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Slope stability of reclaimed coal mines through a new water filling index

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Journal of Rock Mechanics and Geotechnical Engineering 2024年第3期16卷 828-839页

作者： Antonios Mikroutsikos Alexandros I.Theocharis Nikolaos C.Koukouzas Ioannis E.Zevgolis Chemical process&Energy Resources institute Centre for Research&Technology HellasAthensGreece School of Mining and metallurgical Engineering National Technical University of AthensAthensGreece

A common reclamation practice for closed coal surface mines is filling them with water to form pit *** creation and sustainability of these lakes are significantly affected by the stability of the corresponding *** present study provides a general framework for analyzing the water filling’s effect on slope stability based on a new water filling index,which can indirectly consider the factors affecting the process and efficiently quantify the filling speed’s *** assumptions of the proposed approach are thoroughly discussed,and the range of the water filling index is ***,the safety factor is calculated using the finite element method with the shear strength reduction technique during the filling process for various conditions(soil properties,slope geometry,hydraulic conditions,and water filling speed).Results are presented as normalized stability charts for practical *** the water filling,the stability gradually decreases until the reservoir reaches a critical level of 10%e40%of the total height;it then increases to even more stable conditions than the initial ***,the present analysis allows for the preliminary stability evaluation of a coal mine during the formation of a pit lake and the appropriate quantification of the water filling’s effect.

关键词： Post-coal era Open-pit flooding Stability charts Critical level

A compact route for efficient production of high-purity β-Ga2O3 powder

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Rare Metals 2024年第9期43卷 4573-4584页

作者： Xiao-Wei Zhou Gao-Jie Chen Liang Xu Zhi-Jun Shao Cheng Yang Yong-Pan Tian Zhuo Zhao School of metallurgical Engineering Anhui University of Technology Low-Carbon research institute Anhui University of Technology

The present study has proposed a compact process for the production of high-purity β-Ga2O3powder by simply using gallium metal and water as the raw materials. The process basically consists of two essential steps including hydrothermal synthesis of Ga OOH and calcination of Ga OOH for the production of the target product of β-Ga2O3. Thermodynamic evaluation and systematic experiments were conducted for process parameter optimization. X-ray diffractometer（XRD）, scanning electron microscopy（SEM）, thermogravimetryDdifferential scanning calorimetry（TG-DSC） and X-ray photoelectron spectroscopy（XPS） were utilized to clarify the reaction mechanisms of the hydrothermal synthesis and transformation of Ga OOH to β-Ga2O3by calcination. Chemical analysis of the final product of β-Ga2O3obtained under the optimal conditions was carried out with inductively coupled plasma mass spectrometry（ICP-MS）, and the results showed that the contents of the representative impurities such as Ni, Cu, In, Mn, Co, Zn and Cr are obviously lower than the requirement of 5N β-Ga2O3standard, exhibiting excellent application prospect of the proposed process to produce high-purity β-Ga2O3.

关键词： Calcination Hydrothermal synthesis Purity Reaction mechanism β-Ga2O3

Error-based adaptive optimal tracking control of nonlinear discrete-time systems

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Science China(Information Sciences) 2024年第1期67卷 154-167页

作者： Chun LI Jinliang DING Frank L.LEWIS Tianyou CHAI State Key Laboratory of Synthetical Automation for process Industries Northeastern University UTA research institute The University of Texas at Arlington

In this paper,for the output tracking problem of nonlinear discrete-time systems,a performance index is newly defined using the adaptive dynamic programming(ADP) technique to completely eliminate tracking errors in *** contrast to traditional definitions of performance indices in other ADP-based methods,the proposed performance index is not only designed from the perspective of output tracking errors but also introduced errors of system states and control inputs at adjacent stages,which is suitable for practical situations in many industrial applications,such as the alumina production,the flotation process,and the mineral grinding *** proved that the obtained controller can make the system output fully track the given reference trajectory by applying the iterative criteria of the ADP *** addition,the proposed algorithm was implemented using a data-driven technique and neural networks to avoid analyzing and deducing the complicated dynamics of actual industrial ***,using historical data for a forced-circulation evaporation system in the alumina production process,the effect of the proposed approach was verified through a numerical simulation and compared with that of the proportional-integral controller.

关键词： adaptive dynamic programming iterative criteria performance index tracking errors tracking problem

Non-equilibrium kinetic separation of thulium,yttrium and erbium on the surface of freely rising oil droplets

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Journal of Rare Earths 2024年第1期42卷 200-209,I0007页

作者： Na Sui Shukai Miao Kaihui Cui Fancheng Meng Kun Huang School of metallurgical and Ecological Engineering University of Science and Technology BeijingBeijing100083China Beijing Key Laboratory of Green Recovery and Extraction of Rare and Precious Metals University of Science and Technology BeijingBeijing100083China Key Laboratory of Green process and Engineering Institute of Process EngineeringChinese Academy of SciencesBeijing100190China

It is difficult to achieve selective separation and enrichment of different rare earths from high abundance yttrium ores efficiently only dependent on their discrepancy in thermodynamic *** present work suggests a new strategy based on non-equilibrium kinetic separation of Er and Tm on the surface of freely rising oil droplets to control the separation order of *** is revealed that the mutual separation of Er/Tm is significantly promoted with the separation coefficient of 2.89 during the non-equilibrium extraction with the addition of diethylenetriaminepentaacetic acid(DTPA).The extraction sequence of Tm,Er and Y can be controlled as Tm>Y>Er,thus Y can be selectively enriched during the process of separation of Er and Tm,Such a sequence is subject to the controllable dissociation rates of RE(Ⅲ)-DTPA complexes and extraction abilities of P507 with the three RE(Ⅲ)*** dissociation rate is dependent on the stabilities of RE(Ⅲ)-DTPA complexes and follows the sequence ofY(Ⅲ)—DTPA Er>Y to Tm>Y>Er.

关键词： DTPA Interface interaction Non-equilibrium kinetic separation Rare earths P507

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Microstructural evolution and deformation behavior of friction stir welded twin-induced plasticity steel

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Journal of Materials Science & Technology 2024年第2期169卷 68-81页

作者： Ke Qiao Kuaishe Wang Jia Wang Zhengyang Hao Yating Xiang Peng Han Jun Cai Qi Yang Wen Wang School of metallurgical Engineering National and Local Joint Engineering Research Center for Functional Materials ProcessingXi’an University of Architecture and TechnologyXi’an 710055China Shanghai research institute of Materials Shanghai 200437China

The weldability of twin-induced plasticity(TWIP)steel with ultra-high strength via friction stir welding(FSW)technique was investigated,and microstructural evolution and deformation behavior of whole and micro-zones of FSW TWIP joint were studied for the first *** results showed that the content of recrystallized grains in the stir zone(SZ)increased from 10.5%of basal material(BM)to 14.2%,and that of heat affected zone(HAZ)increased to 78.6%.The percentage of annealing twins decreased from 26.8%in BM to 11%in SZ,while increased to 35%in *** with the BM,the ultimate tensile strength and yield strength of the FSW joint increased to 1036 and 550 MPa,respectively,reaching 106.7%and 110.9%of BM,*** elongation of the entire joint was 50.5%,which was lower than that of BM due to the nonuniform deformation during the tensile *** engineering strain was mainly concentrated in BM and SZ and transferred to each other during the tensile test,while the engineering strain in HAZ was always the ***,the tensile fracture occurred in the *** order of ultimate tensile strength of micro-zones in the FSW joint was as follows:HAZ>BM≈*** order of yield strength was as follows:HAZ>BM>SZ.

关键词： Twin-induced plasticity steel Friction stir welding Microstructure Mechanical property Deformation behavior

Ultralong hydroxyapatite-based forward osmosis membrane for freshwater generation

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Frontiers of Chemical Science and Engineering 2024年第9期18卷 37-49页

作者： Mohamed Gamal Gomaa Hamdy Maamoun Abdel-Ghafar Francesco Galiano Francesca Russo Alberto Figoli El-Sayed Ali Abdel-Aal Abdel-Hakim Taha Kandil Bahaa Ahmed Salah Central metallurgical research and Development institute(CMRDI) 11421 CairoEgypt Chemistry Department Faculty of ScienceHelwan University11795 CairoEgypt institute on Membrane Technology(CNR-ITM) 87036 RendeItaly

Increasing global water shortages are accelerating the pace of membrane manufacturing,which generates many environmentally harmful *** challenges need a radical rethink of developing innovative membranes that can address freshwater production without generating environmentally harmful *** work utilized the synthesized ultra-long hydroxyapatite(UHA)by the solvothermal method using the green solvent oleic acid in preparing UHA-based forward osmosis *** membranes were developed using different loading ratios of graphene oxide(GO)by vacuum-assisted filtration *** prepared GO/UHA membranes were identified using X-ray diffraction,scanning electron microscope,Fourier-transform infrared spectroscopy,and X-ray photoelectron *** contact angle and pore size distribution were determined for the obtained GO/UHA *** obtained hierarchical porous structure in the prepared membranes with interconnected channels results in a stable water flux with reverse salt *** best water flux rate of 42±2 L·m^(–2)·h^(–1)was achieved using the 50 mg GO/UHA membrane,which is 3.3 times higher than the pristine membrane,and a reverse salt flux of 67 g·m^(-2)·h^(–1).The obtained results showed a promising capability of a new generation of sustainable inorganic-based membranes that can be utilized in freshwater generation by energy-efficient techniques such as forward osmosis.

关键词： forward osmosis ultra-long hydroxyapatite graphene oxide inorganic-based membrane

New formula for predicting the plastic buckling pressure of steel torispherical heads under internal pressure

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2024年第8期25卷 618-630页

作者： Sheng YE Keming LI Jinyang ZHENG Shan SUN institute of process Equipment Zhejiang UniversityHangzhou 310027China Engineering research Center for High Pressure process Equipment and Safety of Ministry of Education Hangzhou 310027China State Key Laboratory of Fluid Power and Mechatronic Systems Hangzhou 310058China

Thin-walled torispherical heads under internal pressure can fail by plastic buckling because of compressive circumferential stresses in the head ***,existing formulas still have limitations,such as complicated expressions and low accuracy,in determining buckling *** this paper,we propose a new formula for calculating the buckling pressure of torispherical heads based on elastic-plastic analysis and experimental ***,a finite element(FE)method based on the arc-length method is established to calculate the plastic buckling pressure of torispherical heads,considering the effects of material strain hardening and geometrical *** buckling pressure results calculated by the FE method in this paper have good consistency with those of BOSOR5,which is a program for calculating the elastic-plastic bifurcation buckling pressure based on the finite difference energy ***,the effects of geometric parameters,material parameters,and restraint form of head edge on buckling pressure are ***,a new formula for calculating plastic buckling pressure is developed by fitting the curve of FE results and introducing a reduction factor determined from experimental ***,based on the experimental results,we compare the predictions of the new formula with those of existing *** is shown that the new formula has a higher accuracy than the existing ones.

关键词： Torispherical head Plastic buckling Elastic-plastic analysis Prediction formula Finite element method

Stabilization/solidification mechanisms of tin tailings and fuming slag-based geopolymers for different heavy metals

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Frontiers of Environmental Science & Engineering 2024年第5期18卷 43-55页

作者： Xian Zhou Zhengfu Zhang Hui Yang School of Materials Science and Engineering Kunming University of Science and TechnologyKunming650093China Kunming metallurgical research institute Co. Ltd.Kunming650031China

Tin mine tailings(TMT)and fuming slag(FS)contain many heavy metals(As,Cr,Cu,Zn and Mn)that cause severe pollution to the ***,geopolymers were prepared using TMT,FS and flue gas desulfurization gypsum(FGDG)to immobilize heavy metals,and their compressive strength and heavy metal leaching toxicity were *** was first determined that T4F5(TMT:FS=4:5)sample exhibited the highest compressive strength(7.83 MPa).T4F5 achieved 95%immobilization efficiency for As and Cr,and nearly 100%for Cu,Zn and Mn,showing good immobilization performance.A series of characterization analyses showed that heavy metal cations can balance the charge in the geopolymer and replace Al in the geopolymer structure to form covalent *** addition,about 2%–20%of heavy metal Fe was immobilized in hydration products,heavy metal hydroxides and non-bridging Si–O and Al–O coordination with silica-aluminate ***_(3)^(3−) was oxidized into AsO_(4)^(3−),which may form Ca–As or Fe–As ***_(2)O_(7)^(2−)was converted to CrO_(4)^(2−)under alkaline environment and then combined with OH−to form Cr(OH)3 ***^(2+)may react directly with dissolved silicate to form Mn_(2)SiO_(4) and also form Mn(OH)_(2) *** unstable Mn(OH)_(2) can be further oxidized to MnO_(2).The heavy metal cations were immobilized in the silicoaluminate lattice,while the anions tended to form insoluble *** results may benefit the industry and government for better handling of TMT,FS and solid wastes containing the abovementioned five heavy metals.

关键词： Heavy metals Cementitious materials Tin tailings Stabilization/solidification Redox

research progress and future prospects in the service security of key blast furnace equipment

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International Journal of Minerals,Metallurgy and Materials 2024年第10期31卷 2121-2135页

作者： Yanxiang Liu Kexin Jiao Jianliang Zhang Cui Wang Lei Zhang Xiaoyue Fan School of metallurgical and Ecological Engineering University of Science and Technology BeijingBeijing 100083China research institute of Macro-Safety Science University of Science and Technology BeijingBeijing 100083China

The safety and longevity of key blast furnace(BF)equipment determine the stable and low-carbon production of *** pa-per presents an analysis of the heat transfer characteristics of these components and the uneven distribution of cooling water in parallel pipes based on hydrodynamic principles,discusses the feasible methods for the improvement of BF cooling intensity,and reviews the pre-paration process,performance,and damage characteristics of three key equipment pieces:coolers,tuyeres,and hearth ***-thermoere,to attain better control of these critical components under high-temperature working conditions,we propose the application of optimized technologies,such as BF operation and maintenance technology,self-repair technology,and full-lifecycle management ***,we propose further researches on safety assessments and predictions for key BF equipment under new operating conditions.

关键词： blast furnace equipment service security blast furnace campaign self-repair

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