The novel process of hydrogen-based shaft furnaces(HSFs)has attracted considerable attention because of their significant reduction of CO_(2)emissions.In this study,the interaction of H_(2)and CO with Fe_(tet1)-and Fe...The novel process of hydrogen-based shaft furnaces(HSFs)has attracted considerable attention because of their significant reduction of CO_(2)emissions.In this study,the interaction of H_(2)and CO with Fe_(tet1)-and Fe_(oct2)-terminated Fe_(3)O_(4)(111)surfaces under HSF conditions,including their adsorption and reduction behaviors,was investigated using the density functional theory method.The results indicated that the H_(2)molecule adsorbed onto the Fe_(tet1)-terminated surface with an adsorption energy(AE)of-1.36 eV,whereas the CO molecule preferentially adsorbed on the Fe_(oct2)-terminated surface with an AE of-1.56 eV.Both H_(2)and CO can readily undergo reduction on the Fe_(tet1)-terminated surface(corresponding to energy barriers of 0.83 eV and 2.23 eV,respectively),but kinetically the reaction of H2is more favorable than that of CO.With regard to the thermodynamics at 400-1400 K,the H_(2)was easy to be adsorbed,while the CO would like to react on the Fe_(tet1)-terminated surface.These thermodynamically tendencies were reversed on the Fe_(oct2)-terminated surface.The thermodynamic disadvantage of the reaction of H_(2)on the Fe_(tet1)-terminated surface was offset by an increase in the temperature.Furthermore,the adsorption of H2 and CO on the Fe_(tet1)-terminated surface was competitive,whereas the adsorption of them on the Fe_(oct2)-terminated surface was synergistic.Therefore,iron ores with a higher proportion of Fe_(tet1)-terminated surface can be applied for the HSF process.In conjunction with the increases in the reduction temperature and the ratio of H_(2)in the reducing gas would promote efficient HSF smelting.These observations provide effective guidance for optimizing the practical operation parameters and advancing the development of the HSF process.展开更多
Hydrogen-based mineral phase transformation(HMPT)technology has demonstrated its effectiveness in separating iron and enriching rare earths from Bayan Obo refractory ores.However,further research is needed to clarify ...Hydrogen-based mineral phase transformation(HMPT)technology has demonstrated its effectiveness in separating iron and enriching rare earths from Bayan Obo refractory ores.However,further research is needed to clarify the phase composition and floatability of rare earths obtained after HMPT owing to the associated phase transformations.This study explored the mineralogical characteristics and separation behavior of rare earths in HMPT-treated iron tailings.Process mineralogy studies conducted via BGRIMM process mineralogy analysis and X-ray diffraction revealed that the main valuable minerals in the tailings included rare-earth oxides(9.15wt%),monazite(5.31wt%),and fluorite(23.52wt%).The study also examined the impact of mineral liberation and gangue mineral intergrowth on flotation performance.Flotation tests achieved a rare-earth oxide(REO)grade of 74.12wt% with a recovery of 34.17% in open-circuit flotation,whereas closed-circuit flotation resulted in a REO grade of 60.27wt% with a recovery of 73%.Transmission electron microscopy and scanning electron microscopy coupled with energy-dispersive spectroscopy revealed that monazite remained stable during the HMPT process,while bastnaesite was transformed into Ce_(7)O_(12)and CeF_(3),leading to increased collector consumption.Nonetheless,the HMPT process did not significantly affect the flotation performance of rare earths.The enrichment of fluorite in the tailings highlighted its further recovery potential.The integration of HMPT with magnetic separation and flotation presents an efficient strategy for recovering rare earths,iron,and fluorite from Bayan Obo ores.展开更多
The steel industry’s transition to hydrogen-based ironmaking necessitates a deeper understanding of magnetite ore reduction,a crucial yet underexplored pathway for decarbonization.This study systematically investigat...The steel industry’s transition to hydrogen-based ironmaking necessitates a deeper understanding of magnetite ore reduction,a crucial yet underexplored pathway for decarbonization.This study systematically investigates the combined effects of particle size and gangue composition on hydrogen-based reduction behavior of four industrial magnetite ore concentrates with varying CaO and MgO con-tents.Thermogravimetric analysis at 973 K,interrupted reduction experiments,and post-reduction characterization steps are used to eval-uate reduction extent and phase transformations across different particle size fractions and bulk ores.The finer fractions generally exhibit faster and more complete reduction.However,this trend is overridden by gangue effects in certain ores.Magnetite ores with MgO as gangue tend to form magnesio-wustite solid solution(Mg,Fe)O during reduction,resulting in dense microstructures that impede hydrogen diffusion and limit reduction progress.In contrast,magnetite ores with CaO as gangue facilitate the formation of intermediate calcium fer-rites,which promote porous morphology and enhanced reducibility.Notably,even the finer particles of ore containing MgO show a lower reduction degree than the coarser particles of the ore containing CaO as gangue.This highlights the dominant role of gangue composition in governing reduction kinetics,intermediate phase formation and final product morphology.These findings contribute to the growing knowledge necessary to enable fossil-free ironmaking by emphasizing the importance of considering both granulometric characteristics and heterogeneity when evaluating magnetite ores for hydrogen-based reduction.展开更多
The hydrogen-based reduction and electric smelting technology is a green and low-carbon process for treating low-grade ore and complex symbiotic iron ore.In this study,the hydrogen-based reduction of boron-bearing iro...The hydrogen-based reduction and electric smelting technology is a green and low-carbon process for treating low-grade ore and complex symbiotic iron ore.In this study,the hydrogen-based reduction of boron-bearing iron concentrate and the low-temperature separation compared with the high-temperature melting separation of slag and iron from a boron-bearing iron concentrate were studied.The metallization rate of the boron-bearing iron concentrate reached 99.63%after hydrogen-based reduction at 1050℃,and the metallic iron was interwoven with olivine(Mg_(2)SiO_(4))in the reduced ore.In addition,the high-temperature melting separation of iron and slag could be accomplished at 1550℃for 60 min,where boron was mainly distributed in the form of a glass phase in the slag with a mass fraction of B_(2)O_(3)of 22.69%,and 0.35%of boron(mass fraction)was melted into liquid iron.By contrast,iron and slag were efficiently separated at a lower temperature(1300℃)for 10 min and enhanced by super-gravity.Almost all the boron content was enriched into a suanite phase in the slag with a considerably high mass fraction of B_(2)O_(3)(35.61%)and a high recovery ratio(99.37%),and the mass fraction of boron decreased to 0.15%in iron.Compared with high-temperature melting separation,low-temperature separation combined with hydrogen-based reduction greatly improved the enrichment of boron in slag and prevented the melting of boron into iron.展开更多
A hydrogen-based membrane biofilm reactor （MBfR） using H2 as electron donor was investigated to remove nitrate from groundwater. When nitrate was first introduced to the MBfR, denitrification took place on the shell...A hydrogen-based membrane biofilm reactor （MBfR） using H2 as electron donor was investigated to remove nitrate from groundwater. When nitrate was first introduced to the MBfR, denitrification took place on the shell side of the membranes immediately, and the effluent concentration of nitrate continuously decreased with 100% removal rate on day 45 under the influent nitrate concentration of 5 mg NO3^--N/L, which described the acclimating and enriching process of autohydrogenotrophic denitrification bacteria. A series of short-term experiments were applied to investigate the effects of hydrogen pressures and nitrate loadings on deniWification. The results showed that nitrate reduction rate improved as H2 pressure increasing, and over 97% of total nitrogen removal rate was achieved when the nitrate loading increased from 0.17 to 0.34 g NO3^--N/（m^2.day） without nitrite accumulation. The maximum deniwification rate was 384 g N/（m^3.day）. Partial sulfate reduction, which occurred in parallel to nitrate reduction, was inhibited by denitrififcation due to the competition for H2. This research showed that MBfR is effective for removing nitrate from the contaminated groundwater.展开更多
A laboratory trial was conducted for evaluating the capability of a continuously stirred hydrogen-based membrane biofllm reactor to simultaneously reduce nitrate （NO3--N）, sulfate （SO42-）, bromate （BrO3-）, hexav...A laboratory trial was conducted for evaluating the capability of a continuously stirred hydrogen-based membrane biofllm reactor to simultaneously reduce nitrate （NO3--N）, sulfate （SO42-）, bromate （BrO3-）, hexavalent chromium （Cr（VI）） and para- chloronitrobenzene （p-CNB）. The reactor contained two bundles of hollow fiber membranes functioning as an autotrophic biofiim carder and hydrogen pipe as well. On the condition that hydrogen was supplied as electron donor and diffused into water through membrane pores, autohydrogenotrophic bacteria were capable of reducing contaminants to forms with lower toxicity. Reduction occurred within 1 day and removal fluxes for NO3--N, SO42-, BrO3-, Cr（VI）, and p-CNB reached 0.641, 2.396, 0.008, 0.016 and 0.031 g/（day.m2）, respectively after 112 days of continuous operation. Except for the fact that sulfate was 37% removed under high surface loading, the other four contaminants were reduced by over 95 %. The removal flux comparison between phases varying in surface loading and 1-12 pressure showed that decreasing surface loading or increasing 1-12 pressure would promote removal flux. Competition for electrons occurred among the five contaminants. Electron-equivalent flux analysis showed that the amount of utilized hydrogen was mainly controlled by NO3--N and SO42- reduction, which accounted for over 99% of the electron flux altogether. It also indicated the electron acceptor order, showing that nitrate was the most prior electron acceptor while sulfate was the second of the five contaminants.展开更多
Steel production causes a third of all industrial CO_(2) emissions due to the use of carbon-based substances as reductants for iron ores,making it a key driver of global warming.Therefore,research efforts aim to repla...Steel production causes a third of all industrial CO_(2) emissions due to the use of carbon-based substances as reductants for iron ores,making it a key driver of global warming.Therefore,research efforts aim to replace these reductants with sustainably produced hydrogen.Hydrogen-based direct reduction(HyDR)is an attractive processing technology,given that direct reduction(DR)furnaces are routinely operated in the steel industry but with CH_(4) or CO as reductants.Hydrogen diffuses considerably faster through shaft-furnace pellet agglomerates than carbon-based reductants.However,the net reduction kinetics in HyDR remains extremely sluggish for high-quantity steel production,and the hydrogen consumption exceeds the stoichiometrically required amount substantially.Thus,the present study focused on the improved understanding of the influence of spatial gradients,morphology,and internal microstructures of ore pellets on reduction efficiency and metallization during HyDR.For this purpose,commercial DR pellets were investigated using synchrotron high-energy X-ray diffraction and electron microscopy in conjunction with electron backscatter diffraction and chemical probing.Revealing the interplay of different phases with internal interfaces,free surfaces,and associated nucleation and growth mechanisms provides a basis for developing tailored ore pellets that are highly suited for a fast and efficient HyDR.展开更多
本文采用电熔炉冶炼低品位DRI,开展百公斤级扩大化试验,探索低品位DRI电熔炉冶炼特性,包括渣铁分离效果、铁水渗碳效果、铁收得率等,并利用设计软件计算吨铁电耗、煤耗等指标。试验结果表明,DRI球由于具有团疏松多孔的结构,在熔炼过程...本文采用电熔炉冶炼低品位DRI,开展百公斤级扩大化试验,探索低品位DRI电熔炉冶炼特性,包括渣铁分离效果、铁水渗碳效果、铁收得率等,并利用设计软件计算吨铁电耗、煤耗等指标。试验结果表明,DRI球由于具有团疏松多孔的结构,在熔炼过程中始终漂浮在熔池上方;在二次电压120 V下,电极始终为浸没式操作,不能实现刷弧或明弧操作。通过从顶部加入无烟煤和DRI的混合物料可以实现良好的铁还原和铁水渗碳效果,铁水含碳量平均值为3.09%。在低碱度渣型和高渣率下,所得渣Fe O含量平均值为1.47%,铁收得率平均值高达98.84%。低品位DRI热态入炉生产液体热金属所需的理论吨铁电耗为511 k W·h/t,而冷态入炉的理论吨铁电耗为770 k W·h/t,热态DRI直接入炉冶炼可以节能约50%。展开更多
Percussion drilling is a promising approach for hot dry rock(HDR)fragmentation.However,understanding of HDR fragmentation mechanism under multi-dimensional percussion remains limited and hinders the corresponding dril...Percussion drilling is a promising approach for hot dry rock(HDR)fragmentation.However,understanding of HDR fragmentation mechanism under multi-dimensional percussion remains limited and hinders the corresponding drilling performance.Herein,an innovative true triaxial multi-dimensional percussion device was developed for the study of HDR fragmentation mechanism under in-situ temperature and stress conditions.Multi-dimensional percussion,involving both axial and torsional components,was applied to drilling in granite and carbonatite rocks sampled from the typical HDR target areas.Multiscale visualization techniques and a whale optimization-variational mode decomposition algorithm were employed to investigate the rock failure patterns and drilling energy characteristics.Results indicated that multi-dimensional percussion enhances brittle-ductile mixed failure in granite,characterized by transgranular,intergranular,and combined fracture patterns that promote rock cracking.In contrast,carbonatite drillhole displays enhanced brittle fragmentation and tortuous failure surface dominated by transgranular fracture pattern.Frequency-domain characteristics of penetration force signals for multidimensional percussion,especially the significant dominant frequency,amplitude,and high-frequency dissipation,indicate an increase in net energy for drilling into HDR and intensified rock fragmentation.Further,the effect of impact frequency on rock fragmentation performance was emphasized to maximize drilling efficiency.The optimal regulation schemes between axial and torsional impact frequencies are identified as 15 Hz+15 Hz for granite and 30 Hz+15 Hz for carbonatite.The reliability of the optimization approach was validated through a field test that employed a novel impactor in the geothermal well Fushen-1.展开更多
CeO_(2) based semiconductor are widely used in solar-driven photothermal catalytic dry reforming of methane(DRM)reaction,but still suffer from low activity and low light utilization efficiency.This study developed gra...CeO_(2) based semiconductor are widely used in solar-driven photothermal catalytic dry reforming of methane(DRM)reaction,but still suffer from low activity and low light utilization efficiency.This study developed graphite-CeO_(2) interfaces to enhance solar-driven photothermal catalytic DRM.Compared with carbon nanotubes-modified CeO_(2)(CeO_(2)-CNT),graphite-modified CeO_(2)(CeO_(2)-GRA)constructed graphite-CeO_(2) interfaces with distortion in CeO_(2),leading to the formation abundant oxygen vacancies.These graphite-CeO_(2) interfaces with oxygen vacancies enhanced optical absorption and promoted the generation and separation of photogenerated carriers.The high endothermic capacity of graphite elevated the catalyst surface temperature from 592.1−691.3℃,boosting light-to-thermal conversion.The synergy between photogenerated carriers and localized heat enabled Ni/CeO_(2)-GRA to achieve a CO production rate of 9985.6 mmol/(g·h)(vs 7192.4 mmol/(g·h)for Ni/CeO_(2))and a light-to-fuel efficiency of 21.8%(vs 13.8%for Ni/CeO_(2)).This work provides insights for designing graphite-semiconductor interfaces to advance photothermal catalytic efficiency.展开更多
In today's fast-paced modern life, whether for fitness training, outdoor adventures, or daily commutes, we all yearn for quick-dry apparel that can rapidly wick away moisture and keep our bodies dry and comfortabl...In today's fast-paced modern life, whether for fitness training, outdoor adventures, or daily commutes, we all yearn for quick-dry apparel that can rapidly wick away moisture and keep our bodies dry and comfortable. As a standout in functional textiles, quick-dry fabrics are becoming the top choice for more and more people, thanks to their exceptional moisture-wicking performance and rapid drying capabilities.展开更多
To improve the controlled release ability,we prepared attapulgite into microspheres by spray drying.This research began with a thorough thermogravimetric analysis to optimize attapulgite's heat treatment for drug ...To improve the controlled release ability,we prepared attapulgite into microspheres by spray drying.This research began with a thorough thermogravimetric analysis to optimize attapulgite's heat treatment for drug loading.By advanced spray drying,attapulgite was transformed into microspheres,refining its drug release characteristics.Various parameters were examined,achieving optimal particle size and morphology at 25%solid content,2.5%dispersant,and 3% binder.Attapulgite microspheres demonstrated exceptional encapsulation efficiency,exceeding 95% for doxorubicin hydrochloride,highlighting their versatility in drug delivery.FTIR and XRD were used to predict changes in material properties after spray drying.Notably,cytotoxicity tests confirmed the high biocompatibility of attapulgite microspheres,devoid of cell death induction.Attapulgite microsphere loaded with doxorubicin enable sustained drug release and maintain killing ability against tumor cells.This study confirms the viability of spray dried attapulgite microspheres for efficient drug loading and delivery and provides insights for innovative drug delivery systems that utilize the unique properties of attapulgite to advance therapeutics.展开更多
Background Feeding spray dried plasma(SDP)to weanling pigs improves growth,but there is a lack of research on how SDP impacts oxidative stress and inflammatory response in lactating sows,and performance of their pigle...Background Feeding spray dried plasma(SDP)to weanling pigs improves growth,but there is a lack of research on how SDP impacts oxidative stress and inflammatory response in lactating sows,and performance of their piglets after weaning.Therefore,an experiment was conducted to test the hypothesis that sows fed a diet with SDP in late gestation and lactation have improved reproductive performance and reduced inflammation compared with sows fed no SDP.The second hypothesis was that pigs weaned from sows fed 0.5%SDP in lactation have reduced diarrhea incidence and improved growth performance during the initial 14 d of the nursery period regardless of dietary SDP.Results The percent of low vitality or starved pigs during lactation was less(P<0.05)from sows fed 0.5%dietary SDP compared with sows fed the diet without SDP.Dietary SDP did not influence oxidative stress markers in the plasma of sows,but serum cytokines increased(P<0.05)in sows fed the diet with 0.5%SDP compared with sows fed the diet without SDP.Pigs weaned from young sows fed no SDP or from mature sows fed 0 or 0.5%SDP had a greater gain to feed ratio when fed a phase 1 diet containing 6%SDP compared with pigs fed a diet without SDP,but the gain to feed ratio of pigs weaned from young sows fed 0.5%dietary SDP was not affected by dietary SDP in phase 1(interaction,P<0.05).Regardless of sow treatment,pigs fed a phase 1 diet with 6%SDP had greater(P<0.05)growth performance than pigs fed a phase 1 diet without SDP,and pigs fed the phase 1 diet with 6%SDP had reduced(P<0.05)diarrhea incidence in phase 1.Conclusions Feeding 0.5%dietary SDP to sows may reduce the number of mummified pigs and increase pig vitality during lactation,but adding 0.5%SDP to sow diets during lactation did not improve post-weaning performance of pigs fed a starter diet with 6%SDP.展开更多
AIM:To investigate the association between active corneal epithelial dendritic cells(CEDCs)and ocular pain in patients with dry eye disease(DED).METHODS:This cross-sectional study enrolled 67 DED patients,who were div...AIM:To investigate the association between active corneal epithelial dendritic cells(CEDCs)and ocular pain in patients with dry eye disease(DED).METHODS:This cross-sectional study enrolled 67 DED patients,who were divided into two groups based on numerical rating scale(NRS)scores:the mild pain group(n=44)and the moderate-to-severe pain group(n=23).In vivo confocal microscopy(IVCM)was used to image the subbasal layer of the central cornea.Corneal nerve characteristics were analyzed using ACCMetrics software,while CEDCs were quantified manually with Image J software.Regression and correlation analyses were performed to assess the impact of active CEDCs on ocular pain.Additionally,the Luminex method was employed to compare the concentrations of inflammation-related cytokines in tears between patients with≥2 CEDCs and those with<2 CEDCs.Differences in cytokine levels between the two groups were analyzed using Student’s t-test.RESULTS:The study included 44 eyes of 44 patients with mild ocular pain(12 males and 32 females)and 23 eyes of 23 patients with moderate-to-severe ocular pain(3 males and 20 females).The mean age was 36.2±13.5y in the mild pain group and 39.7±12.4y in the moderate to severe pain group.There were no significant differences in age or sex between the two groups(P=0.30;P=0.19).Multivariable regression analysis showed that older age[odds ratio(OR)=1.05,95%confidence interval(CI)1.00–1.11]and a higher number of CEDCs(OR=1.80,95%CI 1.17–2.76)were associated with ocular pain.Patients with≥2 CEDCs had significantly higher tear concentrations of interleukin(IL)-6(P<0.05),IL-8(P<0.05),and tumor necrosis factor(TNF)-α(P<0.05)compared to those with<2 active CEDCs.CONCLUSION:The findings suggest that infiltrating CEDCs in the corneal subbasal layer are a potential risk factor for ocular pain in DED.展开更多
Ni-based catalysts hold great potential in the light-driven dry reforming of methane(DRM)for syngas production due to their low cost and comparable catalytic performance to conventional noble-metal catalysts.However,t...Ni-based catalysts hold great potential in the light-driven dry reforming of methane(DRM)for syngas production due to their low cost and comparable catalytic performance to conventional noble-metal catalysts.However,the currently available Ni-based catalysts are confronted with low light-driven DRM efficiency and poor stability attributed to the coking.Herein,an atomically dispersed Ni-loaded CeO_(2)(Ni/CeO_(2))for light-drivenDRMis prepared by employing a polyol-mediated doping method to allow the high loading concentration of Ni on the CeO_(2),which overcomes the conventional atomically dispersed metal problem of low loading content.The atomically dispersed nature of the Ni can induce enormous CH4 activation sites for the reaction and photothermal effects for driving the reaction,while the CeO_(2) can facilitateCO_(2) activation.Therefore,the optimized atomically dispersed Ni-loaded CeO_(2) demonstrates an excellent light-drivenDRMperformance forH_(2)(626.5 mmol gcat^(-1) h^(-1))and CO(728.5 mmol gcat^(-1) h^(-1))production.More importantly,the optimized sample sustains its DRM performance after 100 h of continuous test,and such excellent stability of the presence of enormous Ni–O pairs can prevent the rapid conversion of CH_(x) intermediates into coke.This work demonstrates the meticulous design of non-noble metal catalysts for the lightdriven DRM with both high performance and stability.展开更多
基金financially supported by the Key Program of National Natural Science Foundation of China(No.U23A20608)the Liaoning Province Science and Technology Plan Joint Program(Key Research and Development Program Project),China(No.2023JH2/101800058)+3 种基金the Science&Technology Plan Project of Hebei Province,China(No.23314601L)the Project of Hydrogen-Based Shaft Furnace Reduction-Electric Furnace Melting And Separation Technology Research and Application for High-Titanium Magnetite Iron Ore(No.HG2023239)the General Program of National Natural Science Foundation of China(No.52274253)the Special Project for Major Scientific and Technological Achievements Transformation in Hebei Province,China(No.23284101Z)。
文摘The novel process of hydrogen-based shaft furnaces(HSFs)has attracted considerable attention because of their significant reduction of CO_(2)emissions.In this study,the interaction of H_(2)and CO with Fe_(tet1)-and Fe_(oct2)-terminated Fe_(3)O_(4)(111)surfaces under HSF conditions,including their adsorption and reduction behaviors,was investigated using the density functional theory method.The results indicated that the H_(2)molecule adsorbed onto the Fe_(tet1)-terminated surface with an adsorption energy(AE)of-1.36 eV,whereas the CO molecule preferentially adsorbed on the Fe_(oct2)-terminated surface with an AE of-1.56 eV.Both H_(2)and CO can readily undergo reduction on the Fe_(tet1)-terminated surface(corresponding to energy barriers of 0.83 eV and 2.23 eV,respectively),but kinetically the reaction of H2is more favorable than that of CO.With regard to the thermodynamics at 400-1400 K,the H_(2)was easy to be adsorbed,while the CO would like to react on the Fe_(tet1)-terminated surface.These thermodynamically tendencies were reversed on the Fe_(oct2)-terminated surface.The thermodynamic disadvantage of the reaction of H_(2)on the Fe_(tet1)-terminated surface was offset by an increase in the temperature.Furthermore,the adsorption of H2 and CO on the Fe_(tet1)-terminated surface was competitive,whereas the adsorption of them on the Fe_(oct2)-terminated surface was synergistic.Therefore,iron ores with a higher proportion of Fe_(tet1)-terminated surface can be applied for the HSF process.In conjunction with the increases in the reduction temperature and the ratio of H_(2)in the reducing gas would promote efficient HSF smelting.These observations provide effective guidance for optimizing the practical operation parameters and advancing the development of the HSF process.
基金the financial support received from the Key Program of National Natural Science Foundation of China(No.52130406)the National Key R&D Program of China(Nos.2021YFC2901000 and 2022YFC2905800)+1 种基金the General Program of National Natural Science Foundation of China(No.52274253)Natural Science Foundation Innovation Group Project of Hubei Province,China(No.2023AFA044)。
文摘Hydrogen-based mineral phase transformation(HMPT)technology has demonstrated its effectiveness in separating iron and enriching rare earths from Bayan Obo refractory ores.However,further research is needed to clarify the phase composition and floatability of rare earths obtained after HMPT owing to the associated phase transformations.This study explored the mineralogical characteristics and separation behavior of rare earths in HMPT-treated iron tailings.Process mineralogy studies conducted via BGRIMM process mineralogy analysis and X-ray diffraction revealed that the main valuable minerals in the tailings included rare-earth oxides(9.15wt%),monazite(5.31wt%),and fluorite(23.52wt%).The study also examined the impact of mineral liberation and gangue mineral intergrowth on flotation performance.Flotation tests achieved a rare-earth oxide(REO)grade of 74.12wt% with a recovery of 34.17% in open-circuit flotation,whereas closed-circuit flotation resulted in a REO grade of 60.27wt% with a recovery of 73%.Transmission electron microscopy and scanning electron microscopy coupled with energy-dispersive spectroscopy revealed that monazite remained stable during the HMPT process,while bastnaesite was transformed into Ce_(7)O_(12)and CeF_(3),leading to increased collector consumption.Nonetheless,the HMPT process did not significantly affect the flotation performance of rare earths.The enrichment of fluorite in the tailings highlighted its further recovery potential.The integration of HMPT with magnetic separation and flotation presents an efficient strategy for recovering rare earths,iron,and fluorite from Bayan Obo ores.
文摘The steel industry’s transition to hydrogen-based ironmaking necessitates a deeper understanding of magnetite ore reduction,a crucial yet underexplored pathway for decarbonization.This study systematically investigates the combined effects of particle size and gangue composition on hydrogen-based reduction behavior of four industrial magnetite ore concentrates with varying CaO and MgO con-tents.Thermogravimetric analysis at 973 K,interrupted reduction experiments,and post-reduction characterization steps are used to eval-uate reduction extent and phase transformations across different particle size fractions and bulk ores.The finer fractions generally exhibit faster and more complete reduction.However,this trend is overridden by gangue effects in certain ores.Magnetite ores with MgO as gangue tend to form magnesio-wustite solid solution(Mg,Fe)O during reduction,resulting in dense microstructures that impede hydrogen diffusion and limit reduction progress.In contrast,magnetite ores with CaO as gangue facilitate the formation of intermediate calcium fer-rites,which promote porous morphology and enhanced reducibility.Notably,even the finer particles of ore containing MgO show a lower reduction degree than the coarser particles of the ore containing CaO as gangue.This highlights the dominant role of gangue composition in governing reduction kinetics,intermediate phase formation and final product morphology.These findings contribute to the growing knowledge necessary to enable fossil-free ironmaking by emphasizing the importance of considering both granulometric characteristics and heterogeneity when evaluating magnetite ores for hydrogen-based reduction.
文摘The hydrogen-based reduction and electric smelting technology is a green and low-carbon process for treating low-grade ore and complex symbiotic iron ore.In this study,the hydrogen-based reduction of boron-bearing iron concentrate and the low-temperature separation compared with the high-temperature melting separation of slag and iron from a boron-bearing iron concentrate were studied.The metallization rate of the boron-bearing iron concentrate reached 99.63%after hydrogen-based reduction at 1050℃,and the metallic iron was interwoven with olivine(Mg_(2)SiO_(4))in the reduced ore.In addition,the high-temperature melting separation of iron and slag could be accomplished at 1550℃for 60 min,where boron was mainly distributed in the form of a glass phase in the slag with a mass fraction of B_(2)O_(3)of 22.69%,and 0.35%of boron(mass fraction)was melted into liquid iron.By contrast,iron and slag were efficiently separated at a lower temperature(1300℃)for 10 min and enhanced by super-gravity.Almost all the boron content was enriched into a suanite phase in the slag with a considerably high mass fraction of B_(2)O_(3)(35.61%)and a high recovery ratio(99.37%),and the mass fraction of boron decreased to 0.15%in iron.Compared with high-temperature melting separation,low-temperature separation combined with hydrogen-based reduction greatly improved the enrichment of boron in slag and prevented the melting of boron into iron.
基金supported by the National Natural Science Foundation of China (No.50978190)the National High Technology Research and Development Program (863) of China (No.2009AA062902)
文摘A hydrogen-based membrane biofilm reactor （MBfR） using H2 as electron donor was investigated to remove nitrate from groundwater. When nitrate was first introduced to the MBfR, denitrification took place on the shell side of the membranes immediately, and the effluent concentration of nitrate continuously decreased with 100% removal rate on day 45 under the influent nitrate concentration of 5 mg NO3^--N/L, which described the acclimating and enriching process of autohydrogenotrophic denitrification bacteria. A series of short-term experiments were applied to investigate the effects of hydrogen pressures and nitrate loadings on deniWification. The results showed that nitrate reduction rate improved as H2 pressure increasing, and over 97% of total nitrogen removal rate was achieved when the nitrate loading increased from 0.17 to 0.34 g NO3^--N/（m^2.day） without nitrite accumulation. The maximum deniwification rate was 384 g N/（m^3.day）. Partial sulfate reduction, which occurred in parallel to nitrate reduction, was inhibited by denitrififcation due to the competition for H2. This research showed that MBfR is effective for removing nitrate from the contaminated groundwater.
基金supported by the National Natural Science Foundation of China (No.50978190)
文摘A laboratory trial was conducted for evaluating the capability of a continuously stirred hydrogen-based membrane biofllm reactor to simultaneously reduce nitrate （NO3--N）, sulfate （SO42-）, bromate （BrO3-）, hexavalent chromium （Cr（VI）） and para- chloronitrobenzene （p-CNB）. The reactor contained two bundles of hollow fiber membranes functioning as an autotrophic biofiim carder and hydrogen pipe as well. On the condition that hydrogen was supplied as electron donor and diffused into water through membrane pores, autohydrogenotrophic bacteria were capable of reducing contaminants to forms with lower toxicity. Reduction occurred within 1 day and removal fluxes for NO3--N, SO42-, BrO3-, Cr（VI）, and p-CNB reached 0.641, 2.396, 0.008, 0.016 and 0.031 g/（day.m2）, respectively after 112 days of continuous operation. Except for the fact that sulfate was 37% removed under high surface loading, the other four contaminants were reduced by over 95 %. The removal flux comparison between phases varying in surface loading and 1-12 pressure showed that decreasing surface loading or increasing 1-12 pressure would promote removal flux. Competition for electrons occurred among the five contaminants. Electron-equivalent flux analysis showed that the amount of utilized hydrogen was mainly controlled by NO3--N and SO42- reduction, which accounted for over 99% of the electron flux altogether. It also indicated the electron acceptor order, showing that nitrate was the most prior electron acceptor while sulfate was the second of the five contaminants.
基金financial support from the Walter Benjamin Programme of the Deutsche Forschungsgemeinschaft(No.468209039)the financial support from Capes-Humboldt(No.88881.512949/2020-01)the financial support from the Heisenberg Programme of the Deutsche Forschungsgemeinschaft(SP16662/1)。
文摘Steel production causes a third of all industrial CO_(2) emissions due to the use of carbon-based substances as reductants for iron ores,making it a key driver of global warming.Therefore,research efforts aim to replace these reductants with sustainably produced hydrogen.Hydrogen-based direct reduction(HyDR)is an attractive processing technology,given that direct reduction(DR)furnaces are routinely operated in the steel industry but with CH_(4) or CO as reductants.Hydrogen diffuses considerably faster through shaft-furnace pellet agglomerates than carbon-based reductants.However,the net reduction kinetics in HyDR remains extremely sluggish for high-quantity steel production,and the hydrogen consumption exceeds the stoichiometrically required amount substantially.Thus,the present study focused on the improved understanding of the influence of spatial gradients,morphology,and internal microstructures of ore pellets on reduction efficiency and metallization during HyDR.For this purpose,commercial DR pellets were investigated using synchrotron high-energy X-ray diffraction and electron microscopy in conjunction with electron backscatter diffraction and chemical probing.Revealing the interplay of different phases with internal interfaces,free surfaces,and associated nucleation and growth mechanisms provides a basis for developing tailored ore pellets that are highly suited for a fast and efficient HyDR.
文摘本文采用电熔炉冶炼低品位DRI,开展百公斤级扩大化试验,探索低品位DRI电熔炉冶炼特性,包括渣铁分离效果、铁水渗碳效果、铁收得率等,并利用设计软件计算吨铁电耗、煤耗等指标。试验结果表明,DRI球由于具有团疏松多孔的结构,在熔炼过程中始终漂浮在熔池上方;在二次电压120 V下,电极始终为浸没式操作,不能实现刷弧或明弧操作。通过从顶部加入无烟煤和DRI的混合物料可以实现良好的铁还原和铁水渗碳效果,铁水含碳量平均值为3.09%。在低碱度渣型和高渣率下,所得渣Fe O含量平均值为1.47%,铁收得率平均值高达98.84%。低品位DRI热态入炉生产液体热金属所需的理论吨铁电耗为511 k W·h/t,而冷态入炉的理论吨铁电耗为770 k W·h/t,热态DRI直接入炉冶炼可以节能约50%。
基金supported by the Major Program of National Natural Science Foundation of China(No.52192624)the Innovative Research Group Project of National Natural Science Foundation of China(No.52421002)+3 种基金Major Science and Technology Project of Yunnan Province(No.202302AF080001)NSFC Key International(Regional)Cooperative Research Projects(No.52020105001)General Program of National Natural Science Foundation of China(Nos.52204019 and 52274016)the Foundation of State Key Laboratory of Petroleum Resources and Prospecting(No.PRE/DX-2402)。
文摘Percussion drilling is a promising approach for hot dry rock(HDR)fragmentation.However,understanding of HDR fragmentation mechanism under multi-dimensional percussion remains limited and hinders the corresponding drilling performance.Herein,an innovative true triaxial multi-dimensional percussion device was developed for the study of HDR fragmentation mechanism under in-situ temperature and stress conditions.Multi-dimensional percussion,involving both axial and torsional components,was applied to drilling in granite and carbonatite rocks sampled from the typical HDR target areas.Multiscale visualization techniques and a whale optimization-variational mode decomposition algorithm were employed to investigate the rock failure patterns and drilling energy characteristics.Results indicated that multi-dimensional percussion enhances brittle-ductile mixed failure in granite,characterized by transgranular,intergranular,and combined fracture patterns that promote rock cracking.In contrast,carbonatite drillhole displays enhanced brittle fragmentation and tortuous failure surface dominated by transgranular fracture pattern.Frequency-domain characteristics of penetration force signals for multidimensional percussion,especially the significant dominant frequency,amplitude,and high-frequency dissipation,indicate an increase in net energy for drilling into HDR and intensified rock fragmentation.Further,the effect of impact frequency on rock fragmentation performance was emphasized to maximize drilling efficiency.The optimal regulation schemes between axial and torsional impact frequencies are identified as 15 Hz+15 Hz for granite and 30 Hz+15 Hz for carbonatite.The reliability of the optimization approach was validated through a field test that employed a novel impactor in the geothermal well Fushen-1.
文摘CeO_(2) based semiconductor are widely used in solar-driven photothermal catalytic dry reforming of methane(DRM)reaction,but still suffer from low activity and low light utilization efficiency.This study developed graphite-CeO_(2) interfaces to enhance solar-driven photothermal catalytic DRM.Compared with carbon nanotubes-modified CeO_(2)(CeO_(2)-CNT),graphite-modified CeO_(2)(CeO_(2)-GRA)constructed graphite-CeO_(2) interfaces with distortion in CeO_(2),leading to the formation abundant oxygen vacancies.These graphite-CeO_(2) interfaces with oxygen vacancies enhanced optical absorption and promoted the generation and separation of photogenerated carriers.The high endothermic capacity of graphite elevated the catalyst surface temperature from 592.1−691.3℃,boosting light-to-thermal conversion.The synergy between photogenerated carriers and localized heat enabled Ni/CeO_(2)-GRA to achieve a CO production rate of 9985.6 mmol/(g·h)(vs 7192.4 mmol/(g·h)for Ni/CeO_(2))and a light-to-fuel efficiency of 21.8%(vs 13.8%for Ni/CeO_(2)).This work provides insights for designing graphite-semiconductor interfaces to advance photothermal catalytic efficiency.
文摘In today's fast-paced modern life, whether for fitness training, outdoor adventures, or daily commutes, we all yearn for quick-dry apparel that can rapidly wick away moisture and keep our bodies dry and comfortable. As a standout in functional textiles, quick-dry fabrics are becoming the top choice for more and more people, thanks to their exceptional moisture-wicking performance and rapid drying capabilities.
基金Funded by the Major Special Projects of Technological Innovation of Hubei Province(No.2017ACA168)the Open Fund Project of Sanya Science and Education Innovation Park of Wuhan University of Technology(No.2021KF0012)the Guangdong Basic and Applied Basic Research Foundation(No.2021B1515120091)。
文摘To improve the controlled release ability,we prepared attapulgite into microspheres by spray drying.This research began with a thorough thermogravimetric analysis to optimize attapulgite's heat treatment for drug loading.By advanced spray drying,attapulgite was transformed into microspheres,refining its drug release characteristics.Various parameters were examined,achieving optimal particle size and morphology at 25%solid content,2.5%dispersant,and 3% binder.Attapulgite microspheres demonstrated exceptional encapsulation efficiency,exceeding 95% for doxorubicin hydrochloride,highlighting their versatility in drug delivery.FTIR and XRD were used to predict changes in material properties after spray drying.Notably,cytotoxicity tests confirmed the high biocompatibility of attapulgite microspheres,devoid of cell death induction.Attapulgite microsphere loaded with doxorubicin enable sustained drug release and maintain killing ability against tumor cells.This study confirms the viability of spray dried attapulgite microspheres for efficient drug loading and delivery and provides insights for innovative drug delivery systems that utilize the unique properties of attapulgite to advance therapeutics.
基金support from APC LLC,Ankeny,IA,USA,is greatly appreciated.
文摘Background Feeding spray dried plasma(SDP)to weanling pigs improves growth,but there is a lack of research on how SDP impacts oxidative stress and inflammatory response in lactating sows,and performance of their piglets after weaning.Therefore,an experiment was conducted to test the hypothesis that sows fed a diet with SDP in late gestation and lactation have improved reproductive performance and reduced inflammation compared with sows fed no SDP.The second hypothesis was that pigs weaned from sows fed 0.5%SDP in lactation have reduced diarrhea incidence and improved growth performance during the initial 14 d of the nursery period regardless of dietary SDP.Results The percent of low vitality or starved pigs during lactation was less(P<0.05)from sows fed 0.5%dietary SDP compared with sows fed the diet without SDP.Dietary SDP did not influence oxidative stress markers in the plasma of sows,but serum cytokines increased(P<0.05)in sows fed the diet with 0.5%SDP compared with sows fed the diet without SDP.Pigs weaned from young sows fed no SDP or from mature sows fed 0 or 0.5%SDP had a greater gain to feed ratio when fed a phase 1 diet containing 6%SDP compared with pigs fed a diet without SDP,but the gain to feed ratio of pigs weaned from young sows fed 0.5%dietary SDP was not affected by dietary SDP in phase 1(interaction,P<0.05).Regardless of sow treatment,pigs fed a phase 1 diet with 6%SDP had greater(P<0.05)growth performance than pigs fed a phase 1 diet without SDP,and pigs fed the phase 1 diet with 6%SDP had reduced(P<0.05)diarrhea incidence in phase 1.Conclusions Feeding 0.5%dietary SDP to sows may reduce the number of mummified pigs and increase pig vitality during lactation,but adding 0.5%SDP to sow diets during lactation did not improve post-weaning performance of pigs fed a starter diet with 6%SDP.
基金Supported by the National Natural Science Foundation of China(No.82171022No.81974128).
文摘AIM:To investigate the association between active corneal epithelial dendritic cells(CEDCs)and ocular pain in patients with dry eye disease(DED).METHODS:This cross-sectional study enrolled 67 DED patients,who were divided into two groups based on numerical rating scale(NRS)scores:the mild pain group(n=44)and the moderate-to-severe pain group(n=23).In vivo confocal microscopy(IVCM)was used to image the subbasal layer of the central cornea.Corneal nerve characteristics were analyzed using ACCMetrics software,while CEDCs were quantified manually with Image J software.Regression and correlation analyses were performed to assess the impact of active CEDCs on ocular pain.Additionally,the Luminex method was employed to compare the concentrations of inflammation-related cytokines in tears between patients with≥2 CEDCs and those with<2 CEDCs.Differences in cytokine levels between the two groups were analyzed using Student’s t-test.RESULTS:The study included 44 eyes of 44 patients with mild ocular pain(12 males and 32 females)and 23 eyes of 23 patients with moderate-to-severe ocular pain(3 males and 20 females).The mean age was 36.2±13.5y in the mild pain group and 39.7±12.4y in the moderate to severe pain group.There were no significant differences in age or sex between the two groups(P=0.30;P=0.19).Multivariable regression analysis showed that older age[odds ratio(OR)=1.05,95%confidence interval(CI)1.00–1.11]and a higher number of CEDCs(OR=1.80,95%CI 1.17–2.76)were associated with ocular pain.Patients with≥2 CEDCs had significantly higher tear concentrations of interleukin(IL)-6(P<0.05),IL-8(P<0.05),and tumor necrosis factor(TNF)-α(P<0.05)compared to those with<2 active CEDCs.CONCLUSION:The findings suggest that infiltrating CEDCs in the corneal subbasal layer are a potential risk factor for ocular pain in DED.
基金financial support from the National Key R&D Program of China(2022YFE0126500)the National Natural Science Foundation of China(52261135635.52372165,U23A2091,22150610467)+1 种基金the Natural Science Foundation of Anhui Province(2308085MB32)the Scientific and Technological Research Council of Turkey(TUBITAK,122N434).
文摘Ni-based catalysts hold great potential in the light-driven dry reforming of methane(DRM)for syngas production due to their low cost and comparable catalytic performance to conventional noble-metal catalysts.However,the currently available Ni-based catalysts are confronted with low light-driven DRM efficiency and poor stability attributed to the coking.Herein,an atomically dispersed Ni-loaded CeO_(2)(Ni/CeO_(2))for light-drivenDRMis prepared by employing a polyol-mediated doping method to allow the high loading concentration of Ni on the CeO_(2),which overcomes the conventional atomically dispersed metal problem of low loading content.The atomically dispersed nature of the Ni can induce enormous CH4 activation sites for the reaction and photothermal effects for driving the reaction,while the CeO_(2) can facilitateCO_(2) activation.Therefore,the optimized atomically dispersed Ni-loaded CeO_(2) demonstrates an excellent light-drivenDRMperformance forH_(2)(626.5 mmol gcat^(-1) h^(-1))and CO(728.5 mmol gcat^(-1) h^(-1))production.More importantly,the optimized sample sustains its DRM performance after 100 h of continuous test,and such excellent stability of the presence of enormous Ni–O pairs can prevent the rapid conversion of CH_(x) intermediates into coke.This work demonstrates the meticulous design of non-noble metal catalysts for the lightdriven DRM with both high performance and stability.
