scholarly journals The Magnetic Beneficiation of Coal

1985 ◽  
Vol 2 (1) ◽  
pp. 1-48
Author(s):  
S. E. Male
Keyword(s):  
Magnetic Separation ◽  
Separation Technique ◽  
Particle Sizes ◽  
Coal Processing ◽  
Power Station ◽  
Wide Range ◽  
Pulverized Fuel ◽  
Process Material

The magnetic demineralization of coal can produce a fuel containing lower leveIs of sulphur and ash forming minerals. The ability of the magnetic separation technique to process material over a wide range of particle sizes (I-1000 µm) and to operate on either liquid or gaseous feed enables a number of possible coal processing applications. These range from dry desulphurization of power station pulverized fuel to the cleaning of solvent refined coals. This article reviews work on the development of magnetic separation as applied to coal processing.

Effects of fines on liquefaction behaviour in well-graded materials

2017 ◽  
Vol 54 (10) ◽  
pp. 1460-1471 ◽  
Author(s):  
Katherine A. Kwa ◽  
David W. Airey
Keyword(s):  
Critical State ◽  
Soil Mechanics ◽  
State Parameter ◽  
Triaxial Tests ◽  
Particle Sizes ◽  
Graded Materials ◽  
Fines Content ◽  
Cyclic Resistance ◽  
Wide Range ◽  
Soil Behaviour

This study uses a critical state soil mechanics perspective to understand the mechanics behind the liquefaction of metallic ores during transport by ship. These metallic ores are transported at relatively low densities and have variable gradings containing a wide range of particle sizes and fines contents. The effect of the fines content on the location of the critical state line (CSL) and the cyclic liquefaction behaviour of well-graded materials was investigated by performing saturated, standard drained and undrained monotonic and compression-only cyclic triaxial tests. Samples were prepared at four different gradings containing particle sizes from 9.5 mm to 2 μm with fines (<75 μm) contents of 18%, 28%, 40%, and 60%. In the e versus log[Formula: see text] plane, where e is void ratio and [Formula: see text] is mean effective stress, the CSLs shifted upwards approximately parallel to one another as the fines content was increased. Transitional soil behaviour was observed in samples containing 28%, 40%, and 60% fines. A sample’s cyclic resistance to liquefaction depended on a combination of its density and state parameter, which were both related to the fines content. Samples with the same densities were more resistant to cyclic failure if they contained higher fines contents. The state parameter provided a useful prediction for general behavioural trends of all fines contents studied.

Molecular Dynamics Study of Anatase TiO2 Nanoparticles in Water and Vacuum Environments

2012 ◽  
Author(s):  
George Okeke ◽  
Robert B. Hammond ◽  
S. Joseph Antony
Keyword(s):  
Molecular Dynamics ◽  
Surface Tension ◽  
Surface Energy ◽  
Tio2 Nanoparticles ◽  
Anatase Tio2 ◽  
Particle Sizes ◽  
Metallic Oxides ◽  
Wide Range ◽  
Enhanced Properties ◽  
Dynamics Simulations

Nanoparticles are nanometer sized metallic oxides which possess enhanced properties that are desirable to a wide range of industries. In this study, we investigate structural and surface properties of anatase TiO2 nanoparticles in vacuum and water environments using molecular dynamics simulations. The particle sizes ranged from 2 to 6 nm and simulations were performed at 300 K. Surface energy of the particles in vacuum was seen to be higher than that of the particles in water by about 100% for the smaller particles (i.e. 2 and 3nm) and about 60% for the larger particles (i.e. 4 to 6 nm). Surface energy of the particles in both environments, is seen to increase to a maximum (optimum value) as the particle size increases after which no further significant increase is observed. In vacuum, studies carried out at temperatures ranging from 300–2500 K showed a high dependence of surface energy on temperature. The estimated surface tension of water is seen to agree quite well with that of experiments.

Development of the Shell-Koppers coal gasification process

1981 ◽  
Vol 300 (1453) ◽  
pp. 111-120 ◽  
Keyword(s):  
Coal Gasification ◽  
Combined Cycle ◽  
Hard Coal ◽  
Steam Turbines ◽  
Power Station ◽  
Gasification Process ◽  
Coal Gasifier ◽  
Large Size ◽  
Wide Range ◽  
By Products

The Shell-Koppers process for the gasification of coal under pressure, based on the principles of entrained-bed technology, is characterized by: practically complete gasification of virtually all solid fuels; production of a clean gas without by-products; high throughput; high thermal efficiency and efficient heat recovery; environmental acceptability. There are numerous possible future applications for this process. The gas produced (93-98 vol. % hydrogen and carbon monoxide) is suitable for the manufacture of hydrogen or reducing gas and, with further processing, substitute natural gas (s.n.g.). Moreover, the gas can be used for the synthesis of ammonia, methanol and liquid hydrocarbons. Another possible application of this process is as an integral part of a combined-cycle power station featuring both gas and steam turbines. The integration of a Shell-Koppers coal gasifier with a combined-cycle power station will allow of electricity generation at 42-45 % efficiency for a wide range of feed coals. The development programme includes the operation of a 150 t/day gasifier at Deutsche Shell’s Harburg refinery since November 1978 and of a 6 t/day pilot plant a Royal Dutch Shell’s Amsterdam laboratories from December 1976 onwards. Both facilities run very successfully. With hard coal a conversion of 99% is reached while producing a gas with only 1 vol. % CO 2 . The next step will be the construction and operation of one or two 1000 t/day prototype plants which are scheduled for commissioning in 1983-4. Towards the end of the 1980s large commercial units with a capacity of 2500 t/day are contemplated. The economy, especially of these large size units, is very competitive.

scholarly journals Performance and adsorption mechanism of a magnetic calcium silicate hydrate composite for phosphate removal and recovery

2018 ◽  
Vol 2017 (2) ◽  
pp. 578-591 ◽  
Author(s):  
Lihong Peng ◽  
Hongliang Dai ◽  
Yifeng Wu ◽  
Zheqin Dai ◽  
Xiang Li ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Magnetic Separation ◽  
Adsorption Kinetics ◽  
Calcium Silicate ◽  
Calcium Silicate Hydrate ◽  
Phosphate Removal ◽  
Separation Technique ◽  
Phosphate Adsorption ◽  
X Ray ◽  
Removal And Recovery

Abstract A novel magnetic calcium silicate hydrate composite (Fe3O4@CSH) was proposed for phosphorus (P) removal and recovery from a synthetic phosphate solution, facilitated by a magnetic separation technique. The Fe3O4@CSH material was characterized by transmission electron microscopy (TEM), scanning electron microscopy (SEM), powder Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), zeta-potential and magnetic curves. The chemical composition and structure of Fe3O4@CSH and the successful surface loading of hydroxyl functional groups were confirmed. Phosphate adsorption kinetics, isotherm, and thermodynamic experiments showed that adsorption reaches equilibrium at 24 h, with a maximum adsorption capacity of 55.84 mg P/g under optimized experimental conditions. Adsorption kinetics fitted well to the pseudo second-order model, and equilibrium data fit the Freundlich isotherm model. Thermodynamic analysis provided a positive value for ΔH° (129.84 KJ/mol) and confirmed that phosphate adsorption on these materials is endothermic. The P-laden Fe3O4@CSH materials could be rapidly separated from aqueous solution by a magnetic separation technique within 1 min. A removal rate of more than 60% was still obtained after eight adsorption/desorption cycles, demonstrating the excellent reusability of the particles. The results demonstrated that the Fe3O4@CSH materials had high P-adsorption efficiency and were reusable.

Criticality Characteristics and Sensitivity Analysis of Fukushima Debris Beds Containing MCCI Products

2020 ◽  
Vol 6 (4) ◽  
Author(s):  
María Freiría López ◽  
Michael Buck ◽  
Jörg Starflinger
Keyword(s):  
Sensitivity Analysis ◽  
Nuclear Power ◽  
Realistic Model ◽  
Power Station ◽  
Wide Range ◽  
Core Meltdown ◽  
Erosion Factor ◽  
The Impact ◽  
Control Rods ◽  
Core Concrete

Abstract This study investigates the criticality characteristics of debris beds that may have been formed through the molten–core–concrete-interaction (MCCI) at the pedestal floor of the damaged reactors in Fukushima Daiichi Nuclear Power Station. These were modeled as UO2-concrete systems submerged in water. First, a conservative model was used to evaluate the impact that the presence of concrete has on the neutron multiplication factor (keff) of debris beds. The good moderation capacities of concrete were proved, and it was found that recriticality would be possible under the considered conservative assumptions. Second, a more realistic model was used to perform an uncertainty and sensitivity analysis of a wide range of debris parameters (debris porosity, core meltdown grade, debris size, debris composition, concrete erosion factor, etc.). In this case, the results indicate that the probability of a recriticality event is very remote. It was also found that the presence of boron (B4C) from the control rods within debris has by far the highest influence on keff.

Intensive horticulture in Eastern Europe

1974 ◽  
Vol 8 (2) ◽  
pp. 70-73
Author(s):  
R Gardner
Keyword(s):  
Waste Water ◽  
Eastern Europe ◽  
Large Scale ◽  
Power Station ◽  
The West ◽  
Wide Range ◽  
Temperature And Humidity ◽  
Station Waste ◽  
Northern Russia ◽  
Extremes Of Temperature

Eastern Europe, extending from northern Russia to Czechoslovakia and Bulgaria, embraces a wide range of climates, all experiencing wider extremes of temperature and humidity than the maritime climates of the West. Noteworthy technological features of horticultural production include the development of walk-in plastic tunnels supported on tubular metal frames, the use of power station waste water for greenhouse heating, and the large-scale use of peat as a substrate in place of soil.

scholarly journals Sorting of Particles Using Inertial Focusing and Laminar Vortex Technology: A Review

Micromachines ◽  
2019 ◽  
Vol 10 (9) ◽  
pp. 594 ◽  
Author(s):  
Annalisa Volpe ◽  
Caterina Gaudiuso ◽  
Antonio Ancona
Keyword(s):  
Particle Sizes ◽  
Label Free ◽  
Comprehensive Overview ◽  
Efficient Manner ◽  
Medical Treatments ◽  
Inertial Focusing ◽  
Physical Mechanisms ◽  
Micro Fluidics ◽  
Wide Range ◽  
Sample Separation

The capability of isolating and sorting specific types of cells is crucial in life science, particularly for the early diagnosis of lethal diseases and monitoring of medical treatments. Among all the micro-fluidics techniques for cell sorting, inertial focusing combined with the laminar vortex technology is a powerful method to isolate cells from flowing samples in an efficient manner. This label-free method does not require any external force to be applied, and allows high throughput and continuous sample separation, thus offering a high filtration efficiency over a wide range of particle sizes. Although rather recent, this technology and its applications are rapidly growing, thanks to the development of new chip designs, the employment of new materials and microfabrication technologies. In this review, a comprehensive overview is provided on the most relevant works which employ inertial focusing and laminar vortex technology to sort particles. After briefly summarizing the other cells sorting techniques, highlighting their limitations, the physical mechanisms involved in particle trapping and sorting are described. Then, the materials and microfabrication methods used to implement this technology on miniaturized devices are illustrated. The most relevant evolution steps in the chips design are discussed, and their performances critically analyzed to suggest future developments of this technology.

scholarly journals A green chemical route for the synthesis of Mn3O4 nanoparticles

2009 ◽  
Vol 7 (3) ◽  
pp. 555-559 ◽  
Author(s):  
Zehra Durmus ◽  
Hüseyin Kavas ◽  
Abdulhadi Baykal ◽  
Muhammet Toprak
Keyword(s):  
Room Temperature ◽  
Particle Sizes ◽  
Chemical Route ◽  
Tem Analysis ◽  
X Ray ◽  
Profile Fitting ◽  
Transmission Electron ◽  
Wide Range ◽  
Long Range Interactions ◽  
Mn3o4 Nanoparticles

AbstractA novel environmental friendly, room temperature route using an ionic liquid 1-n-butyl-3-methylimidazolium hydroxide ([BMIM]OH) for the synthesis of Mn3O4 nanoparticles is presented. The product was characterized using Fourier transform infrared spectroscopy, X-ray powder diffraction, and transmission electron microscopy. Phase purity was confirmed by XRD, and X-ray line profile fitting determined a crystallite size of 42 ± 11 nm. TEM analysis revealed various morphologies. EPR measurements have indicated the existence of long-range interactions, due to the wide range of particle sizes and morphologies observed.

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