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Depression mechanism of sulfite ions on sphalerite and Pb^(2+)activated sphalerite in the flotation separation of galena from sphalerite

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International Journal of Minerals,Metallurgy and Materials 2025年第2期32卷 335-345页

作者： Feng Zhang Chenyang Zhang Linlin Wu Wei Sun Hongliang Zhang Jianhua Chen Yong Pei Songjiang Li engineering Research Center of Ministry of Education for Carbon Emission Reduction in Metal Resource exploitation and Utilization Hunan International Joint Research Center for Efficient and Clean Utilization of Critical Metal Mineral ResourcesSchool of Minerals Processing and BioengineeringCentral South UniversityChangsha 410083China State Key Laboratory of Mineral Processing Beijing General Research Institute of Mining&MetallurgyBeijing 100160China Hunan Provincial Key Laboratory of Micro&Nano Materials Interfaces Science College of Chemistry and Chemical EngineeringCentral South UniversityChangsha 410083China School of resources Environment and MaterialsGuangxi UniversityNanning 530004China department of Chemistry Xiangtan UniversityXiangtan 411105China China Railway Resource Group Co.Ltd Beijing 102300China

The depression mechanism of sulfite ions on sphalerite and Pb^(2+)activated sphalerite in the flotation separation of galena from sphalerite still lacked in-depth ***,the depression mechanism of sulfite ions on sphalerite and Pb^(2+)activated sphalerite in the flotation separation of galena from sphalerite was further systematically investigated with experiments and density functional theory(DFT)*** X-ray photoelectric spectroscopy(XPS)results,DFT calculation results,and frontier molecular orbital analysis indicated that sulfite ions were difficult to be adsorbed on sphalerite surface,suggesting that sulfite ions achieved depression effects on sphalerite through other non-adsorption ***,the oxygen content in the surface of sphalerite treated with sulfite ions in creased,which enhanced the hydrophilicity of the sphalerite and further increased the difference in hydrophilicity between sphalerite and ***,sulfite ions were chelated with lead ions to form PbSO_(3)in *** hydrophilic PbSO_(3)was more easily adsorbed on sphalerite than *** interaction between sulfite ions and lead ions could effectively inhibit the activation of *** addition the UV spectrum showed that after adding sulfite ions,the peak of perxanthate in the sphalerite treated xanthate solution was significantly stronger than that in the galena with xanthate solution,indicating that xanthate interacted more readily with sulfite ions and oxygen mo lecules within the sphalerite system,leading to the formation of ***,sulfite ions hardly depressed the flotation of ga lena and could promote the flotation of galena to some *** study deepened the understanding of the depression mechanism o sulfite ions on sphalerite and Pb^(2+)activated sphalerite.

关键词： sphalerite galena sulfite ion density functional theory depression mechanism

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Study on the law of methane seepage in the wall of drainage roadway in mining seam-group

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Journal of Coal Science & engineering(China) 2005年第2期11卷 64-66页

作者：刘健罗勇刘泽功石必明 department of resources exploitation and management engineering department of Modern Mechanics University of Science and Technology of China Hefei 230026China

Based on the equation of the gas flow continuity and state, Darcy law and Langmuir equation, the law of methane seepage in the wall of drainage roadway was studied. The governing equation of methane one-way seepage in the seam was founded. By solving the equation, the calculation of methane seepage velocity in the coal wall was worked out. The result has really applied worth and will give beneficial references to re-lated research, it provides preventing coal and gas outbursts with theoretical gist.

关键词： drainage roadway methane seepage governing equation methane drainage

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Comparison of stem volume estimates from terrestrial point clouds for mature Douglas-fir(Pseudotsuga menziessi(Mirb.)Franco)

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Information Processing in Agriculture 2023年第3期10卷 334-346页

作者： Rong Fang Bogdan M.Strimbu Forest engineering Resourcesand Management DepartmentOregon State UniversityCorvallisOR 97333 ORUSA

As a complement to traditional estimates of stem dimensions from numerical models,terrestrial light detection and ranging(Lidar)provides direct stem diameter and volume values using cylindrical models constructed from point *** study used two approaches to estimate total stem volume using Lidar and compared them with two empirical equations,one used by the Forest Inventory Analysis in the Pacific Northwest(FIA-PNW)and one based on a taper *** fitted point clouds of 10 Douglas-fir with three sets of cylinder models that are distinguished by their segment length(i.e.0.5 m,1 m,and 2 m),then developed three taper equations based on the point-cloud-based diameter estimated *** estimated the total stem volume of the tree with eight models:six-point cloudbased(*** taper and three cylinders)and two ***,we used simulations to extrapolate the volume estimations of various methods for different diameters at breast height(DBH)*** found that all the point-cloud-based taper equations were similar in their performance(R2¼0:94,RMSE=4.6 cm)and produced mean volume estimates greater than mean estimates of the existing *** cylinder models produced 11–16%greater mean volume estimates than the FIA-PNW estimate,with the 0.5 m segment length producing the greatest values,followed by the 1 m and 2 m segment *** simulated data suggested that the mean volume estimates of a given DBH class are different when using different computation *** revealed a combined effect of the computation methods and the DBH class on the mean volume *** conclude that the point-cloud-based taper equations,after being symmetrically calibrated,would be consistent with the regional stem volume estimates,whereas the cylinder models would be better in estimating individual stem *** constructing Lidar-based cylinder models in future applications,cylinder segment length would need to be adjusted to the length and DBH of the stem

关键词： Lidar Cylinder models Cylinder segment length Taper equations Forest inventory and analysis

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Dissolutive wetting process and interfacial characteristic of molten Sn–17Bi–0.5Cu alloy on copper substrate

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Rare Metals 2013年第6期32卷 537-543页

作者： Bing-Sheng Xu Li-Kun Zang Zhang-Fu Yuan Yan Wu Zhou Zhou Beijing Key Laboratory for Solid Waste Utilization and management Department of Energy and Resources EngineeringCollege of Engineering Peking University department of Chemistry School of Chemistry and Biology EngineeringUniversity of Science and Technology Beijing Beijing Key Laboratory for Solid Waste Utilization and management Department of Energy and Resources Engineering College of Engineering Peking University Beijing Key Laboratory for Solid Waste Utilization and management Department of Energy and Resources Engineering College of Engineering Peking University

The reactive spreading processes of Sn–17Bi–0.5Cu melt alloy on Cu substrate were studied by sessile drop method in the temperature range of 523–673 *** contact angles between the solder and Cu substrate at different times were recorded with high-resolution CCD digital *** smallest contact angle was observed at623 and 673 *** spreading radius does not increase monotonously with the temperature *** can be attributed to the strong dissolution of Cu substrate into the liquid solder,which hinders the solder from *** line area configuration of the Sn–17Bi–0.5Cu/Cu system was discussed by the description of the equilibrium *** calculated results based on experiments of the tension balances along each of the three interfaces show good agreement with theoretical *** compounds at the Sn–17Bi–0.5Cu/Cu interface are identified as Cu6Sn5adjacent to the solder and Cu3Sn adjacent to the Cu substrate,*** results are of practical interest for composite lead-free solders’preparations and joining of Sn–17Bi–0.5Cu to Cu substrate.

关键词： Lead-free solder Reactive wetting Sessile drop method Interfaces

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Identifcation of large-scale goaf instability in underground mine using particle swarm optimization and support vector machine

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International Journal of Mining Science and Technology 2013年第5期23卷 701-707页

作者： Zhou Jian Li Xibing Hani S.Mitri Wang Shiming Wei Wei School of resources and Safety engineering Central South University Hunan Key Lab of resources exploitation and Hazard Control for Deep Metal Mines department of Mining and Materials engineering McGill University

An approach which combines particle swarm optimization and support vector machine(PSO–SVM)is proposed to forecast large-scale goaf instability(LSGI).Firstly,influencing factors of goaf safety are analyzed,and following parameters were selected as evaluation indexes in the LSGI:uniaxial compressive strength(UCS)of rock,elastic modulus(E)of rock,rock quality designation(RQD),area ration of pillar(Sp),the ratio of width to height of the pillar(w/h),depth of ore body(H),volume of goaf(V),dip of ore body(a)and area of goaf(Sg).Then LSGI forecasting model by PSO-SVM was established according to the influencing *** performance of hybrid model(PSO+SVM=PSO–SVM)has been compared with the grid search method of support vector machine(GSM–SVM)*** actual data of 40 goafs are applied to research the forecasting ability of the proposed method,and two cases of underground mine are also validated by the proposed *** results indicated that the heuristic algorithm of PSO can speed up the SVM parameter optimization search,and the predictive ability of the PSO–SVM model with the RBF kernel function is acceptable and robust,which might hold a high potential to become a useful tool in goaf risky prediction research.

关键词： Goaf Risk identifcation Underground mine Prediction Particle swarm optimization Support vector machine

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Assessment of sealed fire states by fire characteristic

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Journal of Coal Science & engineering(China) 2006年第1期12卷 68-72页

作者：袁树杰 SZLAZAK Nikodem OBRACAJ Dariusz department of resources exploitation and management engineering Anhui University of Science and Technology Huainan 232001 China Faculty of Mining and Geoengineering AGH University of Science and Technology Cracow 30-059Poland

The paper presented assessment of sealed fire states in underground coal mines by so-called 'fire characteristic', which graphically described tendencies of fire gas components-oxygen, nitrogen, carbon dioxide, carbon monoxide and hydrocarbons-in time. In order to mark gas components tendencies in time the authors applied the time series analysis. The case studied confirmed, that analysis of fire gas components tendencies in time and their correlation allow to elicit proper conclusions about fire state assessment. Assessment of fire states based on single value of fire indexes without considering their trends in time and correlation between trends of gas components would give wrong results The suggested method can appropriately indicate fire states in a sealed area.

关键词： coal mines mine fires spontaneous combustion sealed areas

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Tracing suspended and bed sediments during high and low water periods using geochemical characteristics-Case study:Vazrood watershed,northern Iran

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Journal of Mountain Science 2024年第2期21卷 470-483页

作者： KARIMI Nabiyeh GHOLAMI Leila KAVIAN Ataollah KHALEDI DARVISHAN Abdulvahed department of Watershed management Faculty of Natural ResourcesSari Agricultural Sciences and Natural Resources UniversitySari ***Iran department of Watershed management engineering Faculty of Natural ResourcesTarbiat Modares UniversityNoor ***Iran

Complete and comprehensive information about sediment dynamic and identification of hotspots of sediment production and transport are necessary for understanding the erosion processes and increasing the efficiency of soil and water conservation *** studies used the sediment fingerprint techniques to investigate the contribution of different sources in suspended and bed sediment yield of the ***,the contribution of various land use/land covers in suspended and bed sediment yield for the great Caspian Sea basin is in an aura of ambiguity and the present study was conducted to gather information about an important part of this area in northern Iran,where rangelands are located upstream of Hyrcanian forests and dense agricultural lands are located *** surface soil of different land use/land covers including forest,rangeland,agriculture and streambank lands were sampled in 30 *** and bed sediments were sampled in the watershed outlet in two high and low water *** characteristics of soil and sediment samples containing 59 elements were measured using ICP-OES GBC *** reliable and suitable tracers from 59 elements were then selected using Range test,Kruskal-Wallis and Discriminant Function Analysis,respectively,in FingerPro package of R *** results showed that for suspended sediment,streambank and rangeland had the highest contributions of 86.2%and 47.5%,respectively,in two high and low water *** bed sediment,in two high and low water periods,rangeland and streambank had the highest contributions of 73.8%and 84.4%,*** use change and especially human activities such as agriculture,road construction and development of residential areas along the main river riparian zone has led to a significant increase in suspended and bed sediments.

关键词： Caspian Sea basin FingerPro Geochemistry Sediment transport Tracer combination

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Inhibiting soil loss and runoff from small plots induced by an individual freeze-thaw cycle using three rangeland species

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International Soil and Water Conservation Research 2020年第3期8卷 228-236页

作者： Milad Hatefi Seyed Hamidreza Sadeghi Reza Erfanzadeh Morteza Behzadfar department of Watershed management engineering Faculty of Natural ResourcesTarbiat Modares UniversityIran department of Rangeland management Faculty of Natural ResourcesTarbiat Modares UniversityNoorIran

This study investigated the role of three rangeland species *** trichophorum,Medicago sativa,and Lolium prenne on mitigating of effects of a freeze-thaw(FT)cycle on runoff generation and soil loss from small experimental *** plots(0.5×0.5m)were prepared in three replicates for control(i.e.,under a FT cycle only)and treatments(i.e.,individually planted with the study species and subject to a FT cycle).The treated plots were then placed at a slope of 20%and subjected to simulated rainfall with intensity of 70 mm h-1 and 30 min *** results of the study showed a significant effect(P<0.05)of the plants on controlling runoff and soil loss after a FT ***,the detrimental effects of the FT cycle due to performance of ice lenses and formation of an active melting layer in the soil surface were ameliorated by the presence of litter on the soil and root-binding effect of the *** to runoff increased by 54,111 and 10%,runoff volume decreased by 27,68 and 0.4%and soil loss changed by-34,-62,and+6.5%in the plots planted with ***,*** and ***,*** results of the current study indicated that *** had the maximum benefit on reducing runoff and soil loss from the plots undergoing a FT cycle.

关键词： Biological measures Frosted soil Plant binding effects Soil hydrology

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Spatiotemporal distribution of soil moisture in gully facies

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International Soil and Water Conservation Research 2020年第1期8卷 15-25页

作者： Seyed Hamidreza Sadeghi Gholam Ali Ghaffari Abdulsaleh Rangavar Zeinab Hazbavi Vijay P.Singh department of Watershed management engineering Faculty of Natural ResourcesMember of Agrohydrology GroupTarbiat Modares UniversityNoor***Mazandaran ProvinceIran department of Watershed management engineering Faculty of Natural Resources and Marine SciencesTarbiat Modares UniversityNoor46417-76489Iran Scientific Member of Khorasan Razavi Research Centre for Agriculture and Natural resources MashhadIran Watershed management Sciences and engineering Department of Watershed Management EngineeringFaculty of Natural ResourcesTarbiat Modares UniversityIran department of Watershed management engineering Faculty of Natural ResourcesTarbiat Modares UniversityNoor ***Mazandaran ProvinceIran Water engineering Department of Biological and Agricultural Engineering&Zachry Department of CivilEngineeringTexas A and M UniversityCollege StationTX77843-2117USA

Gully erosion is one of the most important forms of land degradation in many regions of the *** the process of gully erosion therefore is important for better management of the wa-tersheds prone to gully ***,many different aspects of gully erosion,like hydrological behavior,are still not fully *** present study investigates the spatial distribution of soil moisture content(SMC),as one of the hydrological factors,at different depths and points across the cross section in the vicinity of the headcut of three gullies located in the Kalat County,Khorasan Razavi Province,*** were measured at depths of 10,20,30,50,70 and 100 cm at each seven points across the study cross sections one to three days after occurrence of three rain *** sampling points were symmetrically located at a distance of 50 cm outside the gully banks,two at the vertex of the sidewalls,two in the middle of the sidewalls and one at the center of gully cross *** were measured using a weighted *** of the study revealed a broad range of changes in SMCs at various depths and *** minimum and maximum SMCs were found to be about 2%and 38%,respectively,for the study period and gullies under *** coefficient of variation(CV)had drastic changes for various gullies and storm events from 2 to 107%.Results further indicated that SMC moved from the sidewalls towards the floor of the cross ***,the maximum SMC for storm events was associated with the point located in the center of gullies,which indicated the role of gully system in draining soil *** findings of this study will help watershed managers un-derstand the important role of gully facies in changing water content of the soil that affects other eco-hydrological processes.

关键词： Soil moisture capacity Soil water Subsurface runoff Water erosion

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Removal of antibiotics in a parallel-plate thin-film-photocatalytic reactor: Process modeling and evolution of transformation by-products and toxicity

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Journal of Environmental Sciences 2017年第10期29卷 114-122页

作者： Can Burak?zkal Zacharias Frontistis Maria Antonopoulou Ioannis Konstantinou Dionissios Mantzavinos Süreyya Meric Environmental engineering Namik Kemal University Faculty of Engineering department of Chemical engineering University of Patras department of Environmental&Natural resources management University of Patras department of Chemistry University of Ioannina

Photocatalytic degradation of sulfamethoxazole（SMX） antibiotic has been studied under recycling batch and homogeneous flow conditions in a thin-film coated immobilized system namely parallel-plate（PPL） reactor. Experimentally designed, statistically evaluated with a factorial design（FD） approach with intent to provide a mathematical model takes into account the parameters influencing process performance. Initial antibiotic concentration, UV energy level, irradiated surface area, water matrix（ultrapure and secondary treated wastewater） and time, were defined as model parameters. A full of 2~5 experimental design was consisted of 32 random experiments. PPL reactor test experiments were carried out in order to set boundary levels for hydraulic, volumetric and defined defined process parameters. TTIP based thin-film with polyethylene glycol ＋ TiO2 additives were fabricated according to pre-described methodology. Antibiotic degradation was monitored by High Performance Liquid Chromatography analysis while the degradation products were specified by LC–TOF-MS analysis. Acute toxicity of untreated and treated SMX solutions was tested by standard Daphnia magna method. Based on the obtained mathematical model, the response of the immobilized PC system is described with a polynomial equation. The statistically significant positive effects are initial SMX concentration,process time and the combined effect of both, while combined effect of water matrix and irradiated surface area displays an adverse effect on the rate of antibiotic degradation by photocatalytic oxidation. Process efficiency and the validity of the acquired mathematical model was also verified for levofloxacin and cefaclor antibiotics. Immobilized PC degradation in PPL reactor configuration was found capable of providing reduced effluent toxicity by simultaneous degradation of SMX parent compound and TBPs.

关键词： Thin-film photocatalysis Sulfamethoxazole (SMX) Levofloxacin (LVX) Cefaclor (CFL) Factorial design Modeling Parallel-plate reactor

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