By adding small amount of TiO2, aluminum slag could be used to synthesize cor- dierite. α-Al2O3, TiO2 and dehydrated talc could generate solid solution to accelerate the solid-state reaction to form cordierite. The e...By adding small amount of TiO2, aluminum slag could be used to synthesize cor- dierite. α-Al2O3, TiO2 and dehydrated talc could generate solid solution to accelerate the solid-state reaction to form cordierite. The experimental results show that the content of cordierite increases with the increase of TiO2 added. 3.0% of TiO2 is determined to be the best amount, because all crystalline substances are converted into cordierite at this content. Philips X’pert plus software analysis shows that when the content of TiO2 is from 0 to 1.0%, cordierite has the same hexagonal structure as the single crystal and the lattice parameters change slightly; when the content of TiO2 is from 1.0 to 2.0%, the cordierite still keeps hexagonal structure but the lattice parameters change greatly; when the content of TiO2 is from 2.0 to 3.5%, the cordierite is converted from hexagonal into rhombic and the lattice parameters change accordingly.展开更多
The properties of SiC kiln furniture bonded with fine silicon powderare related to the bonder’s crystal structure. At high temperature, it will crystallize ina-cristobalite with great bulk effect. MnO2 mineralizer ca...The properties of SiC kiln furniture bonded with fine silicon powderare related to the bonder’s crystal structure. At high temperature, it will crystallize ina-cristobalite with great bulk effect. MnO2 mineralizer can make a-cristobalite convertto a-tridymite whose bulk effect is small. The crystal structure and its amount were investigated with XRD technique. The influence of different amounts of MnO2 on thecrystal structure and polycrystal transformation, and that of crystal structure on theproperties of kiln furniture were studied. The best proportion of MnO2 added was determined to be 2.0%.展开更多
People are making excessive demands for their drinking water as they pay more and more attentions to the quality of life. Mineral water contains more calcium, magnesium and lots of trace elements than the running wate...People are making excessive demands for their drinking water as they pay more and more attentions to the quality of life. Mineral water contains more calcium, magnesium and lots of trace elements than the running water, and therefore it is good for the digestion, promotion of metabolism, prevention of cardiovascular diseases and osteoporosis, and promotion of Children growth. It has become a favourite drink for many people.展开更多
Soil contamination by heavy metals has presented severe risks to human health through food chain.As one of the most promising remediation technologies,in-situ immobilization strategy has been widely adopted in practic...Soil contamination by heavy metals has presented severe risks to human health through food chain.As one of the most promising remediation technologies,in-situ immobilization strategy has been widely adopted in practice.However,considering the large quantities of contaminated soil,it is still a huge challenge to design low-cost amendments with strong and long-term immobilization ability.Layered double hydroxides(LDHs)have drawn tremendous attention in fundamental research and practical application because of their unique properties.Moreover,owing to its super-stable mineralization effect to heavy metal ions,LDHs have exhibited great potential in the field of soil remediation.In this work,we mainly focused on the scale production strategy of LDHs with low-cost,and its application in soil remediation.Besides,several key challenges in using LDHs as amendments for immobilization of heavy metal ions are presented.We hope that this mini-review could shed light on the sustainable development of LDHs as amendment for heavy metals in future research directions.展开更多
Many architectural research studies have focused on creating new materials to reduce the exploitation of non-renewable natural resources,achieve sustainable development,and reduce carbon emissions.Desert sand(DS)has a...Many architectural research studies have focused on creating new materials to reduce the exploitation of non-renewable natural resources,achieve sustainable development,and reduce carbon emissions.Desert sand(DS)has attracted interest from researchers who have conducted numerous experimental investigations as a possible replacement for river sand.The idea of utilising DS in place of natural fine aggregates in construction has been demonstrated in the literature.However,to analyse and gain confidence in using DS in concrete,a thorough study of its various properties is needed.Therefore,this study addresses the morphological,chemical,and physical characteristics of DS from multiple perspectives.This review presents a study on the durability of desert sand concrete(DSC)and the use of DS cement-based products,and highlights investigations on the design of mix proportions and fresh and hardened properties of DSC.Research issues are emerging around the use of DS in engineered cementitious composites(ECC)materials and the investigation of desert sand powder(DSP)as mineral admixtures.Many issues need to be resolved quickly,which is crucial for the use of DS.In summary,research on DS is still in its early stages,and no systematic research results have been obtained at present.This review makes several recommendations and attempts to explain why DS will likely be widely used as a building material in the future.展开更多
HALOGENS are typical mineralizer elements and play a very important role in remobilization and resettlement of the ore-forming mental elements in the hydrothermal deposits. Studies of tracer system on halogens mineral...HALOGENS are typical mineralizer elements and play a very important role in remobilization and resettlement of the ore-forming mental elements in the hydrothermal deposits. Studies of tracer system on halogens mineralizer include the following aspects: (i) halogens’ role as mineralizer in ore-forming action;(ii) halogens importance as tracer elements in formation and evolution of the epithermal ore deposit;(iii) halogens’ significance as guidance in looking for the buried orebodies. Guizhou is a concentrated area of epithermal Hg, Sb and Au deposits, where are distributed famousepithermal deposits such as the Wanshan Hg deposit, the Banpo Sb deposit, the Danzhai Hg-Au depositand the Lannigou Au deposit. Many researches into geological and geochemical characteristics of thesedeposits have been done, but few study on halogen mineralizer.展开更多
Background:Excessive use of inorganic trace minerals(ITMs)in swine production leads to high fecal mineral excretion and environmental risks,while most studies on organic trace minerals(OTMs)focus on single elements,wi...Background:Excessive use of inorganic trace minerals(ITMs)in swine production leads to high fecal mineral excretion and environmental risks,while most studies on organic trace minerals(OTMs)focus on single elements,with limited data on the synergistic effects and molecular mechanisms of combined OTMs(Fe,Cu,Mn,Zn)in growing-finishing pigs.Methods:This study aimed to investigate the effects of graded levels of micromineral proteinates(combined OTMs)on growth performance,mineral metabolism,and mRNA expression of mineral regulatory proteins.A total of 360 crossbred Duroc×Landrace×Large White pigs(initial body weight 47.1±4.8 kg)were randomly assigned to 6 dietary treatments:basal diet without microminerals(CON),basal diet with ITMs at commercially recommended levels(IT),and basal diets with 15%(OT 15%),25%(OT 25%),35%(OT 35%)commercially recommended levels(CRL)of combined micromineral proteinates.After a 70-day feeding trial,samples were analyzed using ICP-OES,ELISA,and RT-qPCR.Results:Results showed that reduced levels(15-35%CRL)of micromineral proteinates did not significantly affect average daily gain,average daily feed intake,or feed conversion ratio(gain-to-feed ratio)compared to IT(P>0.05),but significantly increased plasma Cu(1.73-1.83μg/mL)and Zn(1.72-1.97μg/mL)concentrations(P<0.05)and elevated activities of Cu/Zn-superoxide dismutase(32.9-35.9 U/L)and manganese superoxide dismutase(20.5-24.1 U/L)compared to CON(P<0.05),with no significant differences from IT(P>0.05).Fecal excretion of Fe,Cu,Mn,and Zn was significantly reduced by 35-50%in OT 15%-OT 35%groups compared to IT(P<0.05).OT 25%group exhibited the highest apparent absorptivity of Fe(38.5%),Cu(27.8%),and Zn(42.4%)(P<0.05),which was associated with significantly regulated mRNA expression of mineral regulatory proteins:upregulated DMT1,FPN1,ZIP4,and MT1A in the duodenum,and modulated HAMP,ATP7B,ZIP14,and ZnT1 in the liver(P<0.05).Conclusion:In conclusion,dietary supplementation with 25%CRL or less of combined micromineral proteinates can fully meet the nutritional needs of growing-finishing pigs,improve mineral absorptivity,and reduce fecal mineral excretion by regulating intestinal and hepatic mineral transport and homeostatic proteins,providing a sustainable alternative to high-dose ITMs.展开更多
Uranyl arsenate minerals,which exhibit low solubility,serve as major sinks for U and As,playing a crucial role in controlling the mobility of U and As in the environment.However,the specific mechanisms underly-ing the...Uranyl arsenate minerals,which exhibit low solubility,serve as major sinks for U and As,playing a crucial role in controlling the mobility of U and As in the environment.However,the specific mechanisms underly-ing the formation of uranyl arsenate minerals have remained largely elusive.Herein,the formation pathway of the non-charged UO_(2)(H_(2)AsO_(4))_(2)·nH_(2)O0 complex was investigated to elucidate the early formation of the UO_(2)(H_(2)AsO_(4))_(2)·nH_(2)O mineral(where n represents the stoichiometric number of H_(2)O),a representative uranyl arsenate mineral.Based on the combination experiments of U(VI)and As(V),our findings underscore the sig-nificant dependence of UO_(2)(H_(2)AsO_(4))_(2)·nH_(2)O0 formation on solution pH(4.0–10.0).Density functional theory(DFT)calculations reveal a two-step reaction involving two distinct pathways(Pathway 1 and Pathway 2)for the formation of UO_(2)(H_(2)AsO_(4))_(2)·nH_(2)O,and the intermediate was confirmed by in situ Raman and fluorescence spec-troscopy.Specifically,the hydroxyl‑connected uranyl(UO_(2)OH^(+))reacts with the protonated arsenate(H_(2)AsO_(4)^(-))species to form the intermediate UO_(2)HAsO4·H_(2)O(Pathway 1)or UO_(2)OH–H2AsO4(Pathway 2)with a U/As ratio of 1:1.Meanwhile,all the transition states also were obtained and the energy barrier suggested that the UO_(2)(H_(2)AsO_(4))_(2)·2H_(2)O0 formed by Pathway 1 is thermodynamically favored over Pathway 2,and may serve as the primary fundamental structural unit or precursor for the early formation of the UO_(2)(H_(2)AsO_(4))_(2)·nH_(2)O mineral phase.Altogether,this study contributes to advancing the understanding of the formation of uranyl arsenate min-erals at the molecular scale and provides a theoretical basis for predicting and regulating uranium and arsenic mobilization in their coexisting environment.展开更多
This review summarizes studies of hydrothermal alteration minerals at the Qiucun gold deposit in southeastern China and focuses on characterization and mapping of the deposit using hyperspectral remote sensing.The dep...This review summarizes studies of hydrothermal alteration minerals at the Qiucun gold deposit in southeastern China and focuses on characterization and mapping of the deposit using hyperspectral remote sensing.The deposit exhibits multistage fluid-rock interaction,as evidenced by systematic alteration assemblages,including silicification,sericitization by white micas,the development of argillaceous clays,variable chloritization,and locally significant carbonate alteration.We describe the genetic importance of such mineral groups and emphasize their diagnostic Visible and Near-Infrared to Short-Wave Infrared(VNIR-SWIR)spectral signatures,especially Al-OH,Mg-OH/Fe-OH,and CO3 absorption bands,which make it possible to distinguish between minerals,not to mention the fact that,in some instances,compositional trends may be predicted.This review’s methodological advances are discussed beginning with data collection at satellite,airborne,and ground levels,proceeding to processing procedures,such as atmospheric and topographic correction,and culminating in spectral analysis,including continuum removal,spectral matching,and unmixing/classification techniques.An integrated study of hyperspectral findings reveals that alteration minerals develop spatially coherent zones that are strongly controlled by fault/fracture structures and host-rock reactivity,producing proximal silicification/sericitization cores and larger silicified/larcenies of argillaceous rocks owing to diverse apex coverings of carbonate.This should be combined with petrography and geochemistry to address overprinting,mixed pixels,and surface weathering,and to couple mineral maps with ore-forming processes.The review finds that hyperspectral remote sensing offers a solid modeling platform for the deposit-scale alteration at Qiucun and other hydrothermal gold systems,and outlines the directions for future research to integrate quantitatively and more threedimensional alteration characterization.展开更多
Driven by the rapid advancement of wind,solar,and electric vehicle technologies,the global copper demand has increased significantly,prompting greater attention to complex and refractory copper-bearing minerals.As a r...Driven by the rapid advancement of wind,solar,and electric vehicle technologies,the global copper demand has increased significantly,prompting greater attention to complex and refractory copper-bearing minerals.As a representative example,valleriite is widely distributed in Cu-Ni sulfide ores and regarded as the second-most important copper-bearing phase after chalcopyrite.Structurally,valleriite features a layered crystal lattice composed of alternating hydrophobic sulfide and hydrophilic hydroxide layers,imparting it characteristics intermediate between sulfide and oxide ores.This unique structure,combined with its fine grain size,poor crystallinity,and complex intergrowths,greatly limits the efficiency of conventional beneficiation methods,such as flotation and magnetic separation.This review systematically summarizes the global distribution and physicochemical properties of valleriite and critically assesses beneficiation studies reported over the past seven decades.Furthermore,key factors contributing to poor recovery are identified,and potential strategies for improving the processing of valleriite-bearing ores are proposed.展开更多
Purpose-The utilization of alkali-free accelerators,primarily based on aluminum sulfate,in shotcrete often leads to significant shrinkage and cracking,jeopardizing long-term durability.This study aims to mitigate this...Purpose-The utilization of alkali-free accelerators,primarily based on aluminum sulfate,in shotcrete often leads to significant shrinkage and cracking,jeopardizing long-term durability.This study aims to mitigate this issue by investigating the efficacy of silica fume(SF)and fly ash(FA),individually and combined,in controlling the shrinkage deformation of shotcrete.Design/methodology/approach-Shotcrete mixtures were prepared with cement partially replaced by SF,FA,or their combination(SF-FA).Aluminum sulfate was used as an accelerator.The shrinkage behavior under sealed and dry conditions was monitored.The underlying mechanisms were elucidated through hardened airvoid analysis,mercury intrusion porosimetry(MIP),and internal humidity tracking.Findings-Contrary to some previous studies,both individual and combined incorporation of mineral admixtures reduced the 28-day shrinkage.The SF-FA composite exhibited the most substantial reduction(23.72%sealed,17.76%dry),followed by SF alone(18.11%sealed)and FA alone(11.35%sealed).Mechanism analysis revealed that the admixtures refined the pore structure,reduced the volume of harmful pores,and,crucially,optimized the air-void system by increasing the population of fine bubbles.This created an internal buffering effect that alleviates capillary stress.The synergistic effect in the SF-FA group is attributed to complementary pore-filling at dual scales.Originality/value-This work demonstrates that,within an aluminum sulfate-accelerated shotcrete system,silica fume can effectively reduce shrinkage when its pore-refining effect is counterbalanced by a welloptimized micro-bubble network.It provides the first comprehensive evidence of the synergistic shrinkagereducing mechanism of SF and FA in such systems,offering a practical strategy for mix design optimization to enhance the volume stability of shotcrete.展开更多
Examining carbonate dissolution kinetics at mineral-water interface is crucial to understand numerous environmental and geochemical processes,including global carbon cycling,CO_(2)sequestration in deep geological rese...Examining carbonate dissolution kinetics at mineral-water interface is crucial to understand numerous environmental and geochemical processes,including global carbon cycling,CO_(2)sequestration in deep geological reservoirs,and trace elements release in terrestrial and aquatic environments.Here we explored the effect of circumneutral to alkaline pH solutions(pH 6-11)on dissolution kinetics of pure dolomite and Ca and Mg release stoichiometry in flow-through reactor experiments at 25±1℃.Results revealed that the dolomite dissolution rates obtained from effluent Ca and Mg concentrations(R_(Ca)and R_(Mg)in mol/cm^(2)/s)were dependent on input solution pH and HCO_(3)^(-)log activity.The pH dependence of dissolution rates showed two distinct trends,i.e.,at circumneutral pH ranging between 6 and 8,the dissolution rate decreased with increasing pH,with minimum rate at pH 8.While in the highly alkaline pH range(pH 9-11),the dolomite dissolution rate increased with an increasing pH.Irrespective of the input pH,the dolomite dissolution rates indicated a reverse relationship with HCO_(3)^(-)log activity,with the lowest dissolution rate(R Ca=3.80×10^(-12)mol/cm^(2)/s)at pH 8 where HCO_(3)^(-)log activity attained the highest value(-3.957).The lower R Ca and R Mg obtained at pH 8 compared to all the other pH could possibly be attributed to an inhibition caused by high HCO_(3)^(-)log activity in solution at this pH.Dolomite dissolution rates were non-stoichiometric at all the experimental pH values,showing higher preferential Ca over Mg release(R_(Ca)>R_(Mg))whereas an opposite trend was observed at pH 8,with R_(Ca)<R_(Mg)at the steady state.Saturation index values calculated using geochemical speciation modelling were positive for Mg-bearing minerals(brucite,dolomite,artinite)at alkaline pH of 10-11,indicating favourable conditions for their precipitation under studied conditions.This study provides insights on the significance of log ion activities of HCO_(3)^(-)and Me-OH^(+)under varying pH for elucidating the dissolution mechanism of dolomite in circumneutral to alkaline aqueous environments.展开更多
Recovered samples of Jilin H5 chondrite experimentally shocked to 12-133 GPa were studied to explore the behavior of opaque minerals under shock loading using SEM-EDS,Raman spectroscopy,and TIMA.The following results ...Recovered samples of Jilin H5 chondrite experimentally shocked to 12-133 GPa were studied to explore the behavior of opaque minerals under shock loading using SEM-EDS,Raman spectroscopy,and TIMA.The following results were obtained.Firstly,at pressures lower than 53GPa,the opaque minerals still keep the unmelted state,while at 78 GPa and higher,FeNi metal and troilite form eutectic intergrowths occurring as disorderly fine veinlets filling the shock-induced fractures in silicate minerals.Secondly,single kamacite grains still maintain their contour at 12 GPa,but a part of brittle troilite grains was fragmented and squeezed into the shock-induced fractures within kamacite grains.At53 and 133 GPa,many more troilite fragments are poured in the kamacite interior to form disordered hybrid aggregates or to form squiggly strips,respectively.Similar phenomena are observed within single troilite grains,but the mineral squeezed into troilite grains is kamacite.Thirdly,chromite is a hard and refractory oxide mineral.When the shock pressure rises step by step from 12 to 133 GPa,the shock effect of chromite is only fragmentation.Its grain size decreases from tens of um at 53 GPa to a few um at 133 GPa.And,fourthly,native copper exhibits distinct redistribution behavior at high temperature.In Jilin samples shock-loaded to 12 GPa,copper initially located at troilite-kamacite interfaces partially transferred into small troilite grains containing fine FeNi particles.At 53 and 133 GPa,native copper preferentially transferred into larger troilite grains containing more particles of eutectic FeNi metal.展开更多
Sargassum muticum is a globally distributed seaweed with high economic potential,yet its detailed nutritional composition remains undercharacterized.In this study,we analyzed the nutritional profiles of five thallus p...Sargassum muticum is a globally distributed seaweed with high economic potential,yet its detailed nutritional composition remains undercharacterized.In this study,we analyzed the nutritional profiles of five thallus portions,namely apical fronds,middle fronds,basal fronds,receptacles and air bladders,to assess their economic value accordingly.Results showed that middle fronds had the highest crude protein(31.98%)and crude fiber(7.10%)contents,indicating their suitability for protein-rich functional foods or dietary fiber supplements.Receptacles exhibited the highest levels of crude lipid(1.11%)and polyunsaturated fatty acids(123.01mg/g),suggesting potential for bioactive lipid extraction in nutraceutical applications.By contrast,basal fronds were enriched in saturated(86.41 mg/g)and monounsaturated fatty acids(38.38 mg/g).The essential amino acid index ranged from 0.74 to 0.87,and total amino acid content peaked in middle fronds(77.90 mg/g),highlighting their high protein quality.Apical fronds had the highest calcium content(15611.95 mg/kg),and receptacles contained the highest phosphorus content(1224.45 mg/kg),supporting targeted mineral supplementation.The maximum concentrations of all trace elements were found in receptacles,reinforcing their pharmaceutical potential.This study provides foundational data on the nutrient composition of different thallus parts of S.muticum,which may support future research and potential utilization efforts in China.展开更多
Bayan Obo rare earth mine is the largest light rare earth resource worldwide,primarily extracts rare earth elements(REEs)from mixed RE concentrates with bastnaesite and monazite.Nevertheless,the adoption of the concen...Bayan Obo rare earth mine is the largest light rare earth resource worldwide,primarily extracts rare earth elements(REEs)from mixed RE concentrates with bastnaesite and monazite.Nevertheless,the adoption of the concentrated sulfuric acid roasting metallurgical process has resulted in damage to the environment.Therefore,this paper adopted the method of selective mineral phase transformation(MPT)followed by enhanced micro-flotation.By determining the optimal MPT co nditions,the flotation recovery of bastnaesite-roasted products by the collector(phthalic acid,PA)is improved,and the enhanced separation of bastnaesite with monazite is realized.The results show that with the increase of roasting temperature and time,the bastnaesite decomposition product is CeOF and monazite does not change significantly.Subsequent micro-flotation exhibits a gradual decline in the PA consumption of bastnaesiteroasted products,while the flotation recovery of monazite-roasted products remains poor.The artificial mixed ore experiments result in a CeOF foam product with a content of 94.14%and a recovery of 85.80%,and a monazite tank product with a content of 73.53%and a recovery of 87.87%.Compared with the preroasting ore,the surface and interior of bastnaesite-roasted products develop numerous cracks and porosities,and no obvious structural damage is observed in monazite-roasted particles.As the roasting temperature increases,the mineral particles undergo recrystallization or closure,reducing the specific surface area of bastnaesite-roasted products and enhancing hydrophobicity,leading to diminished PA consumption.Fourier transform infrared and other flotation-relation tests show that PA is chemisorbed on the surface of CeOF.The MPT conditions are optimized in this study,which provides a reference for further advancing the efficient separation of bastnaesite and monazite.展开更多
Hydrochloric acid(HCl)extensively exists in deep underground projects,arising from the transportation of industrial raw materials or fracturing fluids of petroleum engineering.It results in corrosion,which can signifi...Hydrochloric acid(HCl)extensively exists in deep underground projects,arising from the transportation of industrial raw materials or fracturing fluids of petroleum engineering.It results in corrosion,which can significantly impact the stability of surrounding rock structures.Therefore,in-depth analysis of the degradation of rock corroded by the HCl solution is an essential task for underground engineering.In this study,the granite specimens are initially treated with the HCl solution with various concentrations.Then,the tests and analyses,such as electrical conductivity(EC)measurements,mineral composition assays,and Brazilian splitting tests,are employed to investigate the corrosion mechanism of the HCl solution.Our results and findings are generally as follows:(1)As the immersion time increases,the EC exhibits a relatively high level at pH value of 1,a decreasing trend at pH value of 3,and an increasing trend at pH value of 5 and 7.(2)The HCl solutions with various concentration have different effect on mineral composition,characterized by an increase in proportion of SiO_(2) and a reduction in proportion of Na_(2)O,Al_(2)O_(3),K_(2)O,MgO,and CaO,as the solution pH value decreases.(3)After immersion in the solutions with pH values of 1,3,and 5,the tensile strength of the granite decreases by 23.85%,20.84%,and 20.24%;the average stiffness of the specimen decreases by 29.29%,23.43%,and 11.97%;the proportion of releasable energy increases by 6%,4%,and -2%;the releasable energy decreases by 54.96%,26.09%,and 14.52%;and the dissipated energy decreases by approximately 68.85%,41.39%,and 5.41%,respectively.(4)The evolution of physical and mechanical properties of the immersed granite specimen can be analyzed from a chemical aspect.The corrosive action of HCl cleaves Si–O and Al–O chemical bonds within the granite,particularly altering the tetrahedral structures of its silicate components.This process involves breaking existing chemical bonds and the formation of new ones,ultimately destroying the silicate molecular structures.As the concentration of HCl increases,the rate of these reactions accelerates,progressively weakening the chemical bonds and consequently deteriorating the mechanical characteristics of the granite.These findings can deepen our knowledge about the corrosion effect of HCI solutions on natural surrounding rocks and serve as references for further research on rock corrosion mechanisms in underground engineering.展开更多
This study proposed a deep learning-based nanoindentation simulation method to address the challenge of obtaining the mechanical parameters of rock-forming minerals and the complexity of regression analysis.This appro...This study proposed a deep learning-based nanoindentation simulation method to address the challenge of obtaining the mechanical parameters of rock-forming minerals and the complexity of regression analysis.This approach enables the accurate assessment of rock-forming minerals'mechanical parameters.A material database of nanoindentation load-depth(P-h)curves was generated using the material point method(MPM)to characterize the mechanical behavior of major rock-forming minerals(quartz,albite,and muscovite)in sandstone.We used Bayesian hyperparameter optimization to determine the optimal hyperparameters for training a deep neural network(DNN).The trained DNN model accurately predicted the material parameters of rock-forming minerals using experimental nanoindentation P-h data.Numerical simulations of the uniaxial compression of heterogeneous sandstones were conducted using the predicted parameters to assess the sandstones’macro-mechanical characteristics.The research findings provide new insights into the fundamental mechanical behavior of heterogeneous rock materials.展开更多
As a distinctive unshaped refractory material used in steelmaking induction furnace linings,significant variations in raw material performance,particularly erosion resistance,have been observed across silica sources f...As a distinctive unshaped refractory material used in steelmaking induction furnace linings,significant variations in raw material performance,particularly erosion resistance,have been observed across silica sources from different regions.To clarify the causes of performance discrepancies and reveal the erosion resistance mechanisms,erosion resistance experiments were conducted on three quartzite raw materials from distinct regions.Furthermore,the enhancement effects of mineralizers on the raw material with the poorest performance were investigated,and the erosion resistance mechanisms of representative raw materials and mineralization effects in silica ramming materials were proposed.The results demonstrated that the presence of dolomite and iron oxide in raw materials is critical for improving the erosion resistance of silica ramming materials.However,the material with 1 wt.%dolomite as a standalone mineralizer exhibited optimal erosion resistance compared to iron oxide composite mineralizers.This improvement is attributed to the formation of uniformly distributed tridymite and an appropriate liquid phase,which mitigates volume expansion effects caused by quartz phase transformation,thereby minimizing aggregate cracking.Additionally,magnesium derived from dolomite plays a specialized role in the operational environment,with the synergistic effects of these two factors collectively enhancing the material’s erosion resistance.展开更多
International Journal of Minerals,Metallurgy and Materials is dedicated to the publication and the dissemination of original research articles (and occasional invited reviews) in the fields of Minerals,Metallurgy and ...International Journal of Minerals,Metallurgy and Materials is dedicated to the publication and the dissemination of original research articles (and occasional invited reviews) in the fields of Minerals,Metallurgy and Materials.It is covered by EI Compendex,SCI Expanded,Chemical Abstract,etc.Manuscript preparation The following components are required for a complete manuscript:Title,Author(s),Author affiliation(s),Abstract,Keywords,Main text,Acknowledgements and References.展开更多
Recent studies have confirmed the critical and essential role of elemental hydrolysis in metallogenic processes,such as metal migration and precipitation.However,the kinetic processes,characteristics,and formation mec...Recent studies have confirmed the critical and essential role of elemental hydrolysis in metallogenic processes,such as metal migration and precipitation.However,the kinetic processes,characteristics,and formation mechanisms of hydrolyzed precipitates require further comprehensive investigation.This paper is based on a systematic investigation of the hydrolysis mechanisms of Pb and Zn in various systems under ambient temperature and pressure,the storage conditions of the hydrolyzed precipitates,and the characterization of these precipitates.The results indicate that the hydrolysis behaviors of Pb and Zn exhibit significant differences across various systems.Within the monometallic regime,there is a pronounced disparity in the hydrolysis rates between Pb ions and Zn ions.Pb ions demonstrate a substantially higher degree of hydrolysis,a trend that persists over time and remains largely unaffected by the fluid retention or isolation"phenomenon in the surrounding environment.Both hydrolytic precipitation rates were observed to decrease in the mixed system,with Zn ions exhibiting less reduction than Pb ions.After hydrolysis,hydrolyzed precipitates can remain in the fluid environment for extended periods of time,which can lead to re-dissolution.Over time,this re-dissolution can increase,eventually leading to significant loss of hydrolyzed precipitates.The hydrolyzed precipitates obtained from the experiments primarily consisted of alkaline carbonates of Pb and Zn.Notably,the crystalline characteristics of the hydrolysis products of Pb and Zn ions exhibited significant differences across various experimental systems;however,the crystallographic characteristics of the primary hydrolysis products are essentially identical to those of their corresponding natural counterparts.Based on the findings from physical phase analysis and previous research,it is concluded that the hydrolysis process consists of three main stages:oxides/hydroxides,carbonates,and alkali carbonates.In the Pb-Zn-NaCl-H_(2)O system,the proportion of the basic carbonate products of Pb and Zn is 6:2.This research offers an in-depth analysis of the hydrolysis dynamics of lead and zinc under ambient temperature and pressure conditions.Furthermore,it characterizes the crystallization features of the hydrolyzed precipitates and reconstructs the three stages of the formation process.This study holds significant scientific value for understanding the metallogenic mechanisms of Pb and Zn.展开更多
基金This project was supported by the 863 Project (2003AA322020)
文摘By adding small amount of TiO2, aluminum slag could be used to synthesize cor- dierite. α-Al2O3, TiO2 and dehydrated talc could generate solid solution to accelerate the solid-state reaction to form cordierite. The experimental results show that the content of cordierite increases with the increase of TiO2 added. 3.0% of TiO2 is determined to be the best amount, because all crystalline substances are converted into cordierite at this content. Philips X’pert plus software analysis shows that when the content of TiO2 is from 0 to 1.0%, cordierite has the same hexagonal structure as the single crystal and the lattice parameters change slightly; when the content of TiO2 is from 1.0 to 2.0%, the cordierite still keeps hexagonal structure but the lattice parameters change greatly; when the content of TiO2 is from 2.0 to 3.5%, the cordierite is converted from hexagonal into rhombic and the lattice parameters change accordingly.
文摘The properties of SiC kiln furniture bonded with fine silicon powderare related to the bonder’s crystal structure. At high temperature, it will crystallize ina-cristobalite with great bulk effect. MnO2 mineralizer can make a-cristobalite convertto a-tridymite whose bulk effect is small. The crystal structure and its amount were investigated with XRD technique. The influence of different amounts of MnO2 on thecrystal structure and polycrystal transformation, and that of crystal structure on theproperties of kiln furniture were studied. The best proportion of MnO2 added was determined to be 2.0%.
文摘People are making excessive demands for their drinking water as they pay more and more attentions to the quality of life. Mineral water contains more calcium, magnesium and lots of trace elements than the running water, and therefore it is good for the digestion, promotion of metabolism, prevention of cardiovascular diseases and osteoporosis, and promotion of Children growth. It has become a favourite drink for many people.
基金supported by the National Natural Science Foundation of China(21978023)the Fundamental Research Funds for the Central Universities(XK1803-05)+1 种基金the Inno-vative Achievement Commercialization Service-Platform of Indus-trial Catalysis(2019-00900-2-1)the National Basic Research Program of China(2014CB932104)。
文摘Soil contamination by heavy metals has presented severe risks to human health through food chain.As one of the most promising remediation technologies,in-situ immobilization strategy has been widely adopted in practice.However,considering the large quantities of contaminated soil,it is still a huge challenge to design low-cost amendments with strong and long-term immobilization ability.Layered double hydroxides(LDHs)have drawn tremendous attention in fundamental research and practical application because of their unique properties.Moreover,owing to its super-stable mineralization effect to heavy metal ions,LDHs have exhibited great potential in the field of soil remediation.In this work,we mainly focused on the scale production strategy of LDHs with low-cost,and its application in soil remediation.Besides,several key challenges in using LDHs as amendments for immobilization of heavy metal ions are presented.We hope that this mini-review could shed light on the sustainable development of LDHs as amendment for heavy metals in future research directions.
文摘Many architectural research studies have focused on creating new materials to reduce the exploitation of non-renewable natural resources,achieve sustainable development,and reduce carbon emissions.Desert sand(DS)has attracted interest from researchers who have conducted numerous experimental investigations as a possible replacement for river sand.The idea of utilising DS in place of natural fine aggregates in construction has been demonstrated in the literature.However,to analyse and gain confidence in using DS in concrete,a thorough study of its various properties is needed.Therefore,this study addresses the morphological,chemical,and physical characteristics of DS from multiple perspectives.This review presents a study on the durability of desert sand concrete(DSC)and the use of DS cement-based products,and highlights investigations on the design of mix proportions and fresh and hardened properties of DSC.Research issues are emerging around the use of DS in engineered cementitious composites(ECC)materials and the investigation of desert sand powder(DSP)as mineral admixtures.Many issues need to be resolved quickly,which is crucial for the use of DS.In summary,research on DS is still in its early stages,and no systematic research results have been obtained at present.This review makes several recommendations and attempts to explain why DS will likely be widely used as a building material in the future.
文摘HALOGENS are typical mineralizer elements and play a very important role in remobilization and resettlement of the ore-forming mental elements in the hydrothermal deposits. Studies of tracer system on halogens mineralizer include the following aspects: (i) halogens’ role as mineralizer in ore-forming action;(ii) halogens importance as tracer elements in formation and evolution of the epithermal ore deposit;(iii) halogens’ significance as guidance in looking for the buried orebodies. Guizhou is a concentrated area of epithermal Hg, Sb and Au deposits, where are distributed famousepithermal deposits such as the Wanshan Hg deposit, the Banpo Sb deposit, the Danzhai Hg-Au depositand the Lannigou Au deposit. Many researches into geological and geochemical characteristics of thesedeposits have been done, but few study on halogen mineralizer.
基金financially supported by the Hainan Province Science and Technology Special Fund(Grant no:ZDYF2024XDNY187).
文摘Background:Excessive use of inorganic trace minerals(ITMs)in swine production leads to high fecal mineral excretion and environmental risks,while most studies on organic trace minerals(OTMs)focus on single elements,with limited data on the synergistic effects and molecular mechanisms of combined OTMs(Fe,Cu,Mn,Zn)in growing-finishing pigs.Methods:This study aimed to investigate the effects of graded levels of micromineral proteinates(combined OTMs)on growth performance,mineral metabolism,and mRNA expression of mineral regulatory proteins.A total of 360 crossbred Duroc×Landrace×Large White pigs(initial body weight 47.1±4.8 kg)were randomly assigned to 6 dietary treatments:basal diet without microminerals(CON),basal diet with ITMs at commercially recommended levels(IT),and basal diets with 15%(OT 15%),25%(OT 25%),35%(OT 35%)commercially recommended levels(CRL)of combined micromineral proteinates.After a 70-day feeding trial,samples were analyzed using ICP-OES,ELISA,and RT-qPCR.Results:Results showed that reduced levels(15-35%CRL)of micromineral proteinates did not significantly affect average daily gain,average daily feed intake,or feed conversion ratio(gain-to-feed ratio)compared to IT(P>0.05),but significantly increased plasma Cu(1.73-1.83μg/mL)and Zn(1.72-1.97μg/mL)concentrations(P<0.05)and elevated activities of Cu/Zn-superoxide dismutase(32.9-35.9 U/L)and manganese superoxide dismutase(20.5-24.1 U/L)compared to CON(P<0.05),with no significant differences from IT(P>0.05).Fecal excretion of Fe,Cu,Mn,and Zn was significantly reduced by 35-50%in OT 15%-OT 35%groups compared to IT(P<0.05).OT 25%group exhibited the highest apparent absorptivity of Fe(38.5%),Cu(27.8%),and Zn(42.4%)(P<0.05),which was associated with significantly regulated mRNA expression of mineral regulatory proteins:upregulated DMT1,FPN1,ZIP4,and MT1A in the duodenum,and modulated HAMP,ATP7B,ZIP14,and ZnT1 in the liver(P<0.05).Conclusion:In conclusion,dietary supplementation with 25%CRL or less of combined micromineral proteinates can fully meet the nutritional needs of growing-finishing pigs,improve mineral absorptivity,and reduce fecal mineral excretion by regulating intestinal and hepatic mineral transport and homeostatic proteins,providing a sustainable alternative to high-dose ITMs.
基金supported by the National Natural Science Foundation of China(Nos.U20A20267 and 22376223)Hunan Provincial Natural Science Foundation(No.2023JJ0065).
文摘Uranyl arsenate minerals,which exhibit low solubility,serve as major sinks for U and As,playing a crucial role in controlling the mobility of U and As in the environment.However,the specific mechanisms underly-ing the formation of uranyl arsenate minerals have remained largely elusive.Herein,the formation pathway of the non-charged UO_(2)(H_(2)AsO_(4))_(2)·nH_(2)O0 complex was investigated to elucidate the early formation of the UO_(2)(H_(2)AsO_(4))_(2)·nH_(2)O mineral(where n represents the stoichiometric number of H_(2)O),a representative uranyl arsenate mineral.Based on the combination experiments of U(VI)and As(V),our findings underscore the sig-nificant dependence of UO_(2)(H_(2)AsO_(4))_(2)·nH_(2)O0 formation on solution pH(4.0–10.0).Density functional theory(DFT)calculations reveal a two-step reaction involving two distinct pathways(Pathway 1 and Pathway 2)for the formation of UO_(2)(H_(2)AsO_(4))_(2)·nH_(2)O,and the intermediate was confirmed by in situ Raman and fluorescence spec-troscopy.Specifically,the hydroxyl‑connected uranyl(UO_(2)OH^(+))reacts with the protonated arsenate(H_(2)AsO_(4)^(-))species to form the intermediate UO_(2)HAsO4·H_(2)O(Pathway 1)or UO_(2)OH–H2AsO4(Pathway 2)with a U/As ratio of 1:1.Meanwhile,all the transition states also were obtained and the energy barrier suggested that the UO_(2)(H_(2)AsO_(4))_(2)·2H_(2)O0 formed by Pathway 1 is thermodynamically favored over Pathway 2,and may serve as the primary fundamental structural unit or precursor for the early formation of the UO_(2)(H_(2)AsO_(4))_(2)·nH_(2)O mineral phase.Altogether,this study contributes to advancing the understanding of the formation of uranyl arsenate min-erals at the molecular scale and provides a theoretical basis for predicting and regulating uranium and arsenic mobilization in their coexisting environment.
基金supported by the Jiangsu Province Frontier Leading Technology Basic Research Special Project-Research on the New Optoelectronic Imaging and Information Processing Basic Theory and Method(No:BK20192003).
文摘This review summarizes studies of hydrothermal alteration minerals at the Qiucun gold deposit in southeastern China and focuses on characterization and mapping of the deposit using hyperspectral remote sensing.The deposit exhibits multistage fluid-rock interaction,as evidenced by systematic alteration assemblages,including silicification,sericitization by white micas,the development of argillaceous clays,variable chloritization,and locally significant carbonate alteration.We describe the genetic importance of such mineral groups and emphasize their diagnostic Visible and Near-Infrared to Short-Wave Infrared(VNIR-SWIR)spectral signatures,especially Al-OH,Mg-OH/Fe-OH,and CO3 absorption bands,which make it possible to distinguish between minerals,not to mention the fact that,in some instances,compositional trends may be predicted.This review’s methodological advances are discussed beginning with data collection at satellite,airborne,and ground levels,proceeding to processing procedures,such as atmospheric and topographic correction,and culminating in spectral analysis,including continuum removal,spectral matching,and unmixing/classification techniques.An integrated study of hyperspectral findings reveals that alteration minerals develop spatially coherent zones that are strongly controlled by fault/fracture structures and host-rock reactivity,producing proximal silicification/sericitization cores and larger silicified/larcenies of argillaceous rocks owing to diverse apex coverings of carbonate.This should be combined with petrography and geochemistry to address overprinting,mixed pixels,and surface weathering,and to couple mineral maps with ore-forming processes.The review finds that hyperspectral remote sensing offers a solid modeling platform for the deposit-scale alteration at Qiucun and other hydrothermal gold systems,and outlines the directions for future research to integrate quantitatively and more threedimensional alteration characterization.
基金supported by the Key Research and Development Special Project of Xinjiang Uygur Autonomous Region of China(No.2024B040029)the National Natural Science Foundation of China(No.52204301)the Hunan Province Graduate Student Independent Exploration Project,China(No.1053320220682).
文摘Driven by the rapid advancement of wind,solar,and electric vehicle technologies,the global copper demand has increased significantly,prompting greater attention to complex and refractory copper-bearing minerals.As a representative example,valleriite is widely distributed in Cu-Ni sulfide ores and regarded as the second-most important copper-bearing phase after chalcopyrite.Structurally,valleriite features a layered crystal lattice composed of alternating hydrophobic sulfide and hydrophilic hydroxide layers,imparting it characteristics intermediate between sulfide and oxide ores.This unique structure,combined with its fine grain size,poor crystallinity,and complex intergrowths,greatly limits the efficiency of conventional beneficiation methods,such as flotation and magnetic separation.This review systematically summarizes the global distribution and physicochemical properties of valleriite and critically assesses beneficiation studies reported over the past seven decades.Furthermore,key factors contributing to poor recovery are identified,and potential strategies for improving the processing of valleriite-bearing ores are proposed.
文摘Purpose-The utilization of alkali-free accelerators,primarily based on aluminum sulfate,in shotcrete often leads to significant shrinkage and cracking,jeopardizing long-term durability.This study aims to mitigate this issue by investigating the efficacy of silica fume(SF)and fly ash(FA),individually and combined,in controlling the shrinkage deformation of shotcrete.Design/methodology/approach-Shotcrete mixtures were prepared with cement partially replaced by SF,FA,or their combination(SF-FA).Aluminum sulfate was used as an accelerator.The shrinkage behavior under sealed and dry conditions was monitored.The underlying mechanisms were elucidated through hardened airvoid analysis,mercury intrusion porosimetry(MIP),and internal humidity tracking.Findings-Contrary to some previous studies,both individual and combined incorporation of mineral admixtures reduced the 28-day shrinkage.The SF-FA composite exhibited the most substantial reduction(23.72%sealed,17.76%dry),followed by SF alone(18.11%sealed)and FA alone(11.35%sealed).Mechanism analysis revealed that the admixtures refined the pore structure,reduced the volume of harmful pores,and,crucially,optimized the air-void system by increasing the population of fine bubbles.This created an internal buffering effect that alleviates capillary stress.The synergistic effect in the SF-FA group is attributed to complementary pore-filling at dual scales.Originality/value-This work demonstrates that,within an aluminum sulfate-accelerated shotcrete system,silica fume can effectively reduce shrinkage when its pore-refining effect is counterbalanced by a welloptimized micro-bubble network.It provides the first comprehensive evidence of the synergistic shrinkagereducing mechanism of SF and FA in such systems,offering a practical strategy for mix design optimization to enhance the volume stability of shotcrete.
基金funding enabled and organized by CAUL and its Member Institutionsby COMSTEQ-TWAS research grant 2018(18-268 RG/EAS/AS_C)。
文摘Examining carbonate dissolution kinetics at mineral-water interface is crucial to understand numerous environmental and geochemical processes,including global carbon cycling,CO_(2)sequestration in deep geological reservoirs,and trace elements release in terrestrial and aquatic environments.Here we explored the effect of circumneutral to alkaline pH solutions(pH 6-11)on dissolution kinetics of pure dolomite and Ca and Mg release stoichiometry in flow-through reactor experiments at 25±1℃.Results revealed that the dolomite dissolution rates obtained from effluent Ca and Mg concentrations(R_(Ca)and R_(Mg)in mol/cm^(2)/s)were dependent on input solution pH and HCO_(3)^(-)log activity.The pH dependence of dissolution rates showed two distinct trends,i.e.,at circumneutral pH ranging between 6 and 8,the dissolution rate decreased with increasing pH,with minimum rate at pH 8.While in the highly alkaline pH range(pH 9-11),the dolomite dissolution rate increased with an increasing pH.Irrespective of the input pH,the dolomite dissolution rates indicated a reverse relationship with HCO_(3)^(-)log activity,with the lowest dissolution rate(R Ca=3.80×10^(-12)mol/cm^(2)/s)at pH 8 where HCO_(3)^(-)log activity attained the highest value(-3.957).The lower R Ca and R Mg obtained at pH 8 compared to all the other pH could possibly be attributed to an inhibition caused by high HCO_(3)^(-)log activity in solution at this pH.Dolomite dissolution rates were non-stoichiometric at all the experimental pH values,showing higher preferential Ca over Mg release(R_(Ca)>R_(Mg))whereas an opposite trend was observed at pH 8,with R_(Ca)<R_(Mg)at the steady state.Saturation index values calculated using geochemical speciation modelling were positive for Mg-bearing minerals(brucite,dolomite,artinite)at alkaline pH of 10-11,indicating favourable conditions for their precipitation under studied conditions.This study provides insights on the significance of log ion activities of HCO_(3)^(-)and Me-OH^(+)under varying pH for elucidating the dissolution mechanism of dolomite in circumneutral to alkaline aqueous environments.
基金Science and Technology Planning Project of Guangdong Province,2023B1212060048,Xiande Xie。
文摘Recovered samples of Jilin H5 chondrite experimentally shocked to 12-133 GPa were studied to explore the behavior of opaque minerals under shock loading using SEM-EDS,Raman spectroscopy,and TIMA.The following results were obtained.Firstly,at pressures lower than 53GPa,the opaque minerals still keep the unmelted state,while at 78 GPa and higher,FeNi metal and troilite form eutectic intergrowths occurring as disorderly fine veinlets filling the shock-induced fractures in silicate minerals.Secondly,single kamacite grains still maintain their contour at 12 GPa,but a part of brittle troilite grains was fragmented and squeezed into the shock-induced fractures within kamacite grains.At53 and 133 GPa,many more troilite fragments are poured in the kamacite interior to form disordered hybrid aggregates or to form squiggly strips,respectively.Similar phenomena are observed within single troilite grains,but the mineral squeezed into troilite grains is kamacite.Thirdly,chromite is a hard and refractory oxide mineral.When the shock pressure rises step by step from 12 to 133 GPa,the shock effect of chromite is only fragmentation.Its grain size decreases from tens of um at 53 GPa to a few um at 133 GPa.And,fourthly,native copper exhibits distinct redistribution behavior at high temperature.In Jilin samples shock-loaded to 12 GPa,copper initially located at troilite-kamacite interfaces partially transferred into small troilite grains containing fine FeNi particles.At 53 and 133 GPa,native copper preferentially transferred into larger troilite grains containing more particles of eutectic FeNi metal.
基金financially supported by the National Key Research and Development Program of China(No.2024YFD2400300)the National Natural Science Foundation of China(No.32402995)+1 种基金the Taishan Scholar Foundation of Shandong Province(No.tsqn202211067)the Fundamental Research Fund for the Central Universities(No.202262002)。
文摘Sargassum muticum is a globally distributed seaweed with high economic potential,yet its detailed nutritional composition remains undercharacterized.In this study,we analyzed the nutritional profiles of five thallus portions,namely apical fronds,middle fronds,basal fronds,receptacles and air bladders,to assess their economic value accordingly.Results showed that middle fronds had the highest crude protein(31.98%)and crude fiber(7.10%)contents,indicating their suitability for protein-rich functional foods or dietary fiber supplements.Receptacles exhibited the highest levels of crude lipid(1.11%)and polyunsaturated fatty acids(123.01mg/g),suggesting potential for bioactive lipid extraction in nutraceutical applications.By contrast,basal fronds were enriched in saturated(86.41 mg/g)and monounsaturated fatty acids(38.38 mg/g).The essential amino acid index ranged from 0.74 to 0.87,and total amino acid content peaked in middle fronds(77.90 mg/g),highlighting their high protein quality.Apical fronds had the highest calcium content(15611.95 mg/kg),and receptacles contained the highest phosphorus content(1224.45 mg/kg),supporting targeted mineral supplementation.The maximum concentrations of all trace elements were found in receptacles,reinforcing their pharmaceutical potential.This study provides foundational data on the nutrient composition of different thallus parts of S.muticum,which may support future research and potential utilization efforts in China.
基金Project supported by the National Key R&D Program of China(2022YFC2905800)the National Natural Science Foundation of China(52174242)the National Youth Talent Support Program(QNBJ-2023-03)。
文摘Bayan Obo rare earth mine is the largest light rare earth resource worldwide,primarily extracts rare earth elements(REEs)from mixed RE concentrates with bastnaesite and monazite.Nevertheless,the adoption of the concentrated sulfuric acid roasting metallurgical process has resulted in damage to the environment.Therefore,this paper adopted the method of selective mineral phase transformation(MPT)followed by enhanced micro-flotation.By determining the optimal MPT co nditions,the flotation recovery of bastnaesite-roasted products by the collector(phthalic acid,PA)is improved,and the enhanced separation of bastnaesite with monazite is realized.The results show that with the increase of roasting temperature and time,the bastnaesite decomposition product is CeOF and monazite does not change significantly.Subsequent micro-flotation exhibits a gradual decline in the PA consumption of bastnaesiteroasted products,while the flotation recovery of monazite-roasted products remains poor.The artificial mixed ore experiments result in a CeOF foam product with a content of 94.14%and a recovery of 85.80%,and a monazite tank product with a content of 73.53%and a recovery of 87.87%.Compared with the preroasting ore,the surface and interior of bastnaesite-roasted products develop numerous cracks and porosities,and no obvious structural damage is observed in monazite-roasted particles.As the roasting temperature increases,the mineral particles undergo recrystallization or closure,reducing the specific surface area of bastnaesite-roasted products and enhancing hydrophobicity,leading to diminished PA consumption.Fourier transform infrared and other flotation-relation tests show that PA is chemisorbed on the surface of CeOF.The MPT conditions are optimized in this study,which provides a reference for further advancing the efficient separation of bastnaesite and monazite.
基金National Science Fund for Distinguished Young Scholars,Grant/Award Number:52225403State Key Laboratory of Intelligent Construction and Healthy Operation and Maintenance of Deep Underground Engineering,Grant/Award Number:SDGZK2404Fundamental Research Funds for the Central Universities,Grant/Award Number:2023KYJD1006。
文摘Hydrochloric acid(HCl)extensively exists in deep underground projects,arising from the transportation of industrial raw materials or fracturing fluids of petroleum engineering.It results in corrosion,which can significantly impact the stability of surrounding rock structures.Therefore,in-depth analysis of the degradation of rock corroded by the HCl solution is an essential task for underground engineering.In this study,the granite specimens are initially treated with the HCl solution with various concentrations.Then,the tests and analyses,such as electrical conductivity(EC)measurements,mineral composition assays,and Brazilian splitting tests,are employed to investigate the corrosion mechanism of the HCl solution.Our results and findings are generally as follows:(1)As the immersion time increases,the EC exhibits a relatively high level at pH value of 1,a decreasing trend at pH value of 3,and an increasing trend at pH value of 5 and 7.(2)The HCl solutions with various concentration have different effect on mineral composition,characterized by an increase in proportion of SiO_(2) and a reduction in proportion of Na_(2)O,Al_(2)O_(3),K_(2)O,MgO,and CaO,as the solution pH value decreases.(3)After immersion in the solutions with pH values of 1,3,and 5,the tensile strength of the granite decreases by 23.85%,20.84%,and 20.24%;the average stiffness of the specimen decreases by 29.29%,23.43%,and 11.97%;the proportion of releasable energy increases by 6%,4%,and -2%;the releasable energy decreases by 54.96%,26.09%,and 14.52%;and the dissipated energy decreases by approximately 68.85%,41.39%,and 5.41%,respectively.(4)The evolution of physical and mechanical properties of the immersed granite specimen can be analyzed from a chemical aspect.The corrosive action of HCl cleaves Si–O and Al–O chemical bonds within the granite,particularly altering the tetrahedral structures of its silicate components.This process involves breaking existing chemical bonds and the formation of new ones,ultimately destroying the silicate molecular structures.As the concentration of HCl increases,the rate of these reactions accelerates,progressively weakening the chemical bonds and consequently deteriorating the mechanical characteristics of the granite.These findings can deepen our knowledge about the corrosion effect of HCI solutions on natural surrounding rocks and serve as references for further research on rock corrosion mechanisms in underground engineering.
基金supported by the National Key Research and Development Program of China(Grant no.2023YFC3009005)the Chongqing Technology Innovation and Application Development Special Key Project(Grant no.CSTB2022TIAD-KPX0135)the Fundamental Research Funds for the Central Universities(Grant no.2023CDJKYJH068).
文摘This study proposed a deep learning-based nanoindentation simulation method to address the challenge of obtaining the mechanical parameters of rock-forming minerals and the complexity of regression analysis.This approach enables the accurate assessment of rock-forming minerals'mechanical parameters.A material database of nanoindentation load-depth(P-h)curves was generated using the material point method(MPM)to characterize the mechanical behavior of major rock-forming minerals(quartz,albite,and muscovite)in sandstone.We used Bayesian hyperparameter optimization to determine the optimal hyperparameters for training a deep neural network(DNN).The trained DNN model accurately predicted the material parameters of rock-forming minerals using experimental nanoindentation P-h data.Numerical simulations of the uniaxial compression of heterogeneous sandstones were conducted using the predicted parameters to assess the sandstones’macro-mechanical characteristics.The research findings provide new insights into the fundamental mechanical behavior of heterogeneous rock materials.
基金the National Natural Science Foundation of China(U24A20101).
文摘As a distinctive unshaped refractory material used in steelmaking induction furnace linings,significant variations in raw material performance,particularly erosion resistance,have been observed across silica sources from different regions.To clarify the causes of performance discrepancies and reveal the erosion resistance mechanisms,erosion resistance experiments were conducted on three quartzite raw materials from distinct regions.Furthermore,the enhancement effects of mineralizers on the raw material with the poorest performance were investigated,and the erosion resistance mechanisms of representative raw materials and mineralization effects in silica ramming materials were proposed.The results demonstrated that the presence of dolomite and iron oxide in raw materials is critical for improving the erosion resistance of silica ramming materials.However,the material with 1 wt.%dolomite as a standalone mineralizer exhibited optimal erosion resistance compared to iron oxide composite mineralizers.This improvement is attributed to the formation of uniformly distributed tridymite and an appropriate liquid phase,which mitigates volume expansion effects caused by quartz phase transformation,thereby minimizing aggregate cracking.Additionally,magnesium derived from dolomite plays a specialized role in the operational environment,with the synergistic effects of these two factors collectively enhancing the material’s erosion resistance.
文摘International Journal of Minerals,Metallurgy and Materials is dedicated to the publication and the dissemination of original research articles (and occasional invited reviews) in the fields of Minerals,Metallurgy and Materials.It is covered by EI Compendex,SCI Expanded,Chemical Abstract,etc.Manuscript preparation The following components are required for a complete manuscript:Title,Author(s),Author affiliation(s),Abstract,Keywords,Main text,Acknowledgements and References.
基金financed jointly by the National Natural Science Foundation of China(42472127,42172086)the Yunnan Major Science and Technological Projects(202202AG050014)+2 种基金the Yunnan Major Project of Basic Research(202401BN070001-002)Yunnan Mineral Resources Prediction and Evaluation Engineering Research Center(2011)Innovation Team Program of Kunming University of Science and Technology,Yunnan Province。
文摘Recent studies have confirmed the critical and essential role of elemental hydrolysis in metallogenic processes,such as metal migration and precipitation.However,the kinetic processes,characteristics,and formation mechanisms of hydrolyzed precipitates require further comprehensive investigation.This paper is based on a systematic investigation of the hydrolysis mechanisms of Pb and Zn in various systems under ambient temperature and pressure,the storage conditions of the hydrolyzed precipitates,and the characterization of these precipitates.The results indicate that the hydrolysis behaviors of Pb and Zn exhibit significant differences across various systems.Within the monometallic regime,there is a pronounced disparity in the hydrolysis rates between Pb ions and Zn ions.Pb ions demonstrate a substantially higher degree of hydrolysis,a trend that persists over time and remains largely unaffected by the fluid retention or isolation"phenomenon in the surrounding environment.Both hydrolytic precipitation rates were observed to decrease in the mixed system,with Zn ions exhibiting less reduction than Pb ions.After hydrolysis,hydrolyzed precipitates can remain in the fluid environment for extended periods of time,which can lead to re-dissolution.Over time,this re-dissolution can increase,eventually leading to significant loss of hydrolyzed precipitates.The hydrolyzed precipitates obtained from the experiments primarily consisted of alkaline carbonates of Pb and Zn.Notably,the crystalline characteristics of the hydrolysis products of Pb and Zn ions exhibited significant differences across various experimental systems;however,the crystallographic characteristics of the primary hydrolysis products are essentially identical to those of their corresponding natural counterparts.Based on the findings from physical phase analysis and previous research,it is concluded that the hydrolysis process consists of three main stages:oxides/hydroxides,carbonates,and alkali carbonates.In the Pb-Zn-NaCl-H_(2)O system,the proportion of the basic carbonate products of Pb and Zn is 6:2.This research offers an in-depth analysis of the hydrolysis dynamics of lead and zinc under ambient temperature and pressure conditions.Furthermore,it characterizes the crystallization features of the hydrolyzed precipitates and reconstructs the three stages of the formation process.This study holds significant scientific value for understanding the metallogenic mechanisms of Pb and Zn.
