Flocculation Settling Characteristics of Ultra-Fine Iron Tailings with Rich Gypsum

Because of the uniqueness of geological mineralization, tailings obtained from Chenchao Iron Mine have low SiO2 content of only 27.80%. Content of Al2O3 and MgO is 13.31% and CaSO4 is 22.09%. The fineness modulus of the ores is large enough for convenient mineral separation, thus resulting in 16.03% −5 μm particles and 27.76% −10 μm particles in the tailings, respectively. The average particle size is only 69.36 μm; it belongs to the category of very fine tailings. The natural sedimentation of tailings is extremely slow due to the comprehensive effects of their physical and chemical properties. Hence, sedimentation tests using four types of flocculating agents are conducted to accelerate the sedimentation of the tailings of Chenchao Iron Mine. Compared with natural sedimentation, the flocculating sedimentation is considerably quicker. Among the four flocculants, the sedimentation of sample using the special BASF flocculant is the fastest. When the tailings of 1 ton add this flocculant of 20 g, the maximum settling concentration reaches 60.98% after 40 min and its special gravity is 1.577 g/cm3, thus it fulfills future requirements of filling technologies. As the largest iron mine in the mid-southern region of China, Chenchao Iron Mine must turn to filling mining. This study can provide technological support for goaf management and environment-friendly treatment of solid waste in the Yangtze River basin, which plays important roles in ecological protection.

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Structural, optical, opto-thermal and thermal properties of ZnS–PVA nanofluids synthesized through a radiolytic approach

Beilstein Journal of Nanotechnology ◽

10.3762/bjnano.6.55 ◽

2015 ◽

Vol 6 ◽

pp. 529-536 ◽

Cited By ~ 33

Author(s):

Alireza Kharazmi ◽

Nastaran Faraji ◽

Roslina Mat Hussin ◽

Elias Saion ◽

W Mahmood Mat Yunus ◽

...

Keyword(s):

Electrostatic Force ◽

Low Cost ◽

Dose Range ◽

Average Particle Size ◽

Chemical Properties ◽

Thermal Effusivity ◽

Average Particle ◽

Zns Nanoparticles ◽

Transmission Electron ◽

Physical And Chemical

This work describes a fast, clean and low-cost approach to synthesize ZnS–PVA nanofluids consisting of ZnS nanoparticles homogeneously distributed in a PVA solution. The ZnS nanoparticles were formed by the electrostatic force between zinc and sulfur ions induced by gamma irradiation at a dose range from 10 to 50 kGy. Several experimental characterizations were conducted to investigate the physical and chemical properties of the samples. Fourier transform infrared spectroscopy (FTIR) was used to determine the chemical structure and bonding conditions of the final products, transmission electron microscopy (TEM) for determining the shape morphology and average particle size, powder X-ray diffraction (XRD) for confirming the formation and crystalline structure of ZnS nanoparticles, UV–visible spectroscopy for measuring the electronic absorption characteristics, transient hot wire (THW) and photoacoustic measurements for measuring the thermal conductivity and thermal effusivity of the samples, from which, for the first time, the values of specific heat and thermal diffusivity of the samples were then calculated.

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Synthesis and characterization of single-crystalline CdS nanorods prepared by γ-irradiation

Journal of Materials Research ◽

10.1557/jmr.2009.0011 ◽

2009 ◽

Vol 24 (1) ◽

pp. 227-236 ◽

Cited By ~ 5

Author(s):

Haijiao Zhang ◽

Gang Liu ◽

Xiaojuan Wan ◽

Huijiao Guo ◽

Zheng Jiao ◽

...

Keyword(s):

Average Particle Size ◽

Chemical Properties ◽

Average Particle ◽

Γ Irradiation ◽

Single Crystalline ◽

Cds Nanorods ◽

Selected Area Electron Diffraction ◽

Photoelectric Properties ◽

Physical And Chemical ◽

Soft Templates

Under γ-irradiation, thiacetamide (TAA) releases S2−in acidic solutions (e.g., pH = 3), and the S2−can react with available Cd2+in soft templates to form CdS nanorods. Single-crystalline CdS nanorods were prepared in this study. The effects of various synthesis parameters on the crystalline type, morphology, average particle size, and photoelectric properties were thoroughly investigated, including the concentrations of reactants, dose of irradiation, and the type and dosage of templates. The structure and selected physical and chemical properties of products were characterized by x-ray diffraction (XRD), Fourier transform infrared (FTIR), ultraviolet-visible (UV-vis), selected area electron diffraction (SAED), transmission electron microscopy (TEM), and photoluminescence (PL) spectrophotometer techniques. Results indicated that the ratio of reactants to templates greatly affected the morphology of CdS nanorods; the types of soft templates also had significant effects on the morphology and crystalline type of the nanorod products.

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Commercial Cokes and Graphites as Anode Materials for Lithium - Ion Cells

MRS Proceedings ◽

10.1557/proc-496-575 ◽

1997 ◽

Vol 496 ◽

Cited By ~ 1

Author(s):

David J. Derwin ◽

Kim Kinoshita ◽

Tri D. Tran ◽

Peter Zaleski

Keyword(s):

Electron Microscopy ◽

Ethylene Carbonate ◽

Average Particle Size ◽

Chemical Properties ◽

Lithium Ion ◽

Reversible Capacity ◽

Bet Surface Area ◽

Average Particle ◽

Electrochemical Characteristics ◽

Wide Range

AbstractSeveral types of carbonaceous materials from Superior Graphite Co. were investigated for lithium ion intercalation. These commercially available cokes, graphitized cokes and graphites have a wide range of physical and chemical properties. The coke materials were investigated in propylene carbonate based electrolytes and the graphitic materials were studied in ethylene carbonate / dimethyl solutions to prevent exfoliation. The reversible capacities of disordered cokes are below 230 mAh / g and those for many highly ordered synthetic (artificial) and natural graphites approached 372 mAh / g (LiC6). The irreversible capacity losses vary between 15 to as much as 200 % of reversible capacities for various types of carbon. Heat treated cokes with the average particle size of 10 microns showed marked improvements in reversible capacity for lithium intercalation. The electrochemical characteristics are correlated with data obtained from scanning electron microscopy (SEM), high resolution transmission electron microscopy (TAM), X - ray diffraction (XRD) and BET surface area analysis. The electrochemical performance, availability, cost and manufacturability of these commercial carbons will be discussed.

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Variation of soil nutrients and bacterial community diversity of different land utilization types in Yangtze River Basin, Chongqing Municipality

PeerJ ◽

10.7717/peerj.9386 ◽

2020 ◽

Vol 8 ◽

pp. e9386

Author(s):

Yanlin Li ◽

Chunmei Zeng ◽

Meijun Long

Keyword(s):

Land Use ◽

River Basin ◽

Yangtze River ◽

Yangtze River Basin ◽

Chemical Properties ◽

Physical And Chemical Properties ◽

Chongqing Municipality ◽

Land Use Types ◽

Physical And Chemical ◽

And Chemical Properties

The diversity and community distribution of soil bacteria in different land use types in Yangtze River Basin, Chongqing Municipality were studied by using Illumina MiSeq analysis methods. Soil physical and chemical properties were determined, and correlation analyses were performed to identify the key factors affecting bacterial numbers and α-diversity in these soils. The results showed that the soil physical and chemical properties of different land use types decrease in the order: mixed forest (M2) > pure forest (P1) > grassland (G3) > bare land (B4). There were significant differences in bacterial diversity and communities of different land use types. The diversity of different land use types showed the same sequence with the soil physical and chemical properties. The abundance and diversity of bacterial in M2 and P1 soils was significantly higher than that in G3 and B4 soils. At phylum level, G3 and B4 soils were rich in only Proteobacteria and Actinobacteria, whereas M2 and P1 soils were rich in Proteobacteria, Actinobacteria and Firmicutes. At genus level, Faecalibacterium and Agathobacter were the most abundant populations in M2 soil and were not found in other soils. Pearson correlation analysis showed that soil moisture content, pH, AN, AP, AK and soil enzyme activity were significantly related to bacterial numbers, diversity and community distribution.

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Physico-chemical properties and nutrient content of some slow pyrolysis biochars produced from different feedstocks

Bangladesh Journal of Scientific Research ◽

10.3329/bjsr.v29i2.32327 ◽

2017 ◽

Vol 29 (2) ◽

pp. 111-122 ◽

Cited By ~ 5

Author(s):

Mahmudul Islam Piash ◽

Md Faruque Hossain ◽

Zakia Parveen

Keyword(s):

Rice Straw ◽

Water Hyacinth ◽

Organic Waste ◽

Farmyard Manure ◽

Average Particle Size ◽

Chemical Properties ◽

Average Particle ◽

Organic Carbon Content ◽

Corn Cob ◽

Slow Pyrolysis

Six slow pyrolysis biochars viz. farmyard manure (FM), water hyacinth (WH), domestic organic waste (DW), quick compost (QC), corn cob (CC) and rice straw (RS) were analyzed for their physical and chemical properties. Biochar yielding capacity varied from 34 to 51%, depending on the used feedstock. Water hyacinth biochar exhibited the highest water holding capacity (495%), whereas corn cob biochar had the lowest (146%) regardless of its highest pore volume. Brunauer-Emmett-Teller (BET) specific surface area was found maximum among the plant derived biochars except corn cob. Rice straw biochar exhibited the least mean pore diameter while highest in domestic organic waste. All biochars possessed pH values more than 9. CEC of water hyacinth (WH) was highest, while lowest was in quick compost (QC) biochar. Smallest average particle size (0.54 ?m2) was exhibited by water hyacinth biochar. Organic carbon content ranged from 33 to 49%. Nutrient (N, P, K and S) status of biochar produced from domestic organic waste (DW) was found the maximum compared to the rest and corn cob (CC) biochar showed the lowest nutritional value.Bangladesh J. Sci. Res. 29(2): 111-122, December-2016

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ESTUDO DA QUÍMICA DE SUPERFÍCIE PARA SELEÇÃO DE PROTETIVOS HIDRORREPELENTES E SUPORTE TECNOLÓGICO PARA CONSERVAÇÃO E RESTAURO DE BENS PÉTREOS

Revista Geonomos ◽

10.18285/geonomos.v24i2.886 ◽

2016 ◽

Author(s):

Daniel Silva Barbutti ◽

Roberto Carlos da Conceição Ribeiro

Keyword(s):

Zeta Potential ◽

Protective Coatings ◽

Chemical Properties ◽

X Ray Diffraction ◽

Technological Support ◽

X Ray ◽

Before And After ◽

Ph Range ◽

Physical And Chemical ◽

Selection Of

ResumoNeste estudo foram avaliadas as interações entre três representantes minerais constituintes das rochas ornamentais graníticas (quartzo, microclina e muscovita) e três protetivos comerciais com propriedades hidrorrepelentes. Os minerais foram caracterizados química e mineralogicamente por análises de fluorescência e difração de Raios-X (FRX e DRX, respectivamente), enquanto os protetivos foram caracterizados por meio de espectroscopia de infravermelho com transformada de Fourier (FTIR). Para avaliação da eficácia dos protetivos, foram realizados estudos de mobilidade eletroforética a partir da avaliação do potencial zeta dos minerais em função do pH, antes e após tratamento com cada produto. Os resultados indicaram melhor desempenho do protetivo a base de siloxano, reduzindo a eletronegatividade da superfície de todos os minerais, principalmente na faixa levemente ácida de pH entre 3 e 6, onde ocorrem os principais intemperismos capazes de alterar as propriedades físico-químicas de rochas expostas em centros urbanos. Foram visualizadas reduções médias de até 15mV para quartzo, 5 mV para muscovita e 20 mV para microclina. Análises prévias das rochas de um monumento e dos protetivos inicialmente elegidos para proteção são importantes para a correta conservação e restauro dos bens pétreos que resguardam seus valores artísticos e culturais. Palavras Chave: conservação e restauro, potencial zeta, mineral AbstractSURFACE CHEMISTRY STUDY FOR THE SELECTION OF HYDRORPEPEAL PROTEINS AND TECHNOLOGICAL SUPPORT FOR CONSERVATION AND RESTORATION OF STONE ASSETS. Interactions between the main minerals that compose the granitic dimension stones (quartz, microcline and muscovite) and three commercial hydrophobic protective coatings were investigated in this study. The minerals were characterized chemically and mineralogically through fluorescence X-ray analysis (XRF) and X-ray diffraction (XRD) respectively, while the protective coatings were characterized by Fourier transform infrared spectroscopy (FTIR). The interactions between minerals and protective coatings were evaluated by zeta potential measurements of the minerals as a function of pH before and after surface treatment with each product. The results showed that only one protective coating was able to reduce the electronegativity in all mineral samples, especially in mildly acidic pH range, where several outdoor weathering effects occur, modifying the physical and chemical properties of stone-built monuments in urban environment. Previous analysis of the stones that constitute the monument as well as preselected products for its treatment are considered important to guide the proper conservation and restoration of stone-built cultural heritages that enshrine their artistic and historical values. Keywords: conservation & restoration, zeta potential, mineral

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Moisture, Temperature, and Salinity of a Typical Desert Plant (Haloxylon ammodendron) in an Arid Oasis of Northwest China

Sustainability ◽

10.3390/su13041908 ◽

2021 ◽

Vol 13 (4) ◽

pp. 1908

Author(s):

Li Zhao ◽

Wanjing Li ◽

Guang Yang ◽

Ke Yan ◽

Xinlin He ◽

...

Keyword(s):

Soil Water ◽

Salt Content ◽

Chemical Properties ◽

Northwest China ◽

Water Sources ◽

Desert Plant ◽

Haloxylon Ammodendron ◽

Type Curve ◽

Ecological Protection ◽

Physical And Chemical

The physical and chemical characteristics of soil and water sources affect desert plants’ growth, which is essential for the ecological protection in arid areas. The typical patch patterns of Haloxylon ammodendron in the oasis-desert ecotone in the southern margin of the Manas River Basin consists of bare patches (BP) and vegetation patches (VP). The water sources of H. ammodendron were studied using stable isotope technology, and the soil physical and chemical properties were monitored and analyzed. The results showed that the soil moisture presented a reversed “S” type curve, and the total salt content of the soil presented an “S” type curve. A “wet island” and “cold island” were formed in the low salt area with H. ammodendron at the center. NaCl was most abundant in the BP soil, and the milligram equivalent of Cl− was 80–90%, while CaSO4 was most abundant in the VP soil, in which the milligram equivalent of SO42− was 80–100%. Before the rain, H. ammodendron mainly relied on the soil water from a deeper layer (≥60 cm) to maintain its growth. However, after the rain, H. ammodendron mainly relied on shallow soil water (<60 cm) to maintain its growth.

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Experimental Study on Permeability Coefficient in Layered Fine Tailings under Seepage Condition

Geofluids ◽

10.1155/2021/8850138 ◽

2021 ◽

Vol 2021 ◽

pp. 1-14

Author(s):

Tao Dong ◽

Ping Cao ◽

Rong Gui ◽

Qibin Lin ◽

Zhizhen Liu

Keyword(s):

Permeability Coefficient ◽

Average Particle Size ◽

Average Particle ◽

Tailings Dam ◽

Test Results ◽

Initial State ◽

Fine Grained ◽

Tailings Dams ◽

Fine Tailings ◽

Seepage Characteristics

Nearly half of the tailings dams in China are in a state of high-security risks and overservice, and the safety of these tailings dams has always been a concern for relevant scholars. The seepage characteristics of tailings are one of the essential factors affecting the safety of tailings dam. Now, due to the improvement of mineral processing technology, there are many fine tailings dam; the study of the seepage characteristics of the tailings dam is no longer applicable. Fine-grained tailings form uneven deposition in these tailings dams, resulting in the permeability of tailings not conforming to the previous law. Therefore, it is of great significance to study the permeability of fine-grained tailings with uneven deposition. In this paper, the physical model of the simulated tailings dam is established to study the influence of the dry beach slope on the distribution and deposition law of fine tailings during discharge. The test results show that the average particle size of tailings decreases along the length of dry beach, showing the phenomenon of coarsening upstream and thinning downstream. Then, based on the data of fine tailings deposition, the variation characteristics of the permeability coefficient of layered tailings under stable and unstable seepage conditions are studied. The test results show that the variation process of tailings permeability coefficient can be divided into four stages: rapid compaction stage, slow compaction stage, failure stage, and stable stage. Under stable and unstable seepage conditions, the permeability coefficients of unstratified tailing sand are about 10% and 15% higher, respectively, than those in the initial state. The permeability coefficient of layered tailings formed by uneven settlement changes more obviously, which is about 12% and 20% higher than the initial state.

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Characterization of Silver Nanoparticles Synthesized using Chemical Method and its Antibacterial Property

Biointerface Research in Applied Chemistry ◽

10.33263/briac106.72577264 ◽

2020 ◽

Vol 10 (6) ◽

pp. 7257-7264

Keyword(s):

Pseudomonas Aeruginosa ◽

Silver Nanoparticles ◽

Bacillus Subtilis ◽

Average Particle Size ◽

Chemical Properties ◽

Xrd Analysis ◽

Solid Particles ◽

Average Particle ◽

Face Centered Cubic ◽

Tem Analysis

Metal nanoparticles are gaining importance nowadays in nanoscience. The nanoparticle had better physical and chemical properties compared with solid particles due to their large surface area. The silver nanoparticles are employed mostly in medical and electrical applications having outstanding conductivity and antimicrobial activity. In the present investigation, NaBH4 and ethanol were used as a reductant and stabilizer agent from silver nitrate salt as a precursor. The silver nanoparticles obtained were characterized using Fourier-transform infrared spectroscopy (FT-IR), X-Ray diffraction (XRD) and high-resolution transmission electron microscopy (HRTEM) to determine their morphology and size. In XRD analysis, the average particle size was found to be 18.31 nm. The TEM analysis shows crystalline morphology with a face-centered cubic structure. The antibacterial activity was tested against two bacterial cultures, namely Bacillus subtilis and Pseudomonas aeruginosa. The inhibition zones of 19mm and 17mm were observed against Bacillus subtilis and Pseudomonas aeruginosa, respectively.

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The Effect of the Malt Grinding Degree on the pH Value and Extract Content in Beer Mash

Agricultural Engineering ◽

10.1515/agriceng-2018-0035 ◽

2018 ◽

Vol 22 (4) ◽

pp. 43-49

Author(s):

Marcin Natoniewski ◽

Leszek Rydzak ◽

Agata Wyciszkiewicz ◽

Tomasz Guz

Keyword(s):

Particle Size ◽

Food Production ◽

Ph Value ◽

Average Particle Size ◽

Average Particle ◽

Malt Extract ◽

Chemical Changes ◽

Extract Content ◽

Physical And Chemical ◽

Degree Of Fragmentation

AbstractIn recent years, a dynamic development of brewing has been observed. Increasingly, production of malt and beer takes place even in smaller industrial factories, breweries restaurants or at home. Extraction is a process applied in a variety of industries, including food production, as a way of extracting specific ingredients from their mixtures. As a result of this process, not only sugars, proteins, fats, enzymes, vitamins, colorants, fragrances and flavors, but also malt and hop extracts are being isolated. In the process of mashing, in which the malt ingredients are being extracted, many biochemical, physical and chemical changes take place. The aim of the study was to analyze the effect of the degree of fragmentation of pilsner type malt on the amount of extract obtained and the pH of the mash. It has been observed that the degree of malt fragmentation has a significant effect on the content of the extract in the mash: the more fragmented malt, the more malt extract in mash produced using the malt. It has also been found that the pH of the mash increases with the average particle size of malt.

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