Porous Permeable Ceramics for Filter Elements Cleaning Hot Gases from Dust

The filtering characteristics (air permeability, efficiency) of porous permeable ceramic materials with different microstructures are determined. The requirements on ceramic filter elements are formulated; specifications for a module-type plant with ceramic filter elements are prepared. The use of these elements for cleaning hot gases from dust, apart from the ecological effect, yield an economic effect manifested as additional energy produced due to recovery of waste gas heat. __________ Translated from Steklo i Keramika, No. 5, pp. 14 – 18, May, 2005.     

Concentration and distribution of sixty-one elements in coals from DPR Korea

Fifty coal samples (28 anthracite and 22 lignites) were collected from both main and small coal mines in DPR Korea prioritized by resource distribution and coal production. The concentrations of 61 elements in 50 coal samples were determined by several multielement and element-specific techniques, including inductively coupled plasma atomic emission spectrometry (ICP-AES), and inductively coupled plasma mass spectrometry (ICP-MS), ion chromatogram (IC), cold-vapor atomic absorption spectrometry (CV-AAS), and hydride generation atomic absorption spectrometry (HGAAS). The ranges, arithmetic means and geometric means of concentrations of these elements are presented. A comparison with crustal abundances (Clarke values) shows that some potentially hazardous elements in the coals of DPR Korea are highly enriched Li, B, S, Cl, Zn, As, Se, Cd, Sn, Sb, W, Te, Hg, Ag, Pb, and La, Ce, Dy, Tm, Ge, Mo, Cs, Tl, Bi, Th and U are moderately enriched. A comparison of ranges and means of elemental concentrations in DPR Korea, Chinese, and world coals shows the ranges of most elements in DPR Korea coals are very close to the ranges of world coals. Arithmetic means of most elements in DPR Korea coals are close to that of American coals. Most elements arithmetic means are higher in Jurassic and Paleogene coals than coals of other ages. In DPR Korea coals, only seven elements in early Permian coals are higher than other periods: Li, Zn, Se, Cd, Hg, Pb, and Bi. Only five elements B, As, Sr, Mo, W in Neogene coals have arithmetic means higher than others. SiO₂ and Al₂O₃ in ashes are more than 70% except six samples. The correlation between ash yields and major elements from high to low is in the order of Si>Al>Ti>K>Mg>Fe>Na>Ca>P>S. Most elements have high positive correlation with ash (r>0.5) and show high inorganic affinity.     

Fine particle and trace element emissions from an anthracite coal-fired power plant equipped with a bag-house in China

Fine particle and trace element emissions from energy production are associated with significant adverse human health effects. In this investigation, the fine particles and trace elements emitted from the combustion of pulverized anthracite coal at a 220 MW power plant were determined experimentally in the size range from 30 nm to 10 μm with 12 channels. The particulate size distributions and morphological characteristics before and after the bag-house were evaluated. The uncontrolled and controlled emission factors of particles are compared with the calculated values from the US Environment Protection Agency, AP-42. Size-classified relative enrichment factors of As, Hg, Se, Cd, Cr, Cu, Al, V, Zn, Mn, Fe were obtained. Relative distributions of trace elements between bottom ash, fly ash and flue gas are determined by mass balance method. The bag-house collection efficiencies of particles and trace elements in the particulate phase are obtained. Finally, the controlled and uncontrolled emission factors of elements of different particulate size fractions are obtained, which will provide useful information for PM_2.5 and PM₁₀ emission inventory development, toxic and hazardous pollutant emission estimates and emission standards established for metal-based pollutants from a pulverized coal-fired boiler.     

Design and efficiency of sectional large-diameter diamond wheels

This paper considers the design and industrial application of a circular grinding wheel of diameter 600 mm based on a multiple-use body with a groove along its diameter in which special elements are fastened. These elements are based on a binder with a diamond-bearing surface layer and are shaped as overlapping parallelepipeds with a clearance between the cutting layers of the elements. __________ Translated from Steklo i Keramika, No. 4, pp. 29–30, April, 2006.     

Surface Diamond-Abrasive Grinding of Glass with Tools Based on Plate Elements: Fine Grinding

The authors analyze diamond-abrasive tools intended for fine grinding of flat surfaces made of optical glass, glass ceramics, or ceramics, which are based on plate-shaped elements making it possible to vary the space factor of the circular zones and the whole faceplate. The advantages of platelike faceplate elements over spotlike elements are demonstrated based on comparative studies. __________ Translated from Steklo i Keramika, No. 8, pp. 26 – 28, August, 2005.     

Separation of Rare-Earth Elements from Apatite

Abstract

Current interest in apatite deposits as possible economic sources for rare-earth elements (1, 2) focuses attention on the problems concerning separation of these elements from solutions containing a large amount of calcium phosphate. In this connection Werner et al. (3, 4) have investigated the extraction of these elements from nitric acid solutions of Kola-apatite by tri-isobutylphosphate and have shown that this extraction is possible from nitric acid of a high acidity. A consideration of available extraction data (5) on the system tri-n-butylphosphat (TBP)-nitric acid shows that a group separation of the rare-earth elements (in addition to a few other elements such as zirconium and hafnium) could be performed by liquid-liquid extraction. If, however, an extraction chromatographic column is used with TBP as the stationary phase, it can also be expected that the rare earth will be absorbed fiom apatite dissolved in strong nitric acid media, while most of the other ions present are not absorbed and can be removed by washing with strong nitric acid. The distribution coefficients of rare-earth elements in this system are not only high, but also show large enough variation to obtain a fractional sepaIation of these elements, or at least some of the heavier ones, by further elution with nitric acid of lower acidity.     

Mineral matter identification in some Pakistani coals

Extractions of some of the inorganic elements from Pakistani coal samples were made with ammonium acetate, HCl, HNO₃, and acid mixture. The various extracts and the residues were analyzed for the inorganic elements like Cu, Zn, Mn, Fe, Ca, Mg, K and Na. Even though ammonium acetate and acids extracted a considerable amount of inorganic elements, complete demineralization was not achieved. These elements are present both in the form of ion exchangeable cations (extractable with ammonium acetate) and as part of discrete-mineral particles (extractable with acids).     

Accumulation of trace elements in coals from various basins of Russia

The average concentrations of trace elements in coals from the South Fergana, North Sos’va, Kizelovsk, South Yakutian, Transbaikalia, Pechora, and Zyryansk deposits and some deposits of the Kuznetsk and Primor’e Basins are compared. The degrees of trace element concentration were calculated both on a total coal weight basis (Q _i ) for individual basins and on a mineral matter basis (Q _i ^A ) with reference to Clarke numbers in clay rocks. Ratios between the concentrations of typomorphic trace elements on a coal mineral matter basis were calculated for the deposits of basins with different geologic-geochemical formation conditions (X _i ^A ); the concentration ratios between the pairs of typomorphic trace elements in the considered coal basins (Z _i ) were also calculated. Typomorphic elements are the trace elements with Q _i > 1.4 or Q _i ^A > 2. Coal basins of different origin have different numbers of typomorphic trace elements calculated in terms of the parameter Q _i and, to a lesser degree, the parameter Q _i ^A . Coal basins differ considerably from each other in both the ratios between the average concentrations of the same trace element in the mineral matter of coal (parameter X _i ^A ) and the ratios between the concentrations of two different trace elements (parameter Z _i ). In the basins under discussion, the mineral matter of coals from formations created in areal rift genesis regions, in particular, Triassic-Jurassic coals and, to a lesser degree, Carboniferous coals, are enriched in trace elements to the greatest extent. Coals from subgeosynclinal formations have a maximum number of typomorphic trace elements (in terms of the average concentrations in the mineral matter), practically the majority of the test elements with the exception of Nb, Sn, Ni, and Sc. Coals from young mobile platforms are characterized by a similar number of typomorphic trace elements with the exception of Nb, Zn, Y, and Yb. Coals from geosynclinal formations have a somewhat smaller set of typomorphic trace elements, whereas a minimum number of typomorphic elements is characteristic of coals from platform basins.     

Feasibility of the Detection of Trace Elements in Particulate Matter Using Online High-Resolution Aerosol Mass Spectrometry

The feasibility of using an online thermal-desorption electron-ionization high-resolution aerosol mass spectrometer (HR-AMS) for the detection of particulate trace elements was investigated by analyzing data from Mexico City obtained during the MILAGRO 2006 field campaign. This potential application is of interest due to the real-time data provided by the AMS, its high sensitivity and time resolution, and the widespread availability and use of this instrument. High-resolution mass spectral analysis, isotopic ratios, and ratios of different ions containing the same elements are used to constrain the chemical identity of the measured ions. The detection of Cu, Zn, As, Se, Sn, and Sb is reported. There was no convincing evidence for the detection of other trace elements commonly reported in ambient particulate matter (PM). The elements detected tend to be those with lower melting and boiling points, as expected given the use of a vaporizer at 600°C in this instrument. The detection limit (DL) is estimated at approximately 0.3 ng m^?3 for 5 min of data averaging. Concentration time series obtained from the AMS data were compared to concentration records determined from offline analysis of particle samples from the same times and locations by inductively coupled plasma based techniques (ICP; PM_2.5) and proton-induced X-ray emission (PIXE; PM_1.1 and PM_0.3). The degree of correlation and agreement between the three instruments (AMS, ICP, and PIXE) varied depending on the element. The AMS shows promise for real-time detection of some trace elements, although additional work including laboratory calibrations with different chemical forms of these elements is needed to further develop this technique and to understand the differences with the ambient data from the other techniques. The trace elements peaked in the morning as expected for primary sources, and the many detected plumes suggest the presence of multiple point sources, probably industrial, in Mexico City, which are variable in time and space, in agreement with previous studies.

Copyright 2012 American Association for Aerosol Research     

Homogeneity of multilayers produced with a static mixer

A multiflux static mixer can be used to produce multilayered structures. The flow is repeatedly cut, stretched and stacked by mixing elements in the channel of such a device. In the standard design, however, the obtained layer thicknesses are inhomogeneous. The causes for the multiflux static mixer's deviation from ideal behavior are identified by 3D numeical simulations as unequal pressure drops in the separating flows. Changes in the arrangements of the elements are proposed and their effects are verified by simulations and experiments. A significant improvement of the layer homogeneity is achieved by introducing additional elements with separatings walls at the inlets and at the outlets of the mixing elements.     

Interaction of a metallic liner with lumped elements and transfer of perturbations over these elements

Results of an experimental and numerical study of interaction of a metallic liner accelerated by an explosion to a velocity of several kilometers per second with lumped elements in the form of plates are presented. Parameters of perturbations transferred over these elements are quantified. __________ Translated from Fizika Goreniya i Vzryva, Vol. 44, No. 6, pp. 107–113, November–December, 2008.     

Theory on colloidal double-layer interactions

The potential energy between two interacting colloidal particles is derived by a knowledge of the energy of interaction of two parallel flat plates. The proposed method maps pairs of infinitesimal surface elements from the two interacting bodies to parallel plate-like elements. The results obtained from this theory are compared with the Derjaquin approximation for large kR and the Levine and Dube approximation for small kR.     

叶面肥专用黄腐酸类物质的应用与筛选

在实验室对不同来源的腐植酸类物质进行了溶解能力、与微量元素的复配能力以及生物活性等性能的检验,结果表明,不同表源的腐植酸物质溶解性能有很大差异,与微量元素复合配置高水溶性营养液,表现出不同的沉淀性能,各物质均表现出一定的生物活性.通过对不同腐植酸产品性能的研究,给出了应用最终的筛选结论.     

Elements of gas cleaning and dust removal systems lined with refractory concretes

Principles are considered for the construction of concrete linings for furnaces, gas ducts, cyclones and other elements of gas cleaning and dust removal systems subject to the action of high temperature, chemically corrosive gases, and abrasive wear. Examples are provided of manufacturing lined elements of gas cleaning systems made of refractory concretes in various branches of industry. __________ Translated from Novye Ogneupory, No. 11, pp. 15–19, November 2007.     

Characterization of flue gas desulfurization particulates in equalization basins

Particulates in pilot-scale flue gas desulfurization (FGD) scrubber water were characterized by powder X-ray diffraction, scanning electron microscopy with energy dispersive spectroscopy, and size analysis based on Stokes’ Law after settling in an equalization basin of a pilot-scale constructed wetland treatment system. Three sources were interpreted for specific particle types identified in samples analyzed: FGD wet scrubbing processes, coal combustion byproducts, and uncombusted material from coal. Gypsum (CaSO₄ · 2H₂O) from the FGD scrubbing process comprises ∼95% of the particulates. Iron oxide particles and cenospheres in the particulate samples are interpreted as coal combustion products. Particles interpreted as originating from unburned coal contain carbon and metals including Zn and Fe. The most abundant elements in the particulates analyzed are O, C, Ca, S, Fe, and Si, with maximum mean content of individual elements ranging from 13% to 70% among particle types. Less abundant elements include Al, K, Mg, Ti, and Mo, with maximum mean content from 0.1% to 3.8%.     

Thermodynamic equilibrium study of trace element mobilisation under pulverised fuel combustion conditions

The thermodynamic equilibrium distributions of the trace elements lead, arsenic, zinc, copper, nickel, chromium, manganese and boron have been examined using the factwin computational software and associated databases. It is found that the facility for simulation of these elements in a comprehensive model of the oxide melt formed by the major coal mineral elements and (in the early stages of combustion) in an extended sulphide melt model enhances the value of the predictions over those for earlier restricted fact melt models. This is emphasised by comparison with the limitations of predictions for strontium, barium and vanadium, for which no solution models are available in factwin. The influence of sulphur and chlorine concentration variations on the mobilities of the elements varies, and can differ markedly between oxidising and reducing conditions. The predictions are extensively compared with published partitioning results calculated from experimental observations on large combustors. Given the uncertainties involved in both observations and predictions, the degree of agreement is considered satisfactory. The condensation sequence from the equilibrium gas phase at 1300 K has been predicted on cooling, in isolation, by 10 K steps. An alkali sulphate-based melt is predicted to form, and the majority of the other elements are predicted to form sulphates, implying development of a complex sulphate melt, which cannot at present be modelled.     

Crystal structure and lithium ionic transport behavior of Li site doped Li7La3Zr2O12

Doping some elements on Li site of LLZO is an effective method to stabilize it as cubic phase and improve Li⁺ conductivity. The reported possible Li site elements calculated by first principle are Be, B, Al, Fe, Zn, Ga and the Ga-doped LLZO shows the a higher conductivity than other LLZO. However, whether these elements all can stable LLZO as cubic phase are needed to be verified and the reason of Ga exhibits higher conductivity is not clear enough. In this work, all these elements are tried to be doped on Li site and the results show that the Al, or Fe, or Ga can stable LLZO as cubic phase while the others does not. The Ga-doped LLZO exhibits the highest conductivity of 1.31×10⁻³ S•cm^-1 due to the transform of group space from Ia-3d to I-43d, shorter distances between different Li⁺, and Ga can improve the grain size.     

Mineral matter and elemental concentrations in selected western canadian coals

Major and trace element analyses were performed on coals from various locations in western Canada, and on low-temperature (150 °C) and high-temperature (1000 °C) coal ash produced from these coals. Elemental analyses were carried out by X-ray fluorescence spectroscopy and intense neutron activation analyses. Based on their trace elements, the coals in this study fall into two groups: 1. low-rank coals (lignite-subbituminous) of late Cretaceous and Tertiary age; and 2. high-rank coal (bituminous-semianthracite) of Jurassic-Cretaceous age. The elemental analyses of the coals and coal ash indicate that the local conditions had considerable influence on the concentrations of certain trace elements.Antimony and selenium in coals are the only elements which are enriched relative to concentrations in the earth's crust; arsenic is concentrated in lignite to subbituminous coal, but is depleted in bituminous-anthracite coals; as expected the ash of these coals showed many more instances of enrichment.     

Trace element geochemistry of the Obed Mountain deposit coals, Alberta, Canada

This study reports on the elemental concentrations and vertical variation of coal seams from the Obed Mountain deposit, Alberta Foothills, Canada. Results from two sections of Seam 1 show that the major elements (i.e. Al, Fe, Mg, K, Na, Ti, and Si) have high concentrations in intervals having high ash content, with the only exception of Ca. Similarities are apparent, in both sections, in the vertical variations of Th, U, Se, and Zn; Rb, Cs, and K; Sb, Mo, and W; Mn and Sr; and Ba, Cr, Co, Hf, and Sc. These similarities are also evident among the REEs, notably between Ce and La; also between Dy, Eu, and Sm. Most elements, with the exception of Ba and Sr are slightly more concentrated in Section 2 of Seam 1, located approximately 1.5Fig. km away from Section 1. Compared to Seam 1, Seam 2 has lower mean concentrations of elements. Boron in the coal ranges from 27 to 100 ppmw, though most values are less than 50 ppmw. Boron concentrations suggest a freshwater depositional environment. The element is depleted in the sedimentary partings (12–29 ppmw only) and is enriched in the coal interval near the roof and immediately beneath the partings. This enrichment shows possible downward mobilization of boron. Vertical variations of elements are helpful in delineating the boundaries between coal and sedimentary partings in the succession. The Obed Mountain coals are “clean” by world standards and their elemental concentrations are comparable with those in coals of a lower rank from the same coal formation used for power generation in Alberta. All sedimentary partings have low concentrations of Ba, Hf, Sc, Sr, Ta, Th, U, and REEs; this, along with the absence of an Eu negative anomaly suggests a non-volcanic origin for the partings.     

Physical bases of quasi-isostatic compaction of powder materials

The physical bases of quasi-isostatic compaction and the kinetics of elastically compacting elements in a pressing regime are studied, making it possible to establish the reasons for compact breakage and to create in molds a reliable construction for anti-breakage devices providing preparation of unbroken articles and high quality. A design theory is developed for scale dimensions of compacting elements. Calculation equations are provided for their original dimensions. Translated from Novye Ogneupory, No. 2, pp. 12–17, February 2009.