses a significant threat to aquatic organisms due to its high toxicity.Reducing or eliminating the dye waste from the water is necessary for a healthy and sustainable aquaculture.This study investigat...Dye wastewater poses a significant threat to aquatic organisms due to its high toxicity.Reducing or eliminating the dye waste from the water is necessary for a healthy and sustainable aquaculture.This study investigated the adsorption properties of Congo red dye on Mytilus edulis shell powders prepared by calcination at 500℃,700℃,and 900℃.The modified shell powder products were analyzed by SEM(scanning eletron microscopy)and FTIR(fourier transform infrared spectroscopy)for the morphology and structural characterization.The effects of different calcination temperatures,reaction times,reaction temperatures,and initial concentration of Congo red on the adsorption properties were investigated.The adsorption kinetics and isothermal adsorption models were also established.The results revealed that the shell powder calcinated at 900℃showed the best adsorption capacity on Congo red from aqueous solution.The adsorption reaction reached equilibrium after 150 min and followed by the pseudo-second-order kinetic model.At 25℃,96.2%of the Congo red in the solution could be removed,and the adsorption capacity could reach at least 1015 mg g^(–1).The adsorption isotherm is fit with the Freundlich model,indicating a multiphase adsorption process.These results are helpful for cleaning and treating printing and dyeing effluents as well as high-value utilization of shell waste resources.展开更多
The effects of calcination temperature and mechanical ball milling on the physicochemical properties of electrolytic manganese residue(EMR),mineral phase transition,pozzolanic activity,and pore structure were studied....The effects of calcination temperature and mechanical ball milling on the physicochemical properties of electrolytic manganese residue(EMR),mineral phase transition,pozzolanic activity,and pore structure were studied.The experimental results show that the strength activity index(SAI)of 20%EMR mixed mortar at 28 days is 90.54%,95.40%,and 90.73%,respectively,after pretreatment with EMR at 800℃calcined for 3,5,and 8 min.This is mainly attributed to the high temperature decomposition of gypsum dihydrate to form activated calcium oxide.In addition,high temperature and mechanical force destroys the Si-O chemical bond and promotes the formation of calcium silicate gel structure.Due to the existence of a large number of gypsum phases in EMR mixed mortar,a large number of ettringite,C-S-H,aluminosilicate,C-A-S-H,and AFm are formed,which strongly verifies the volcanic activity of EMR.The leaching test shows that high temperature calcination has a significant effect on the stabilization of NH_(3)-N.However,the curing effect of Mn^(2+)is significant only in the calcination at 1000℃,but both Mn^(2+)and NH_(3)-N in the calcined EMR are higher than the emission standard.The encapsulation effect of EMR composite mortar provided by hydration products,and the buffering capacity of the Si-Al system for solidification of heavy metals and strong alkalis are conducive to the stability of Mn^(2+)and NH_(3)-N.After the EMR mixed mortar is aged for 3 days,Mn and NH_(3)-N are completely lower than the emission standard.In general,the EMR mixed mortar can meet the requirements for green building use.展开更多
Aceh in Indonesia is rich inmarine resources and abundant fishery products such as oyster.Traditionally,fishermen only harvest oysters and discard the shells,which can cause pollution and environmental contamination.W...Aceh in Indonesia is rich inmarine resources and abundant fishery products such as oyster.Traditionally,fishermen only harvest oysters and discard the shells,which can cause pollution and environmental contamination.Waste Oyster Shells(WOS)contain a high percentage of calcium carbonate(CaCO_(3))that experiences thermal decomposition at high temperature,following the reaction CaCO_(3)→CaO+CO_(2)(ΔT=825℃).At temperature>900℃,dead-burned lime is formed,which severely influences CaO reactivity.However,the optimum temperature for producing high CaO content is still uncertain.Therefore,this study aimed to determine the optimum calcination temperature to produce high CaO content,assess initial setting time of WOS paste,and identify the best compressive strength of paste.For the experiment,WOS was used as a partial cement replacement(with a size of 0.075 mm)in paste at a proportion of 5%and calcined at temperature of 700℃,800℃,900℃,and 1000℃.The specimens used were an ebonite ring(dimensions:70 mm bottom diameter,60 mm top diameter,and 40 mm height)and a cube(dimensions:5 cm×5 cm×5 cm).The experiment was conducted following the ASTM(American Society for Testing andMaterials)standards and optimumcompressive strength values were analyzed using ANOVA(Analysis of Variance)and Response Surface Methodology(RSM)through the Design Expert software.The results showed that WOS calcined at 1000℃ increased CaO content by approximately 57.40%.Furthermore,the initial setting time test of 5%WOS paste at 1000℃ showed a more uniform binding performance compared to conventional cement paste,with an initial setting time of 75 min and a penetration depth of 15 mm.In line with the analysis,optimum compressive strength of 71.028 MPa with a desirability value of 0.986 was achieved at 5%cement replacement and calcination temperature of 786.44℃.展开更多
To advance the precise regulation and high-value utilization of halloysite nanotubes(HNTs),this work systematically investigated five treatment strategies,including calcination,acid treatment,alkali treatment,acid tre...To advance the precise regulation and high-value utilization of halloysite nanotubes(HNTs),this work systematically investigated five treatment strategies,including calcination,acid treatment,alkali treatment,acid treatment of calcined HNTs,and alkali treatment of calcined HNTs,to modulate their structural and application properties.The structural characteristics,surface properties,and methylene blue(MB)adsorption capacity of HNTs under multiple treatments were systematically analyzed.Calcination at varying temperatures modified the crystal structure,morphology,and surface properties of HNTs,with higher calcination temperatures reducing their reactivity towards MB.Moderate acid treatment expanded the lumen and decreased the surface potential of HNTs,significantly enhancing MB adsorption capacity.In contrast,alkali treatment dispersed the multilayered walls of HNTs and raised surface potential,reducing MB affinity.Acid treatment of calcined HNTs effectively increased their specific surface areas by leaching most of Al while maintaining the tubular structure,thereby maximizing MB adsorption.Alkali treatment of calcined HNTs destroyed the tubular structure and resulted in poor MB adsorption.HNTs pre-calcined at 600℃ for 3 h and acid-treated at 60℃ for 8 h exhibited an optimal specific surface area of443 m^(2)·g^(-1)and an MB adsorption capacity of 190 mg·g^(-1).Kinetic and Arrhenius equation fittings indicated that chemical reactions control interactions of acids and alkalis with HNTs.This study provides a comprehensive comparison and analysis of five treatment methods,offering insights into regulating the structures and surface properties of HNTs by controlling the treatment condition,thereby laying a foundation for their efficient utilization in practical applications.展开更多
Cement production,while essential for global infrastructure,contributes significantly to carbon dioxide emissions,accounting for approximately 7%of total emissions.To mitigate these environmental impacts,flash calcina...Cement production,while essential for global infrastructure,contributes significantly to carbon dioxide emissions,accounting for approximately 7%of total emissions.To mitigate these environmental impacts,flash calcination of kaolinitic clays has been investigated as a sustainable alternative.This technique involves the rapid heating of clays,enabling their use as supplementary cementitious materials.The primary objective of this study was to modify the color of calcined clay in various atmospheres(oxidizing,inert,and reducing)to achieve a grayish tone similar to commercial cement while preserving its reactive properties.The experimental procedure employed a tubular reactor with precise control of gas flows(atmospheric air,nitrogen,and a carbon monoxide–nitrogen mixture).Physicochemical characterization of the raw clay was conducted before calcination,with analyses repeated on the calcined clays following experimentation.Results indicated that clay calcined in an oxidizing atmosphere acquired a reddish hue,attributed to the oxidation of iron in hematite.The Clay exhibited a pinkish tone in an inert atmosphere,while calcination in a reducing atmosphere yielded the desired grayish color.Regarding pozzolanic activity,clays calcined in oxidizing and inert atmospheres displayed robust strength,ranging from 82%to 87%.Calcination in a reducing atmosphere resulted in slightly lower strength,around 74%,likely due to the clay’s chemical composition and the calcination process,which affects compound formation and material reactivity.展开更多
The Ni-ZnFe_(2)O_(4)(NixZn_(1-x)Fe_(2)O_(4),x=0.4-0.7)spinel was synthesized using Zn2+extracted from electric arc furnace dust(EAFD),nickel chloride hexahydrate,and Fe^(3+)extracted from iron scale as raw materials.T...The Ni-ZnFe_(2)O_(4)(NixZn_(1-x)Fe_(2)O_(4),x=0.4-0.7)spinel was synthesized using Zn2+extracted from electric arc furnace dust(EAFD),nickel chloride hexahydrate,and Fe^(3+)extracted from iron scale as raw materials.The zinc was selectively extracted from EAFD using CaO roasting followed by NH_(4)Cl solution leaching.The ferric ion was leached from iron scale using HCl solution as acid lixiviant.The experimental results demonstrate a high level of efficiency in the extraction of zinc,with a rate of 97.5%,and the leaching rate of ferric ion is 96.89%.The composition of the leaching solution is primary zinc and iron with low calcium,which is beneficial to the preparation of spinel ferrite.The influence of Ni content(x)and calcination temperature on the synthesis and magnetic properties of NixZn_(1-x)Fe_(2)O_(4)compounds was investigated by X-ray diffraction,scanning electron microscopy,and vibrating sample magnetometry.The results revealed that both Ni content and calcination temperature significantly affect the synthesis and magnetic properties of spinel NixZn_(1-x)Fe_(2)O_(4).Under the conditions of Ni content set at x=0.6,calcination temperature of 1100℃,and a duration of 2 h,a spinel NixZn_(1-x)Fe_(2)O_(4)with high saturation magnetization(Ms=65.7 A m2 kg-1)and low coercivity(Hc=0.056 A m^(-1))was obtained.展开更多
Surface regulation is a crucial technique for improving catalytic performance in heterogeneous catalysis.Although perovskite oxides containing noble metals show good performance and excellent thermal stability,the enc...Surface regulation is a crucial technique for improving catalytic performance in heterogeneous catalysis.Although perovskite oxides containing noble metals show good performance and excellent thermal stability,the encapsulation of noble metals in perovskite lattice restricts the exposure/usage of active sites.Herein,a method of high-temperature calcination coupling with selective dissolution was adopted to tune the physicochemical environment on the LaPd_(0.1)Mn_(0.9)O_(3)catalyst surface.The X-ray diffraction(XRD)and Raman results reveal that more Pd species emerge on the surface by elevating the calcination temperature,resulting in improved catalytic toluene oxidation activity.A further acid-etching of the LPMO-900 catalyst can also boost catalytic performance,being attributed to the enhanced redox ability and abundant surface oxygen vacancies.In addition,the optimized catalyst also exhibits excellent resistance to sintering and water vapor.This study provides new avenues for the rational design of highly efficient perovskite-based catalysts.展开更多
Catalytic oxidation of soot is of great importance for emission control on diesel vehicles.In this work,a highly active Cs/Co/Ce-Sn catalyst was investigated for soot oxidation,and it was unexpectedly found that high-...Catalytic oxidation of soot is of great importance for emission control on diesel vehicles.In this work,a highly active Cs/Co/Ce-Sn catalyst was investigated for soot oxidation,and it was unexpectedly found that high-temperature calcination greatly improved the activity of the catalyst.When the calcination temperature was increased from 500℃ to 750℃,T_(50) decreased from 456.9℃ to 389.8℃ in a NO/O_(2)/H_(2)O/N_(2) atmosphere.Characterization results revealed that high-temperature calcination can promote the ability to transfer negative charge density from Cs to other metal cations in Cs/Co/Ce-Sn,which will facilitate the production of more oxygen defects and the generation of more surface-active oxygen species.Surfaceactive oxygen species are beneficial to the oxidation of NO to NO_(2),leading to the high yield of NO_(2) exploitation.Therefore,the Cs/Co/Ce-Sn catalyst calcined at 750℃ demonstrated higher activity than that calcined at 500℃.This work provides a pathway to prepare high efficiency catalysts for the removal of soot and significant insight into the effects of calcination on soot oxidation catalysts.展开更多
We focus on a novel and economical route for the synthesis of Si fertilizer via the calcination method using lithium pyroxene acid-leaching residues as the starting materials.The molar ratio of Si/K/Ca of 1:1.4:0.8,ca...We focus on a novel and economical route for the synthesis of Si fertilizer via the calcination method using lithium pyroxene acid-leaching residues as the starting materials.The molar ratio of Si/K/Ca of 1:1.4:0.8,calcination temperature of 900℃and calcination time of 120 min were identified as the optimal conditions to maximize the available Si content of the prepared Si fertilizer.The performance of the resulting product satisfies the Chinese agricultural standard for silica fertilizers,providing a new solution for the large-scale harmless and sustainable reuse of lithium pyroxene tailings.The X-ray diffraction(XRD)and Fourier transform infrared spectroscopy(FTIR)characterization elucidated the formation mechanism of silica fertilizers,and identified KAlSiO_(4)and K_(4)CaSi_(3)O_(9)as the primary silicates products.Observation of the surface morphology of the samples was conducted by scanning electron microscopy(SEM)and X-ray energy dispersive spectrometry(EDS),and compositional analysis of the micro-regions.The acceleration action of CaCO_(3)in the decomposition process of lithium pyroxene acid-leaching residues was demonstrated by the thermogravimetry-differential scanning calorimetry(TG-DSC)test.Determination of heavy metal elements in Si fertilizer was performed by ICP-OES.Potting experiments confirmed that the best growth of pakchoi was achieved when 5 g·kg^(-1)of Si fertilizer was applied.These evidence suggests that the Si fertilizer prepared in this study is a promising candidate for a silica-supplemented soil.展开更多
High-plastic clays with significant volume change due to moisture variations present critical challenges to civil engineering structures.Limestone calcined clay cement(LC3),an innovative and sustainable hydraulic bind...High-plastic clays with significant volume change due to moisture variations present critical challenges to civil engineering structures.Limestone calcined clay cement(LC3),an innovative and sustainable hydraulic binder,demonstrates significant potential for improving the engineering characteristics of such soils.Nevertheless,the impact of LC3 on the physico-mechanical characteristics of treated soil under a cyclic wet-dry environment remains unclear.This study for the first time investigates LC3's impact on the long-term durability of treated high-plastic clays through comprehensive macro-micro testing including physical,mechanical,mineralogical,and microstructural investigations with an emphasis on wet-dry cycles.The results revealed that LC3 treatment exhibits significant resistance to wet-dry cycles by completely mitigating the swelling potential,and a considerable reduction in plasticity resulting in enhanced workability.The compressibility and shear strength parameters have been significantly improved to several orders of magnitude.However,after six wet-dry cycles,a slight to modest reduction is observed,but overall durability remains superior to untreated soil.Cohesive and structural bonding ratios quantitatively assessed the impact of wet-dry cycles emphasizing the advantage of LC3 treatment.According to mineralogical and microstructural evaluation,the mechanism behind the adverse effects of wet-dry cycles on the compressibility and strength behavior of LC3-treated soil is mainly attributed to:(1)weakening of CSH/C(A)SH and ettringite(AFt)phases by exhibiting lower peak intensities;and(2)larger pore spaces due to repeated wet-dry cycles.These findings highlight LC3's performance in enhancing the long-term behavior and resilience of treated soils in real-world scenarios,providing durable solutions for infrastructure challenges.展开更多
This study explores the controllable synthesis of CuAlO_(2) using copper hydroxide and pseudo-boehmite powders as raw materials via a simple solid-phase ball milling method,along with its catalytic performance investi...This study explores the controllable synthesis of CuAlO_(2) using copper hydroxide and pseudo-boehmite powders as raw materials via a simple solid-phase ball milling method,along with its catalytic performance investigation in methanol steam reforming(MSR).Various catalysts were prepared under different conditions,such as calcination temperature,calcination atmosphere,and heating rate.Characterization techniques including BET,XRD,XPS,SEM and H2-TPR were employed to analyze the samples.The results revealed significant effects of calcination temperature on the phase compositions,specific surface area,reduction performance,and surface properties of the CA-T catalysts.Based on the findings,a synthesis route of CuAlO_(2) via the solid-phase method was proposed,highlighting the importance of high calcination temperature,nitrogen atmosphere,and low heating rate for CuAlO_(2) formation.Catalytic evaluation data demonstrated that CuAlO_(2) could catalyze MSR without pre-reduction,with the catalytic performance of CA-T catalysts being notably influenced by calcination temperature.Among the prepared catalysts,the CA-1100 catalyst exhibited the highest catalytic activity and stability.The findings of this study might be useful for the further study of the catalytic material for sustained release catalysis,including the synthesis of catalytic materials and the regulation of sustained release catalytic performance.展开更多
基金supported by the Natural Science Foundation of Fujian Province (No. T08J0129)the Science and Technology Developing Foundation of Fuzhou University (No. 2008-XQ-001)2007-year New Century Talents Supporting Program of Fujian Province (No.XSJRC2007-17)
文摘We aim in this research at synthesizing high-purity aluminium titanate with sludge from the aluminium profile factory by shock cooling method, and mainly discuss the effect of calcining reaction temperature and holding time on crystalline, microstructure and content of aluminum titanate materials to determine the preferred calcining temperature and holding time. XRD and SEM methods were utilized to characterize the crystalline and microstructure of each specimen, Rietveld Quantification software was used for the determination of different crystalline contents of specimens, and Philips plus software was applied to determine the cell parameters of aluminium titanate in different specimens. According to the experimental results, preferred calcining temperature is determined as 1400℃ and preferred holding time is 2 h, at which the grains of aluminum titanate grow completely and the purity of aluminum titanate is 97.2wt%.
文摘Energy saving has been an important concept in modern industry especially to the countries and regions with energy shortage such as China and Japan. Utilization of Coal-Water Slurry （CWS） can improve the burning efficiency of coal and reduce the pollutions of soot, sulfide and the nitride by burning lump coal directly. The CWS is a promising energy saving technique and the effectual substitute of oil. The study on the preparation and application of the CWS has made progresses in many aspects. The present paper studied the basal problems for applying the CWS on the rotary kilns during the calcining-dolomite process in the magnesium factory, summarized the key points for the application process of the CWS and gave the corresponding solutions.
基金Funded by the Project for Science and Technology Plan of Wuhan City(200910321092)the Youth Science Plan for Light of the Morning Sun of Wuhan City (200750731270)
文摘The effects of microwave sintering and conventional H2 sintering on the microstructure and properties of W-15Cu alloy using ultrafine W-15Cu composite powder fabricated by spray drying ＆ calcining-continuous reduction technology were investigated. In comparison to the conventional HE sintering processing, microwave sintering to W-15Cu can be achieved at lower sintering temperature and shorter sintering time. Furthermore, higher performances in microwave sintered compacts were obtained, but high microwave sintering temperature or long microwave sintering time could result in coarser microstructures.
基金financially supported by the National Natural Science Foundation of China (Grant Nos. 51964031 and 52164039)。
文摘The application of high-sulfur petroleum coke after desulfurization in aluminum electrolysis anodes is an important development trend. However, removing sulfur from high-sulfur petroleum coke is still a significant challenge.This study proposes alkali calcining and reflux washing to examine the impacts of temperature, particle size, the mass ratio of Na_(2)CO_(3) to NaOH, and total sodium addition on the desulfurization efficiency and mechanism. The results show that the desulfurization rate increases with increasing temperature, increasing total sodium content, and decreasing particle size. The addition of alkali can significantly reduce the opening-ring reaction temperature of thiophene and convert organic sulfur into inorganic sulfur(Na_(2)S). Three washing methods were compared, and reflux washing was selected to separate inorganic sulfur(Na_(2)S) from calcined petroleum coke. The sulfur content in petroleum coke decreased from 7.29% to 1.90%, with a desulfurization rate of 80.13% under optimal conditions. The petroleum coke was analyzed before and after desulfurization using X-Ray diffraction(XRD), Scanning Electron Microscopy(SEM), Infrared Spectroscopy(IR), Thermogravimetric Analysis and Differential Scanning Calorimetry(TG-DSC), Gaschromatography-mass Spectrometry(GC-MS). The results show that thiophene and benzothiophene in petroleum coke are decomposed and converted into octane and ethyl cyclohexane. These new observations are expected to provide further understanding and guidance for the utilization of highsulfur petroleum coke.
文摘The swung gel fibers were hea, ted to 400 ℃ at 0. .5 ,1, 1.5,2,2.5,3and4 ℃ min^-1 of heating rate, respectivel, and soaked.for 1 h ; then heated to 600 ℃ at 3 ℃ min ^-1 of.heating rate amt soaked for 1 h at last calcined m 1 000, 1 100, 1 200, 1 300, and 1 400 ℃.for 1 h, respectively.
基金supported by the National Natural Science Foundation of China (Grant Nos. 51102022 and 50872046)the China Postdoctoral Science Foundation (Grant No. 2011M501413)+1 种基金the Special Fund for Basic Scientific Research of Central Colleges, Changan University (Grant No. CHD2012ZD015)the Special Fund for Basic Research support programs of Chang an Univer sity
文摘Single-crystal alpha alumina （α-Al2O3） platelets were synthesized by calcining a powder mixture of bayerite （α-AI（OH）3） and potassium sulfate （K2SO4） at 900℃. The crystalline phase evolutions and morphologies of the samples were characterized by X-ray diffraction （XRD）, scanning electron microscopy （SEM）, and transmission electron microscopy （TEM）. The synthesized samples mainly consisted of single-crystal α-Al2O3 platelets with a diameter of 0.5-1.5 μm and a thickness of 50-150 nm. Moreover, with 3, 5, and 8 wt% （referred to the obtained alumina） α-Al2O3 seeds adding into the powder mixture of bayerite and potassium sulfate, the average diameter of α-Al2O3 platelets can be reduced to 450, 240, and 220 nm, respectively. It is found that the sequence of the phase transformation is the bayerite （α-Al（OH）3） → boehmite （γ-AIOOH） →γ-Al2O3 → α-Al2O3. Further analysis indicated that K2SO4 can promote the phase transformation from α-Al2O3 to α-Al2O3 and the formation of single-crystal α-Al2O3 platelets might be attributed to the liquid phase K3AI（SO4）3.
基金This work was supported by the Basic Science Center Project for National Natural Science Foundation of China(No.72088101)the National Key Research and Development Program of China(No.2020YFC1909800)the Hunan Provincial Innovation Founda-tion for Postgraduate(No.2021zzts0298).
文摘In this work,a novel process consisting of calcining-slaking followed by gravity separation for the enrichment of niobium(Nb)and titanium(Ti)from carbonatite pyrochlore ore was proposed,validated and compared with the current mainstream flotation method.During calcining of the pyrochlore ore,within which the carbonates were transformed into lime.Subsequently,when the calcined ore was slaked,lime was transformed into hydroxide with fine particles which were amenable to gravity separation.After calcining at 900℃for 60 min,slaking at 90℃for 10 min with a liquid–solid ratio of 3:1(mL/g),approximately 40%of tailings can be removed by gravity separation,the recoveries of Nb and Ti were 94.7%and 91.0%,and the enrichment ratios of Nb and Ti were 1.61 and 1.43,respectively.The new approach exhibits high separation efficiency of carbonate gangue minerals and valuable minerals,satisfactory recoveries of niobium as well as titanium can be achieved.
基金supported by the National Natural Science Foundation of China (No.50734007)Technology Project of Yunnan Province (No.2007GA002)
文摘The incremental improved Back-Propagation （BP） neural network prediction model using the Levenberg-Marquardt algorithm based on optimizing theory is put forward, which can solve the problems existing in the process of calcinations for ammonium diuranate （ADU） by microwave heating, such as long testing cycle, high testing quan- tity, difficulty of optimization for process parameters. Many training data probably were offered by the way of increment batch and the limitation of the system mem- ory could make the training data infeasible when the sample scale was large. The prediction model of the nonlinear system is built, which can effectively predict the experiment of microwave calcining of ADU, and the incremental improved BP neural network is very useful in overeoining the local minimum problem, finding the global optimal solution and accelerating the convergence speed.
文摘To improve separation efficiency of the photogenerated electron-hole pairs,constructing a heterojunction is considered to be a promising strategy.However,the fabrication of heterojunction via a facile route to achieve a substantial improvement in photocatalytic performance is still challenging.In this work,a well-designed nanosheet-based rodlike step-scheme(S-scheme)heterojunction Bi_(4)O_(5)I_(2)/Bi_(4)O_(5)Br_(2) with rich oxygen vacancies(OVs)(Bi_(4)O_(5)I_(2)/Bi_(4)O_(5)Br_(2)-OV)was easily synthesized by calcining BiOAc0.6Br0.2I0.2(Ac-=CH3 COO-)precursor.The as-prepared Bi4O5I2/Bi4O5Br2-OV exhibited excellent visible light photocatalytic performance towards antibiotic tetracycline(TC)and dye rhodamine B(Rh B)degradation and removal rate reached 90.2% and 97.0%within 120 min,respectively,which was higher than those of Bi4O5I2-OV(56.8% and 71.8%),Bi4O5Br2-OV(47.4%and 68.4%),solid solution BiOAc0.6Br0.2I0.2(67.0% and 84.0%)and Bi_(4)O_(5)I_(2)/Bi_(4)O_(5)Br_(2) with poor oxygen vacancies(Bi4O5I2/Bi4O5Br2-P)(30.6%and 40.4%).Owing to the release of heat and generation of reducing carbon during calcining the precursor with Ac-,it could not only reduce the generation temperature of Bi-rich bismuth oxyhalides,which thus decreased particle size and increased surface areas,but also introduce surface OVs,which could trap photoelectrons and inhibit the recombination of carriers.In addition,the calcination of single solid solution precursor benefited to the formation of well-alloyed interfaces with larger contact areas between 2D/2D nanosheet-like materials,which facilitates charge carriers transfer at the interfaces.The Bi4O5I2/Bi4O5Br2-OV also shows the desirable removal rate for TC and Rh B in actual wastewater or in the presence of some electrolytes.This study provides an effective and simple strategy for designing OVs modified Bi-rich oxyhalides heterojunctions.
基金funded by the National Key Research and Development Program of China(No.2023YFD2401105)the Fujian Science and Technology Planning ProjectSTS Program(No.2021T3013)。
文摘Dye wastewater poses a significant threat to aquatic organisms due to its high toxicity.Reducing or eliminating the dye waste from the water is necessary for a healthy and sustainable aquaculture.This study investigated the adsorption properties of Congo red dye on Mytilus edulis shell powders prepared by calcination at 500℃,700℃,and 900℃.The modified shell powder products were analyzed by SEM(scanning eletron microscopy)and FTIR(fourier transform infrared spectroscopy)for the morphology and structural characterization.The effects of different calcination temperatures,reaction times,reaction temperatures,and initial concentration of Congo red on the adsorption properties were investigated.The adsorption kinetics and isothermal adsorption models were also established.The results revealed that the shell powder calcinated at 900℃showed the best adsorption capacity on Congo red from aqueous solution.The adsorption reaction reached equilibrium after 150 min and followed by the pseudo-second-order kinetic model.At 25℃,96.2%of the Congo red in the solution could be removed,and the adsorption capacity could reach at least 1015 mg g^(–1).The adsorption isotherm is fit with the Freundlich model,indicating a multiphase adsorption process.These results are helpful for cleaning and treating printing and dyeing effluents as well as high-value utilization of shell waste resources.
基金Funded by the National Natural Science Foundation of China(No.52178216)the Gansu Provincial Science and Technology Programme(No.23JRRA813)。
文摘The effects of calcination temperature and mechanical ball milling on the physicochemical properties of electrolytic manganese residue(EMR),mineral phase transition,pozzolanic activity,and pore structure were studied.The experimental results show that the strength activity index(SAI)of 20%EMR mixed mortar at 28 days is 90.54%,95.40%,and 90.73%,respectively,after pretreatment with EMR at 800℃calcined for 3,5,and 8 min.This is mainly attributed to the high temperature decomposition of gypsum dihydrate to form activated calcium oxide.In addition,high temperature and mechanical force destroys the Si-O chemical bond and promotes the formation of calcium silicate gel structure.Due to the existence of a large number of gypsum phases in EMR mixed mortar,a large number of ettringite,C-S-H,aluminosilicate,C-A-S-H,and AFm are formed,which strongly verifies the volcanic activity of EMR.The leaching test shows that high temperature calcination has a significant effect on the stabilization of NH_(3)-N.However,the curing effect of Mn^(2+)is significant only in the calcination at 1000℃,but both Mn^(2+)and NH_(3)-N in the calcined EMR are higher than the emission standard.The encapsulation effect of EMR composite mortar provided by hydration products,and the buffering capacity of the Si-Al system for solidification of heavy metals and strong alkalis are conducive to the stability of Mn^(2+)and NH_(3)-N.After the EMR mixed mortar is aged for 3 days,Mn and NH_(3)-N are completely lower than the emission standard.In general,the EMR mixed mortar can meet the requirements for green building use.
文摘Aceh in Indonesia is rich inmarine resources and abundant fishery products such as oyster.Traditionally,fishermen only harvest oysters and discard the shells,which can cause pollution and environmental contamination.Waste Oyster Shells(WOS)contain a high percentage of calcium carbonate(CaCO_(3))that experiences thermal decomposition at high temperature,following the reaction CaCO_(3)→CaO+CO_(2)(ΔT=825℃).At temperature>900℃,dead-burned lime is formed,which severely influences CaO reactivity.However,the optimum temperature for producing high CaO content is still uncertain.Therefore,this study aimed to determine the optimum calcination temperature to produce high CaO content,assess initial setting time of WOS paste,and identify the best compressive strength of paste.For the experiment,WOS was used as a partial cement replacement(with a size of 0.075 mm)in paste at a proportion of 5%and calcined at temperature of 700℃,800℃,900℃,and 1000℃.The specimens used were an ebonite ring(dimensions:70 mm bottom diameter,60 mm top diameter,and 40 mm height)and a cube(dimensions:5 cm×5 cm×5 cm).The experiment was conducted following the ASTM(American Society for Testing andMaterials)standards and optimumcompressive strength values were analyzed using ANOVA(Analysis of Variance)and Response Surface Methodology(RSM)through the Design Expert software.The results showed that WOS calcined at 1000℃ increased CaO content by approximately 57.40%.Furthermore,the initial setting time test of 5%WOS paste at 1000℃ showed a more uniform binding performance compared to conventional cement paste,with an initial setting time of 75 min and a penetration depth of 15 mm.In line with the analysis,optimum compressive strength of 71.028 MPa with a desirability value of 0.986 was achieved at 5%cement replacement and calcination temperature of 786.44℃.
基金Tural Science Foundation of China(No.52274255)the Young Scientists Fund of the National Natural ScienceFoundation of China(No.52404276)+3 种基金Fundamental Re-search Funds for the Central Universities,China(Nos.N2301003,N2201008,N2201004,and N2301025)Liaon-ingRevitalizationTalentsProgram,China(No.XLYC2202028)Postdoctoral Foundation of NortheasternUniversity,Young Elite Scientists Sponsorship Program byChina Association for Science and Technology(No.2022QNRC001)and China Postdoctoral Science Founda-tion(No.2022M720025)。
文摘To advance the precise regulation and high-value utilization of halloysite nanotubes(HNTs),this work systematically investigated five treatment strategies,including calcination,acid treatment,alkali treatment,acid treatment of calcined HNTs,and alkali treatment of calcined HNTs,to modulate their structural and application properties.The structural characteristics,surface properties,and methylene blue(MB)adsorption capacity of HNTs under multiple treatments were systematically analyzed.Calcination at varying temperatures modified the crystal structure,morphology,and surface properties of HNTs,with higher calcination temperatures reducing their reactivity towards MB.Moderate acid treatment expanded the lumen and decreased the surface potential of HNTs,significantly enhancing MB adsorption capacity.In contrast,alkali treatment dispersed the multilayered walls of HNTs and raised surface potential,reducing MB affinity.Acid treatment of calcined HNTs effectively increased their specific surface areas by leaching most of Al while maintaining the tubular structure,thereby maximizing MB adsorption.Alkali treatment of calcined HNTs destroyed the tubular structure and resulted in poor MB adsorption.HNTs pre-calcined at 600℃ for 3 h and acid-treated at 60℃ for 8 h exhibited an optimal specific surface area of443 m^(2)·g^(-1)and an MB adsorption capacity of 190 mg·g^(-1).Kinetic and Arrhenius equation fittings indicated that chemical reactions control interactions of acids and alkalis with HNTs.This study provides a comprehensive comparison and analysis of five treatment methods,offering insights into regulating the structures and surface properties of HNTs by controlling the treatment condition,thereby laying a foundation for their efficient utilization in practical applications.
基金financial support for the research and for the publication costs of the articlesupported by Santa Catarina State Research Support Foundation(FAPESC)National Council for Scientific and Technological Development(CNPq no 302903/2023-2).
文摘Cement production,while essential for global infrastructure,contributes significantly to carbon dioxide emissions,accounting for approximately 7%of total emissions.To mitigate these environmental impacts,flash calcination of kaolinitic clays has been investigated as a sustainable alternative.This technique involves the rapid heating of clays,enabling their use as supplementary cementitious materials.The primary objective of this study was to modify the color of calcined clay in various atmospheres(oxidizing,inert,and reducing)to achieve a grayish tone similar to commercial cement while preserving its reactive properties.The experimental procedure employed a tubular reactor with precise control of gas flows(atmospheric air,nitrogen,and a carbon monoxide–nitrogen mixture).Physicochemical characterization of the raw clay was conducted before calcination,with analyses repeated on the calcined clays following experimentation.Results indicated that clay calcined in an oxidizing atmosphere acquired a reddish hue,attributed to the oxidation of iron in hematite.The Clay exhibited a pinkish tone in an inert atmosphere,while calcination in a reducing atmosphere yielded the desired grayish color.Regarding pozzolanic activity,clays calcined in oxidizing and inert atmospheres displayed robust strength,ranging from 82%to 87%.Calcination in a reducing atmosphere resulted in slightly lower strength,around 74%,likely due to the clay’s chemical composition and the calcination process,which affects compound formation and material reactivity.
基金supported by the National Natural Science Foundation of China(No.52374344).
文摘The Ni-ZnFe_(2)O_(4)(NixZn_(1-x)Fe_(2)O_(4),x=0.4-0.7)spinel was synthesized using Zn2+extracted from electric arc furnace dust(EAFD),nickel chloride hexahydrate,and Fe^(3+)extracted from iron scale as raw materials.The zinc was selectively extracted from EAFD using CaO roasting followed by NH_(4)Cl solution leaching.The ferric ion was leached from iron scale using HCl solution as acid lixiviant.The experimental results demonstrate a high level of efficiency in the extraction of zinc,with a rate of 97.5%,and the leaching rate of ferric ion is 96.89%.The composition of the leaching solution is primary zinc and iron with low calcium,which is beneficial to the preparation of spinel ferrite.The influence of Ni content(x)and calcination temperature on the synthesis and magnetic properties of NixZn_(1-x)Fe_(2)O_(4)compounds was investigated by X-ray diffraction,scanning electron microscopy,and vibrating sample magnetometry.The results revealed that both Ni content and calcination temperature significantly affect the synthesis and magnetic properties of spinel NixZn_(1-x)Fe_(2)O_(4).Under the conditions of Ni content set at x=0.6,calcination temperature of 1100℃,and a duration of 2 h,a spinel NixZn_(1-x)Fe_(2)O_(4)with high saturation magnetization(Ms=65.7 A m2 kg-1)and low coercivity(Hc=0.056 A m^(-1))was obtained.
基金Project supported by the National Key R&D Program of China(2023YFC3710300)the National Natural Science Foundation of China(U23A2099,22276111)+1 种基金the Taishan Scholar Project of Shandong Province(202306031)the Natural Science Foundation of Shandong Province(2023HWYQ-024)。
文摘Surface regulation is a crucial technique for improving catalytic performance in heterogeneous catalysis.Although perovskite oxides containing noble metals show good performance and excellent thermal stability,the encapsulation of noble metals in perovskite lattice restricts the exposure/usage of active sites.Herein,a method of high-temperature calcination coupling with selective dissolution was adopted to tune the physicochemical environment on the LaPd_(0.1)Mn_(0.9)O_(3)catalyst surface.The X-ray diffraction(XRD)and Raman results reveal that more Pd species emerge on the surface by elevating the calcination temperature,resulting in improved catalytic toluene oxidation activity.A further acid-etching of the LPMO-900 catalyst can also boost catalytic performance,being attributed to the enhanced redox ability and abundant surface oxygen vacancies.In addition,the optimized catalyst also exhibits excellent resistance to sintering and water vapor.This study provides new avenues for the rational design of highly efficient perovskite-based catalysts.
基金supported by the National Natural Science Foundation of China(Nos.22206183,52225004)the National Key R&D Program of China(No.2022YFC3701804)+1 种基金the Strategic Priority Research Program of the Chinese Academy of Sciences(No.XDA23010201)the Youth Innovation Promotion Association of Chinese Academy of Sciences(No.2022309)。
文摘Catalytic oxidation of soot is of great importance for emission control on diesel vehicles.In this work,a highly active Cs/Co/Ce-Sn catalyst was investigated for soot oxidation,and it was unexpectedly found that high-temperature calcination greatly improved the activity of the catalyst.When the calcination temperature was increased from 500℃ to 750℃,T_(50) decreased from 456.9℃ to 389.8℃ in a NO/O_(2)/H_(2)O/N_(2) atmosphere.Characterization results revealed that high-temperature calcination can promote the ability to transfer negative charge density from Cs to other metal cations in Cs/Co/Ce-Sn,which will facilitate the production of more oxygen defects and the generation of more surface-active oxygen species.Surfaceactive oxygen species are beneficial to the oxidation of NO to NO_(2),leading to the high yield of NO_(2) exploitation.Therefore,the Cs/Co/Ce-Sn catalyst calcined at 750℃ demonstrated higher activity than that calcined at 500℃.This work provides a pathway to prepare high efficiency catalysts for the removal of soot and significant insight into the effects of calcination on soot oxidation catalysts.
文摘We focus on a novel and economical route for the synthesis of Si fertilizer via the calcination method using lithium pyroxene acid-leaching residues as the starting materials.The molar ratio of Si/K/Ca of 1:1.4:0.8,calcination temperature of 900℃and calcination time of 120 min were identified as the optimal conditions to maximize the available Si content of the prepared Si fertilizer.The performance of the resulting product satisfies the Chinese agricultural standard for silica fertilizers,providing a new solution for the large-scale harmless and sustainable reuse of lithium pyroxene tailings.The X-ray diffraction(XRD)and Fourier transform infrared spectroscopy(FTIR)characterization elucidated the formation mechanism of silica fertilizers,and identified KAlSiO_(4)and K_(4)CaSi_(3)O_(9)as the primary silicates products.Observation of the surface morphology of the samples was conducted by scanning electron microscopy(SEM)and X-ray energy dispersive spectrometry(EDS),and compositional analysis of the micro-regions.The acceleration action of CaCO_(3)in the decomposition process of lithium pyroxene acid-leaching residues was demonstrated by the thermogravimetry-differential scanning calorimetry(TG-DSC)test.Determination of heavy metal elements in Si fertilizer was performed by ICP-OES.Potting experiments confirmed that the best growth of pakchoi was achieved when 5 g·kg^(-1)of Si fertilizer was applied.These evidence suggests that the Si fertilizer prepared in this study is a promising candidate for a silica-supplemented soil.
基金The financial support of the National Natural Science Foundation of China(Grant No.42030714)the National Key R&D Program of China(Grant No.2019YFC1509900)is greatly acknowledged.
文摘High-plastic clays with significant volume change due to moisture variations present critical challenges to civil engineering structures.Limestone calcined clay cement(LC3),an innovative and sustainable hydraulic binder,demonstrates significant potential for improving the engineering characteristics of such soils.Nevertheless,the impact of LC3 on the physico-mechanical characteristics of treated soil under a cyclic wet-dry environment remains unclear.This study for the first time investigates LC3's impact on the long-term durability of treated high-plastic clays through comprehensive macro-micro testing including physical,mechanical,mineralogical,and microstructural investigations with an emphasis on wet-dry cycles.The results revealed that LC3 treatment exhibits significant resistance to wet-dry cycles by completely mitigating the swelling potential,and a considerable reduction in plasticity resulting in enhanced workability.The compressibility and shear strength parameters have been significantly improved to several orders of magnitude.However,after six wet-dry cycles,a slight to modest reduction is observed,but overall durability remains superior to untreated soil.Cohesive and structural bonding ratios quantitatively assessed the impact of wet-dry cycles emphasizing the advantage of LC3 treatment.According to mineralogical and microstructural evaluation,the mechanism behind the adverse effects of wet-dry cycles on the compressibility and strength behavior of LC3-treated soil is mainly attributed to:(1)weakening of CSH/C(A)SH and ettringite(AFt)phases by exhibiting lower peak intensities;and(2)larger pore spaces due to repeated wet-dry cycles.These findings highlight LC3's performance in enhancing the long-term behavior and resilience of treated soils in real-world scenarios,providing durable solutions for infrastructure challenges.
基金supported by the Scientific Research Foundation for High-level Talents of Anhui University of Science and Technology(2023yjrc51)the National Natural Science Foundation of China(22172184)+2 种基金the Foundation of State Key Laboratory of Coal Conversion(J24-25-603)the Fundamental Research Project of ICC-CAS(SCJC-DT-2023-01)Weiqiao-UCAS Special Projects on Low-Carbon Technology Development(GYY-DTFZ-2022-015)。
文摘This study explores the controllable synthesis of CuAlO_(2) using copper hydroxide and pseudo-boehmite powders as raw materials via a simple solid-phase ball milling method,along with its catalytic performance investigation in methanol steam reforming(MSR).Various catalysts were prepared under different conditions,such as calcination temperature,calcination atmosphere,and heating rate.Characterization techniques including BET,XRD,XPS,SEM and H2-TPR were employed to analyze the samples.The results revealed significant effects of calcination temperature on the phase compositions,specific surface area,reduction performance,and surface properties of the CA-T catalysts.Based on the findings,a synthesis route of CuAlO_(2) via the solid-phase method was proposed,highlighting the importance of high calcination temperature,nitrogen atmosphere,and low heating rate for CuAlO_(2) formation.Catalytic evaluation data demonstrated that CuAlO_(2) could catalyze MSR without pre-reduction,with the catalytic performance of CA-T catalysts being notably influenced by calcination temperature.Among the prepared catalysts,the CA-1100 catalyst exhibited the highest catalytic activity and stability.The findings of this study might be useful for the further study of the catalytic material for sustained release catalysis,including the synthesis of catalytic materials and the regulation of sustained release catalytic performance.
