Comparison of short-term and long-term performances for polymer-stabilized sand and clay

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Sepehr Rezaeimalek

2017-04-01

Full Text Available A series of tests were carried out on sulfate rich, high-plasticity clay and poorly-graded natural sand to study the effectiveness of a methylene diphenyl diisocyanate based liquid polymer soil stabilizer in improving the unconfined compressive strength (UCS of freshly stabilized soils and aged sand specimens. The aged specimens were prepared by exposing the specimens to ultraviolet radiation, freeze-thaw, and wet-dry weathering. The polymer soil stabilizer also mitigated the swelling of the expansive clay. For clay, the observations indicated that the sequence of adding water and liquid polymer had great influence on the gained UCS of stabilized specimens. However, this was shown to be of little importance for sand. Furthermore, sand samples showed incremental gains in UCS when they were submerged in water. This increase was significant for up to 4 days of soaking in water after 4 days of ambient air curing. Conversely, the clay samples lost a large fraction of their UCS when soaked in water; however, their remaining strength was still considerable. The stabilized specimens showed acceptable endurance under weathering action, although sample yellowing due to ultraviolet radiation was evident on the surface of the specimens. Except for moisture susceptibility of the clay specimens, the results of this study suggested the liquid stabilizer could be successfully utilized to provide acceptable strength, durability and mitigated swelling.

Coliquefaction of coal, tar sand bitumen and plastic (interaction among coal, bitumen and plastic); Sekitan/tar sand bitumen/plastic no kyoekika ni okeru kyozon busshitsu no eikyo

Energy Technology Data Exchange (ETDEWEB)

Yamaguchi, H.; Okuyama, Y.; Matsubara, K. [NKK Corp., Tokyo (Japan); Kamo, T.; Sato, Y. [National Institute for Resources and Environment, Tsukuba (Japan)

1996-10-28

For the improvement of economy, coliquefaction of coal, tar sand bitumen and plastic was performed under low hydrogen pressure, to investigate the influence of interaction among these on the liquefaction characteristics. For comparison, coliquefaction was also performed under the hydrogen pressure same as the NEDOL process. In addition, for clarifying its reaction mechanism, coliquefaction of dibenzyl and plastic was performed as a model experiment, to illustrate the distribution of products and composition of oil, and to discuss the interaction between dibenzyl and various plastics, and between various plastics. Under direct coal liquefaction conditions, coprocessing of Tanito Harum coal, Athabasca tar sand and plastic was carried out under low hydrogen pressure with an autoclave. The observed value of oil yield was higher than the calculated value based on the values from separate liquefaction of coal and plastic, which suggested the interaction between coal and the mixed plastic. The results of coliquefaction of coal, tar sand bitumen and plastic could be explained from the obtained oil yield and its composition by the coliquefaction of dibenzyl and plastic. 2 refs., 3 tabs.

Effect of mechanical and chemical clay removals by hydrocyclone and dispersants on coal flotation

Energy Technology Data Exchange (ETDEWEB)

Oats, W.J.; Ozdemir, O.; Nguyen, A.V. [University of Queensland, Brisbane, Qld. (Australia). School of Chemical Engineering

2010-04-15

Fine minerals, mostly clays, are known to have a detrimental effect on coal flotation. This paper focuses on the effect of mechanical and chemical removals of fine minerals by hydrocyclone and dispersants on coal flotation. The experimental results showed that the flotation recovery slightly increased from medium acidic to medium alkaline ranges. The flotation experiments carried out with dispersants at different dosages showed that the dispersants did not enhance the flotation recovery significantly. However, the removal of the fine fraction from the feed using a hydrocyclone significantly increased the flotation recovery. The bubble-particle attachment tests also indicated that the attachment time between an air bubble and the coal particles increased in the presence of clay particles. These attachment time results clearly showed that the clay particles adversely affected the flotation of coal particles by covering the coal surfaces which reduced the efficiency of bubble-coal attachment. An analysis based on the colloid stability theory showed that the clay coating was governed by the van der Waals attraction and that the double-layer interaction played a secondary role. It was also concluded that the best way to increase the flotation recovery in the presence of clays was to remove these fine minerals by mechanical means such as hydrocylones.

Sorption of Cesium on smectite-rich clays from the Bohemian Massif (Czech Republic) and their mixtures with sand.

Science.gov (United States)

Vejsada, J; Jelínek, E; Randa, Z; Hradil, D; Prikryl, R

2005-01-01

Sorption is an important process for the transport of radionuclides through backfill materials in a radioactive waste underground repository. Within this study, sorption of Cs on selected Czech clay materials and their mixtures with sand was investigated by batch tests. The experiments were performed under oxic conditions at 25 degrees C. Synthetic groundwater as a liquid phase and unconditioned clays (as they were provided by their producer) were used to reach the natural conditions as close as possible. Distribution ratios (Rds) of Cs for all selected clays rise with increase of the clay fraction in clay/sand mixtures in agreement with previous works studying sorption behaviour of such mixtures. The rise of Rds is from 10(2) cm3 g(-1) for mixtures with 80% of sand to 10(3) cm3 g(-1) for pure clays. There are significant differences between natural and technologically modified clays.

The Influences of a Clay Lens on the Hyporheic Exchange in a Sand Dune

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Chengpeng Lu

2018-06-01

Full Text Available A laboratory flume simulating a riverbed sand dune containing a low-permeability clay lens was constructed to investigate its influence on the quality and quantity of hyporheic exchange. By varying the depths and spatial locations of the clay lens, 24 scenarios and one blank control experiment were created. Dye tracers were applied to visualize patterns of hyporheic exchange and the extent of the hyporheic zone, while NaCl tracers were used to calculate hyporheic fluxes. The results revealed that the clay lens reduces hyporheic exchange and that the reduction depends on its spatial location. In general, the effect was stronger when the lens was in the center of the sand dune. The effect weakened when the lens was moved near the boundary of the sand dune. A change in horizontal location had a stronger influence on the extent of the hyporheic zone compared with a change in depth. The size of the hyporheic zone changed with the depth and position of the clay lens. There was a maximum of hyporheic extent with the lens at a depth of 0.1 m caused by changes of water flow paths.

Depositional history of the Fire Clay coal bed (Late Duckmantian), Eastern Kentucky, USA

Science.gov (United States)

Greb, S.F.; Eble, C.F.; Hower, J.C.

1999-01-01

More than 3800 coal thickness measurements, proximate analyses from 97 localities, and stratigraphic and sedimentological analyses from more than 300 outcrops and cores were used in conjunction with previously reported palynological and petrographic studies to map individual benches of the coal and document bench-scale variability in the Fire Clay (Hazard No. 4) coal bed across a 1860 km2 area of the Eastern Kentucky Coal Field. The bench architecture of the Fire Clay coal bed consists of uncommon leader benches, a persistent but variable lower bench, a widespread, and generally thick upper bench, and local, variable rider benches. Rheotrophic conditions are inferred for the leader benches and lower bench based on sedimentological associations, mixed palynomorph assemblages, locally common cannel coal layers, and generally high ash yields. The lower bench consistently exhibits vertical variability in petrography and palynology that reflects changing trophic conditions as topographic depressions infilled. Infilling also led to unconfined flooding and ultimately the drowning of the lower bench mire. The drowned mire was covered by an air-fall volcanic-ash deposit, which produced the characteristic flint clay parting. The extent and uniform thickness of the parting suggests that the ash layer was deposited in water on a relatively flat surface without a thick canopy or extensive standing vegetation across most of the study area. Ash deposits led to regional ponding and establishment of a second planar mire. Because the topography had become a broadly uniform, nutrient-rich surface, upper-bench peats became widespread with large areas of the mire distant to clastic sources. Vertical sections of thick (> 70 cm), low-ash yield, upper coal bench show a common palynomorph change from arborescent lycopod dominance upward to fern and densospore-producing, small lycopod dominance, inferred as a shift from planar to ombrotrophic mire phases. Domed mires appear to have been

Characterization of sands and mineral clays in channel and floodplain deposits of Portuguesa river, Venezuela

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Orlando José González Clemente

2013-11-01

Full Text Available In the main channel and floodplain of Portuguesa River were studied the mineralogical characteristics of sand and clay minerals respectively. The methodology consisted of X-ray diffraction (XRD analysis, for both mineral fractions. The results indicated the presence of mainly of quartz sands with minor amounts of chlorite, muscovite, calcite and feldspar which are considered quartz sand mature. Its origin is related to the source area and rework of soils and sediments of the floodplain. The clay fraction is characterized by the presence of 13 mineral crystalline phases consisting mainly of quartz, muscovite and chlorite, and clay minerals such as kaolinite, vermiculite, montmorillonite and nontronita. Its detrital origin may be due to mineral neoformation and inheritance. Therefore both mineral fractions consist mainly of quartz and kaolinite, which are essential components of the source area as well as the Quaternary alluvial deposits and the soils that make up the region.

Methane Hydrate Formation and Dissociation in the Presence of Silica Sand and Bentonite Clay

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Kumar Saw V.

2015-11-01

Full Text Available The formation and dissociation of methane hydrates in a porous media containing silica sand of different sizes and bentonite clay were studied in the presence of synthetic seawater with 3.55 wt% salinity. The phase equilibrium of methane hydrate under different experimental conditions was investigated. The effects of the particle size of silica sand as well as a mixture of bentonite clay and silica sand on methane hydrate formation and its dissociation were studied. The kinetics of hydrate formation was studied under different subcooling conditions to observe its effects on the induction time of hydrate formation. The amount of methane gas encapsulated in hydrate was computed using a real gas equation. The Clausius-Clapeyron equation is used to estimate the enthalpy of hydrate dissociation with measured phase equilibrium data.

Mixtures of coal ash and compost as substrates for highbush blueberry

Energy Technology Data Exchange (ETDEWEB)

Black, B.L.; Zimmerman, R.H. [ARS, Beltsville, MD (USA). USDA Henry A Wallace Beltsville Agriculture Research Center, Fruit Lab.

2002-07-01

Bottom ash from a coal-fired power plant and two composts were tested as components of soil-free media and as soil amendments for growing highbush blueberry (Vaccinium corymbosum L.). Combinations of ash and compost were compared to Berryland sand, and Manor clay loam, and compost amended Manor clay loam. The pH of all treatment media was adjusted to 4.5 with sulfur at the beginning of the experiment. In 1997, plants of 'Bluecrop' and 'Sierra' were planted in 15-dm{sup 3} pots containing the pH-adjusted treatment media. The first substantial crop was harvested in 1999. At the end of the 1999 season, one half of the plants were destructively harvested for growth analysis. The remaining plants were cropped again in 2000. Yield and fruit size data were collected in both seasons, and leaf and fruit samples were collected in 1999 for elemental analysis. The presence of coal ash or composted biosolids in the media had no detrimental effect on leaf or fruit elemental content. Total growth and yield of both cultivars was reduced in clay loam soil compared to Berryland sand, whereas growth and yield of plants in coal ash-compost was similar to or exceeded that of plants in Berryland sand.

Permeability Characteristics of Compacted and Stabilized Clay with Cement, Peat Ash and Silica Sand

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Seyed Esmaeil Mousavi

2016-06-01

Full Text Available The present paper investigates the influence of stabilization with cement, peat ash, and silica sand on permeability coefficient (kv of compacted clay, using a novel approach to stabilize the clay with peat ash as a supplementary material of cement in the compacted and stabilized soil. In order to assess the mentioned influence, test specimens of both untreated and stabilized soil have been tested in the laboratory so that their permeability could be evaluated. Falling head and one dimensional consolidation tests of laboratory permeability were performed on the clay specimens and the chemical compositions of the materials as well as microstructure of the stabilized soil with 18% cement, 2% peat ash, and 5% silica sand were investigated, using X-ray fluorescence and scanning electron microscopy respectively. Results show that for soil stabilization with up to 8% cement content (of the dry weight of the soil, the average value of coefficient of permeability (kv is very close to that of untreated soil, whereas the kv value decreases drastically for 18% cement under identical void ratio conditions. It is further revealed that addition of 18% cement, 2% peat ash, and 5% silica sand had decreased the coefficient of permeability by almost 2.2 folds after 24 h, while about 1.7 folds increase was observed in coefficient of permeability once 13.5% of cement, 1.5% of peat ash, and 20% of silica sand were added. The partial replacement of cement with the 2% peat ash can reduce the consumption of cement for soil stabilization.

Distribution of clay minerals in the process streams produced by the extraction of bitumen from Athabasca oil sands

Energy Technology Data Exchange (ETDEWEB)

Kaminsky, H.A.W.; Etsell, T.H.; Ivey, D.G. [Alberta Univ., Edmonton, AB (Canada). Dept. of Chemical and Materials Engineering; Omotoso, O. [Natural Resources Canada, Devon, AB (Canada). CETC

2009-02-15

The clay minerals present in the oil sands were studied with particular reference to how they are partitioned in bitumen ore during the extraction process. Bitumen production from surface-mined oil sands accounts for nearly two-thirds of the total bitumen production in Alberta. Every cubic meter of mined ore results in 1.3 cubic meters of mature fine tailings (MFT). The characteristic differences between the clay minerals that report to the froth versus the tailings streams were also examined to determine which minerals could impact different unit operations in the bitumen extraction process. X-ray diffraction and random powder samples were used to quantify the clay minerals. Particle size distribution and clay activity balances were also conducted. The degree of partitioning during the conditioning and flotation stages in a batch extractor was determined by the surface properties of the clay minerals. The water-continuous tailings stream was separated into fine and coarse tailings fractions through sedimentation. The study showed that bitumen-clay interactions may be dominated by kaolinite or iron oxides. Clays are responsible for the poor settling behaviour of MFTs. The clay minerals present in the oil sands include illite, illite-smectite, kaolinite, kaolinite-smectite, and chlorite. The close proximity of the tailings ponds to the Athabasca River and volatile organic compounds (VOCs) emission require that the ponds be reclaimed to a natural landscape before mine closure. In addition to its impact on fine tailings reclamation, clay mineralogy plays a role in extraction froth flotation and emulsion stability during froth treatment. The mineralogy of the froth solids was found to be different from the mineralogy of the middlings and tailings solids. 39 refs., 6 tabs., 6 figs.

A Visual Basic program to classify sediments based on gravel-sand-silt-clay ratios

Science.gov (United States)

Poppe, L.J.; Eliason, A.H.; Hastings, M.E.

2003-01-01

Nomenclature describing size distributions is important to geologists because grain size is the most basic attribute of sediments. Traditionally, geologists have divided sediments into four size fractions that include gravel, sand, silt, and clay, and classified these sediments based on ratios of the various proportions of the fractions. Definitions of these fractions have long been standardized to the grade scale described by Wentworth (1922), and two main classification schemes have been adopted to describe the approximate relationship between the size fractions.Specifically, according to the Wentworth grade scale gravel-sized particles have a nominal diameter of ⩾2.0 mm; sand-sized particles have nominal diameters from <2.0 mm to ⩾62.5 μm; silt-sized particles have nominal diameters from <62.5 to ⩾4.0 μm; and clay is <4.0 μm. As for sediment classification, most sedimentologists use one of the systems described either by Shepard (1954) or Folk (1954, 1974). The original scheme devised by Shepard (1954) utilized a single ternary diagram with sand, silt, and clay in the corners to graphically show the relative proportions among these three grades within a sample. This scheme, however, does not allow for sediments with significant amounts of gravel. Therefore, Shepard's classification scheme (Fig. 1) was subsequently modified by the addition of a second ternary diagram to account for the gravel fraction (Schlee, 1973). The system devised by Folk (1954, 1974) is also based on two triangular diagrams (Fig. 2), but it has 23 major categories, and uses the term mud (defined as silt plus clay). The patterns within the triangles of both systems differ, as does the emphasis placed on gravel. For example, in the system described by Shepard, gravelly sediments have more than 10% gravel; in Folk's system, slightly gravelly sediments have as little as 0.01% gravel. Folk's classification scheme stresses gravel because its concentration is a function of

Water repellency of clay, sand and organic soils in Finland

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K. RASA

2008-12-01

Full Text Available Water repellency (WR delays soil wetting process, increases preferential flow and may give rise to surface runoff and consequent erosion. WR is commonly recognized in the soils of warm and temperate climates. To explore the occurrence of WR in soils in Finland, soil R index was studied on 12 sites of different soil types. The effects of soil management practice, vegetation age, soil moisture and drying temperature on WR were studied by a mini-infiltrometer with samples from depths of 0-5 and 5-10 cm. All studied sites exhibited WR (R index >1.95 at the time of sampling. WR increased as follows: sand (R = 1.8-5.0 < clay (R = 2.4-10.3 < organic (R = 7.9-undefined. At clay and sand, WR was generally higher at the soil surface and at the older sites (14 yr., where organic matter is accumulated. Below 41 vol. % water content these mineral soils were water repellent whereas organic soil exhibited WR even at saturation. These results show that soil WR also reduces water infiltration at the prevalent field moisture regime in the soils of boreal climate. The ageing of vegetation increases WR and on the other hand, cultivation reduces or hinders the development of WR.;

The coal deposits of the Alkali Butte, the Big Sand Draw, and the Beaver Creek fields, Fremont County, Wyoming

Science.gov (United States)

Thompson, Raymond M.; White, Vincent L.

1952-01-01

Large coal reserves are present in three areas located between 12 and 20 miles southeast of Riverton, Fremont County, central Wyoming. Coal in two of these areas, the Alkali Butte coal field and the Big Sand Draw coal field, is exposed on the surface and has been developed to some extent by underground mining. The Beaver Creek coal field is known only from drill cuttings and cores from wells drilled for oil and gas in the Beaver Creek oil and gas field.These three coal areas can be reached most readily from Riverton, Wyo. State Route 320 crosses Wind River about 1 mile south of Riverton. A few hundred yards south of the river a graveled road branches off the highway and extends south across the Popo Agie River toward Sand Draw oil and gas field. About 8 miles south of the highway along the Sand Draw road, a dirt road bears east and along this road it is about 12 miles to the Bell coal mine in the Alkali Butte coal field. Three miles southeast of the Alkali Butte turn-off, 3 miles of oiled road extends southwest into the Beaver Creek oil and gas field. About 6 miles southeast of the Beaver Creek turn-off, in the valley of Little Sand Draw Creek, a dirt road extends east 1. mile and then southeast 1 mile to the Downey mine in the Big Sand Draw coal field. Location of these coal fields is shown on figure 1 with their relationship to the Wind River basin and other coal fields, place localities, and wells mentioned in this report. The coal in the Alkali Butte coal field is exposed partly on the Wind River Indian Reservation in Tps. 1 and 2 S., R. 6 E., and partly on public land. Coal in the Beaver Creek and Big Sand Draw coal fields is mainly on public land. The region has a semiarid climate with rainfall averaging less than 10 in. per year. When rain does fall the sandy-bottomed stream channels fill rapidly and are frequently impassable for a few hours. Beaver Creek, Big Sand Draw, Little Sand Draw, and Kirby Draw and their smaller tributaries drain the area and flow

Permeability Characteristics of Compacted and Stabilized Clay with Cement, Peat Ash and Silica Sand

OpenAIRE

Seyed Esmaeil Mousavi; Leong Sing Wong

2016-01-01

The present paper investigates the influence of stabilization with cement, peat ash, and silica sand on permeability coefficient (kv) of compacted clay, using a novel approach to stabilize the clay with peat ash as a supplementary material of cement in the compacted and stabilized soil. In order to assess the mentioned influence, test specimens of both untreated and stabilized soil have been tested in the laboratory so that their permeability could be evaluated. Falling head and one dimension...

Deposition of Suspended Clay to Open and Sand-Filled Framework Gravel Beds in a Laboratory Flume

Science.gov (United States)

Mooneyham, Christian; Strom, Kyle

2018-01-01

Pulses of fine sediment composed of sand, silt, and clay can be introduced to gravel bed rivers through runoff from burn-impacted hillslopes, landslides, bank failure, or the introduction of reservoir sediment as a result of sluicing or dam decommissioning. Here we present a study aimed at quantifying exchange between suspensions of clay and gravel beds. The questions that motivate the work are: how do bed roughness and pore space characteristics, shear velocity (u∗), and initial concentration (C0) affect clay deposition on or within gravel beds? Where does deposition within these beds occur, and can deposited clay be resuspended while the gravel is immobile? We examine these questions in a laboratory flume using acrylic, open-framework gravel, and armored sand-gravel beds under conditions of varying u∗ and C0. Deposition of clay occurred to all beds (even with Rouse numbers ˜ 0.01). We attribute deposition under full suspension conditions to be an outcome of localized protected zones where clay can settle and available pore space in the bed. For smooth wall cases, protection came from the viscous wall region and the development of bed forms; for the rough beds, protection came from separation zones and low-velocity pore spaces. Bed porosity was the strongest influencer of nondimensional deposition rate; deposition increased with porosity. Deposition was inversely related to u∗ for the acrylic bed runs; no influence of u∗ was found for the porous bed runs. Increases in discharge resulted in resuspension of clay from acrylic beds; no resuspension was observed in the porous bed runs.

Determining the degree of break up of coal strata and clay interlayers by looseners at the Chukurovo pit

Energy Technology Data Exchange (ETDEWEB)

Atanasov, A B; Stoyanov, D S; Yordanov, Y M

1983-01-01

One of the rational technologies for selective mining of thin coal strata with complex geological structure is that one in which different types of mechanical looseners are used. Identification of the degree of break up of the rock is accomplished most rapidly and precisely using seismoacoustical methods. The evaluation is conducted relative to the speed of propagation of elastic waves in the mass. SVM seismic receivers were used at the Chukurovo pit to determine the speed of propagation of an elastic wave in coals and clays. Shafts 10 meters long were drilled in three experimental fields using the SVB-2 machine. The speed of propagation of an elastic wave in the coals and in sandy clays was determined for different shaft depths every meter. After comparing the obtained results with standard tables from different companies, the possibility of breaking up the coal and clay interlayers in the experimental sectors by looseners with motors different in type and capacity was determined.

Use of clay-mineral alteration patterns to define syntectonic permeability of joints (cleat) in Pennsylvania anthracite coal

Energy Technology Data Exchange (ETDEWEB)

Daniels, E.J.; Marshak, S.; Altaner, S.P. [Chevron Oil Field Research Company, La Habra, CA (United States)

1996-10-15

Joints (cleat) in Pennsylvania anthracite contain two distinct clay-mineral assemblages, both of which formed by alteration of preexisting kaolinite at peak metamorphic conditions during the Alleghanian orogeny. The first assemblage, NH{sub 4} - illite or pyrophyllite {+-} quartz, formed by reaction of kaolinite with methane-rich fluids derived from within the coal. The second assemblage, sudoite {+-} tosudite {+-} rectorite {+-} berthierine, formed by the reaction of kaolinite with ferromagnesian-bearing hydrothermal fluids which must have come from outside the coal. In an earlier paper, the authors suggested that the first assemblage indicated clay diagenesis in low-permeability environments, and that the second assemblage indicated clay diagenesis in high-permeability environments. If this premise is correct, then the distribution of clay-mineral alteration assemblages serves to define syntectonic permeability variations in coal cleat. The first assemblage dominates in the coal matrix itself, in isolated cleat, in cleat that parallel the regional trend of Alleghanian folds, and in the mirror portions of cleat oriented perpendicular to the fold trends, suggesting that these regions are low-permeability environments. The second assemblage dominates in the hackle fringe of interconnected cleat that trend perpendicular to the strike of the Appalachian orogen, suggesting that these regions are high-permeability environments. These results emphasize that syntectonic cleat permeability is a function of cleat orientation, macroscopic cleat interconnetivity and orientation, as well as microscopic cleat-surface morphology.

Test work of sand compaction pile method on coal ash soil foundation. Sekitanbai jiban ni okeru sand compaction pile koho no shiken seko

Energy Technology Data Exchange (ETDEWEB)

Goto, K.; Maeda, S.; Shibata, T. (The Kansai Electric Power Co. Inc., Osaka (Japan))

1992-01-25

As an electric power supply source after the 1990 {prime}s, Nos. 5 and 6 units are additionally being constructed by Kansai Electric Power in its Himeji Power Station No.1 which is an exclusively LNG burning power station. The additional construction site of those units is of soil foundation reclaimed with coal ash which was used residual product in the existing No.1 through No.4 units. As a result of soil foundation survey, the coal ash layer and sand layer were known to be of material to be possibly liquidized at the time of earthquake. As measures against the liquidization, application was basically made of a sand compaction pile (SCP) method which is economical and abundant in record. However, that method was so short of record in the coal ash layer that its evaluation was difficult in soil reforming effect. Therefore, its applicability was evaluated by a work test on the site, which resulted in a confirmation that the coal ash as well as the sand can be sufficiently reformed by the SCP method. Started in September, 1991, the additional construction of Nos. 5 and 6 units in Himeji Power Station No.1 uses a 1.5m pitch SCP method to reform the soil foundation. 3 refs., 10 figs., 1 tab.

Modeling spatial variability of sand-lenses in clay till settings using transition probability and multiple-point geostatistics

DEFF Research Database (Denmark)

Kessler, Timo Christian; Nilsson, Bertel; Klint, Knud Erik

2010-01-01

(TPROGS) of alternating geological facies. The second method, multiple-point statistics, uses training images to estimate the conditional probability of sand-lenses at a certain location. Both methods respect field observations such as local stratigraphy, however, only the multiple-point statistics can...... of sand-lenses in clay till. Sand-lenses mainly account for horizontal transport and are prioritised in this study. Based on field observations, the distribution has been modeled using two different geostatistical approaches. One method uses a Markov chain model calculating the transition probabilities...

Influence of clay particles on the transport and retention of titanium dioxide nanoparticles in quartz sand.

Science.gov (United States)

Cai, Li; Tong, Meiping; Wang, Xueting; Kim, Hyunjung

2014-07-01

This study investigated the influence of two representative suspended clay particles, bentonite and kaolinite, on the transport of titanium dioxide nanoparticles (nTiO2) in saturated quartz sand in both NaCl (1 and 10 mM ionic strength) and CaCl2 solutions (0.1 and 1 mM ionic strength) at pH 7. The breakthrough curves of nTiO2 with bentonite or kaolinite were higher than those without the presence of clay particles in NaCl solutions, indicating that both types of clay particles increased nTiO2 transport in NaCl solutions. Moreover, the enhancement of nTiO2 transport was more significant when bentonite was present in nTiO2 suspensions relative to kaolinite. Similar to NaCl solutions, in CaCl2 solutions, the breakthrough curves of nTiO2 with bentonite were also higher than those without clay particles, while the breakthrough curves of nTiO2 with kaolinite were lower than those without clay particles. Clearly, in CaCl2 solutions, the presence of bentonite in suspensions increased nTiO2 transport, whereas, kaolinite decreased nTiO2 transport in quartz sand. The attachment of nTiO2 onto clay particles (both bentonite and kaolinite) were observed under all experimental conditions. The increased transport of nTiO2 in most experimental conditions (except for kaolinite in CaCl2 solutions) was attributed mainly to the clay-facilitated nTiO2 transport. The straining of larger nTiO2-kaolinite clusters yet contributed to the decreased transport (enhanced retention) of nTiO2 in divalent CaCl2 solutions when kaolinite particles were copresent in suspensions.

The effective stress concept in saturated sand-clay buffer

International Nuclear Information System (INIS)

Graham, J.; Oswell, J.M.; Gray, M.N.

1992-01-01

Tests were performed on mixtures of sand and bentonite, to investigate whether the behavior of the mixture can be expressed in terms of effective stresses, defined as the tensor difference between externally applied total stresses and pore water pressures measured outside the cell. Within acceptable bounds of experimental error, the tests show that effective stress can be used to describe consolidation and shear behaviour. However, because part of the effective stress in the clay is derived from net interparticle repulsive (unit) forces seated in diffuse double layers around aggregations of bentonite particles, the applicability of the concept has at this stage been restricted to conditions of constant volume (or possibly constant straining rate), constant chemistry, and constant temperature

Numerical Evaluation on the Different Shapes of Gravelly Sand Columns to Increase the Loading Capacity of Soft Clay

Directory of Open Access Journals (Sweden)

Meghzili Sif Allah

2017-01-01

Full Text Available Improvement on soft clay by the installation of stone column is one of the most popular methods followed worldwide. Different analytical and numerical solutions have already been developed for understanding the load transfer mechanism of soft soil reinforced with stone column. This study investigated a bearing capacity of the gravelly sand column, installed in soft clay bed at 15kpa of undrained shear strength. The column variable of length and diameter ratio at 7, 8 and 9 were evaluated. On top of that, the combination of two diameters in single column was tested and the uniform diameter was used as a control. In the numerical analysis, Mohrcoulomb model was adopted in the idealization of the behaviour of the gravelly sand column and soft clay materials. The results revealed that the optimum design that gave the highest loading capacity of the combination 11=12 of column diameter was the length and diameter ratio of 8.

Simultaneous sorption of As, B, Cr, Mo and Se from coal fly ash leachates by Al(sup3+)-pillared bentonite clay: implication for the construction of activated geo-synthetic clay liner

CSIR Research Space (South Africa)

Masindi, Vhahangwele

2017-03-01

Full Text Available successfully removed oxyanion species from generated coal FA leachates. This study shows that Al(sup3+)-modified bentonite clay is an effective adsorbent for oxyanion species in coal FA leachates and could be applied as a reactive barrier in coal FA retention...

Effect of coal mine dust and clay extracts on the biological activity of the quartz surface

Energy Technology Data Exchange (ETDEWEB)

Stone, V.; Jones, R.; Rollo, K.; Duffin, R.; Donaldson, K.; Brown, D.M. [Napier University, Edinburgh (United Kingdom). School of Life Science

2004-04-01

Modification of the quartz surface by aluminum salts and metallic iron have been shown to reduce the biological activity of quartz. This study aimed to investigate the ability of water soluble extracts of coal mine dust (CMD), low aluminum clays (hectorite and montmorillonite) and high aluminum clays (attapulgite and kaolin) to inhibit the reactivity of the quartz surface. DQ12 induced significant haemolysis of sheep erythrocytes in vitro and inflammation in vivo as indicated by increases in the total cell numbers, neutrophil cell numbers, MIP-2 protein and albumin content of bronchoalveolar lavage (BAL) fluid. Treatment of DQ12 with CMD extract prevented both haemolysis and inflammation. Extracts of the high aluminum clays (kaolin and attapulgite) prevented inhibition of DQ12 induced haemolysis, and the kaolin extract inhibited quartz driven inflammation. DQ12 induced haemolysis by coal mine dust and kaolin extract could be prevented by pre-treatment of the extracts with a cation chellator. Extracts of the low aluminum clays (montmorillonite and hectorite) did not prevent DQ12 induced haemolysis, although the hectorite extract did prevent inflammation. These results suggest that CMD, and clays both low and rich in aluminum, all contain soluble components (possibly cations) capable of masking the reactivity of the quartz surface.

Evaluation of Turf-Grass and Prairie-Vegetated Rain Gardens in a Clay and Sand Soil, Madison, Wisconsin, Water Years 2004-08

Science.gov (United States)

Selbig, William R.; Balster, Nicholas

2010-01-01

The U.S. Geological Survey, in cooperation with a consortium of 19 cities, towns, and villages in Dane County, Wis., undertook a study to compare the capability of rain gardens with different vegetative species and soil types to infiltrate stormwater runoff from the roof of an adjacent structure. Two rain gardens, one planted with turf grass and the other with native prairie species, were constructed side-by-side in 2003 at two locations with different dominant soil types, either sand or clay. Each rain garden was sized to a ratio of approximately 5:1 contributing area to receiving area and to a depth of 0.5 foot. Each rain garden, regardless of vegetation or soil type, was capable of storing and infiltrating most of the runoff over the 5-year study period. Both rain gardens in sand, as well as the prairie rain garden in clay, retained and infiltrated 100 percent of all precipitation and snowmelt events during water years 2004-07. The turf rain garden in clay occasionally had runoff exceed its confining boundaries, but was still able to retain 96 percent of all precipitation and snowmelt events during the same time period. Precipitation intensity and number of antecedent dry days were important variables that influenced when the storage capacity of underlying soils would become saturated, which resulted in pooled water in the rain gardens. Because the rooftop area that drained runoff to each rain garden was approximately five times larger than the area of the rain garden itself, evapotranspiration was a small percentage of the annual water budget. For example, during water year 2005, the maximum evapotranspiration of total influent volume ranged from 21 percent for the turf rain garden in clay to 25 percent for the turf rain garden in sand, and the minimum ranged from 12 percent for the prairie rain garden in clay to 19 percent for the prairie rain garden in sand. Little to no runoff left each rain garden as effluent and a small percentage of runoff returned to the

Content of arsenic, selenium, mercury in the coal, food, clay and drinking water on the Zhaotong fluorosis area, eastern Yunnan Province

Energy Technology Data Exchange (ETDEWEB)

Luo Kun-li; Li Hui-jie; Chen Tong-bin (and others) [Chinese Academy of Sciences, Beijing (China). Institute of Geographic Sciences and Natural Resources Research

2008-03-15

About 160 samples of coal, corn, capsicum and drinking water were collected from the endemic fluorosis area of Zhenxiong and Weixin County, Zhaotong City of Yunnan Province, to determine the arsenic (As), selenium (Se) and mercury (Hg) content by AAF-800. The study found that the As content in the main coal seam from the Late Permian coal mines in Zhaotong City is 8.84 mg/kg and some civil coal can reach 89.09 mg/kg. The Se and Hg in the coal samples of Late Permian is lower, but Se and Hg are more concentrated in the pyritic coal balls and the pyritic gangue of the coal seam. The As content in corn and capsicum dried by coal-burning is more than 0.7 mg/kg, the natural standard amount of arsenic content permitted in food by China. The Se and Hg content in corn dried by coal-burning is lower than the natural standard of Se and Hg content in food in China but the Se and Hg content of capsicum dried by coal-burning exceeds the amount permitted by the natural standard for food in China. Clay, used as an additive for the coal-burning process and as a binder in making briquettes, contains a high content of As, generally more than 16 mg/kg. However, the Se and Hg content of clay itself are low. The As, Se and Hg content of drinking water are lower than the natural standard of As, Se and Hg content in the drinking water. So, there is high-As content coal and high-As content dried corn and capsicum in the endemic fluorosis area of Zhaotong City of Yunnan Province. The high As content of the dried corn and capsicum might have originated from the high arsenic content of burnt coal and clay. 30 refs., 4 tabs.

Research of Deformation of Clay Soil Mixtures Mixtures

OpenAIRE

Romas Girkontas; Tadas Tamošiūnas; Andrius Savickas

2014-01-01

The aim of this article is to determine clay soils and clay soils mixtures deformations during drying. Experiments consisted from: a) clay and clay mixtures bridges (height ~ 0,30 m, span ~ 1,00 m); b) tiles of clay and clay, sand and straw (height, length, wide); c) cylinders of clay; clay and straw; clay, straw and sand (diameter; height). According to the findings recommendations for clay and clay mixtures drying technology application were presented. During the experiment clay bridge bear...

Performance of soft clay stabilized with sand columns treated by silica fume

Directory of Open Access Journals (Sweden)

Samueel Zeena

2018-01-01

Full Text Available In many road construction projects, if weak soil exists, then uncontrollable settlement and critical load carrying capacity are major difficult problems to the safety and serviceability of roads in these areas. Thus ground improvement is essential to achieve the required level of performance. The paper presents results of the tests of four categories. First category was performed on saturated soft bed of clay without any treatment, the second category shed light on the improvement achieved in loading carrying capacity and settlement as a result of reinforcing with conventional sand columns at area replacement ratio = 0.196. The third set investigates the bed reinforced by sand columns stabilized with dry silica fume at different percentages (3, 5 and 7% and the fourth set investigates the behavior of sand columns treated with slurry silica fume at two percentages (10 and 12%. All sand columns models were constructed at (R.D= 60%. Model tests were performed on bed of saturated soil prepared at undrained shear strength between 16-20 kPa for all models. For all cases, the model test was loaded gradually by stress increments up to failure. Stress deformation measurements are recorded and analyzed in terms of bearing improvement ratio and settlement reduction ratio. Optimum results were indicated from soil treated with sand columns stabilized with 7% dry silica fume at medium state reflecting the highest bearing improvement ratio (3.04 and the settlement reduction ratio (0.09 after 7 days curing. While soil treated with sand columns stabilized with 10% slurry silica fume provided higher bearing improvement ratio 3.13 with lower settlement reduction ratio of 0.57 after 7-days curing.

Acid rock drainage passive remediation using alkaline clay and impacts of vegetation and saturated sand barrier

Science.gov (United States)

Plaza, F.; Wen, Y.; Liang, X.

2017-12-01

Acid rock drainage (ARD) caused by abundance of coal refuse (CR) deposits in mining regions requires adequate treatment to prevent serious water pollution due to its acidity and high concentrations of sulfate and metals/metalloids. Over the past decades, various approaches have been explored and developed to remediate ARD. This study uses laboratory experiments to investigate the effectiveness and impacts of ARD passive remediation using alkaline clay (AC), a by-product of the aluminum refining process. Twelve column kinetic leaching experiments were set up with CR/AC mixing ratios ranging from 1%AC to 10%AC. Samples were collected from these columns to measure the pH, sulfate, metals/metalloids, acidity and alkalinity. Additional tests of XRD and acid base accounting were also conducted to better characterize the mineral phase in terms of the alkalinity and acidity potential. Based on the leachate measurement results, these columns were further classified into two groups of neutral/near neutral pH and acidic pH for further analysis. In addition, impacts of the vegetation and saturated sand layer on the remediation effectiveness were explored. The results of our long-term (more than three years in some cases) laboratory experiments show that AC is an effective ARD remediation material for the neutralization of leachate pH and immobilization of sulfate and metals such as Fe, Mn, Cu, Zn, Ni, Pb, Cd, Co. The CR/AC mixing ratios higher than 3%AC are found to be effective, with 10% close to optimal. Moreover, the results demonstrate the benefits of using vegetation and a saturated sand barrier. Vegetation acted as a phytoaccumulation/phytoextraction agent, causing an additional immobilization of metals. The saturated sand barrier blocked the oxygen and water diffusion downwards, leading to a reduction of the pyrite oxidation rate. Finally, the proposed remediation approach shows that the acidity consumption will likely occur before all the alkalinity is exhausted

Tales from a distant swamp: Petrological and paleobotanical clues for the origin of the sand coal lithotype (Mississippian, Valley Fields, Virginia)

Science.gov (United States)

Hower, J.C.; O'Keefe, J.M.K.; Eble, C.F.

2008-01-01

Tournasian (Mississippian) Price Formation semianthracites (Rmax = 2.40%) in the Valley Fields of southwestern Virginia contain a lithotype described in an early-20th-century report as a "sand" coal. The Center for Applied Energy Research inherited a collection of coals containing sand coal specimens, making it possible to study the lithotype from the long-closed mines. The sand coal consists of rounded quartz sand and maceral assemblages (secretinite, corpogelinite, and rounded collotelinite) along with banded collotelinite, vitrodetrinite, and inertodetrinite assemblages. The association of rounded macerals and similar-size quartz grains suggests transport. Oxidation rims surrounding the rounded collotelinite provides further evidence for transport. Due to the semianthracite rank, palynology could not be performed. Stratigraphic evidence indicates that the Lepidodendropsis flora would have been the dominant mire vegetation. Pteridosperms in this assemblage could have contributed resin rodlets, subsequently metamorphosed to collogelinite or secretinite. While a resin rodlet origin is an intriguing possibility for the origin of the rounded macerals (at least some of the rounded maceral, the rounded collotelinite clearly has a different origin), we cannot definitively prove this origin. ?? 2008 Elsevier B.V. All rights reserved.

ANALYSIS OF DEFORMED STATE STRUCTURES OF THE KYIV METRO RUNNING TUNNELS ON A TRANSITION ZONE FROM SPONDYLOV’S CLAY TO BUCHATSKIY SANDS

Directory of Open Access Journals (Sweden)

V. D. Petrenko

2014-07-01

Full Text Available Purpose. In the section of changes geotechnical conditions of spondylov’s clay to buchatskiy sands may have significant structural deformation of running tunnels. It is necessary to identify the cause of deformities develop ways to minimize and based modeling and calculations to prove the effectiveness of measures to reduce deformation.Methodology. To solve the analysis problem of the stress-strain state (SSS of the system «structure array» it was conducted the numerical simulation using the finite element method (FEM. On the basis of the obtained results the graphs were constructed and the dependencies were determined. Findings. The presence of weak water-saturated soils in tray of the tunnel on an area of transition from spondylov’s clay to buchatskiy sand causes significant increasing in strain construction of tunnels and general vibration liquefaction in soil basis. Also change the physical and mechanical characteristics of soils within the frames of tunnels influences on the level of strain state of most frames. Improved strain state settings of tunnels in areas of change soil characteristics of the array (especially at the bottom of casing can be achieved by chemical consolidation of weak soils. Composition of solutions for fixing the weak soils should be determined based on the study of grain size, porosity, and other parameters of physical and mechanical and physical and chemical characteristics of soils.Originality.The basic cause significant strain on transition zone from spondylov’s clay to buchatskiy sands is found, that is explained by saturated phenomenon vibration liquefaction basis under the tunnel.Practical value.The approaches to reduce the strain in the construction of running tunnels in the transition zone from spondylov’s clay to buchatskiy sands are developed, as well as in the area ofthe station «Glybochytska»the Kyiv Metro.

Dissolution and transport of coal tar compounds in fractured clay-rich residuum

DEFF Research Database (Denmark)

Vulava, Vijay M.; McKay, Larry D.; Broholm, Mette Martina

2012-01-01

the importance of rapid dissolution and transport through the fracture networks. The concentrations continued to rise but did not reach the corresponding effective solubility limit in most cases. Compounds that were less soluble and those that were more susceptible to sorption or matrix diffusion eluted...... at a much slower rate. Analysis of contaminant concentrations in microcore residuum samples indicated that all 10 compounds had spread throughout the entire monolith and had diffused into the fine-grained matrix between fractures. These data suggest that the predominantly fine pore structure did not appear......We investigated the dissolution and transport of organic contaminants from a crude coal tar mixture in a monolith of fractured clay-rich residuum. An electrolyte solution was eluted through the residuum monolith containing a small emplaced source of coal tar under biologically inhibited and mildly...

Treatment for cracked and permeable Houston clay

International Nuclear Information System (INIS)

Vipulanandan, C.; Leung, M.

1991-01-01

In this study, the treatability of a field clay (obtained from Houston, Texas) and a clay-sand mixture to reduce their hydraulic conductivity was evaluated. Remolded field clay and clay-sand mixture with and without methanol contamination were treated to reduce their hydraulic conductivity by permeating very dilute grout solutions. The concentration of sodium silicate in the grout solution was 8%, while the solid content in the cement grout was 0.3%. The hydraulic conductivity of permeable Houston clay (hydraulic conductivity >10 -5 cm/sec) could be reduced to less than 10 -7 cm/sec (U.S. EPA limit for soil barriers) by permeating with a selected combination of grout solutions

Plume persistence caused by back diffusion from thin clay layers in a sand aquifer following TCE source-zone hydraulic isolation.

Science.gov (United States)

Parker, Beth L; Chapman, Steven W; Guilbeault, Martin A

2008-11-14

This paper concludes that back diffusion from one or a few thin clayey beds in a sand aquifer can cause contaminant persistence above MCLs in a sand aquifer long after the source zone initially causing the plume is isolated or removed. This conclusion is based on an intensive case study of a TCE contaminated site in Florida, with the processes evaluated using numerical modeling. At this site, the TCE DNAPL zone formed decades ago, and was hydraulically isolated by means of an innovative system performing groundwater extraction, treatment and re-injection. Treated water is re-injected in a row of injection wells situated a short distance downgradient of the extraction wells, creating a clean-water displacement front to efficiently flush the downgradient plume. This scheme avoids the creation of stagnation zones typical of most groundwater pump-and-treat systems, thereby minimizing the time for aquifer flushing and therefore downgradient cleanup. The system began operation in August 2002 and although the performance monitoring shows substantial declines in concentrations, detectable levels of TCE and degradation products persist downgradient of the re-injection wells, long after the TCE should have disappeared based on calculations assuming a nearly homogenous sand aquifer. Three hypotheses were assessed for this plume persistence: 1) incomplete source-zone capture, 2) DNAPL occurrence downgradient of the re-injection wells, and 3) back diffusion from one or more thin clay beds in the aquifer. After careful consideration, the first two hypotheses were eliminated, leaving back diffusion as the only plausible hypothesis, supported by detailed measurements of VOC concentrations within and near the clay beds and also by numerical model simulations that closely represent the field site hydrogeologic conditions. The model was also used to simulate a more generalized, hypothetical situation where more thin clayey beds occur in a sand aquifer with an underlying aquitard

Characterization of Rare Earth Elements in in Clay Deposits Associated with Central Appalachian Coal Seams

Science.gov (United States)

Scott, M.; Verba, C.; Falcon, A.; Poston, J.; McKoy, M.

2017-12-01

Because of their multiple uses in clean energy technologies, rare earth elements (REE) are critical for national economic and energy security. With no current domestic source, supply remains a major concern for domestic security. Underclay - specifically the layer of stratum beneath a coal bed - is a potentially rich source of REE. This study focuses on the characterization and ion exchange recovery of REE from underclay samples from the Lower Freeport, Middle Kittanning, and Pittsburgh coal seams in West Virginia. Multimodal techniques provided quantitative assessments of REE-bearing mineral phases in select underclays and the influence of organic acid rock treatment on the recovery of REE from both exchangeable and crystalline mineral phases present. All samples are from extensively weathered horizons that contain abundant kaolinite and illite. Total REE concentrations range from 250-450 ppm and all samples have a HREE/LEEE ratio >20%. Rare earth element bearing minerals identified in the clay are monazite, xenotime, florencite, and crandallite. Our selective recovery approach is designed to isolate and recover REE through partial dissolution of the clay matrix and ion exchange rather than dissolution/recovery of phosphate or aluminosilicate bound REE. These results provide a better understanding of coal seam underclay, the affinity of REEs for specific ligands and colloids, and how the rock and ligands respond to different chemical treatments. These processes are important to the development and commercialization of efficient and cost effective methods to extract REE from domestic geologic deposits and recover into salable forms.

Effects of coal and wheat husk additives on the physical, thermal and mechanical properties of clay bricks

Energy Technology Data Exchange (ETDEWEB)

Ahmad, S.; Iqbal, Y.; Muhammad, R.

2017-07-01

The use of by-products as additives in brick industry is gaining increased research attention due to their effective role in decreasing the total energy needs of industrial furnaces. In addition, these additives leave pores upon burning, causing a decrease in thermal conductivity and affect the mechanical properties of bricks as well. In the present study, various proportions of coal and wheat husk were used as additives in the initial ingredients of clay bricks. Microstructure, thermal conductivity, coefficient of thermal diffusivity, water absorption, shrinkage, compressive strength and bulk density of fired clay bricks with and without additives were investigated. Clay bricks containing 5–15wt.% additives were found to be within the permissible limits for most of the recommended standard specifications. (Author)

Dating of authigenic clays related to igneous intrusions in Hunter Valley Coals

International Nuclear Information System (INIS)

Zwingmann, H.

2000-01-01

The Sydney Basin is composed mainly of Permian and Triassic marine and non-marine clastic sedimentary strata together with economically significant coal deposits and volumetrically minor igneous rocks. Many of these igneous rocks are also economically significant not only for their use in the construction industry but also for their deleterious effects on coal mining, particularly in underground mines utilising longwall extraction systems. Igneous activity in the Sydney Basin ranges from Early Permian to Tertiary in age and although episodic in nature, activity was unlikely to have ceased for periods of more than approximately 10 million years (Carr and Facer 1980; Embleton et al. 1982). Dating of the time of emplacement of igneous rocks using the K-Ar isotopic system is a relatively straightforward procedure if suitable analytical facilities and samples of appropriate, fresh, primary minerals are available. In the case of intrusions in coal seams, however, the occurrence of fresh, primary minerals is very rare due to widespread alteration produced by interaction between the igneous rock and fluids in the coal seam. This interaction produces a variety of secondary minerals with most primary minerals and glass being altered to clays (mainly kaolinite) and carbonates. Consequently, relatively few isotopic dates for intrusions into coal seams have been determined. A detailed study of several hundred samples of igneous rocks from the Sydney Basin found only six samples of intrusions into coal seams that were suitable for conventional K-Ar dating (Carr and Facer 1980). Techniques for K-Ar dating of authigenic illite, developed in response to the need by the petroleum industry to understand the timing of diagenesis in petroleum source-rocks and reservoirs, are now well established (Clauer and Chaudhuri 1995). As part of a larger project on the impact of igneous intrusions on coal mining and the alienation of coal reserves, a preliminary investigation of the timing of

Part of the green plan : suppliers are helping the coal and oil sands industries to address environmental concerns

Energy Technology Data Exchange (ETDEWEB)

Sabourin, M.

2009-09-15

The Canadian coal and oil sands industries operate in one of the most stringent environmental regulatory frameworks found in the world. The purpose of the strict regulations is to ensure that Canadian energy resources are developed safely, responsibly and efficiently. Their primary objectives involve the protection of water supplies and aquatic life. This article discussed how suppliers are helping the coal and oil sands industries address environmental concerns. Several examples were provided. In terms of water protection and management, EBA Engineering Consultants has helped mining companies comply with strict environmental regulations and has assisted them in obtaining the necessary permits and establishing monitoring programs. In terms of containment, the Layfield Group's silt and sediment control products has helped prevent fine soil particles from running off into and clouding local water courses. In terms of land reclamation and remediation, IW Kuhn Environmental Ltd., has provided soil remediation services, including re-vegetation using hydroseeding which involves the sowing of seeds with a hosed jet of water. This article also discussed the many green technology products that have been developed and commercialized by EarthRenew for application in coal and oil sands projects. Their patented waste renew facilities can process and cook manures, biosolids or green wastes into organic fertilizers that could be used in land repair applications. 5 figs.

Wave liquefaction in soils with clay content

DEFF Research Database (Denmark)

Kirca, Özgür; Sumer, B. Mutlu; Fredsøe, Jørgen

2012-01-01

The paper presents the results of an experimental study of the influence of clay content (in silt-clay and sand-clay mixtures) on liquefaction beneath progressive waves. The experiments showed that the influence of clay content is very significant. Susceptibility of silt to liquefaction is increa...

A mechanistic study of the uniform corrosion of copper in compacted clay-sand soil

International Nuclear Information System (INIS)

Litke, C.D.; Ryan, S.R.; King, F.

1992-08-01

The results of a study of the mechanism of uniform corrosion of copper under simulated nuclear fuel waste disposal conditions are presented. Evidence is given that suggests that the rate-controlling process is the transport of copper corrosion products away from the corroding surface. In the experiments described here, the copper diffused through a column of compacted clay-sand buffer. The properties of the buffer material, especially its ability to sorb copper species, are significant in determining the rate of uniform corrosion of copper. The evidence that copper diffusion is rate-controlling stems from the effect of γ-radiation on the tests. In the presence of γ-radiation, copper diffused farther along the column of compacted buffer material than in the unirradiated tests, but the corrosion rate was lower. These two effects can be best explained in terms of a slow copper-diffusion process. Irradiation is thought to reduce the extent of sorption of copper by the clay component of the buffer. This results in a more mobile copper species and a smaller interfacial flux of copper (i.e., a lower corrosion rate)

The influence of clay particles on the hydraulic conductivity of sandy soils

NARCIS (Netherlands)

Fahmy, M.I.

1961-01-01

The relation between hydraulic conductivity and size of the sand particles and clay content was investigated in artificial mixtures of sand and clay and in natural soils, in four different ways in the laboratory and field.

In the artificial mixtures coarse aggregates of illitic clay hardly

Silt-clay aggregates on Mars

International Nuclear Information System (INIS)

Greeley, R.

1979-01-01

Viking observations suggest abundant silt and clay particles on Mars. It is proposed that some of these particles agglomerate to form sand size aggregates that are redeposited as sandlike features such as drifts and dunes. Although the binding for the aggregates could include salt cementation or other mechanisms, electrostatic bonding is considered to be a primary force holding the aggregates together. Various laboratory experiments conducted since the 19th century, and as reported here for simulated Martian conditions, show that both the magnitude and sign of electrical charges on windblown particles are functions of particle velocity, shape and composition, atmospheric pressure, atmospheric composition, and other factors. Electrical charges have been measured for saltating particles in the wind tunnel and in the field, on the surfaces of sand dunes, and within dust clouds on earth. Similar, and perhaps even greater, charges are proposed to occur on Mars, which could form aggregates of silt and clay size particles. Electrification is proposed to occur within Martian dust clouds, generating silt-clay aggregates which would settle to the surface where they may be deposited in the form of sandlike structures. By analog, silt-clay dunes are known in many parts of the earth where silt-clay aggregated were transported by saltation and deposited as 'sand.' In these structures the binding forces were later destroyed, and the particles reassumed the physical properties of silt and clay, but the sandlike bedding structure within the 'dunes' was preserved. The bedding observed in drifts at the Viking landing site is suggested to result from a similar process involving silt-clay aggregates on Mars

Biological CO2 conversion to acetate in subsurface coal-sand formation using a high-pressure reactor system

Directory of Open Access Journals (Sweden)

Yoko eOhtomo

2013-12-01

Full Text Available Geological CO2 sequestration in unmineable subsurface oil/gas fields and coal formations has been proposed as a means of reducing anthropogenic greenhouse gasses in the atmosphere. However, the feasibility of injecting CO2 into subsurface depends upon a variety of geological and economic conditions, and the ecological consequences are largely unpredictable. In this study, we developed a new flow-through-type reactor system to examine potential geophysical, geochemical and microbiological impacts associated with CO2 injection by simulating in situ pressure (0–100 MPa and temperature (0–70°C conditions. Using the reactor system, anaerobic artificial fluid and CO2 (flow rate: 0.002 and 0.00001 mL/min, respectively were continuously supplemented into a column comprised of bituminous coal and sand under a pore pressure of 40 MPa (confined pressure: 41 MPa at 40°C for 56 days. 16S rRNA gene analysis of the bacterial components showed distinct spatial separation of the predominant taxa in the coal and sand over the course of the experiment. Cultivation experiments using sub-sampled fluids revealed that some microbes survived, or were metabolically active, under CO2-rich conditions. However, no methanogens were activated during the experiment, even though hydrogenotrophic and methylotrophic methanogens were obtained from conventional batch-type cultivation at 20°C. During the reactor experiment, the acetate and methanol concentration in the fluids increased while the δ13Cacetate, H2 and CO2 concentrations decreased, indicating the occurrence of homo-acetogenesis. 16S rRNA genes of homo-acetogenic spore-forming bacteria related to the genus Sporomusa were consistently detected from the sandstone after the reactor experiment. Our results suggest that the injection of CO2 into a natural coal-sand formation preferentially stimulates homo-acetogenesis rather than methanogenesis, and that this process is accompanied by biogenic CO2 conversion to

Gas detection in sands of high silt-clay content in the Cook Inlet area

International Nuclear Information System (INIS)

Bettis, F.

1976-01-01

When a sand contains a large amount of silt and clay it is often difficult to detect zones that contain gas using only the Archie Saturation Relationship. However, gas may be detected in these shaly formations using certain quick-look techniques. Log examples of these are presented in this paper. The first quick-look technique is an overlay of the neutron log on a density log. The neutron log is shifted relative to the density log to make the two porosity curves track in shaly water sands. Gas-bearing intervals become readily apparent from separations of the two curves where the density porosity is reading higher than the shifted neutron porosity. The second is an overlay of a neutron log on the sonic interval-transit-time log. The sonic log is shifted so as to match the neutron log in average tight sands in the section. This method has proved to be more optimistic than the density-neutron overlay above. It will find the gas-bearing zones, but may result in testing a zone or two which is nonproductive. The third method, used when no neutron log has been run, is a crossplot of the difference, sonic porosity minus density porosity, versus gamma ray API units. This is the most unreliable of the three methods because of the difficulty of determining the end points and the slope of the line on the plot which separates the gas zones from the non-gas zones

Influence of clay content on wave-induced liquefaction

DEFF Research Database (Denmark)

Kirca, V.S. Ozgur; Sumer, B. Mutlu; Fredsøe, Jørgen

2014-01-01

of measurements were carried out: (1) pore-water pressure measurements across the soil depth and (2) water-surface elevation measurements. These measurements were synchronized with video recordings of the liquefaction process from the side. The ranges of the various quantities in the experiments were wave height...... of silt and clay was not liquefied. Sand may become prone to liquefaction with the introduction of clay, contrary to the general perception that this type of sediment is normally liquefaction-resistant under waves. For instance, sand with d50 50:4 mmwas liquefied with CC510:8%, whereas sand with d50 50...

On the origin of calcite-cemented sandstones in the clearwater formation oil-sands, Alberta

Energy Technology Data Exchange (ETDEWEB)

Colquhoun, I.M.

1999-01-01

This thesis examined the formation of calcite-cemented sandstones in the Clearwater Formation within the Cold Lake and southern Primrose areas of the Alberta oil sands. Three stages of diagenesis have been recognized, both in the calcite-cemented sandstones and reservoir sands. Diagenesis of the Clearwater Formation in the Cold Lake and southern Primrose areas ended once the reservoir filled with hydrocarbons, but in the Cold Lake area, diagenesis of water-saturated sands likely continued after hydrocarbon emplacement. The reservoir sands in the formation contain a diverse clay mineral assemblage. In general, 0.7 nm clays dominate the diagenetic clay mineralogy of the Clearwater sands. Reservoir sands that contain large amounts of detrital clays and early diagenetic, grain-coating chlorite/smectite have significantly reduced bitumen-saturation. The presence of detrital and diagenetic smectitic clays complicates the removal of bitumen from the Clearwater formation using cyclic steam stimulation techniques because they swell during steam stimulation and reduce porosity and permeability of reservoir sands. Reservoir sands that contain kaolinite, feldspar and calcite react to form smectitic clays, which swell upon cyclic steam stimulation and further reduce porosity and permeability of reservoir sands. However, in the Cold Lake and Primrose areas, the dominant clay mineral is berthierine, which is associated with high calcite, which help to preserve porosity, permeability and bitumen saturation. The porous nature of bitumen-saturated, calcite-cemented sandstones that are laterally extensive could possibly provide a preferential path for steam to initiate calcite dissolution and produce significant concentrations of dissolved carbon dioxide in injected fluids. It was noted that this may then precipitate as carbonate scale within the reservoir and could cause formation damage or affect production equipment. 207 refs., 9 tabs., 58 figs., 3 appendices.

Geological Investigations on Boulder-Clay of E. Groningen

NARCIS (Netherlands)

Gijzel, van P.; Overweel, C.J.; Veenstra, H.J.

1959-01-01

In this article the results of a study on boulder-clay in the neighbourhood of Winschoten (N.E. Netherlands) are communicated (Chapter I). The underlying sediments of the boulder-clay in this area consist of fine preglacial sands and black clay. In the nuclei of the many drumlins a strongly

Improving the geotechnical behavior of sand through cohesive admixtures

Directory of Open Access Journals (Sweden)

Mohie eldin Mohamed Afify Elmashad

2018-04-01

Full Text Available Irrigation projects in Egypt have been facing tremendous challenges, mostly is the scarcity of irrigation water. The current research presents the effect of different cohesive admixture on the conductivity of siliceous sand in general and its other geotechnical properties. Two different types of conventional swelling clay from (Toshka, 6th of October as well as bentonite were used to construct the irrigation canals and embankment. The results indicated that increase in the plasticity properties of the treated soil also decrease the permeability and infiltration. Moreover, the dry density of 2.08 t/m3 was obtained from sand and 20% 6th of October mixture, also the CBR of 31.20% were obtained from sand and 8% 6th of October mixture. Increasing the bentonite ratio increases the cohesion and decreasing the permeability. The swelling ratios of sand 6th of October Clay mixture is equal to 0.28%, and the fictitious stress at which the swelling ratio is nil, is equal to 16 kPa. Keywords: Sand, Swelling clay, Bentonite, Compaction test, Consolidation test, Triaxial test

Biological CO2 conversion to acetate in subsurface coal-sand formation using a high-pressure reactor system

Science.gov (United States)

Ohtomo, Y.; Ijiri, A.; Ikegawa, Y.; Tsutsumi, M.; Imachi, H.; Uramoto, G.; Hoshino, T.; Morono, Y.; Tanikawa, W.; Hirose, T.; Inagaki, F.

2013-12-01

The geological CO2 sequestration into subsurface unmineable oil/gas fields and coal formations has been considered as one of the possible ways to reduce dispersal of anthropogenic greenhouse gasses into the atmosphere. However, feasibility of CO2 injection largely depends on a variety of geological and economical settings, and its ecological consequences have remained largely unpredictable. To address these issues, we developed a new flow-through-type CO2 injection system designated as the 'geobio-reactor system' to examine possible geophysical, geochemical and microbiological impact caused by CO2 injection under in-situ pressure (0-100 MPa) and temperature (0-70°C) conditions. In this study, we investigated Eocene bituminous coal-sandstones in the northwestern Pacific coast, Hokkaido, Japan, using the geobio-reactor system. Anaerobic artificial fluid and CO2 (flow rate: 0.002 and 0.00001 mL/min, respectively) were continuously supplemented into the coal-sand column under the pore pressure of 40 MPa (confined pressure: 41 MPa) at 40°C for 56 days. Molecular analysis of bacterial 16S rRNA genes showed that predominant bacterial components were physically dispersed from coal to sand as the intact form during experiment. Cultivation experiments from sub-sampling fluids indicated that some terrestrial microbes could preserve their survival in subsurface condition. Molecular analysis of archaeal 16S rRNA genes also showed that no methanogens were activated during experiment. We also anaerobically incubated the coal sample using conventional batch-type cultivation technique with a medium for methanogens. After one year of the batch incubation at 20°C, methane could be detected from the cultures except for the acetate-fed culture. The sequence of archaeal 16S rRNA genes via PCR amplification obtained from the H2 plus formate-fed culture was affiliated with a hydrogenotrophic methanogen within the genus Methanobacterium, whereas the methanol plus trimethylamine culture

Treatment and conditioning of radioactive waste solution by natural clay minerals

International Nuclear Information System (INIS)

El-Dessouky, M.I.; El-Massry, E.H.; Khalifa, S.M.; Aly, H.F.

1999-01-01

Natural inorganic exchangers. Was used to remove caesium, cobalt and europium using zinc sulfate as coagulant also different clay minerals. These calys include, feldrspare, aswanly, bentionite, hematite, mud, calcite, basalt, magnetite, kaoline sand stone, limonite and sand. The factros affecting the removal process namely PH, particle size, temperature and weight of the clay have been studied. Highest removal for Cs-137, Co-60 and Eu-152 and 154 was achived by asswanly and bentonite. Sand stone is more effective than the other clays. Removal of Cs-137 from low level waste solution is in the order the sequence, aswanly (85.5%)> bentonite (82.2%)> sandstone (65.4%). Solidified cement products have been evaluated to determine optimum conditions of mixing most sludges contained clays by testing mechanical strength and leaching rates of the waste products. The solidified waste forms were found more acceptable for handing, storage and ultimate disposal

Microbial assimilation of ¹⁴C of ground and unground plant materials decomposing in a loamy sand and a clay soil

DEFF Research Database (Denmark)

Sørensen, P.; Ladd, J.N.; Amato, M.

1996-01-01

The influence of grinding plant materials on the microbial decomposition and the distribution of plant-derived carbon in soil was measured. Ground and unground, C-14-labelled subclover leaves (Trifolium subterraneum) were added to a loamy sand and clay soil and incubated for 42 d at 25 degrees C....

Effects of sand compaction pile (SCP) driving on the strength of clay outside the improved area; Sand compaction pile no dasetsu ga jiban kairyo ikigai no nendo jiban no kyodo ni oyobosu eikyo

Energy Technology Data Exchange (ETDEWEB)

Matsuda, H. [Yamaguchi University, Yamaguchi (Japan); Takahashi, S. [Ministry of Transport, Tokyo (Japan); Fujiwara, K. [Penta-Ocean Construction Co. Ltd., Tokyo (Japan); Kitayama, N. [Fukken Co. Ltd., Hiroshima (Japan)

1998-06-21

This paper describes effects of the disturbance by the sand compaction pile (SCP) driving operations on the shear strength of clay outside the improved area and the border of region affected by the SCP driving. About 1,400 soil specimens were taken before and after the SCP driving inside and outside the improved area during the foundation improvement at Tokuyama-Shimomatsu Port in Yamaguchi Prefecture. Soil test data of the specimens and strength characteristics of disturbed clay specimens were investigated through the laboratory experiments. The results obtained are as follows. According to the multi-directional simple shear test results, the shear strength immediately after the cyclic shear decreased in 10 to 30% compared with that before the cyclic shear. When recompaction was conducted before the cyclic shear, however, it increased in 50% compared with that before the cyclic shear. The strength of clay decreased by the SCP driving even outside the improved area. When the internal frictional angle of clay, friction coefficient of the improved boundary and driving depth of SCP were determined, it was possible to estimate an area affected by the SCP driving using a combined sliding plane. 21 refs., 18 figs.

Complex resistivity signatures of ethanol in sand-clay mixtures

Science.gov (United States)

Personna, Yves Robert; Slater, Lee; Ntarlagiannis, Dimitrios; Werkema, Dale D.; Szabo, Zoltan

2013-01-01

We performed complex resistivity (CR) measurements on laboratory columns to investigate changes in electrical properties as a result of varying ethanol (EtOH) concentration (0% to 30% v/v) in a sand–clay (bentonite) matrix. We applied Debye decomposition, a phenomenological model commonly used to fit CR data, to determine model parameters (time constant: τ, chargeability: m, and normalized chargeability: mn). The CR data showed a significant (P ≤ 0.001) time-dependent variation in the clay driven polarization response (~ 12 mrad) for 0% EtOH concentration. This temporal variation probably results from the clay–water reaction kinetics trending towards equilibrium in the sand–clay–water system. The clay polarization is significantly suppressed (P ≤ 0.001) for both measured phase (ϕ) and imaginary conductivity (σ″) with increasing EtOH concentration. Normalized chargeability consistently decreases (by up to a factor of ~ 2) as EtOH concentration increases from 0% to 10% and 10 to 20%, respectively. We propose that such suppression effects are associated with alterations in the electrical double layer (EDL) at the clay–fluid interface due to (a) strong EtOH adsorption on clay, and (b) complex intermolecular EtOH–water interactions and subsequent changes in ionic mobility on the surface in the EDL. Changes in the CR data following a change of the saturating fluid from EtOH 20% to plain water indicate strong hysteresis effects in the electrical response, which we attribute to persistent EtOH adsorption on clay. Our results demonstrate high sensitivity of CR measurements to clay–EtOH interactions in porous media, indicating the potential application of this technique for characterization and monitoring of ethanol contamination in sediments containing clays.

Feasibility of using overburden clays for sealing purposes and laboratory testing of the clays

Energy Technology Data Exchange (ETDEWEB)

Mann, J. (Vyzkumny Ustav pro Hnede Uhli, Most (Czechoslovakia))

1992-03-01

Studies properties of overburden clay from North Bohemian surface coal mines for use as sealants of industrial and household waste that will be dumped at Czechoslovak surface mine sites. Basic requirements of sealing layers are optimum compressibility and impermeability by suitable compacting. Laboratory soil mechanical tests of different clay samples were carried out using the Proctor standard tests (PCS) and the Norwegian Geonor A/S - m 45 instrument. Laboratory tests were used to select the best available clay types with optimum density and moisture content. Experimental results of laboratory tests are provided.

Critical State of Sand Matrix Soils

Science.gov (United States)

Marto, Aminaton; Tan, Choy Soon; Makhtar, Ahmad Mahir; Kung Leong, Tiong

2014-01-01

The Critical State Soil Mechanic (CSSM) is a globally recognised framework while the critical states for sand and clay are both well established. Nevertheless, the development of the critical state of sand matrix soils is lacking. This paper discusses the development of critical state lines and corresponding critical state parameters for the investigated material, sand matrix soils using sand-kaolin mixtures. The output of this paper can be used as an interpretation framework for the research on liquefaction susceptibility of sand matrix soils in the future. The strain controlled triaxial test apparatus was used to provide the monotonic loading onto the reconstituted soil specimens. All tested soils were subjected to isotropic consolidation and sheared under undrained condition until critical state was ascertain. Based on the results of 32 test specimens, the critical state lines for eight different sand matrix soils were developed together with the corresponding values of critical state parameters, M, λ, and Γ. The range of the value of M, λ, and Γ is 0.803–0.998, 0.144–0.248, and 1.727–2.279, respectively. These values are comparable to the critical state parameters of river sand and kaolin clay. However, the relationship between fines percentages and these critical state parameters is too scattered to be correlated. PMID:24757417

Adsorption of zinc and lead on clay minerals

Directory of Open Access Journals (Sweden)

Katarína Jablonovská

2006-12-01

Full Text Available Clays (especially bentonite, zeolite and quartz sand are widely used as landfill barriers to prevent contamination of subsoil and groundwater by leachates containing heavy metals. The sorption of zinc and lead on these clays was studied as a function of time and it was found that the initial 1 h our was sufficient to exchange most of the metal ions. The retention efficiency of clay samples of Zn2+ and Pb2+ follows the order of bentonite > zeolite> quartz sand. Whatever the clay sample, lead is retained more than zinc. The concentration of elements in the solution was followed by atomic adsorption spectrofotometry. Bacillus cereus and Bacillus pumilus, previously isolated from the kaoline deposit Horna Prievrana was added into the clay samples to comparise the accumulation of Zn2+ and Pb2+ from the model solution. The study of heavy metal adsorption capacity of bacteria- enriched clay adsorbent showed a high retention efficiency for lead ions as comparised with zinc ions. Biosorption is considered a potential instrument for the removal of metals from waste solutions and for the precious metals recovery as an alternative to the conventional processes.

Basinal analysis of the Ecca and Lowermost Beaufort Beds and associated coal, uranium and heavy mineral beach sand occurrences

International Nuclear Information System (INIS)

Ryan, P.J.; Whitfield, G.G.

1979-01-01

The regional sediment transport directions, major provenance areas and the controlling palaeotectonic and palaeogeographic frameworks of sedimentation have been reconstructed for the Great Karoo Basin during the Permian. Analyses of this magnitude can be useful in regional exploration programmes for coal, uranium and fossil heavy mineral beach sand deposits. The strong palaeogeographic control on coal deposition is demonstrated by the fact that some of the most important deposits accumulated in topographically low lying areas on the pre-Karoo surface. Such areas formed sheltered environments ideal for the growth and accumulation of organic material. Elsewhere relatively slow rates of subsidence of a broad, protected, low lying delta plain controlled the deposition of coal. North of the main Karoo Basin many of the coal deposits are confined to structurally controlled linear basins. Hundreds of sedimentary uranium occurrences of varying grade and size occur within a broad, discontinuous belt in the Lower Beaufort of the southwestern portion of the Karoo Basin. The uranium mineralization occurs in a variety of fluvial deposits usually rich in carbonaceous material. Minute tuffaceous fragments, reflecting contemporaneous vulcanism, form a minor but significant constituent in some of the uraniferous sandstones. The uranium occurrences are confined largely to the Southern and Western Facies of the Lower Beaufort, and occur mainly within the confines of the Karoo Trough. Consolidated heavy mineral beach deposits have been found in the predominantly fluvio-deltaic Middle Ecca Group of the Northern Facies at a number of widely separated locations. These deposits were formed by shore line processes, such as the reworking of delta-front sands, during periods of temporary marine regression

Strength Properties of Aalborg Clay

DEFF Research Database (Denmark)

Iversen, Kirsten Malte; Nielsen, Benjaminn Nordahl; Augustesen, Anders Hust

glacial time are characterised by the absence of this mussel. These deposits are named Aalborg Clay and Aalborg Sand. In the city of Aalborg, a fill layer superposes Aalborg Clay. This layer is at some places found to be 6m thick. This fill layer does not provide sufficient bearing capacity, which has...... resulted in many damaged buildings in Aalborg. To provide sufficient bearing capacity it is therefore necessary either to remove the fill or to construct the building on piles. Both methods imply that the strength of Aalborg Clay is important for the construction. This paper evaluates the strength...

Rheology of oil sands slurries

Energy Technology Data Exchange (ETDEWEB)

Chow, R.; Zhou, J. [Alberta Research Council, Edmonton, AB (Canada). Mineral Oil Sands Unit; Wallace, D. [Dean Wallace Consulting Inc., Beaumont, AB (Canada)

2006-07-01

This study focused on integrating rheology and colloid science to improve recovery of bitumen in surface mined oil sands. Factors that influence recovery, such as conditions of particle interaction, solids concentration and shear rate, were reviewed. In an effort to understand the rheological behaviour of clay-in-water suspensions, an elaborate procedure was developed to separate an inter-bedded clay layer from a site at Albian Sands Energy Inc. The variables were water chemistry, solids concentration, and shear rate. The research study was conducted at the Alberta Research Council with the support of the CONRAD Extraction Group. A controlled stress rheometer was used to provide the quantitative evaluations of the clay slurry properties. The research results indicate that the viscoelastic properties of the slurry are highly influenced by the shear history of the slurry, solids content, calcium concentration, and sample aging. Shear thinning behaviour was observed in all slurry samples, but the slurry viscosity increased with test time for a given shear rate. In order to classify the slurries, a method was developed to distinguish the gel strength. The slurries were then classified into 3 distinct patterns, including no gel, weak gel and strong gel. The evolution of the experimental protocols were described along with the current stability maps that correlate the domains of the gel strength according to the solids concentration, calcium ion content, and shear rate. It was concluded that the rheological properties of oil sands slurries influence bitumen recovery in commercial surface-mined oil sands operations. tabs., figs.

A new low-cost method of reclaiming mixed foundry waste sand based on wet-thermal composite reclamation

OpenAIRE

Fan Zitian; Liu Fuchu; Long Wei

2014-01-01

A lot of mixed clay-resin waste sand from large-scale iron foundries is discharged every day; so mixed waste sand reclamation in low cost and high quality has a great realistic significance. In the study to investigate the possibility of reusing two types of waste foundry sands, resin bonded sand and clay bonded sand which came from a Chinese casting factory, a new low-cost reclamation method of the mixed foundry waste sand based on the wet-thermal composite reclamation was proposed. The wast...

Eocene bituminous coal deposits of the Claiborne group, Webb County, Texas

Science.gov (United States)

Hook, Robert W.; Warwick, Peter D.; Warwick, Peter D.; Karlsen, Alexander K.; Merrill, Matthew D.; Valentine, Brett J.

2011-01-01

Two bituminous coal zones, the San Pedro and the Santo Tomas, in the middle Eocene Claiborne Group of Webb County, south Texas (Figure 1), are among the coal resources that are not evaluated quantitatively as part of the current Gulf Coastal Plain coal resource assessment. Coal beds within these zones were mined by underground methods northwest of Laredo until 1939 and have been intermittently mined at the surface since 1979. These coals have long been regarded as unique within the Gulf Coast Tertiary coal-bearing section because they are high-volatile C bituminous in rank and because their physical characteristics resemble upper Carboniferous cannel coals of the Appalachians and Europe.Discontinuous exposures of the Santo Tomas and the underlying San Pedro coal zone extend northwestward from Dolores for approximately 15 to 21 mi along the breaks of the Rio Grande and its tributaries in Webb County (Figure 1). This part of south Texas lies along the southwestern flank of the Rio Grande Embayment, which extends south and southeastwardly through the Mexican States of Coahuila, Nuevo León, and Tamaulipas (Figure 1). Within the embayment, the lower to middle part of the Claiborne Group consists of marine mudstones (Reklaw Formation) in the east and northeast and sandstones and mudstones (Bigford Formation) in the south and southwest (Figure 2). The marine mudstones coarsen upward into fluvial-deltaic sandstones (Queen City Sand) that prograded gulfward across eastern and central Texas (Guevara and Garcia, 1972). To the west and southwest, the interval overlying the Bigford Formation becomes less sandy, and claystones (El Pico Clay) predominate. Although the San Pedro coal zone has been placed traditionally near the top of the Bigford Formation and the Santo Tomas coal zone near the base of the El Pico Clay, recent work has failed to validate a mappable contact between these formations (Warwick and Hook, 1995). The coal beds dip northeast at less than 2 degrees towards

Effect of clay content in rock on oil extraction under alkaline seam conditions

Energy Technology Data Exchange (ETDEWEB)

Vezirov, D Sh; Gorbunov, A T; Kasimov, Sh A; Kashchavtsev, V E; Tairov, N D

1978-01-01

When oil beds are flooded with alkaline solutions, the alkaline concentration in the solution can be significantly reduced as a result of the interaction between clay and alkali. Large losses of alkali in the bed can render the flooding method ineffective. Experimental studies were conducted on porous media containing up to 25% clay at a constant permeability of 1 D in order to determine the oil extraction indices for clay-containing rock. Constant permeability is maintained by using clays, marshalite, and quartz sand in various proportions. Oil having a viscosity of 99.17 sP, and containing a large amount of surfactants, including 1.1% naphthenic acid, was extracted by fresh water and a 0.25% solution of NaOH. The extraction of oil by fresh water and NaOH solution from quartz sand indicated the advantage of using alkaline solutions. The extraction coefficient increased by 11% with the use of this method. As clay is added to the sand, the extraction coefficient decreases, and is reduced to 12.7% when the clay content reaches 25%. Nevertheless, a comparison of data obtained for quartz sand with fresh water on a porous medium containing 25% clay with an alkaline solution, indicates that the extraction coefficient is just 1.5% lower even in the presence of such a large amount of clay. Consequently, alkaline flooding should still be given preference over the usual methods under specific conditions and where the rock has a comparatively large amount of clay, in view of all the basic factors that influence the extraction process. The results obtained can be used for selecting alkaline concentration in evaluating the efficiency of flooding oil beds with alkaline solutions. 2 figures, 2 tables.

Dewatering Behaviour of Fine Oil Sands Tailings : An Experimental Study

NARCIS (Netherlands)

Yao, Y.

2016-01-01

Oil sands tailings are a warm aqueous suspension of sand, silt, clay, residual bitumen and naphtha. The tailings are hydraulically transported and stored in tailing ponds where they segregate, with the sand settling from suspension forming beaches and the remaining tailings flowing to the middle of

Transient electromagnetic mapping of clay units in the San Luis Valley, Colorado

Science.gov (United States)

Fitterman, David V.; Grauch, V.J.S.

2010-01-01

Transient electromagnetic soundings were used to obtain information needed to refine hydrologic models of the San Luis Valley, Colorado. The soundings were able to map an aquitard called the blue clay that separates an unconfined surface aquifer from a deeper confined aquifer. The blue clay forms a conductor with an average resistivity of 6.9 ohm‐m. Above the conductor are found a mixture of gray clay and sand. The gray clay has an average resistivity of 21 ohm‐m, while the sand has a resistivity of greater than 100 ohm‐m. The large difference in resistivity of these units makes mapping them with a surface geophysical method relatively easy. The blue clay was deposited at the bottom of Lake Alamosa which filled most of the San Luis Valley during the Pleistocene. The geometry of the blue clay is influenced by a graben on the eastern side of the valley. The depth to the blue clay is greater over the graben. Along the eastern edge of valley the blue clay appears to be truncated by faults.

Influence of clay mineralogy on clay based ceramic products

International Nuclear Information System (INIS)

Radzali Othman; Tuan Besar Tuan Sarif; Zainal Arifin Ahmad; Ahmad Fauzi Mohd Noor; Abu Bakar Aramjat

1996-01-01

Clay-based ceramic products can either be produced directly from a suitable clay source without the need further addition or such products can be produced from a ceramic body formulated by additions of other raw materials such as feldspar and silica sand. In either case, the mineralogical make-up of the clay component plays a dominating role in the fabrication and properties of the ceramic product. This study was sparked off by a peculiar result observed in one of five local ball clay samples that were used to reformulate a ceramic body. Initial characterisation tests conducted on the clays indicated that these clays can be classified as kaolinitic. However, one of these clays produced a ceramic body that is distinctively different in terms of whiteness, smoothness and density as compared to the other four clays. Careful re-examination of other characterisation data, such as particle size distribution and chemical analysis, failed to offer any plausible explanation. Consequently, the mineralogical analysis by x-ray diffraction was repeated by paying meticulous attention to specimen preparation. Diffraction data for the clay with anomalous behaviour indicated the presence of a ∼ 10A peak that diminished when the same specimen was re-tested after heating in an oven at 12O degree C whilst the other four clays only exhibit the characteristic kaolinite (Al sub 2 O sub 3. 2SiO sub 2. 2H sub 2 0) and muscovite peaks at ∼ 7A and ∼ 10A before and after heat treatment. This suggests the presence of the mineral halloysite (A1 sub 2 0 sub 3. 2SiO sub 2.4H sub 2 0) in that particular clay. This difference in mineralogy can be attributed to account for the variations in physical properties of the final product. Consequently, this paper reviews in general the precautionary measures that must be adhered to during any mineralogical investigation of clay minerals or clay-based materials. The common pitfalls during specimen preparation, machine settings and interpretation of

Utilization of crushed clay brick in cellular concrete production

Directory of Open Access Journals (Sweden)

Ali A. Aliabdo

2014-03-01

Full Text Available The main objective of this research program is to study the effect of using crushed clay brick as an alternative aggregate in aerated concrete. Two series of mixtures were designed to investigate the physico-mechanical properties and micro-structural analysis of autoclave aerated concrete and foamed concrete, respectively. In each series, natural sand was replaced with crushed clay brick aggregate. In both series results showed a significant reduction in unit weight, thermal conductivity and sound attenuation coefficient while porosity has increased. Improvement on compressive strength of autoclave aerated concrete was observed at a percentage of 25% and 50% replacement, while in foamed concrete compressive strength gradually decreased by increasing crushed clay brick aggregate content. A comparatively uniform distribution of pore in case of foamed concrete with natural sand was observed by scanning electron microscope, while the pores were connected mostly and irregularly for mixes containing a percentage higher than 25% clay brick aggregate.

Reclaimability of the spent sand mixture – sand with bentonite – sand with furfuryl resin

Directory of Open Access Journals (Sweden)

J. Dańko

2011-04-01

Full Text Available Introduction of new binding materials and new technologies of their hardening in casting moulds and cores production requires theapplication of reclamation methods adequate to their properties as well as special devices realizing tasks. The spent sands circulationsystem containing the same kind of moulding and core sands is optimal from the point of view of the expected reclamation results.However, in the face of a significant variability of applied technologies and related to them various reclamation methods, the need - of theobtained reclamation products assessment on the grounds of systematic criteria and uniform bases – arises, with a tendency of indicatingwhich criteria are the most important for the given sand system. The reclaimability results of the mixture of the spent moulding sand withGeko S bentonite and the spent core sand with the Kaltharz 404U resin hardened by acidic hardener 100 T3, are presented in the paper.Investigations were performed with regard to the estimation of an influence of core sands additions (10 –25% on the reclaimed materialquality. Dusts and clay content in the reclaim, its chemical reaction (pH and ignition loss were estimated. The verification of the reclaiminstrumental assessment was performed on the basis of the technological properties estimation of moulding sand with bentonite, where the reclaimed material was used as a matrix.

Preliminary study of sand jets in water-capped artificial and real MFT

Energy Technology Data Exchange (ETDEWEB)

Cai, J.; Zhu, D.; Rajaratnam, N. [Alberta Univ., Edmonton, AB (Canada). Dept. of Civil and Environmental Engineering

2008-07-01

A preliminary study of sand jets in water-capped artificial and real MFT was presented. Background information on oil sands tailing reclamation including water capping and sand capping were first discussed, followed by background information to the study, including non-Newtonian fluids and laponite clay, the artificial clay used mainly in small amounts as a rheology modifier in industrial fluids and materials. Although laponite clay is insoluble in water, it hydrates to make a clear and colourless colloidal, which is thixotropic and also behaves as a Bingham plastic fluid. The benefit of using gels made from laponite is the ability to see through to observe the physical processes in it. The objectives of the study were to examine the dynamics of sand jets in water-capped laponite gel and real MFT; improve the understanding of physical processes related to MFT and sand/slurry operations in tailings ponds; and find potential applications in recycling processed water and decommissioning of tailings ponds. It was concluded that it is much more difficult for jets to penetrate water-capped MFT due to larger yield stress in MFT. Future studies will focus on density correction, viscosity adjustment, and sensitivity analysis. tabs., figs.

Effects of clay mineral type and organic matter on the uptake of radiocesium by pasture plants

International Nuclear Information System (INIS)

D'Souza, T.J.

1980-10-01

Studies were undertaken to examine the influence of interaction of clay minerals and organic matter on the uptake of radiocesium by two pasture plants, namely, ryegrass (Lolium italicum L) and red clover (Trifolium pratense L). The clay minerals used were bentonite (2.1 layer type) and kaolinite (1/1 layer type). Mixtures of clay and sand were prepared with 0.5, 10, 20 and 40 per cent clay and treated with organic matter (forest turf) at 0,5 and 10 per cent of the clay-sand mixtures. Results indicated that 134 Cs uptake by plants grown on the kaolinite-clay medium was greater than that on the bentonite-clay medium at a given organic matter level. Increasing the clay content of mixtures resulted in reduction in 134 Cs uptake by both plant species. The plant uptake of 134 Cs increased with additions of organic matter at a given clay content. (author)

A Classification of Clay-Rich Subaqueous Density Flow Structures

NARCIS (Netherlands)

Hermidas, N.; Eggenhuisen, Joris T.; Jacinto, Ricardo Silva; Luthi, S.M.; Toth, Ferenc; Pohl, Florian

2018-01-01

This study presents a classification for subaqueous clay-laden sediment gravity flows. A series of laboratory flume experiments were performed using 9%, 15%, and 21% sediment mixture concentrations composed of sand, silt, clay, and tap water, on varying bed slopes of 6°, 8°, and 9.5°, and with

Anatomy of a shoreface sand ridge revisted using foraminifera: False Cape Shoals, Virginia/North Carolina inner shelf

Science.gov (United States)

Robinson, Marci M.; McBride, Randolph A.

2008-01-01

Certain details regarding the origin and evolution of shelf sand ridges remain elusive. Knowledge of their internal stratigraphy and microfossil distribution is necessary to define the origin and to determine the processes that modify sand ridges. Fourteen vibracores from False Cape Shoal A, a well-developed shoreface-attached sand ridge on the Virginia/North Carolina inner continental shelf, were examined to document the internal stratigraphy and benthic foraminiferal assemblages, as well as to reconstruct the depositional environments recorded in down-core sediments. Seven sedimentary and foraminiferal facies correspond to the following stratigraphic units: fossiliferous silt, barren sand, clay to sandy clay, laminated and bioturbated sand, poorly sorted massive sand, fine clean sand, and poorly sorted clay to gravel. The units represent a Pleistocene estuary and shoreface, a Holocene estuary, ebb tidal delta, modern shelf, modern shoreface, and swale fill, respectively. The succession of depositional environments reflects a Pleistocene sea-level highstand and subsequent regression followed by the Holocene transgression in which barrier island/spit systems formed along the Virginia/North Carolina inner shelf not, vert, ~5.2 ka and migrated landward and an ebb tidal delta that was deposited, reworked, and covered by shelf sand.

Bedform development in mixed sand-mud: The contrasting role of cohesive forces in flow and bed

Science.gov (United States)

Baas, Jaco H.; Davies, Alan G.; Malarkey, Jonathan

2013-01-01

The majority of subaqueous sediment on Earth consists of mixtures of cohesive clay and cohesionless sand and silt, but the role of cohesion on the development and stability of sedimentary bedforms is poorly understood. The results of new laboratory flume experiments on bedform development in cohesive, mixed sand-mud beds are compared with the results of previous experiments in which cohesive forces in high concentration clay flows dominated bedform development. Even though both series of mixed sand-mud experiments were conducted at similar flow velocities, the textural and structural properties of the bedforms were sufficiently different to permit the designation of key criteria for identifying bedform generation under cohesive flows against bedform generation on cohesive substrates. These criteria are essential for improving bedform size predictions in sediment transport modelling in modern sedimentary environments and for the reconstruction of depositional processes in the geological record. The current ripples developing on the cohesive, mixed sand-mud beds, with bed mud fractions of up to 18%, were significantly smaller than equivalent bedforms in noncohesive sand. Moreover, the bedform height showed a stronger inversely proportional relationship with initial bed mud fraction than the bedform wavelength. This is in contrast with the bedforms developing under the cohesive clay flows, which tend to increase in size with increasing suspended clay concentration until the flow turbulence is fully suppressed. Selective removal of clay from the mixed beds, i.e., clay winnowing, was found to be an important process, with 82-100% clay entrained into suspension after 2 h of bedform development. This winnowing process led to the development of a sand-rich armouring layer. This armouring layer is inferred to have protected the underlying mixed sand-mud from prolonged erosion, and in conjunction with strong cohesive forces in the bed may have caused the smaller size of the

Clay preference and particle transport behavior of Formosan subterranean termites (Isoptera: Rhinotermitidae): a laboratory study.

Science.gov (United States)

Wang, Cai; Henderson, Gregg

2014-12-01

Although preference and utilization of clay have been studied in many higher termites, little attention has been paid to lower termites, especially subterranean termites. The Formosan subterranean termite, Coptotermes formosanus Shiraki, can modify its habitat by using clay to fill tree cavities. Here, the biological significance of clay on C. formosanus was investigated. Choice tests showed that significantly more termites aggregated in chambers where clay blocks were provided, regardless of colony group, observation period, or nutritional condition (fed or starved). No-choice tests showed that clay had no observable effect on survivorship, live or dry biomass, water content, and tunneling activity after 33-35 d. However, clay appeared to significantly decrease filter paper consumption (dry weight loss). Active particle (sand, paper, and clay) transport behavior was observed in both choice and no-choice tests. When present, clay was preferentially spread on the substrate, attached to the smooth surfaces of the containers, and used to line sand tunnels. Mechanisms and potential application of clay attraction are discussed. © 2013 Institute of Zoology, Chinese Academy of Sciences.

Treatment and Conditioning of Radioactive Waste Solution by Natural Clay Minerals

International Nuclear Information System (INIS)

El-Dessouky, M.I.; Abdel-Raouf, M.W.; El-Massry, E.H.; Khalifa, S.M.; Aly, H.F.

1999-01-01

Chemical precipitation processes have been used for the treatment of radioactive elements from aqueous solution. The volume reduction is not very great and storage facilities are expensive. There are some radionuclides which are so difficult to be precipitated by this common method, so they may be precipitated by adding solid materials such as natural inorganic exchangers. In this woek, improvement the removal of caesium, cobalt and europium with zinc sulfate as coagulant and different clay minerals have been investigated. These include, Feldespare, Aswanly, Bentionite, Hematite, Mud, Calcite, Basalt, Magnetite, Kaoline, Sand stone, Limonite and Sand. The parameters affecting the precipitation process such as pH, particle size, temperature and weight of the clay have been studied. The results indicate that, the highest removal for Cs-137, Co-60 and Eu-152 and154 by Asswanly, Bentonite and Sand stone is more than the other clays. Removal of Cs-137 from low level waste solution with these three natural clays took the sequence, Aswanly (85.5%) > Bentonite (82.2%) > Sandstone (65.4%). Solidified cement products have been evaluated to determine mechanical strength and leaching rates of the waste products. The solidified waste forms were found more acceptable for handling ,storage and ultimate disposal

Postsedimentary Alterations of Coal-bearing Rocks and New Factors Affecting their Quality and Ingredient Composition as Exemplified by the Akhaltsikhe Brown Coal Deposit (Georgia)

International Nuclear Information System (INIS)

Maghalashvili, G.

2008-01-01

It has been established that in the case when coal-bearing rocks are represented by bentonitic clays, coal undergoes significant alterations, for the bentonitic clays, as a strong absorbent, absorb from the coal under conditions of natural humidity part of organics (humic acids, gums and other moving composite substances) thus depleting the coal, increasing its ash content and accordingly decreasing its calorific capacity. In this case it is expedient to exploit the coal and ''black'' or organics-saturated rocks selectively. It has also been established that the organics-saturated ''black'' bentonite is an excellent organic and mineral fertilizer that has been tested by the autor in the patented man-made soil. At the same time, in the case of coal briquetting, it may be used as a bonding material. (author)

Estimation of bitumen and clay content in fine tailings

International Nuclear Information System (INIS)

Motta Cabrera, S.C.; Bryan, J.; Kantzas, A.

2007-01-01

Fine tailings are the components of tailings ponds and the by-product of the oil sand extraction process, consisting mostly of water with small amounts of bitumen, sand, silts and clays. Because of the large volumes of tailings, an important environmental and production process issue involves the reduction of the remaining bitumen in the tailings stream. This paper presented the results of a study that used low field nuclear magnetic resonance (NMR) in order to estimate the bitumen, clay and water content of synthetic tailings samples. NMR is a non-destructive technique that is utilized to determine compositions of oil and brine emulsions and the viscosity of heavy oil and bitumen as well as in reservoir characterization, measuring properties such as permeability, porosity, mobile and immobile fluids, and fluid saturations. The study prepared and tested numerous samples with variable water, bitumen, sand and clay concentrations in the NMR tool under ambient conditions. Two qualities of water and bitumen were used to prepare the synthetic samples. Each type of water and bitumen was analyzed as a single substance and in a mixture with the typical solids found in tailings composition. These included kaolinite, illite, sodium montmorillonite and sand. These synthetic samples were analyzed using different mixing configurations, as a function of time and in two different NMR tools. It was concluded that NMR is a potential application for on-line determination of tailings streams composition. 18 refs., 3 tabs., 17 figs

Naphtha interaction with bitumen and clays : a preliminary study

Energy Technology Data Exchange (ETDEWEB)

Afara, M.; Munoz, V.; Mikula, R. [Natural Resources Canada, Devon, AB (Canada). CANMET Western Research Centre

2010-07-01

This PowerPoint presentation described a preliminary study conducted to characterize naphtha interactions with bitumen and clays. Coarse tailings, fluid-fine tailings, and froth treatment tailings are produced as a result of surface mine oil sands operations. Solvents are used to produce the bitumens, but the actual fraction of the solvent that evaporates and contributes to VOCs from tailing ponds is poorly understood. This study examined the interactions between the solvent, bitumen and mineral components in froth treatment tails. The study was conducted with aim of quantifying the VOC or solvent escaping from the froth treatment tailings. Samples containing bitumen, clay, a bitumen-clay mixture, or MFT were spiked with 3000 ppm of solvent. The amount of naphtha released was monitored by gas chromatography, mass spectrometry, and flame ionization detection of the evolved gases. The results were expressed as a percentage of the total hydrocarbon peak area of the sample versus a control. Results of the study showed that the naphtha interacted more strongly with the bitumen than with kaolinite and the clay minerals from the oil sands. Although initial solvent evaporation was reduced in the presence of bitumens and clays, long-term solvent releases will need to be quantified. tabs., figs.

Catalysis of gas hydrates by biosurfactants in seawater-saturated sand/clay

Energy Technology Data Exchange (ETDEWEB)

Rogers, R. E.; Kothapalli, C.; Lee, M.S. [Mississippi State University, Swalm School of Chemical Engineering, MS (United States); Woolsey, J. R. [University of Mississippi, Centre of Marine Resources and Environmental Technology, MS (United States)

2003-10-01

Large gas hydrate mounds have been photographed in the seabed of the Gulf of Mexico and elsewhere. According to industry experts, the carbon trapped within gas hydrates is two or three times greater than all known crude oil, natural gas and coal reserves in the world. Gas hydrates, which are ice-like solids formed from the hydrogen bonding of water as water temperature is lowered under pressure to entrap a suitable molecular-size gas in cavities of the developing crystal structure, are found below the ocean floor to depths exhibiting temperature and pressure combinations within the appropriate limits. The experiments described in this study attempt to ascertain whether biosurfactant byproducts of microbial activity in seabeds could catalyze gas hydrate formation. Samples of five possible biosurfactants classifications were used in the experiments. Results showed that biosurfactants enhanced hydrate formation rate between 96 per cent and 288 percent, and reduced hydrate induction time 20 per cent to 71 per cent relative to the control. The critical micellar concentration of rhamnolipid/seawater solution was found to be 13 ppm at hydrate-forming conditions. On the basis of these results it was concluded that minimal microbial activity in sea floor sands could achieve the threshold concentration of biosurfactant that would greatly promote hydrate formation. 28 refs., 2 tabs., 4 figs.

Evaluation of sand reserves in del Plata City

International Nuclear Information System (INIS)

Loureiro, J.

2014-01-01

The purpose of this study is to evaluate the reserve of sand in the zone of del Plata city and beyond. This area is located in the S E edge of the department of San Jose near the mouth of Santa Lucia river. In this zone was identified the mantle of potentially exploitable sand which are based on their particle size, composition and depth of the limits cape. There are two powerful capes of sand separated by clay and silt

Automated mineralogical logging of coal and coal measure core

Energy Technology Data Exchange (ETDEWEB)

Stephen Fraser; Joan Esterle; Colin Ward; Ruth Henwood; Peter Mason; Jon Huntington; Phil Connor; Reneta Sliwa; Dave Coward; Lew Whitbourn [CSIRO Exploration & Mining (Australia)

2006-06-15

A mineralogical core logging system based on spectral reflectance (HyLogger{trademark}) has been used to detect and quantify mineralogies in coal and coal measure sediments. The HyLogger{trademark} system, as tested, operates in the visible-to-shortwave infrared spectral region, where iron oxides, sulphates, hydroxyl-bearing and carbonate minerals have characteristic spectral responses. Specialized software assists with mineral identification and data display. Three Phases of activity were undertaken. In Phase I, carbonates (siderite, ankerite, calcite) and clays (halloysite, dickite) were successfully detected and mapped in coal. Repeat measurements taken from one of the cores after three months demonstrated the reproducibility of the spectral approach, with some spectral differences being attributed to variations in moisture content and oxidation. Also, investigated was HyLogger{trademark} ability to create a 'brightness-profile' on coal materials, and these results were encouraging. In Phase II, geotechnically significant smectitic clays (montmorillonite) were detected and mapped in cores of clastic roof and floor materials. Such knowledge would be useful for mine planning and design purposes. In Phase III, our attempts at determining whether phosphorus-bearing minerals such as apatite could be spectrally detected were less than conclusive. A spectral index could only be created for apatite, and the relationships between the spectrally-derived apatite-index, the XRD results and the analytically-derived phosphorus measurements were ambiguous.

Effects of Moisture Content on the Foundry Properties of Yola Natural Sand

Directory of Open Access Journals (Sweden)

Paul Aondona IHOM

2012-08-01

Full Text Available The effect of moisture content of Yola natural sand has been studied. The moisture content was varied from 1 to 9%. The effect of the moisture content on the green compression strength, green permeability and bulk density was investigated. Particle size distribution of the natural sand, the grain fineness number, average grain size, grain shape and the clay content of the natural sand were also studied. 5% moisture gave the optimum green compression strength of 118.6KN/m2. The dry compression strength increased with moisture content, an optimum value of 4000KN/m2 was obtained at 9% moisture. The Yola natural sand had a grain fineness number of 88.05AFS, average grain size of 335.78 microns and a clay content of 26%. A sand mixture containing 5% moisture was prepared and used to produce a test casting with aluminium scraps, the test casting was sound.

[Carbon sequestration in soil particle-sized fractions during reversion of desertification at Mu Us Sand land.

Science.gov (United States)

Ma, Jian Ye; Tong, Xiao Gang; Li, Zhan Bin; Fu, Guang Jun; Li, Jiao; Hasier

2016-11-18

The aim of this study was to investigate the effects of carbon sequestration in soil particle-sized fractions during reversion of desertification at Mu Us Sand Land, soil samples were collected from quicksand land, semifixed sand and fixed sand lands that were established by the shrub for 20-55 year-old and the arbor for 20-50 year-old at sand control region of Yulin in Northern Shaanxi Province. The dynamics and sequestration rate of soil organic carbon (SOC) associated with sand, silt and clay were measured by physical fractionation method. The results indicated that, compared with quicksand area, the carbon content in total SOC and all soil particle-sized fractions at bothsand-fixing sand forest lands showed a significant increasing trend, and the maximum carbon content was observed in the top layer of soils. From quicksand to fixed sand land with 55-year-old shrub and 50-year-old arbor, the annual sequestration rate of carbon stock in 0-5 cm soil depth was same in silt by 0.05 Mg·hm -2 ·a -1 . The increase rate of carbon sequestration in sand was 0.05 and 0.08 Mg·hm -2 ·a -1 , and in clay was 0.02 and 0.03 Mg·hm -2 ·a -1 at shrubs and arbors land, respectively. The increase rate of carbon sequestration in 0-20 cm soil layer for all the soil particles was averagely 2.1 times as that of 0-5 cm. At the annual increase rate of carbon, the stock of carbon in sand, silt and clay at the two fixed sand lands were increased by 6.7, 18.1 and 4.4 times after 50-55 year-old reversion of quicksand land to fixed sand. In addition, the average percentages that contributed to accumulation of total SOC by different particles in 0-20 cm soil were in the order of silt carbon (39.7%)≈sand carbon (34.6%) > clay carbon (25.6%). Generally, the soil particle-sized fractions had great carbon sequestration potential during reversion of desertification in Mu Us Sand Land, and the slit and sand were the main fractions for carbon sequestration at both fixed sand lands.

PCE and BNS admixture adsorption in sands with different composition and particle size distribution

International Nuclear Information System (INIS)

Alonso, M.M.; Martínez-Gaitero, R.; Gismera-Diez, S.; Puertas, F.

2017-01-01

The choice of a superplasticiser (SP) for concrete is of great complexity, as it is well known that properties of the end product are related to admixture and its compatibility with concrete components. Very few studies have been conducted on the compatibility between SPs and the sand of mortars and concretes, however. Practical experience has shown that sand fineness and mineralogical composition affect water demand and admixture consumption. Clay-containing sand has been found also to adsorb SPs, reducing the amount available in solution for adsorption by the cement. This study analysed the isotherms for PCE and BNS superplasticiser adsorption on four sands with different fineness and compositions commonly used to prepare mortars and concretes. BNS-based SP did not adsorb on sands, while PCE-based admixtures exhibited variable adsorption depending on different factors. The adsorption curves obtained revealed that the higher the sand fineness, the finer the particle size distribution and the higher the clay material, the greater was PCE admixture adsorption/ consumption. [es

PCE and BNS admixture adsorption in sands with different composition and particle size distribution

Directory of Open Access Journals (Sweden)

M. M. Alonso

2017-02-01

Full Text Available The choice of a superplasticiser (SP for concrete is of great complexity, as it is well known that properties of the end product are related to admixture and its compatibility with concrete components. Very few studies have been conducted on the compatibility between SPs and the sand of mortars and concretes, however. Practical experience has shown that sand fineness and mineralogical composition affect water demand and admixture consumption. Clay-containing sand has been found also to adsorb SPs, reducing the amount available in solution for adsorption by the cement. This study analysed the isotherms for PCE and BNS superplasticiser adsorption on four sands with different fineness and compositions commonly used to prepare mortars and concretes. BNS-based SP did not adsorb on sands, while PCE-based admixtures exhibited variable adsorption depending on different factors. The adsorption curves obtained revealed that the higher the sand fineness, the finer the particle size distribution and the higher the clay material, the greater was PCE admixture adsorption/ consumption.

Characterization of oils sands thickened tailings

Energy Technology Data Exchange (ETDEWEB)

Scott, J.D.; Jeeravipoolvarn, S.; Donahue, R.; Ozum, B. [Alberta Univ., Edmonton, AB (Canada). Dept. of Civil and Environmental Engineering

2008-07-01

This presentation discussed the characterization of oils sands thickened tailings. The problem statement was defined as the fact that many laboratory procedures to characterize fine tailings do not take into account the extraction process, and instead use standardized laboratory tests. The purpose of this presentation was to demonstrate how different extraction processes affect the fine tailings geotechnical properties and water chemistry. Properties that were characterized included particle size analysis from hydrometer-sieve tests; per cent clay from methylene blue tests; per cent clay from mineralogy tests; Atterberg limits; water chemistry; and morphology by scanning electron microscopy. The presentation discussed the origin of fines (silt and clay) in tailings; where fine particles come from; tailings materials; mineralogy of tailings; the hydrometer-sieve test on fine tailings and thickened tailings; and the methylene blue test. It was concluded that the great majority of clay minerals in the tailings come from the clay-shale discontinuous seams and layers. For thickened tailings, the dispersed and non-dispersed hydrometer tests show considerable difference in the amount of clay size material. tabs., figs.

The future of water quality and the regulatory environment for the oil sands and coalbed methane development

International Nuclear Information System (INIS)

Kasperski, K.; Mikula, R.

2004-01-01

The use of consolidated tailings in recent years for the surface mined oil sands bitumen extraction process has resulted in major improvements in water consumption because materials are transported more efficiently in a slurry form. Water storage requirements will be reduced as the cost of handling tailings in the conventional manner becomes clearer. Future improvements may be in the form of mine face sand rejection, more advanced tailings treatment, or the use of clays for continuous reclamation. Sand filtering or stacking technologies can improve tailings properties and reduce the amount of water needed per unit of bitumen. It was noted that although the technologies will minimize land disturbance and fresh water consumption, water chemistries will be driven to the point where extraction recovery is impaired and water treatment will be required. The volumes and quality of water that is pumped out to produce coalbed methane (CBM) was also discussed with reference to the origin of water in coal beds, water resource depletion, water disposal, direct land applications, and surface evaporation. The Alberta Energy and Utilities Board and Alberta Environment are responsible for regulating CBM water issues in the province, including water disposal from CBM production. 41 refs., 6 tabs., 8 figs

Groundwater impact studies at three Ontario Hydro coal ash landfills

International Nuclear Information System (INIS)

Johnston, H.M.; Vorauer, A.G.; Chan, H.T.

1992-01-01

Ontario Hydro has produced on the order of 21 million Mg of coal fly ash over the past 40 years, of which, 80% has gone to various landfill sites in the province of Ontario. Hydrogeologic investigations have been performed in the vicinity of three Ontario Hydro coal ash landfill sites to assess the environmental impact of fly ash landfilling on the local groundwater regime. Two of the waste management facilities are associated with thermal generating stations (Lambton TGS and Nanticoke TGS) and are founded on relatively impermeable clay deposits. The third site, Birchwood Park, is a former sand and gravel pit for which the landfill design did not incorporate the use of a liner material. The rates of groundwater flow through the overburden materials a the three sites vary from less than 1 cm/a at the Lambton TGS site, to between 3.45 cm/a and 115 cm/a at contaminant transport at these sites also varies from being controlled by molecular diffusion to advection. This paper discusses the migration rates of contaminants from fly ash leachate at each of the three sites with implications to landfill containment and design

Fluidized bed dry dense medium coal beneficiation

CSIR Research Space (South Africa)

North, Brian C

2017-10-01

Full Text Available medium beneficiation using a fluidized bed was investigated. Bed materials of sand, magnetite and ilmenite were used in a laboratory sized cylindrical fluidized bed. The materials were individually tested, as were mixes of sand and heavy minerals. Coal...

Application of the coal-mining waste in building ceramics production

Directory of Open Access Journals (Sweden)

Vaysman Yakov Iosifovich

Full Text Available In the process of construction ceramics production a substantial quantity of non-renewable natural resources - clays - are used. One of the ways of science development in building materials production is investigation of the possibility of regular materials production using technogenic waste. Application of coal-mining waste (technogenic raw material in charge composition for production of ceramic products provides rational use of fuel, contributes to implementation of resource saving technologies on construction materials production enterprises. Though science development on revealing new raw material sources should be conducted with account for safety, reliability, technical, ecological and economical sides of the problem, which is especially current. The article deals with the problem of coal-mining waste usage in building ceramics production instead of fresh primary component (clay, fluxes, thinning agents and combustible additives. The interdependence between the density and shrinkage of the ceramic products and the amount and quality of coal-mining waste in its composition was established. The optimal proportion of coal-mining waste and clay in building ceramics production was estimated.

Retention and loss of water extractable carbon in soils: effect of clay properties.

Science.gov (United States)

Nguyen, Trung-Ta; Marschner, Petra

2014-02-01

Clay sorption is important for organic carbon (C) sequestration in soils, but little is known about the effect of different clay properties on organic C sorption and release. To investigate the effect of clay content and properties on sorption, desorption and loss of water extractable organic C (WEOC), two experiments were conducted. In experiment 1, a loamy sand alone (native) or mixed with clay isolated from a surface or subsoil (78 and 96% clay) resulting in 90, 158 and 175 g clay kg(-1) soil. These soil treatments were leached with different WEOC concentrations, and then CO2 release was measured for 28 days followed by leaching with reverse osmosis water at the end of experiment. The second experiment was conducted to determine WEOC sorption and desorption of clays isolated from the loamy sand (native), surface soil and subsoil. Addition of clays isolated from surface and subsoil to sandy loam increased WEOC sorption and reduced C leaching and cumulative respiration in percentage of total organic C and WEOC added when expressed per g soil and per g clay. Compared to clays isolated from the surface and subsoil, the native clay had higher concentrations of illite and exchangeable Ca(2+), total organic C and a higher CEC but a lower extractable Fe/Al concentration. This indicates that compared to the clay isolated from the surface and the subsoil, the native clay had fewer potential WEOC binding sites because it had lower Fe/Al content thus lower number of binding sites and the existing binding sites are already occupied native organic matter. The results of this study suggest that in the soils used here, the impact of clay on WEOC sorption and loss is dependent on its indigenous organic carbon and Fe and/or Al concentrations whereas clay mineralogy, CEC, exchangeable Ca(2+) and surface area are less important. © 2013.

Content and distribution of fluorine in rock, clay and water in fluorosis area Zhaotong, Yunnan Province

Energy Technology Data Exchange (ETDEWEB)

Luo, K.; Li, H.; Feng, F. (and others) [Chinese Academy of Sciences, Beijing (China)

2007-04-15

About 160 samples of coal, pyritic coal balls, coal seam gangue, clay, corn, capsicum and drinking water were collected from the endemic fluorosis area of Zhenxiong and Weixin county, China to determine the fluorine content, distribution pattern and source in this fluorosis area. The study shows that the average fluorine content in the coal samples collected from 3 coal mines of the Late Permian coals in Zhenxiong and Weixin county, Zhaotong City, which are the main mining coals there, is 77.13 mg/kg. The average fluorine content coals collected form thee typical fluorosis villages in 72.56 mg/kg. Both of them are close to the world average and little low than the Chinese average. The fluorine content of drinking water is lower than 0.35 mg/L, the clay used as an additive for coal-burning and as a binfer in briquette-making by local residents has a high content of fluorine, ranging from 367-2,435 mg/kg, with the majority higher than 600 mg/kg and an average of 1,084.2 mg/kg. 29 refs., 5 tabs.

BRICKS WITH TOTAL REPLACEMENT OF CLAY BY FLY ASH MIXED WITH DIFFERENT MATERIALS

OpenAIRE

J.N Akhtar; J.Alam; M.N Akhtar

2011-01-01

Fly ash is a powdery substance obtained from the dust collectors in the Thermal power plants that use coal as fuel. From the cement point of view the mineralogy of Fly ash is important as it contains 80% - 90% of glass. The impurities in coal-mostly clays, shale’s, limestone & dolomite; they cannot be burned so they turn up as ash. The Fly ash of class C category was used as a raw material to total replacement of clay for making Fly ash bricks. In present study the effect of Fly ash with high...

A cost comparison of nuclear and fossil power for the Alberta tar sands

International Nuclear Information System (INIS)

Sochaski, R.O.; Smith, D.W.

1977-04-01

One technique envisaged for commercial development of the Alberta tar sands is in-situ removal of bitumen by injection of steam into the formation at high temperature and pressure. The 3000 MW of thermal power required for a typical 20 Gg/d plant could be supplied by a nuclear reactor. Accordingly, an economic comparison was made between a CANDU organic-cooled reactor and a conventional coal-fired station, using a variety of financial ground rules. This analysis shows that for debt-financed cases, nuclear power has essentially no economic competition from coal. For equity cases, the competitive position of a coal-fired station is heavily dependent on the cost of coal delivered to the tar sands area, discount rate, amortization period and inflation rate. (author)

Mechanism of groundwater arsenic removal by goethite-coated mineral sand

Science.gov (United States)

Cashion, J. D.; Khan, S. A.; Patti, A. F.; Adeloju, S.; Gates, W. P.

2017-11-01

Skye sand (Vic, Australia) has been considered for arsenic removal from groundwater. Analysis showed that the silica sand is coated with poorly crystalline goethite, hematite and clay minerals. Mössbauer spectra taken following arsenic adsorption revealed changes in the recoilless fraction and relaxation behaviour of the goethite compared to the original state, showing that the goethite is the main active species.

Fuel options for oil sands

International Nuclear Information System (INIS)

Wise, T.

2005-01-01

This presentation examined fuel options in relation to oil sands production. Options include steam and hydrogen (H 2 ) for upgrading; natural gas by pipeline; bitumen; petroleum coke; and coal. Various cost drivers were also considered for each of the fuel options. It was noted that natural gas has high energy value but the capital cost is low, and that coke's energy value is very low but the capital cost is high. A chart forecasting energy prices was presented. The disposition of Western Canada's northern gas situation was presented. Issues concerning rail transportation for coal were considered. Environmental concerns were also examined. A chart of typical gas requirements for 75,000 B/D oil sands projects was presented. Issues concerning steam generation with gas and mining cogeneration with gas fuel and steam turbines were discussed, as well as cogeneration and H 2 with gas fuels and steam turbines. Various technology and fuel utility options were examined, along with details of equipment and processes. Boiler technologies were reviewed by type as well as fuel and steam quality and pressure. Charts of cogeneration with gas turbine and circulation fluid bed boilers were presented. Gasification processes were reviewed and a supply cost basis was examined. Cost drivers were ranked according to energy, operating considerations and capital investment. Results indicated that fuel costs were significant for gas and coal. Capital costs and capital recovery charge was most significant with coal and gasification technology. Without capital recovery, cash costs favour the use of bitumen and coke. Gasification would need lower capital and lower capital recovery to compete with direct burning. It was concluded that direct burning of bitumen can compete with natural gas. With price volatility anticipated, dual fuel capability for bitumen and gas has merit. Petroleum coke can be produced or retrieved from stockpiles. Utility supply costs of direct burning of coke is

Microbially-accelerated consolidation of oil sands tailings. Pathway I: changes in porewater chemistry.

Science.gov (United States)

Siddique, Tariq; Kuznetsov, Petr; Kuznetsova, Alsu; Arkell, Nicholas; Young, Rozlyn; Li, Carmen; Guigard, Selma; Underwood, Eleisha; Foght, Julia M

2014-01-01

Dispersed clay particles in mine tailings and soft sediments remain suspended for decades, hindering consolidation and challenging effective management of these aqueous slurries. Current geotechnical engineering models of self-weight consolidation of tailings do not consider microbial contribution to sediment behavior, however, here we show that microorganisms indigenous to oil sands tailings change the porewater chemistry and accelerate consolidation of oil sands tailings. A companion paper describes the role of microbes in alteration of clay chemistry in tailings. Microbial metabolism in mature fine tailings (MFT) amended with an organic substrate (hydrolyzed canola meal) produced methane (CH4) and carbon dioxide (CO2). Dissolution of biogenic CO2 lowered the pH of amended MFT to pH 6.4 vs. unamended MFT (pH 7.7). About 12% more porewater was recovered from amended than unamended MFT during 2 months of active microbial metabolism, concomitant with consolidation of tailings. The lower pH in amended MFT dissolved carbonate minerals, thereby releasing divalent cations including calcium (Ca(2+)) and magnesium (Mg(2+)) and increasing bicarbonate (HCO(-) 3) in porewater. The higher concentrations increased the ionic strength of the porewater, in turn reducing the thickness of the diffuse double layer (DDL) of clay particles by reducing the surface charge potential (repulsive forces) of the clay particles. The combination of these processes accelerated consolidation of oil sands tailings. In addition, ebullition of biogenic gases created transient physical channels for release of porewater. In contrast, saturating the MFT with non-biogenic CO2 had little effect on consolidation. These results have significant implications for management and reclamation of oil sands tailings ponds and broad importance in anaerobic environments such as contaminated harbors and estuaries containing soft sediments rich in clays and organics.

Moisture distribution computed from electrical impedance tomographic data of a bentonite clay/sand material

International Nuclear Information System (INIS)

Strobel, G.S.

1995-11-01

Moisture contents values were calculated from electrical impedance-computed tomography measurements and compared with thermocouple psychrometer moisture values. The measurements were taken, in situ and under isothermal conditions, in a bentonite clay/sand packed borehole at the Underground Research Laboratory. Two sets of impedances moisture contents were calculated from the impedance valves--independent of each other. For one set, impedance measurements were fitted to the psychrometer moisture values in a least-squares fit to a generalized calibration curve and, for the second set, an impedance-moisture relationship from laboratory calibrations was applied. The impedance-computed moisture content data showed low scatter and the trends were consistent between the three sets of values. However, the moisture content data computed from the calibration curve were more consistent with those expected from physical arguments. The moisture values from the psychrometer readings were offset and, consequently, so were those produced after applying the fitting strategy. Internal redistribution of moisture appears to have had a more significant effect on the system than did inflow at the boundary. Inflow did cause a significant change but this was localized, during this period, to the outer ∼ 0.05 m of the test hole. No comment was made as to what internal processes caused these responses. (author) 9 refs., 2 tabs., 5 figs

Effect of illite clay and divalent cations on bitumen recovery

Energy Technology Data Exchange (ETDEWEB)

Ding, X. [SNC-Lavalin Inc., Calgary, AB (Canada); Repka, C. [Baker Petrolite Corp., Fort McMurray, AB (Canada); Xu, Z.; Masliyah, J. [Alberta Univ., Edmonton, AB (Canada). Dept. of Chemical and Materials Engineering

2006-12-15

Nearly 35 per cent of Canada's petroleum needs can be met from the Athabasca oil sands, particularly as conventional sources of petroleum decline. The interactions between bitumen and clay minerals play a key role in the recovery process of bitumen because they affect bitumen aeration. The 2 clays minerals found in various oil sands extraction process streams are kaolinite and illite. In this study, doping flotation tests using deionized water and electrokinetic studies were performed to examine the effect of illite clays on bitumen recovery. The effect of magnesium ions was also examined and compared with calcium ions. This paper also discussed the effects of temperature and tailings water chemistry. The negative effect of illite clay on bitumen recovery was found to be associated with its acidity. Denver flotation cell measurements indicated that the addition of calcium or magnesium ions to the flotation deionized water had only a slight effect on bitumen recovery, but the co-addition of illite clay and divalent cations resulted in a dramatic reduction in bitumen recovery. The effect was more significant at lower process temperature and low pH values. Zeta potential distributions of illite suspensions and bitumen emulsions were measured individually and as a mixture to determine the effect of divalent cations on the interaction between bitumen and illite clay. The presence of 1 mM calcium or magnesium ions in deionized water had a pronounced effect on the interactions between bitumen and illite clay. Slime coating of illite onto bitumen was not observed in zeta potential distribution measurements performed in alkaline tailings water. When tests were conducted using plant recycle water, the combination of illite clay and divalent cations did not have an adverse effect on bitumen recovery. 25 refs., 3 tabs., 15 figs.

Influence of Clay Content, Mineralogy and Fabric On Radar Frequency Response of Aquifer Materials

Science.gov (United States)

West, L. J.; Handley, K.

High frequency electromagnetic methods such as ground penetrating radar (GPR) and time domain reflectometry (TDR) are widely employed to measure water saturation in the vadose zone and water filled porosity in the saturated zone. However, previous work has shown that radar frequency dielectric properties are strongly influenced by clay as well as by water content. They have also shown that that the dielectric response of clay minerals is strongly frequency dependent, and that even a small proportion of clay such as that present in many sandstone aquifers can have a large effect at typi- cal GPR frequencies (around 100MHz). Hence accurate water content/porosity deter- mination requires clay type and content to be taken into account. Reported here are dielectric measurements on clay-sand mixtures, aimed at investigating the influence of clay mineralogy, particle shape, and the geometrical arrangement of the mixture constituents on GPR and TDR response. Dielectric permittivity (at 50-1000MHz) was measured for mixtures of Ottawa Sand and various clay minerals or clay size quartz rock flour, using a specially constructed dielectric cell. Both homogeneous and layered mixtures were tested. The influence of pore water salinity, clay type, and particle arrangement on the dielectric response is interpreted in terms of dielectric dispersion mechanisms. The appropriateness of var- ious dielectric mixing rules such as the Complex Refractive Index Method (CRIM) for determination of water content or porosity from field GPR and TDR data are dis- cussed.

Geomechanical properties of lime stabilized clayey sands

International Nuclear Information System (INIS)

Arabani, M.; Karami, M. Veis

2007-01-01

Clayey sands that have low plasticity, low compressibility and high strength under loads, are suitable as a base material for any engineering construction projects as well as for roads and building construction. Decrease of plasticity and compressibility as well as increase in strength of these materials can be obtained by many different methods. Of these methods, lime stabilization is a common, applicable, and easy to use approach that can improve geomechanical and geotechnical properties of clayey sand fills. In this study some important geomechanical properties and geotechnical properties of clayey sands including compressive strength, CBR and elastic plastic behavior are investigated. A range of gradations representative of those gradations found in situ in the north of Iran were selected for testing and samples were artificially rebuilt in the laboratory. The mixes were then stabilized with hydrated lime and cured. Different mechanical tests were performed on mature materials. The stress-strain behavior of lime-stabilized mixes was plotted and a parabolic function was used to estimate the trend of stress-strain behavior. The data show that there is a correlation among the results of uniaxial load test, tensile strength, and CBR of the tested specimens. Also, results of the unconfined compression test and the indirect tensile strength test show that an increase in clay content up to a certain percent, in the clay-sand fills, tends to increase the strength of the materials in compression as well as in tension. (author)

Volcanic ash in feed coal and its influence on coal combustion products

Energy Technology Data Exchange (ETDEWEB)

Brownfield, M.E.; Affolter, R.H.; Cathcart, J.D.; Brownfield, I.K.; Hower, J.C.; Stricker, G.D.; O' Connor, J.T.

2000-07-01

The US Geological Survey and the University of Kentucky Center for Applied Energy Research are collaborating with an Indiana Utility to determine the physical and chemical properties of feed coal and coal combustion products (CCPs) from a coal-fired power plant. The plant utilizes a low-sulfur (.23--.47 weight percent S) coal from the Powder River Basin, Wyoming. Scanning Electron Microscope (SEM) and X-ray diffraction (XRD) analysis of feed coal samples identified two mineral suites. A primary suite (not authigenic) consisting of quartz (detrital and volcanic beta-form grains), biotite, and minor zircon and a secondary authigenic mineral suite containing calcite, alumino-phosphates (crandallite and gorceixite), kaolinite, quartz, anatase, barite, and pyrite. The authigenic minerals are attributed to air-fall and reworked volcanic ash that was deposited in peat-forming mires. The Powder River Basin feed coals contain higher amounts of Ba, Ca, Mg, Na, Sr, and P compared to other analyzed eastern coals. These elements are associated with alumino-phosphate, biotite, calcite, and clay minerals. The element associations are indicative of coal that incorporated volcanic ash during deposition. XRD analysis of CCPs revealed a predominance of glass, perovskite, lime, gehlenite, quartz, and phosphates with minor amounts of periclase, anhydrite, hematite, and spinel group minerals in the fly ash; and quartz, plagioclase (albite and anorthite), pyroxene (augite and fassaite), rhodonite, and akermanite in the bottom ash. Microprobe and SEM analysis of fly ash samples revealed quartz, zircon, monazite, euhedral laths of corundum with merrillite, hematite, dendritic spinels/ferrites, and rounded grains of wollastonite with periclase. The abundant Ca and Mg mineral phases in the fly ashes are related to the presence of carbonate, clay, and phosphate minerals in the feed coal. The Ca- and Mg-rich mineral phases in the CCPs can be attributed to volcanic minerals deposited in the

Geochemistry of dark coastal heavy-mineral beaches sand (Annaba ...

African Journals Online (AJOL)

Acer

3 Institute of Earth and Environmental Science, University of Potsdam, ... Some beaches are characterized by a red-brownish sand colour, the Ain Achir and the ... The occurrence of clays has been determined using the methyl-blue method.

Mineralogy and geotechnical characteristics of some pottery clay

Directory of Open Access Journals (Sweden)

Mujib Olamide ADEAGBO

2016-12-01

Full Text Available The physical properties of soils, which are tremendously influenced by the active clay minerals in soil, are of great importance in geotechnical engineering. This paper investigates the clay-sized particles of the Igbara-Odo pottery clay, and compares results obtained with available data on the bulk sample, to determine their correlation and underline the dependence of the geotechnical properties of the bulk clay material on the clay-sized particles. The bulk clay sample consists of 52% sand-size particles, 21% silt and 27% clay. Analysis of the clay-sized particles and the bulk materials shows: specific gravity of 2.07 and 2.66, liquid limit of 91.0% and 33.0%, plastic limit of 27.5% and 14.3%, plasticity index of 63.5% and 18.7% and a linear shrinkage of 7.9% and 5.4%, for both clay-sized particles and bulk clay respectively. The activity value of the clay material (0.64 suggests the presence of Kaolinite and Ilite; and these were confirmed with X-Ray diffraction on the bulk sample and clay-sized particles. X-Ray diffraction patterns shows distinctive peaks which highlight the dominance of Kaolinite (with 8 peaks in the pottery clay sample for both clay-sized particles and bulk material; while traces of other clay minerals like Illite and Halloysite and rock minerals like Mica, Feldspar and Chrysotile were also found. These results suggest that the clay possesses high viability in the manufacturing of ceramics, refractory bricks, paper, fertilizer and paint. The clay material can be used as a subgrade in road construction, since it possesses low swelling characteristics.

Field test on sand compaction pile method with copper slag sand; Dosuisai slag wo mochiita SCP koho no shiken seko

Energy Technology Data Exchange (ETDEWEB)

Minami, K.; Matsui, H.; Naruse, E.; Kitazume, M. [Port and Harbour Research Inst., Kanagawa (Japan)

1997-09-20

This paper describes the sand compaction pile (SCP) method using copper slag sand. The SCP method is a method by which sand compaction piles are constructed in the ground, and improvement can be obtained in a short period. This method has been widely used even in the port areas for enhancing the bearing power of soft clay ground and the lateral resistance of sheet pile. A great deal of sand is required as a material. The sand requires high permeability, proper size distribution with less fine particle fraction content, easy compaction property with enough strength, and easy discharging property from the casing of construction machines as required properties. Recently, it becomes hard to secure proper sand materials. The copper slag sand is obtained from refining process of copper as a by-product which is quenched in water flow and crushed in water. The copper slag sand has higher particle density than that of sand, excellent permeability, and similar size distribution to that of sand. From compaction drainage triaxial compression test and permeability test, it was found that the mechanical properties of copper slag sand did not change by the crushing of grains with keeping excellent permeability. Through the test construction, applicability of the copper slag sand to the SCP method could be confirmed as an alternate material of sand. 17 refs., 9 figs., 4 tabs.

Geosynthetic clay liners shrinkage under simulated daily thermal cycles.

Science.gov (United States)

Sarabadani, Hamid; Rayhani, Mohammad T

2014-06-01

Geosynthetic clay liners are used as part of composite liner systems in municipal solid waste landfills and other applications to restrict the escape of contaminants into the surrounding environment. This is attainable provided that the geosynthetic clay liner panels continuously cover the subsoil. Previous case histories, however, have shown that some geosynthetic clay liner panels are prone to significant shrinkage and separation when an overlying geomembrane is exposed to solar radiation. Experimental models were initiated to evaluate the potential shrinkage of different geosynthetic clay liner products placed over sand and clay subsoils, subjected to simulated daily thermal cycles (60°C for 8 hours and 22°C for 16 hours) modelling field conditions in which the liner is exposed to solar radiation. The variation of geosynthetic clay liner shrinkage was evaluated at specified times by a photogrammetry technique. The manufacturing techniques, the initial moisture content, and the aspect ratio (ratio of length to width) of the geosynthetic clay liner were found to considerably affect the shrinkage of geosynthetic clay liners. The particle size distribution of the subsoil and the associated suction at the geosynthetic clay liner-subsoil interface was also found to have significant effects on the shrinkage of the geosynthetic clay liner. © The Author(s) 2014.

Efficiency and emissions of coal combustion in two unvented cookstoves

International Nuclear Information System (INIS)

Kaoma, J.; Kasali, G.B.; Ellegaard, A.

1994-01-01

An improved chamber method was employed in the evaluation of the energy conversion and emission characteristics of coal in two unvented cookstoves known as the clay stove and the Maamba stove. Burn rate and stove efficiency were determined together with mission factors for carbon monoxide (CO), nitric oxide (NO) and respirable suspended particulates (RSP). Compared to Maamba stove, the clay stove exhibited a lower burn rate but higher efficiency. The clay stove recorded mean CO, SO 2 , NO 2 , NO and RSP emission factors of 200, 47, 10, 0.4 and 2.4 g/kg, respectively. The Maamba stove emission factors for the same pollutants were 170, 36, n.d., 1.2 and 8.0 g/kg, respectively. The emissions and concentrations of carbon monoxide were less than those previously found with charcoal use, but still exceeded air pollution guidelines by orders of magnitude. Thus the use of coal would not constitute any appreciable improvement over the present charcoal use. Sulphur dioxide emissions and concentrations are quite high, and would constitute a new pollutant in residential areas of Zambia. Particulate emissions and concentrations from coal are higher than from charcoal. In view of specific health risks associated with particulates from coal smoke the domestic use of raw coal is not recommended. 16 refs, 8 figs, 20 tabs

ELECTROKINETIC DENSIFICATION OF COAL FINES IN WASTE PONDS

Energy Technology Data Exchange (ETDEWEB)

E. James Davis

1999-12-18

The objective of this research was to demonstrate that electrokinetics can be used to remove colloidal coal and mineral particles from coal-washing ponds and lakes without the addition of chemical additives such as salts and polymeric flocculants. The specific objectives were: Design and develop a scaleable electrophoresis apparatus to clarify suspensions of colloidal coal and clay particles; Demonstrate the separation process using polluted waste water from the coal-washing facilities at the coal-fired power plants in Centralia, WA; Develop a mathematical model of the process to predict the rate of clarification and the suspension electrical properties needed for scale up.

Spectral Induced Polarization Signatures of Ethanol in Sand-Clay Medium

Science.gov (United States)

The spectral Induced Polarization (SIP) method has previously been investigated as a tool for detecting physicochemical changes occurring as result of clay-organic interactions in porous media. We performed SIP measurements with a dynamic signal analyzer (NI-4551) on laboratory ...

Log evaluation of sub-bituminous coals in Magallanes, Chile

International Nuclear Information System (INIS)

Weltz, L.S.

1976-01-01

In coal exploration a drilling program is normally used for coal inquest through core analysis, with a high cost and operating time. However, in many cases, there is poor cores recovery due to operating procedures and/or formation conditions which leads to the determination of parameters non-representative of the coal seam. The cost and operating time can be minimized through the use of logs which also represent a continuous and in situ sampling. In the case of sub-bituminous coals, the analysis through logs is more complex due to the high content of clay, which masks the presence of water. This paper describes the analysis of sub-bituminous coals in Magallanes-Chile. The main coal seam components are: coal, clay, secondary quartz and water. An interpretation system using the density log, gamma ray, sonic and microlog, based on rho/sub B/-GR and rho/sub B/--Δ/sub T/ cross plots, permits to know the weight percentages of the following elements: total carbon, ash, moisture, which form the main local coal parameters. Empirical relationships permit us to obtain also the heating value and an estimate strength index to elastic-dynamic forces. The results obtained agree within 3 percent with the Laboratory cores analysis. The method is processed through a sequence of simple computer programs for IBM-360

Clay slurry and engineered soils as containment technologies for remediation of contaminated sites

International Nuclear Information System (INIS)

Williams, J.R.; Dudka, S.; Miller, W.P.; Johnson, D.O.

1997-01-01

Clay Slurry and Engineered Soils are containment technologies for remediation of waste disposal sites where leaching, groundwater plumes and surface runoff of contaminants are serious ecological hazards to adjacent environments. This technology is a patent-pending process which involves the use of conditioned clay materials mixed with sand and water to form a readily pourable suspension, a clay slurry, which is either placed into a trench barrier system or allowed to de-water to create Engineered Soils. The Engineered Soil forms a layer impervious to water and air, therefore by inhibiting both water and oxygen from penetrating through the soil the material. This material can be installed in layers and as a vertical barrier to create a surface barrier containment system. The clay percentage in the clay slurry and Engineered Soils varies depending on site characteristics and desired performance standards. For example Engineered Soils with 1-2% of clay (dry wt.) had a hydraulic conductivity (K) of 10 -8 to 10 -1 cm/sec. Tests of tailing materials from a kyanite and pyrite mine showed that the clay slurry was effective not only in reducing the permeability of the treated tailings, but also in decreasing their acidity due to the inherent alkalinity of the clay. The untreated tailings had pH values in the range of 2.4 - 3.1; whereas, the effluent from clay and tailings mixtures had pH values in a slightly alkaline range (7.7-7.9). Pug-mills and high volume slurry pumps can be readily adapted for use in constructing and placing caps and creating Engineered Soils. Moreover, material on site or from a local sand supply can be used to create clay slurries and engineered soils. Clay materials used in cap construction are likewise readily available commercially. As a result, the clay slurry system is very cost effective compared to other capping systems, including the commonly used High Density Polyethylene (HDPE) liner systems

Geotechnical Characterization of Mined Clay from Appalachian Ohio: Challenges and Implications for the Clay Mining Industry

Science.gov (United States)

Moran, Anthony R.; Hettiarachchi, Hiroshan

2011-01-01

Clayey soil found in coal mines in Appalachian Ohio is often sold to landfills for constructing Recompacted Soil Liners (RSL) in landfills. Since clayey soils possess low hydraulic conductivity, the suitability of mined clay for RSL in Ohio is first assessed by determining its clay content. When soil samples are tested in a laboratory, the same engineering properties are typically expected for the soils originated from the same source, provided that the testing techniques applied are standard, but mined clay from Appalachian Ohio has shown drastic differences in particle size distribution depending on the sampling and/or laboratory processing methods. Sometimes more than a 10 percent decrease in the clay content is observed in the samples collected at the stockpiles, compared to those collected through reverse circulation drilling. This discrepancy poses a challenge to geotechnical engineers who work on the prequalification process of RSL material as it can result in misleading estimates of the hydraulic conductivity of the samples. This paper describes a laboratory investigation conducted on mined clay from Appalachian Ohio to determine how and why the standard sampling and/or processing methods can affect the grain-size distributions. The variation in the clay content was determined to be due to heavy concentrations of shale fragments in the clayey soils. It was also concluded that, in order to obtain reliable grain size distributions from the samples collected at a stockpile of mined clay, the material needs to be processed using a soil grinder. Otherwise, the samples should be collected through drilling. PMID:21845150

Geotechnical characterization of mined clay from Appalachian Ohio: challenges and implications for the clay mining industry.

Science.gov (United States)

Moran, Anthony R; Hettiarachchi, Hiroshan

2011-07-01

Clayey soil found in coal mines in Appalachian Ohio is often sold to landfills for constructing Recompacted Soil Liners (RSL) in landfills. Since clayey soils possess low hydraulic conductivity, the suitability of mined clay for RSL in Ohio is first assessed by determining its clay content. When soil samples are tested in a laboratory, the same engineering properties are typically expected for the soils originated from the same source, provided that the testing techniques applied are standard, but mined clay from Appalachian Ohio has shown drastic differences in particle size distribution depending on the sampling and/or laboratory processing methods. Sometimes more than a 10 percent decrease in the clay content is observed in the samples collected at the stockpiles, compared to those collected through reverse circulation drilling. This discrepancy poses a challenge to geotechnical engineers who work on the prequalification process of RSL material as it can result in misleading estimates of the hydraulic conductivity of the samples. This paper describes a laboratory investigation conducted on mined clay from Appalachian Ohio to determine how and why the standard sampling and/or processing methods can affect the grain-size distributions. The variation in the clay content was determined to be due to heavy concentrations of shale fragments in the clayey soils. It was also concluded that, in order to obtain reliable grain size distributions from the samples collected at a stockpile of mined clay, the material needs to be processed using a soil grinder. Otherwise, the samples should be collected through drilling.

Geotechnical Characterization of Mined Clay from Appalachian Ohio: Challenges and Implications for the Clay Mining Industry

Directory of Open Access Journals (Sweden)

Anthony R. Moran

2011-06-01

Full Text Available Clayey soil found in coal mines in Appalachian Ohio is often sold to landfills for constructing Recompacted Soil Liners (RSL in landfills. Since clayey soils possess low hydraulic conductivity, the suitability of mined clay for RSL in Ohio is first assessed by determining its clay content. When soil samples are tested in a laboratory, the same engineering properties are typically expected for the soils originated from the same source, provided that the testing techniques applied are standard, but mined clay from Appalachian Ohio has shown drastic differences in particle size distribution depending on the sampling and/or laboratory processing methods. Sometimes more than a 10 percent decrease in the clay content is observed in the samples collected at the stockpiles, compared to those collected through reverse circulation drilling. This discrepancy poses a challenge to geotechnical engineers who work on the prequalification process of RSL material as it can result in misleading estimates of the hydraulic conductivity of the samples. This paper describes a laboratory investigation conducted on mined clay from Appalachian Ohio to determine how and why the standard sampling and/or processing methods can affect the grain-size distributions. The variation in the clay content was determined to be due to heavy concentrations of shale fragments in the clayey soils. It was also concluded that, in order to obtain reliable grain size distributions from the samples collected at a stockpile of mined clay, the material needs to be processed using a soil grinder. Otherwise, the samples should be collected through drilling.

Coal preparation

International Nuclear Information System (INIS)

Anon.

1991-01-01

The acid rain control legislation has prompted the Department of Energy (DOE) to seek new technology using the Clean Coal Technology program solicitation. The main goal of the program is to reduce SO 2 emissions below 9 Mt/a (10 million stpy) and NO x emission below 5.4 Mt/a (6 million stpy) by the year 2000. This would be accomplished by using precombustion, combustion, post combustion and conversion technology. Utilities are considering installing new scrubbers, switching fuel or possibly deep clean. However, the time required to implement the control technology is short. Due to the legislation, about 110 plants will have to adopt one of the approaches. This paper reports that in characterization of coal, Ames Laboratory used a scanning electron microscope- based, automated image analysis (SEM-AIA) technique to identify coal and mineral matter association. Various forms of organic sulfur were identified using peroxyacetic acid oxidation of coal. This was followed by subsequent microscopic, GC-MS, and HRMS analysis by Southern Illinois University. In ultrafine grinding of coal, it was reported by the Mining and Mineral Institute of Alabama that silica sand or flint shot used less energy compared to steel ball mills

Analysis of waste coal from the enterprises of Kemerovo region as raw materials for production of ceramic materials

Science.gov (United States)

Stolboushkin, A. Yu; Akst, D. V.; Fomina, O. A.; Ivanov, A. I.; Syromyasov, V. A.

2017-09-01

The analysis of waste coal from mining enterprises of Kemerovo region as raw materials for production of building ceramics is given. The results of studies of material, chemical and mineralogical compositions of waste coal from Abashevskaya processing plant (Novokuznetsk) are presented. It was established that the chemical composition of waste coal refers to aluminosilicate raw materials with a high content of alumina and coloring oxides, the residual carbon content in the wastes is 12-25 %. According to the granulometric composition the waste coal is basically a sandy-dusty fraction with a small amount of clay particles (1-3 %). Additional grinding of coal waste and the introduction of a clay additive in an amount of up to 30 % are recommended. The results of the study of the mineral composition of waste coal are presented. Clay minerals are represented in the descending order by hydromuscovite, montmorillonite and kaolinite, minerals-impurities consist of quartz, feldspar fine-dispersed carbonates. The results of the investigation of ceramic-technological properties of waste coal, which belong to the group of moderately plastic low-melting raw materials, are given. As a result of a comprehensive study it was been established that with chemical, granulometric and mineralogical compositions waste coal with the reduced residual carbon can be used in the production of ceramic bricks.

Applications of sand control technology in thermal recovery systems

Energy Technology Data Exchange (ETDEWEB)

Rensvold, R F

1982-01-01

The ever-increasing application of thermal methods to recover low gravity crude oil has warranted the review of existing sand control techniques relative to their compatibility with high temperature environments. The advantages and limitations of a large number of materials are considered. Carrying fluids, granular pack solids, clay stabilizers, and resin-coated pack sands are discussed. Resins used for in situ sand consolidation processes also are reviewed, and their suitability for application in a high temperature steam environment is evaluated. The effects of highly deviated boreholes on the placement of pressure packs also are considered. Full scale gravel pack model studies have provided valuable clues to the procedures and materials that help to create optimum pressure packs. 58 references.

Liquid fuels from Canadian coals

Energy Technology Data Exchange (ETDEWEB)

Taylor, G. W.

1979-06-15

In Canadian energy planning, the central issue of security of supply must be addressed by developing flexible energy systems that make the best possible use of available resources. For liquid fuel production, oil sands and heavy oil currently appear more attractive than coal or biomass as alternatives to conventional crude oil, but the magnitude of their economic advantage is uncertain. The existence of large resources of oil sands, heavy oils, natural gas and low-sulfur coals in Western Canada creates a unique opportunity for Canadians to optimize the yield from these resources and develop new technology. Many variations on the three basic liquefaction routes - hydroliquefaction, pyrolysis and synthesis - are under investigation around the world, and the technology is advancing rapidly. Each process has merit under certain circumstances. Surface-mineable subbituminous and lignite coals of Alberta and Saskatchewan appear to offer the best combination of favorable properties, deposit size and mining cost, but other deposits in Alberta, Nova Scotia and British Columbia should not be ruled out. The research effort in Canada is small by world standards, but it is unlikely that technology could be imported that is ideally suited to Canadian conditions. Importing technology is undesirable: innovation or process modification to suit Canadian coals and markets is preferred; coprocessing of coal liquids with bitumen or heavy oils would be a uniquely Canadian, exportable technology. The cost of synthetic crude from coal in Canada is uncertain, estimates ranging from $113 to $220/m/sup 3/ ($18 to $35/bbl). Existing economic evaluations vary widely depending on assumptions, and can be misleading. Product quality is an important consideration.

Utilization of methane and reclaimed gases in the clay industry

Energy Technology Data Exchange (ETDEWEB)

Hole, W L

1983-03-01

The author first provides information on the supply of coke oven gas to industry by NCB (Coal Products) Ltd. Details are then given of the technique of methane drainage in coal mines, and the markets that have been found for colliery methane in the UK. In particular, the Carlton Main brick scheme is described. In North Staffordshire, five collieries feed into a 10-mile grid supplying a number of brick works in the area. The involvement of NCB (Coal Products) in the reclamation of methane from landfill refuse, and particularly the project at Aveley, Essex, is discussed. A number of markets, including those in the clay industry, are being considered.

Clay minerals behaviour in thin sandy clay-rich lacustrine turbidites (Lake Hazar, Turkey)

Science.gov (United States)

El Ouahabi, Meriam; Hubert-Ferrari, Aurelia; Lamair, Laura; Hage, Sophie

2017-04-01

Turbidites have been extensively studied in many different areas using cores or outcrop, which represent only an integrated snapshot of a dynamic evolving flow. Laboratory experiments provide the missing relationships between the flow characteristics and their deposits. In particular, flume experiments emphasize that the presence of clay plays a key role in turbidity current dynamics. Clay fraction, in small amount, provides cohesive strength to sediment mixtures and can damp turbulence. However, the degree of flocculation is dependent on factors such as the amount and size of clay particles, the surface of clay particles, chemistry and pH conditions in which the clay particles are dispersed. The present study focuses on thin clayey sand turbidites found in Lake Hazar (Turkey) occurring in stacked thin beds. Depositional processes and sources have been previously studied and three types were deciphered, including laminar flows dominated by cohesion, transitional, and turbulence flow regimes (Hage et al., in revision). For the purpose of determine the clay behavior in the three flow regimes, clay mineralogical, geochemical measurements on the cores allow characterising the turbidites. SEM observations provide further information regarding the morphology of clay minerals and other clasts. The study is particularly relevant given the highly alkaline and saline water of the Hazar Lake. Clay minerals in Hazar Lake sediments include kaolinite (1:1-type), illite and chlorite (2:1-type). Hazar lake water is alkaline having pH around 9.3, in such alkaline environment, a cation-exchange reaction takes place. Furthermore, in saline water (16‰), salts can act as a shield and decrease the repulsive forces between clay particle surfaces. So, pH and salt content jointly impact the behaviour of clays differently. Since the Al-faces of clay structures have a negative charge in basic solutions. At high pH, all kaolinite surfaces become negative-charged, and then kaolinite

Inorganic Constituents in Coal

Directory of Open Access Journals (Sweden)

Rađenović A.

2006-02-01

Full Text Available Coal contains not only organic matter but also small amounts of inorganic constituents. More thanone hundred different minerals and virtually every element in the periodic table have been foundin coal. Commonly found group minerals in coal are: major (quartz, pyrite, clays and carbonates,minor, and trace minerals. Coal includes a lot of elements of low mass fraction of the orderof w=0.01 or 0.001 %. They are trace elements connected with organic matter or minerals comprisedin coal. The fractions of trace elements usually decrease when the rank of coal increases.Fractions of the inorganic elements are different, depending on the coal bed and basin. A varietyof analytical methods and techniques can be used to determine the mass fractions, mode ofoccurrence, and distribution of organic constituents in coal. There are many different instrumentalmethods for analysis of coal and coal products but atomic absorption spectroscopy – AAS is theone most commonly used. Fraction and mode of occurrence are one of the main factors that haveinfluence on transformation and separation of inorganic constituents during coal conversion.Coal, as an important world energy source and component for non-fuels usage, will be continuouslyand widely used in the future due to its relatively abundant reserves. However, there is aconflict between the requirements for increased use of coal on the one hand and less pollution onthe other. It’s known that the environmental impacts, due to either coal mining or coal usage, canbe: air, water and land pollution. Although, minor components, inorganic constituents can exert asignificant influence on the economic value, utilization, and environmental impact of the coal.

A novel waste water cleanup, fines sequestration and consolidation technology for oil sands applications

Energy Technology Data Exchange (ETDEWEB)

Soane, D.; Ware, W.; Mahoney, R.; Kincaid, P. [Soane Energy LLC, Cambridge, MA (United States)

2010-07-01

This paper discussed a wastewater technology designed to rapidly sequester suspended fines and other pollutants from the tailings produced during oil sands processes. The technology can also be used to clarify existing tailings ponds, and is expected to help address growing environmental concerns over the remediation of oil sands tailings. The ATA system is comprised of the following 3 components: (1) an activator polymer, (2) a tether polymer, and (3) an anchor particle. A small dose of the activator polymer is added to the fine or mature tailings, which then causes the suspended clay fines to aggregate. The anchor particles are then coated with the tether polymer. The anchor particle is formed from sand derived from coarser tailings. The tether-bearing anchor particles bind to the aggregated clay fines in the activated tailings to form robust complexes that can easily be separated from the waste stream. Output streams from the ATA process include a clean water stream that can be reused in oil sands extraction processes; and a dewatered solid that can be used as landfill as well as in construction and reclamation applications. The sensible heat retained in the recycled water is expected to also reduce the energy requirements of the oil sands extraction process. 6 refs., 1 tab., 5 figs.

Preliminary study of uranium favorability of the Wilcox and Claiborne Groups (Eocene) in Texas

International Nuclear Information System (INIS)

Wilbert, W.P.; Templain, C.J.

1978-01-01

Rocks of the Wilcox and Claiborne Groups crop out in the Texas Gulf Coastal Plain and are represented by a series of sands and shales which reflect oscillation of the strandline. The Wilcox Group (lower Eocene), usually undifferentiated in Texas, consists of very fine sands and clays and abundant lignite. The Claiborne Group (middle Eocene) comprises, in ascending order, Carrizo Sand, Reklaw Formation (clay), Queen City Sand, Weches Formation (clay), Sparta Sand, Cook Mountain Formation (clay), and Yegua Formation (sand). Fluvial systems of the Wilcox and Claiborne Groups exist in east Texas and trend perpendicular to the present coastline. In central Texas, sand bodies are parallel to the present coastline and are strand-plain, barrier-bar systems. Since the time of deposition of the Queen City Sand, a significant fluvial sand buildup occurred in the area of the present Rio Grande embayment where the marine clays pinch out. Known occurrences of mineral matter in the Wilcox and Claiborne (up to the Yegua) are limited to lignite (particularly in the Wilcox), cannel coal in the upper Claiborne, and hydrocarbons throughout. No uranium mineralization is known, and no uranium is likely to be discovered in the Claiborne and Wilcox. Approximately 50 surface samples and many gamma-ray logs showed no significant anomalies. The sands are very good potential host rocks, but no uranium source was discovered. During deposition of the Wilcox and Claiborne Groups, there was no volcanism to serve as a source of uranium (as with the prolific occurrences in the younger rocks of south Texas); also, Precambrian crystalline rocks in the Llano uplift were not exposed

stabilisation of niger delta fat clay with blend of binders for subgrade

African Journals Online (AJOL)

HOD

Construction of roads on fine-grained soils without any form of stabilisation is a major ... and Portland Cement (PC) to improve its plasticity, California Bearing Ratio (CBR), and swell. .... sand, DCA, lateralite, and cement in stabilising a fat clay.

Two-fold sustainability – Adobe with sawdust as partial sand replacement

Science.gov (United States)

Jokhio, Gul A.; Syed Mohsin, Sharifah M.; Gul, Yasmeen

2018-04-01

Adobe is a material that is economic, environment friendly, and provides better indoor air quality. The material required for the preparation of adobe include clay, sand, and sometimes straw or other organic materials. These materials do not require industrial processing or transportation, however, sand mining has been recently posing a threat to the environment. Therefore, to enhance the existing sustainability of adobe, sand can be partially or fully replaced by other waste materials. This approach will not only solve the problem of excessive sand mining, it will also address the issue of waste management. Sawdust is one such waste material that can be used to partially replace sand in Adobe. This paper presents the results of compressive and flexural test carried out on Adobe samples with partial sand replacement by sawdust. The results show that about 4% sand replacement by volume produces higher compressive strength, whereas the flexural strength reduces with the use of sawdust. However, since flexural strength is not a critical property for adobe, it is concluded that replacing sand with sawdust by about 4% of volume will be beneficial.

Formation of the gaseous phase of impurity elements from coal combustion at a thermal power plant

International Nuclear Information System (INIS)

Kizil'shtein, L.Ya.; Levchenko, S.V.; Peretyakt'ko, A.G.

1991-01-01

Data are reported on the distribution of impurity elements in their principal carriers: organic matter, iron sulfides, and clays. Tests with high-temperature combustion of coals and argillites indicate that elements associated with clay minerals largely remain in ash and slag. They do not pass to the gas phase - a factor to be considered in assessment of environmental impact from thermal power plants and specification of toxic concentration levels of impurity elements in coal

Review of coal bottom ash and coconut shell in the production of concrete

Science.gov (United States)

Faisal, S. K.; Mazenan, P. N.; Shahidan, S.; Irwan, J. M.

2018-04-01

Concrete is the main construction material in the worldwide construction industry. High demand of sand in the concrete production have been increased which become the problems in industry. Natural sand is the most common material used in the construction industry as natural fine aggregate and it caused the availability of good quality of natural sand keep decreasing. The need for a sustainable and green construction building material is required in the construction industry. Hence, this paper presents utilization of coal bottom ash and coconut shell as partial sand replacement in production of concrete. It is able to save cost and energy other than protecting the environment. In summary, 30% usage of coal bottom ash and 25% replacement of coconut shell as aggregate replacement show the acceptable and satisfactory strength of concrete.

Characterization of sand lenses and their role for subsurface transport in low-permeability clay tills

DEFF Research Database (Denmark)

Kessler, Timo Christian; Klint, K. E.; Nilsson, B.

2011-01-01

Glacial sediments dominate large parts of the geological topology in Denmark. They predominantly consist of lowpermeability tills, but fractures and sand-lenses constitute zones of enhanced permeability facilitating preferential flow. This study focuses on characterization of sand deposits with r...... the sand lenses in hydro-geological models to successfully characterize subsurface flow and transport, e.g. for remediation activities....

Removal of Cr(VI) from Aqueous Environments Using Micelle-Clay Adsorption

Science.gov (United States)

Qurie, Mohannad; Khamis, Mustafa; Manassra, Adnan; Ayyad, Ibrahim; Nir, Shlomo; Scrano, Laura; Bufo, Sabino A.; Karaman, Rafik

2013-01-01

Removal of Cr(VI) from aqueous solutions under different conditions was investigated using either clay (montmorillonite) or micelle-clay complex, the last obtained by adsorbing critical micelle concentration of octadecyltrimethylammonium ions onto montmorillonite. Batch experiments showed the effects of contact time, adsorbent dosage, and pH on the removal efficiency of Cr(VI) from aqueous solutions. Langmuir adsorption isotherm fitted the experimental data giving significant results. Filtration experiments using columns filled with micelle-clay complex mixed with sand were performed to assess Cr(VI) removal efficiency under continuous flow at different pH values. The micelle-clay complex used in this study was capable of removing Cr(VI) from aqueous solutions without any prior acidification of the sample. Results demonstrated that the removal effectiveness reached nearly 100% when using optimal conditions for both batch and continuous flow techniques. PMID:24222757

Fusion of arkosic sand by intrusive andesite

Science.gov (United States)

Bailey, Roy A.

1954-01-01

An andesite dike in the Valles Mountains of northern New Mexico has intruded and partly fused arkosic sediments for a distance of 50 feet from its contacts. The dike is semi-circular in form, has a maximum width of about 100 feet, and is about 500 feet long. Small associated arcuate dikes are arranged in spiral fashion around the main dike, suggesting that they were intruded along shear fractures similar to those described by Burbank (1941). The fused rocks surrounding the andesite dike are of three general types: 1) partly fused arkosic sand, 2) fused clay, and 3) hybrid rocks. The fused arkosic sand consists of relict detrital grains of quartz, orthoclose, and plagioclase, imbedded in colorless glass containing microlites of tridymite, cordierite, and magnetite. The relict quartz grains are corroded and embayed by glass; the orthoclase is sanidinized and partly fused; and the plagioclase is inverted to the high temperature form and is partly fused. The fused clay, which was originally a mixture of montmorillonite and hydromica, consists primarily of cordierite but also contains needle-like crystals of sillimanite (?) or mullite (?). The hybrid rocks originated in part by intermixing of fused arkosic sediments and andesitic liquid and in part by diffusion of mafic constituents through the fused sediments. They are rich in cordierite and magnetite and also contain hypersthene, augite, and plagioclase. The composition of pigeonite in the andesite indicates that the temperature of the andesite at the time of intrusion probably did not exceed 1200?C. Samples of arkosic sand were fused in the presence of water in a Morey bomb at 1050?C. Stability relations of certain minerals in the fused sand suggest that fusion may have taken place at a lower temperature, however, and the fluxing action of volatiles from the andesite are thought to have made this possible.

Clay Mineralogy of Coal-Hosted Nb-Zr-REE-Ga Mineralized Beds from Late Permian Strata, Eastern Yunnan, SW China: Implications for Paleotemperature and Origin of the Micro-Quartz

Directory of Open Access Journals (Sweden)

Lixin Zhao

2016-05-01

Full Text Available The clay mineralogy of pyroclastic Nb(Ta-Zr(Hf-REE-Ga mineralization in Late Permian coal-bearing strata from eastern Yunnan Province; southwest China was investigated in this study. Samples from XW and LK drill holes in this area were analyzed using XRD (X-ray diffraction and SEM (scanning electronic microscope. Results show that clay minerals in the Nb-Zr-REE-Ga mineralized samples are composed of mixed layer illite/smectite (I/S; kaolinite and berthierine. I/S is the major component among the clay assemblages. The source volcanic ashes controlled the modes of occurrence of the clay minerals. Volcanic ash-originated kaolinite and berthierine occur as vermicular and angular particles, respectively. I/S is confined to the matrix and is derived from illitization of smectite which was derived from the original volcanic ashes. Other types of clay minerals including I/S and berthierine precipitated from hydrothermal solutions were found within plant cells; and coexisting with angular berthierine and vermicular kaolinite. Inferred from the fact that most of the I/S is R1 ordered with one case of the R3 I/S; the paleo-diagenetic temperature could be up to 180 °C but mostly 100–160 °C. The micro-crystalline quartz grains (<10 µm closely associated with I/S were observed under SEM and were most likely the product of desiliconization during illitization of smectite.

The chemical transformation of calcium in Shenhua coal during combustion in a muffle furnace

Energy Technology Data Exchange (ETDEWEB)

Tian, Sida [North China Electric Power Univ., Beijing (China). School of Energy, Power and Mechanical Engineering; Ministry of Education, Beijing (China). Key Lab. of Condition Monitoring and Control for Power Plant Equipment; Zhuo, Yuqun; Chen, Changhe [Tsinghua Univ., Beijing (China). Dept. of Thermal Engineering; Ministry of Education, Beijing (China). Key Lab. for Thermal Science and Power Engineering; Shu, Xinqian [China Univ. of Mining and Technology, Beijing (China). School of Chemical and Environmental Engineering

2013-07-01

The chemical reaction characteristics of calcium in three samples of Shenhua coal, i.e. raw sample, hydrochloric acid washed sample and hydrochloric acid washed light fraction, during combustion in a muffle furnace have been investigated in this paper. Ca is bound by calcite and organic matter in Shenhua coal. X ray diffraction (XRD) phase analysis has been conducted to these samples' combustion products obtained by heating at different temperatures. It has been found that the organically-bound calcium could easily react with clays and transform into gehlenite and anorthite partially if combusted under 815 C, whilst the excluded minerals promoted the conversion of gehlenite to anorthite. Calcite in Shenhua coal decomposed into calcium oxide and partially transformed into calcium sulfate under 815 C, and formed gehlenite and anorthite under 1,050 C. Calcite and other HCl-dissolved minerals in Shenhua coal were responsible mainly for the characteristic that the clay minerals in Shenhua coal hardly became mullite during combustion.

Characterization of Heat-treated Clay Minerals in the Context of Nuclear Waste Disposal

Science.gov (United States)

Matteo, E. N.; Wang, Y.; Kruichak, J. N.; Mills, M. M.

2015-12-01

Clay minerals are likely candidates to aid in nuclear waste isolation due to their low permeability, favorable swelling properties, and high cation sorption capacities. Establishing the thermal limit for clay minerals in a nuclear waste repository is a potentially important component of repository design, as flexibility of the heat load within the repository can have a major impact on the selection of repository design. For example, the thermal limit plays a critical role in the time that waste packages would need to cool before being transferred to the repository. Understanding the chemical and physical changes, if any, that occur in clay minerals at various temperatures above the current thermal limit (of 100 °C) can enable decision-makers with information critical to evaluating the potential trade-offs of increasing the thermal limit within the repository. Most critical is gaining understanding of how varying thermal conditions in the repository will impact radionuclide sorption and transport in clay materials either as engineered barriers or as disposal media. A variety of repository-relevant clay minerals (illite, mixed layer illite/smectite, and montmorillonite), were heated for a range of temperatures between 100-1000 °C. These samples were characterized to determine surface area, mineralogical alteration, and cation exchange capacity (CEC). Our results show that for conditions up to 500 °C, no significant change occurs, so long as the clay mineral remains mineralogically intact. At temperatures above 500 °C, transformation of the layered silicates into silica phases leads to alteration that impacts important clay characteristics. Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy's Nation Nuclear Security Administration under contract DE-AC04-94AL85000. SAND Number: SAND2015-6524 A

Microbial metabolism alters pore water chemistry and increases consolidation of oil sands tailings.

Science.gov (United States)

Arkell, Nicholas; Kuznetsov, Petr; Kuznetsova, Alsu; Foght, Julia M; Siddique, Tariq

2015-01-01

Tailings produced during bitumen extraction from surface-mined oil sands ores (tar sands) comprise an aqueous suspension of clay particles that remain dispersed for decades in tailings ponds. Slow consolidation of the clays hinders water recovery for reuse and retards volume reduction, thereby increasing the environmental footprint of tailings ponds. We investigated mechanisms of tailings consolidation and revealed that indigenous anaerobic microorganisms altered porewater chemistry by producing CO and CH during metabolism of acetate added as a labile carbon amendment. Entrapped biogenic CO decreased tailings pH, thereby increasing calcium (Ca) and magnesium (Mg) cations and bicarbonate (HCO) concentrations in the porewater through dissolution of carbonate minerals. Soluble ions increased the porewater ionic strength, which, with higher exchangeable Ca and Mg, decreased the diffuse double layer of clays and increased consolidation of tailings compared with unamended tailings in which little microbial activity was observed. These results are relevant to effective tailings pond management strategies. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

Diffusion of plutonium in mixtures of bentonite and sand at pH 3

International Nuclear Information System (INIS)

Sharma, H.D.; Oscarson, D.W.

1991-04-01

Apparent diffusion coefficients, D, were measured for Pu in compacted mixtures of bentonite and sand (soil) at 25 degrees C and pH 3. The clay content of the soil ranged from 10 to 100 wt% and the clay dry density, p c (the mass of clay divided by the combined volume of clay and voids), varied from about 0.5 to 1.6 Mg/m 3 . At a clay content of ≥25% and p c > 0.7 Mg/m 3 , D was not significantly affected by either clay content or density and ranged from 2 x 10 -13 to 7 x 10 -13 m 2 /s; at lower clay contents and densities, however, D was as much as an order of magnitude higher. In all systems, a small fraction of the Pu (<10%) migrated faster than the bulk of the Pu; this is attributed to a second stable species of Pu that has a greater mobility

A remediation performance model for enhanced metabolic reductive dechlorination of chloroethenes in fractured clay till

Science.gov (United States)

Manoli, Gabriele; Chambon, Julie C.; Bjerg, Poul L.; Scheutz, Charlotte; Binning, Philip J.; Broholm, Mette M.

2012-04-01

A numerical model of metabolic reductive dechlorination is used to describe the performance of enhanced bioremediation in fractured clay till. The model is developed to simulate field observations of a full scale bioremediation scheme in a fractured clay till and thereby to assess remediation efficiency and timeframe. A relatively simple approach is used to link the fermentation of the electron donor soybean oil to the sequential dechlorination of trichloroethene (TCE) while considering redox conditions and the heterogeneous clay till system (clay till matrix, fractures and sand stringers). The model is tested on lab batch experiments and applied to describe sediment core samples from a TCE-contaminated site. Model simulations compare favorably to field observations and demonstrate that dechlorination may be limited to narrow bioactive zones in the clay matrix around fractures and sand stringers. Field scale simulations show that the injected donor is expected to be depleted after 5 years, and that without donor re-injection contaminant rebound will occur in the high permeability zones and the mass removal will stall at 18%. Long remediation timeframes, if dechlorination is limited to narrow bioactive zones, and the need for additional donor injections to maintain dechlorination activity may limit the efficiency of ERD in low-permeability media. Future work should address the dynamics of the bioactive zones, which is essential to understand for predictions of long term mass removal.

Relationships between coal-quality and organic-geochemical parameters: A case study of the Hafik coal deposits (Sivas Basin, Turkey)

Energy Technology Data Exchange (ETDEWEB)

Erik, N. Yalcin; Sancar, S. [Cumhuriyet University, Department of Geological Engineering, Sivas (Turkey)

2010-09-01

This study provides coal-quality, organic-petrographic and organic-geochemical data on Tertiary subbituminous coal of the Hafik area, northwestern part of the Sivas Basin, Turkey. Coal-petrological studies along with proximate and ultimate analyses were undertaken to determine the organic-petrographic characteristics of the Hafik coals. Huminite reflectances were found to be between 0.38 and 0.48% (corresponding to an organic-material-rich and coal layers), values characteristic of low maturity. This parameter shows a good correlation with calorific values (average 21,060 kJ/kg) and average T{sub max} (422 C) mineral-matter diagenesis, indicating immaturity. The studied coals and organic material underwent only low-grade transformation, a consequence of low lithostatic pressure. Therefore, the Hafik coals are actually subbituminous in rank. Rock-Eval analysis results show types II/III and III kerogens. The organic fraction of the coals is mostly comprised of humic-group macerals (gelinites), with small percentages derived from the inertinite and liptinite groups. In this study, organic-petrographic, organic-geochemical and coal quality data were compared. The Hafik deposit is a high-ash, high-sulfur coal. The mineral matter of the coals is comprised mainly of calcite and clay minerals. (author)

Construction of clay sealings for dumping of brown coal ash and residues from gas desulfurization units. Herstellung von Tonabdichtungen zur Deponierung von Braunkohleaschen und REA-Rueckstaenden

Energy Technology Data Exchange (ETDEWEB)

Kortmann, W

1989-07-01

With the putting into operation of flue gas scrubbers at the brown coal-fired power stations of the RWE not only 5 to 6 Mt conventional power station ash but also up to 2 Mt gypsum and water from the flue gas desulphurisation units are obtained annually, and these residues together with the ash are tipped on mixed dumps. These dumps are enclosed on all sides by a mineral sealing of clay with a thickness of at least 0.6 m. In keeping with the detailed plans for the construction and operation of mixed dumps as submitted to the competent authorities for approval, the sealing must have a permeability of K < 5x10{sup -10} m/s for the dump base and of K < 1x10{sup -10} m/s for the cover of the dump. In order to meet these high quality requirements the clay, which is obtained by opencast working with the aid of bucket wheel excavators, must first of all be crushed for construction of the sealings. In addition to the crushing of the clay to as small a lump size as possible, the adjustment of the correct sealing moisture content of the clay is of primary importance. Conditioning of the clay is effected in the conventional way by means of a pulvimixer, but also by means of a processing plant in pilot operation in the construction of clay sealings for dumps. With the aid of the processing plant clay of a high homogenisation grade is constantly available for sealing construction. The clay is spread on the base and slopes of the dump layer by layer with the aid of scraper dozers, each layer having a compacted thickness of about 20 cm. Compaction of the sealing layers is effected by heavy rammer butt rollers. In the case of highly plastic earth materials of the type used here in the construction of dumps the weight of the compacting roller and also the shape of the rammer butt are of importance. Compaction in the 1:2.5 steep dump slopes by means of a detachable roller steered by a cable has proved very satisfactory.

Hydraulic properties of domestic bentonite-sand mixture as a backfill material in the high-level waste repository

Energy Technology Data Exchange (ETDEWEB)

Cho, Won Jin; Lee, Jae Owan; Kang, Chul Hyung [Korea Atomic Energy Research Institute, Taejeon (Korea)

2000-02-01

This study is intended to investigate the effect of dry density and sand content on hydraulic conductivities of bentonite-sand mixtures. The hydraulic conductivities of bentonite-sand mixtures with dry densities of 1.6 and 1.8 Mg/m{sup 3} are lower than 10{sup -11} m/s if their sand contents are less than 70 wt%. However at the sand content of 90 wt%, the hydraulic conductivities increase sharply. In the case of sand contents not exceeding 70 wt%, the logarithm of the hydraulic conductivity of bentonite-sand mixture increase linearly with increasing sand content. The hydraulic conductivity of the mixture can be explained using 'effective clay dry density' concept. 16 refs., 21 figs., 5 tabs. (Author)

Spatial distribution and longitudinal variation of clay minerals in the Central Indian Basin

Digital Repository Service at National Institute of Oceanography (India)

Valsangkar, A.

in the Central Indian Basin (CIB). The average sand content in the basin is 3.8%, which decreases systematically and longitudinally to 0.3% towards south. The average illite and chlorite major clay mineral abundance also decrease southwards along the four...

Utilization of coal fired power plant by-products. Utilization of coal ash; Sekitan karyoku ni okeru fukusanbutsu no yuko riyo gijutsu. Sekitanbai no yuko riyo

Energy Technology Data Exchange (ETDEWEB)

Kishimoto, K. [The Federation of Electric Power Companies, Tokyo (Japan); Watanabe, M. [Electric Power Development Co. Ltd., Tokyo (Japan)

1997-11-05

The paper introduced the present situation and future task of the tackling with effective use of coal ash discharged from coal thermal power plants. Making the use of the characteristics, coal ash is mostly used in the fields of cement/concrete, civil engineering/construction, and agriculture/forestry/fisheries. In the case of using fly ash to concrete, the effects are the heightening of long-term strength, increase in workability, decrease in hydration heat, control of alkali aggregate reaction, etc. In the civil engineering/construction field, coal ash is allowed to be used for road bed material and mixed civil engineering material as road materials, for revetment back-filling material, soft ground surface layer treatment, soft ground/soil improvement materials, FGC deep layer mixing treatment process, SPC (sand compaction pile) material, etc. as earth work materials. Besides, it is used for light coarse aggregate, light sand, etc., as construction materials, for material substituting ceramics products, etc. as building materials, and for agricultural material, potassium silicate fertilizer and ocean structure in the agriculture/forestry/fisheries field. 4 refs., 2 tabs.

Effect of crude oil contamination on the engineering behavior of clay soils

International Nuclear Information System (INIS)

Rehman, H.; Abdoljaowad, S.N.

2005-01-01

Humans are, unintentionally or intentionally contaminating soil from different sources. The contaminated soil are not only a challenge for the environmentalists but also for geotechnical engineers. When contaminated by crude oil, the soil is subjected to a change in its engineering properties. The soil, which is mostly affected by its environment, is clay, being active electro-chemically. So, a comprehensive laboratory-testing program was performed to compare the engineering properties of an uncontaminated and a contaminated clay. Laboratory tests included all basic and advanced geotechnical tests along with Scanning Electron Microscope (SEM). Crude oil was chosen as the contaminant. The clay was taken from the Al-Qatif area of the Eastern province of Saudi Arabia. The selected soil is considered to be highly expansive in nature. The comparison between uncontaminated and crude oil contaminated clay showed that there would be a significant change in the engineering behavior of the clay if it were contaminated by crude oil. The contaminated clay behaves more like sand, owing to the formation of agglomerates. The coarse-grained soil-like behavior was observed in the strength of the oil-contaminated clay. The contamination has affected the plasticity and the cation exchange capacity of the investigated clay. The swelling pressure of the contaminated clay is 1/3 of that of the uncontaminated clay while the swelling is almost the same. (author)

Mud-farming of fine oil sands tailings

Energy Technology Data Exchange (ETDEWEB)

Yao, Y.; Tol van, F.; Paassen van, L.; Everts, B.; Mulder, A. [Delft Univ. of Technology, Delft (Netherlands). Dept. of Geotechnology

2010-07-01

This PowerPoint presentation discussed an experimental mud-farming technique for fine oil sands tailings. The technique was based on a sub-areal drying technique for dredging sludge developed in the Netherlands for Rotterdam harbour sediments. Between 1960 and 1985, the sludge was deposited in confined disposal sites on land. The sludge was converted to usable clay between 1970 and 1980. The polluted portion of the sludge is stored in a man-made disposal site. The sludge was deposited in thin layers. Stagnant water was then removed. The mud was then dewatered and reused. The sludge was furrowed with amphirol and disc wheels in order to accelerate the ripening process. The dredged material was re-used in a clay factory. The technique was applied to oil sands tailings in order to understand the suction behaviour, sedimentation behaviour, and precipitation deficit of the tailings. State changes of the sludge were monitored. No clear sedimentation phase was identified prior to consolidation. A comparison of material properties showed that the total amount of water to be extracted was more than the Rotterdam sludge, but the suction behaviour was similar. The precipitation deficit from mid-April until September will require a customized deposition strategy. Details and photographs of the experimental studies were included. tabs., figs.

Reduced emissions from inexpensive high-sulphur coal briquettes

International Nuclear Information System (INIS)

Gammage, R.B.; Wachter, E.A.; Wade, J.; Wilson, D.L.; Haas, J.W.; Ahmad, N.; Siltain, F.; Raza, M.Z.

1992-01-01

Airborne emissions were measured during the combustion of Pakistani high-sulphur coal, cold briquetted with lime and clay; comparison was made to emissions from raw coal and traditional fuels burnt in a native, mud-lined Angethi stove. Compared to raw coal, the amended coal gave fourfold reduced emission of respirable-size particles (RSP) and threefold reduced total releases of SO 2 . In domestic cooking, substitution of the amended coal briquettes for traditional fuels will not worsen indoor air quality with respect to CO, SO 2 , NO x , and RSP. The high peak amounts of CO (100--250 ppm), SO 2 (2--5 ppm), and NO x (1--5 ppm) were limited to the early phase of burning. The high thermal value of the coal briquettes together with a simple briquetting technology, make this fuel an attractive energy alternative in countries that are underdeveloped, developing, or experiencing major restructuring

Reservoir characteristics of coal-shale sedimentary sequence in coal-bearing strata and their implications for the accumulation of unconventional gas

Science.gov (United States)

Wang, Yang; Zhu, Yanming; Liu, Yu; Chen, Shangbin

2018-04-01

Shale gas and coalbed methane (CBM) are both considered unconventional natural gas and are becoming increasingly important energy resources. In coal-bearing strata, coal and shale are vertically adjacent as coal and shale are continuously deposited. Research on the reservoir characteristics of coal-shale sedimentary sequences is important for CBM and coal-bearing shale gas exploration. In this study, a total of 71 samples were collected, including coal samples (total organic carbon (TOC) content >40%), carbonaceous shale samples (TOC content: 6%-10%), and shale samples (TOC content TOC content. Clay and quartz also have a great effect on the porosity of shale samples. According to the FE-SEM image technique, nanoscale pores in the organic matter of coal samples are much more developed compared with shale samples. For shales with low TOC, inorganic minerals provide more pores than organic matter. In addition, TOC content has a positive relationship with methane adsorption capacity, and the adsorption capacity of coal samples is more sensitive than the shale samples to temperature.

Method for preventing plugging of water wells by clay

Energy Technology Data Exchange (ETDEWEB)

Blazhkov, V I

1966-01-01

A method is suggested for preventing the plugging of water-bearing sands by clay from drilling fluids. It consists in placing a cement plug in the upper nipple above the filter, in order to prevent its plugging during the installation. The drilling mud passes through the rinsing windows and fills the internal void of the filter column, thus preventing further percolation and plugging of the filter during its lowering. When a 2-filter column is lowered, the clay solution is pumped into the interval between the cement plug and the next filter; this is done gradually in proportion to the addition of new pipes. When the drilling mud level lowers in the annular space between the pipes, the mud cake, together with water-saturated sand, passes through the rinsing windows into the pipes and is removed to the surface by airlift or other methods. This procedure is described in detail, discussed for various conditions of well structure, and illustrated by schematic drawings. Its advantage is in the possibility of separate testing and production of all water-bearing zones in the well, and it does not require the use of pure water for well washing.

Rheological properties of sodium smectite clay

International Nuclear Information System (INIS)

Boergesson, L.; Hoekmark, H.; Karnland, O.

1988-12-01

The rheological properties of Na-smectite Mx-80 have been investigated by various laboratory tests. The investigations include determination of the hydraulic conductivity, the undrained stress-strain-strength properties, the creep properties, the compression and swelling properties in drained and undrained conditions and the undrained thermomechanical properties. Measurements have been made at different densities, clay/sand mixtures and pore water compositions. The influence of temperature, rate of strain and testing technique has also been considered. The investigation has led to a supply of basic data for the material models which will be used at performance calculations. The results have also increased the general understanding of the function of smectitic clay as buffer material. The microstructural behaviour has been considered at the validation of the different test results and the validity of the effective stress theory has been discussed. Comparisons with the properties of Ca-smectite have also been made. (orig.)

Clay sealing for dumps - new findings from suitability tests

Energy Technology Data Exchange (ETDEWEB)

Kunde, L.; Kuntsche, K.; Duellmann, H.

1988-06-01

Extensive suitability tests were carried out in the laboratory and field on various clays of the Lower-Rhineland brown coal mining area. The purpose of these tests was to determine the basic suitability of these clays for use as sealing layers for residue dumps. The tests also furnished criteria according to which a specific imperviousness can be achieved. The results of the tests can be summed up as follows: Since the material properties of the in-situ clays vary widely, not only mean values but also corresponding variation coefficients must be adhered to. For the purpose of checking the quality - contrary to the hitherto applied assessment practice - the decisive factor is not the testing of the dry density as compared to the Proctor density, but the homogeneity of the sealing layer that is achieved as a result of the size reduction and compaction of the pseudo-granular structure. Using suitable equipment, homogeneities, for which permeability coefficients of k less than or equal to 10/sup -9/ m/s in the dump sealing are obtained can be achieved with the clays that were examined.

Simulation Of Enhanced Reductive Dechlorination For Remediation Of Tce In A Fractured Clay System: A New Model Approach And Application To Field Site

DEFF Research Database (Denmark)

Manoli, Gabriele; Chambon, Julie Claire Claudia; Christiansen, Camilla Maymann

2010-01-01

with interspersed sand lenses and stringers. The transport model couples diffusion dominated transport in the clay matrix, with advective‐dispersive transport in the fractures and higher permeability sand lenses. The reactive model calculates sequential reductive dechlorination of TCE (trichloroethylene) to its...... a contamination of trichloroethylene located in a fractured clay till. The site is simulated using the model developed. Fracture geometry, site parameters and degradation rates are based on observations from the site and lab studies. The risk for drinking water is assessed and cleanup times are simulated using...

Microbially-accelerated consolidation of oil sands tailings. Pathway II: solid phase biogeochemistry

Directory of Open Access Journals (Sweden)

Tariq eSiddique

2014-03-01

Full Text Available Consolidation of clay particles in aqueous tailings suspensions is a major obstacle to effective management of oil sands tailings ponds in northern Alberta, Canada. We have observed that microorganisms indigenous to the tailings ponds accelerate consolidation of mature fine tailings (MFT during active metabolism by using two biogeochemical pathways. In Pathway I, microbes alter porewater chemistry to indirectly increase consolidation of MFT. Here, we describe Pathway II comprising significant, direct and complementary biogeochemical reactions with MFT mineral surfaces. An anaerobic microbial community comprising Bacteria (predominantly Clostridiales, Synergistaceae and Desulfobulbaceae and Archaea (Methanolinea/Methanoregula and Methanosaeta transformed FeIII minerals in MFT to amorphous FeII minerals during methanogenic metabolism of an added organic substrate. Synchrotron analyses suggested that ferrihydrite (5Fe2O3. 9H2O and goethite (α-FeOOH were the dominant FeIII minerals in MFT. The formation of amorphous iron sulfide (FeS and possibly green rust entrapped and masked electronegative clay surfaces in amended MFT. Both Pathways I and II reduced the surface charge potential (repulsive forces of the clay particles in MFT, which aided aggregation of clays and formation of networks of pores, as visualized using cryo-scanning electron microscopy. These reactions facilitated the egress of porewater from MFT and increased consolidation of tailings solids. These results have large-scale implications for management and reclamation of oil sands tailings ponds, a burgeoning environmental issue for the public and government regulators.

Microbially-accelerated consolidation of oil sands tailings. Pathway II: solid phase biogeochemistry.

Science.gov (United States)

Siddique, Tariq; Kuznetsov, Petr; Kuznetsova, Alsu; Li, Carmen; Young, Rozlyn; Arocena, Joselito M; Foght, Julia M

2014-01-01

Consolidation of clay particles in aqueous tailings suspensions is a major obstacle to effective management of oil sands tailings ponds in northern Alberta, Canada. We have observed that microorganisms indigenous to the tailings ponds accelerate consolidation of mature fine tailings (MFT) during active metabolism by using two biogeochemical pathways. In Pathway I, microbes alter porewater chemistry to indirectly increase consolidation of MFT. Here, we describe Pathway II comprising significant, direct and complementary biogeochemical reactions with MFT mineral surfaces. An anaerobic microbial community comprising Bacteria (predominantly Clostridiales, Synergistaceae, and Desulfobulbaceae) and Archaea (Methanolinea/Methanoregula and Methanosaeta) transformed Fe(III) minerals in MFT to amorphous Fe(II) minerals during methanogenic metabolism of an added organic substrate. Synchrotron analyses suggested that ferrihydrite (5Fe2O3. 9H2O) and goethite (α-FeOOH) were the dominant Fe(III) minerals in MFT. The formation of amorphous iron sulfide (FeS) and possibly green rust entrapped and masked electronegative clay surfaces in amended MFT. Both Pathways I and II reduced the surface charge potential (repulsive forces) of the clay particles in MFT, which aided aggregation of clays and formation of networks of pores, as visualized using cryo-scanning electron microscopy (SEM). These reactions facilitated the egress of porewater from MFT and increased consolidation of tailings solids. These results have large-scale implications for management and reclamation of oil sands tailings ponds, a burgeoning environmental issue for the public and government regulators.

Mechanism underlying the action of waterglass in the flotation of Karaganda coals

Energy Technology Data Exchange (ETDEWEB)

Vlasova, N S; Shchegoleva, E N

1979-05-01

The effectiveness of activated waterglass in the flotation of coals containing a considerable amount of clay is governed basically by the selectivity of the silicic acid and its dissociation products in relation to the coal surface and the surface of the dirt, as well as its stability and the degree of hydration of the fixed layer of reagent.

Substantiation of the hydrodynamic disintegration of hydraulic fluid’s mineral component of high-clay sand in precious metals placers

Directory of Open Access Journals (Sweden)

N.P. Khrunina

2018-03-01

Full Text Available General regularities and theoretical approaches determining hydroimpulsive effects on the mineral component of the hydraulic fluid are analyzed, with reference to the disintegration of high-clay sands of gold-bearing placers. Theoretical conclusions on the hydrodynamic effect on the solid component of the hydraulic fluid give insight into emerging processes in multicomponent media under hydrodynamic influences initiated by various sources of physical and mechanical influence. It is noted that the theoretical justification of the structurally complex hydrodynamic effect on the hydraulic fluid with the formation of phenomena arising from the collision of solid components with each other and obstacles includes the consideration of changes in such force characteristics as speed, pressure, flow power, and also changes in design parameters and characteristics of the environment. A conceptual approach is given to the theoretical substantiation of the disintegration of the hydraulic fluid’s mineral component using the example of the proposed installation. Calculation of economic indicators for the use of a hydrodynamic generator in comparison with processes based on known technologies has shown significant advantages of using the proposed installation, which can increase productivity and quality production indicators.

Sedimentary controls on modern sand grain coat formation

Science.gov (United States)

Dowey, Patrick J.; Worden, Richard H.; Utley, James; Hodgson, David M.

2017-05-01

Coated sand grains can influence reservoir quality evolution during sandstone diagenesis. Porosity can be reduced and fluid flow restricted where grain coats encroach into pore space. Conversely pore-lining grain coats can restrict the growth of pore-filling quartz cement in deeply buried sandstones, and thus can result in unusually high porosity in deeply buried sandstones. Being able to predict the distribution of coated sand grains within petroleum reservoirs is thus important to help find good reservoir quality. Here we report a modern analogue study of 12 sediment cores from the Anllóns Estuary, Galicia, NW Spain, collected from a range of sub-environments, to help develop an understanding of the occurrence and distribution of coated grains. The cores were described for grain size, bioturbation and sedimentary structures, and then sub-sampled for electron and light microscopy, laser granulometry, and X-ray diffraction analysis. The Anllóns Estuary is sand-dominated with intertidal sand flats and saltmarsh environments at the margins; there is a shallowing/fining-upwards trend in the estuary-fill succession. Grain coats are present in nearly every sample analysed; they are between 1 μm and 100 μm thick and typically lack internal organisation. The extent of grain coat coverage can exceed 25% in some samples with coverage highest in the top 20 cm of cores. Samples from muddy intertidal flat and the muddy saltmarsh environments, close to the margins of the estuary, have the highest coat coverage (mean coat coverage of 20.2% and 21.3%, respectively). The lowest mean coat coverage occurs in the sandy saltmarsh (10.4%), beyond the upper tidal limit and sandy intertidal flat environments (8.4%), close to the main estuary channel. Mean coat coverage correlates with the concentration of clay fraction. The primary controls on the distribution of fine-grained sediment, and therefore grain coat distribution, are primary sediment transport and deposition processes that

Fresh Properties and Flexural Strength of Self-Compacting Concrete Integrating Coal Bottom Ash

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Jamaluddin Norwati

2016-01-01

Full Text Available This paper presents the effect of using coal bottom ash as a partial replacement of fine aggregates in self-compacting concrete (SCC on its fresh properties and flexural strength. A comparison between SCC with various replacements of fine aggregates with coal bottom ash showed that SCC obtained flexural strength decrease on increase of water cement ratio from 0.35 to 0.45. The natural sand was replaced with coal bottom ash up to 30% volumetrically. The fresh properties were investigated by slump flow, T500 spread time, L-box test and sieve segregation resistance in order to evaluate its self-compatibility by compared to control samples embed with natural sand. The results revealed that the flowability and passing ability of SCC mixtures are decreased with higher content of coal bottom ash replacement. The results also showed that the flexural strength is affected by the presence of coal bottom ash in the concrete. In addition, the water cement ratios are influence significantly with higher binder content in concrete.

Clays causing adhesion with tool surfaces during mechanical tunnel driving

Science.gov (United States)

Spagnoli, G.; Fernández-Steeger, T.; Stanjek, H.; Feinendegen, M.; Post, C.; Azzam, R.

2009-04-01

During mechanical excavation with a tunnel boring machine (TBM) it is possible that clays stick to the cutting wheel and to other metal parts. The resulting delays in the progress of construction work, cause great economic damage and often disputes between the public awarding authorities and executing companies. One of the most important factors to reduce successfully the clay adhesion is the use of special polymers and foams. But why does the clay stick to the metal parts? A first step is to recognize which kind of clay mineralogy shows serious adhesion problems. The mechanical properties of clay and clay suspensions are primarily determined by surface chemistry and charge distribution at the interfaces, which in turn affect the arrangement of the clay structure. As we know, clay is a multi-phase material and its behaviour depends on numerous parameters such as: clay mineralogy, clay fraction, silt fraction, sand fraction, water content, water saturation, Atterberg limits, sticky limit, activity, cation exchange capacity, degree of consolidation and stress state. It is therefore likely that adhesion of clay on steel is also affected by these clay parameters. Samples of clay formations, which caused problems during tunnel driving, will be analyzed in laboratory. Mineralogical analyses (diffractometry, etc.) will be carried out to observe which minerals are responsible for adherence problems. To manipulate the physical properties, batch tests will be carried out in order to eliminate or reduce the adhesion on tool surfaces through variation of the zeta potential. Second step is the performance of vane shear tests on clay samples. Different pore fluid (distilled water, pure NaCl solution, ethanol and methanol) will be used to study the variation of the mechanical behaviour of clay depending on the dielectric constant of the fluids. This project is funded by the German Federal Ministry of Education and Research (BMBF) and the DFG (German Research Foundation) in the

Effect of a Dispersant Agent in Fine Coal Recovery from Washery Tailings by Oil Agglomeration (Preliminary Study)

Science.gov (United States)

Yasar, Özüm; Uslu, Tuncay

2017-12-01

Among the fine coal cleaning methods, the oil agglomeration process has important advantages such as high process recovery, more clean product, simple dewatering stage. Several coal agglomeration studies have been undertaken recently and effects of different variables on the process performance have been investigated. However, unlike flotation studies, most of the previous agglomeration studies have not used dispersing agents to minimize slime coating effects of clays. In this study, agglomeration process was applied for recovery of fine coals from coal washery tailings containing remarkable amount of fine coal. Negative effect of fine clays during recovery was tried to be eliminated by using dispersing agent instead of de-sliming. Although ash reductions over 90 % were achieved, performance remained below expectations in terms of combustible matter recovery. However, this study is a preliminary one. It is considered that more satisfied results will be obtained in the next studies by changing the variables such as solid ratio, oil dosage, dispersant type and dosage.

Geophysics comes of age in oil sands development

Energy Technology Data Exchange (ETDEWEB)

Bauman, P. [WorleyParsons Komex, Calgary, AB (Canada); Birch, R.; Parker, D.; Andrews, B. [Calgary Univ., AB (Canada). Dept. of Geology and Geophysics

2008-07-01

This paper discussed geophysical techniques developed for oil sands exploration and production applications in Alberta's oil sands region. Geophysical methods are playing an important role in mine planning, tailings containment, water supply, and land reclamation activities. Geophysics techniques are used to estimate the volume of muskeg that needs to be stripped and stored for future reclamation activities as well as to site muskeg piles and delineate the thickness of clay Clearwater formations overlying Cretaceous oil-bearing sands. 2-D electrical resistivity mapping is used to map river-connected deep bedrock Pleistocene paleovalleys in the region. Geophysical studies are also used to investigate the interiors of dikes and berms as well as to monitor salt migration within tailings piles. Sonic and density logs are used to create synthetic seismograms for mapping the Devonian surface in the region. The new applications included the calculation of bitumen saturation from surface sands and shales; muskeg thickness mapping; and non-intrusive monitoring of leachate plumes. Geophysical techniques included 2-D electrical resistivity imaging; transient electromagnetic (EM) technologies; ground penetrating radar; and high-resolution seismic reflections. Polarization, surface nuclear magnetic resonance and push-probe sensing techniques were also discussed. Techniques were discussed in relation to Alberta's Athabasca oil sands deposits. 4 refs.

The migration of colloidal particles through glacial sand

International Nuclear Information System (INIS)

Harrison, I.; Higgo, J.J.W.; Leader, R.; Noy, D.; Smith, B.; Wealthall, G.; Williams, G.M.

1991-02-01

Significant concentrations of colloids exist in groundwater and radionuclides may be associated with this colloidal material. This must be taken into consideration in any safety case for a radionuclide waste repository. This report describes column experiments with monodisperse latex beads. A selection of beads with diameters ranging from 0.055 μm to 0.6 μm, some plain and some with carboxyl groups attached, were passed through columns of glacial sand. The breakthrough curves and profiles on the sand columns were studied and will be used to develop and validate colloid migration models. The mobility depended on both size and charge, and the beads appeared to move ahead of a 36Cl tracer until they were trapped. After trapping movement was slow with plain beads appearing to be slightly more mobile than carboxylated beads. The beads were shown to sorb strongly on the fine clay particles in the sand and there was evidence to suggest that they moved with the fines rather than independently. (author)

Mass Transfer Behavior of Perfluorinated Chemicals in Saturated Clay-rich Sands: A Laboratory-based Study on Fate and Transport in Groundwater and Sediments

Science.gov (United States)

Greenberg, R. R.; Tick, G. R.; Abbott, J. B., III; Carroll, K. C.

2017-12-01

Perfluoroalkyl substances (PFAS) are a class of emerging contaminants that pose a threat to the human health and the quality of groundwater, surface water, and drinking water supplies. This study aims to elucidate the primary physicochemical factors controlling the fate and transport of the PFAS contaminants, perfluorooctanoic acid (PFOA) and perfluorooctanesulfonic acid (PFOS), in groundwater. Physicochemical processes of intercalation, adsorption, and desorption were investigated for the retention of PFAS at different initial aqueous-phase concentrations in modified-natural sediments composed of sand (40/50 accusand; foc = 0.04% unmodified) with low, medium, and high organic carbon contents (foc = 10, 20, and 50%) and various pre-conditioned clay-fractions. Diffusional mass-transfer limitations were evaluated based on initial PFAS concentration, specific clay structure, and resulting contaminant intercalation (d-spacing changes). A series of short- (48 hr), medium- (7 day) and long-term (30 day) batch and column experiments were conducted to determine physicochemical processes as a function of compound chemistry, sediment geochemistry, sorbent crystalline structure, and contaminant/sediment contact-time. Physicochemical parameters, PFAS concentrations, and sediment characterization were conducted using high performance liquid chromatography (HPLC), X-ray diffraction (XRD), and furnace combustion analytical techniques. The results of PFAS contaminant transport, under the different conditions tested, provide a scientific contribution with application to the development of improved risk assessments, predictions of fate and transport, and more effective remediation strategies for emerging perfluorinated contaminants in soil and groundwater.

Research investigations in oil shale, tar sand, coal research, advanced exploratory process technology, and advanced fuels research: Volume 1 -- Base program. Final report, October 1986--September 1993

Energy Technology Data Exchange (ETDEWEB)

Smith, V.E.

1994-05-01

Numerous studies have been conducted in five principal areas: oil shale, tar sand, underground coal gasification, advanced process technology, and advanced fuels research. In subsequent years, underground coal gasification was broadened to be coal research, under which several research activities were conducted that related to coal processing. The most significant change occurred in 1989 when the agreement was redefined as a Base Program and a Jointly Sponsored Research Program (JSRP). Investigations were conducted under the Base Program to determine the physical and chemical properties of materials suitable for conversion to liquid and gaseous fuels, to test and evaluate processes and innovative concepts for such conversions, to monitor and determine environmental impacts related to development of commercial-sized operations, and to evaluate methods for mitigation of potential environmental impacts. This report is divided into two volumes: Volume 1 consists of 28 summaries that describe the principal research efforts conducted under the Base Program in five topic areas. Volume 2 describes tasks performed within the JSRP. Research conducted under this agreement has resulted in technology transfer of a variety of energy-related research information. A listing of related publications and presentations is given at the end of each research topic summary. More specific and detailed information is provided in the topical reports referenced in the related publications listings.

Mechanism of the action of water glass in the flotation of Karaganda coals

Energy Technology Data Exchange (ETDEWEB)

Vlasova, N S; Shchegoleva, E N

1979-01-01

The effectiveness of activated waterglass in the flotation of coals containing a considerable amount of clay is governed basically by the selctivity of the silicic acid and its dissociation products in relation to the coal surface and the surface of the dirt, as well as its stability and the degree of hydration of the fixed layer of reagent.

Changes of gas pressure in sand mould during cast iron pouring

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J. Mocek

2011-10-01

Full Text Available The paper presents a test method developed to measure changes of gas pressure in sand moulds during manufacture of iron castings. The pressure and temperature measurements were taken in the sand mould layers directly adjacent to the metal – mould interface. A test stand was described along with the measurement methodology. The sensors used allowed studying the fast-changing nature of the processes which give rise to the gas-originated casting defects. The study examined the influence of binders, clays and refining additives on the nature of the gas evolution process. The effect of the base sand type - quartz or olivine - on the nature of pressure changes was compared. The test stand design ensured the stability of technological parameters in the examined mould elements, and a repeatable process of making pilot castings. The main outcome was classification of sand mixtures in terms of pressure occurring during pouring of iron castings. The obtained results confirm the usefulness of the described method for testing gas pressure occurrence in a sand mould.

Description of the physical environment and coal-mining history of west-central Indiana, with emphasis on six small watersheds

Science.gov (United States)

Martin, Jeffrey D.; Crawford, Charles G.; Duwelius, R.F.; Renn, D.E.

1987-01-01

Information on the geology, geomorphology, soils, climate, hydrology, water use, land use, population, and coal mining history of Clay, Owen, Sullivan, and Vigo Counties in Indiana is summarized. Site-specific information is given on the morphology , geology, soils, land use, coal mining history, and hydrologic instrumentation of the six watersheds which are each less than 3 sq mi in area. The Wabash, White, and Eel Rivers are the major drainages in west-central Indiana. Average annual precipitation is about 39.5 in/yr and average annual runoff is about 13 in/yr. The most productive aquifers are confined or unconfined outwash aquifers located along the major rivers. Bedrock aquifers are regionally insignificant but are the sole source of groundwater for areas that lack outwash, alluvium, or sand and gravel lenses in till. Indiana has more than 17 billion short tons of recoverable coal reserves; about 11% can be mined by surface methods. Almost half of Indiana 's surface reserves are in Clay, Owen, Sullivan, and Vigo Counties. More than 50,000 acres in west-central Indiana have been disturbed by surface coal mining from 1941 through 1980. Big Slough and Hooker Creek are streams that drain unmined, agricultural watersheds. Row-crop corn and soybeans are the principal crops. Soils are moderately well drained silt loams, and the watersheds well developed dendritic drainage systems. Unnamed tributaries drain mined and reclaimed watersheds. Ridges of mine spoil have been graded to a gently rolling topography. Soils are well drained and consist of 6 to 12 inches of silt-loam topsoil that was stockpiled and then replaced over shale and sandstone fragments of the graded mine spoil. Grasses and legumes form the vegetative cover in each watershed. Pond Creek and an unnamed tributary to Big Branch are streams that drain mined and unreclaimed watersheds. Soils are very well drained shaly silty loams that have formed on steeply sloping banks. Both watersheds contain numerous

Influence of Biochar on Deposition and Release of Clay Colloids in Saturated Porous Media.

Science.gov (United States)

Haque, Muhammad Emdadul; Shen, Chongyang; Li, Tiantian; Chu, Haoxue; Wang, Hong; Li, Zhen; Huang, Yuanfang

2017-11-01

Although the potential application of biochar in soil remediation has been recognized, the effect of biochar on the transport of clay colloids, and accordingly the fate of colloid-associated contaminants, is unclear to date. This study conducted saturated column experiments to systematically examine transport of clay colloids in biochar-amended sand porous media in different electrolytes at different ionic strengths. The obtained breakthrough curves were simulated by the convection-diffusion equation, which included a first-order deposition and release terms. The deposition mechanisms were interpreted by calculating Derjaguin-Landau-Verwey-Overbeek interaction energies. A linear relationship between the simulated deposition rate or the attachment efficiency and the fraction of biochar was observed ( ≥ 0.91), indicating more favorable deposition in biochar than in sand. The interaction energy calculations show that the greater deposition in biochar occurs because the half-tube-like cavities on the biochar surfaces favor deposition in secondary minima and the nanoscale physical and chemical heterogeneities on the biochar surfaces increase deposition in primary minima. The deposited clay colloids in NaCl can be released by reduction of ionic strength, whereas the presence of a bivalent cation (Ca) results in irreversible deposition due to the formation of cation bridging between the colloids and biochar surfaces. The deposition and release of clay colloids on or from biochar surfaces not only change their mobilizations in the soil but also influence the efficiency of the biochar for removal of pollutants. Therefore, the influence of biochar on clay colloid transport must be considered before application of the biochar in soil remediation. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

Coal combustion by-products: A survey of use and disposal provisions

International Nuclear Information System (INIS)

Jagiella, D.M.

1993-01-01

Over 50% of all electricity in the United States is generated by the combustion of coal. Currently, coal fired power plants produce approximately 85 million to 100 million tons of coal combustion byproducts each year. The generation of these byproducts is expected to increase to 120 million tons by the year 2000, an increase of about 72% over 1984 levels. There are four basic types of byproducts produced by coal combustion - fly as, bottom ash, boiler slag, and flue gas desulfurization sludge (FGD), and are useful as engineering materials in a variety of applications. Fly ash represents nearly 75% of all ash wastes generated in the United States. Fly ash is a powder like substance with bonding properties. The properties of fly ash depend on the type of boiler utilized. The collected fly ash can be used to partially replace cement in concrete or the clay tit bricks or as part of nine reclamation. The technology for use of fly ash in cement concrete and road bases is well developed and has been practical for many years. The United States Environmental Protection Agency (USEPA) has recognized the applications of fly ash and promulgated a federal procurement guideline for the use of fly ash in cement and concrete. Although fly ash is the second most widely used waste product, much opportunity remains to expand the use of this product, In 1984, 80% of all fly ash was not recycled but rather disposed of, Ash particles that do not escape in flue gas as fly ash become bottom ash or boiler slag. Bottom ash and boiler slag settles on the bottom of the power plant's boiler. Bottom ash is a sand like substance which has some bonding capability. Depending on the type of boiler, tile bottom ash may be open-quotes dry bottom ashclose quotes or open-quotes wet bottom ashclose quotes, Wet bottom ash falls in a molten state into water

Coal resources availability in Botswana

International Nuclear Information System (INIS)

Modisi, M.P.

1990-01-01

This paper reports that Southern Africa, and Botswana in particular, is well-endowed with relatively large reserves of coal. The existence of coal in Botswana has been known since the end of the last century. Exploration activities by the Geological Survey and the private sector led to the discovery of major deposits and by the late 1960s reserves capable of supporting a mine at Morupule for the domestic market has been confirmed. The oil crises of 1973-74 and 1978-79 stimulated increased interest in coal exploration the world over and Botswana attracted several private sector companies looking for coal that could be traded on the international market. As a result vast resources and reserves of low to medium quality bituminous coal, suitable for the export market, were proved. Resources amounting to 21,680 million tonnes of in situ coal had been revealed by 1987. Reserves of possible economic exploitation are estimated at 10,180 million tonnes in two coal field areas, namely the Morupule Coal Field and the Mmamabula Coal Field. Since the collapse of oil prices and consequently coal prices in the mid-1980s, enthusiasm for coal exploration has plummeted and relatively little prospecting has taken place. The coal occurs within the Upper Carboniferous to Jurassic Karoo Supergroup which underlies some 60 percent of the country's land surface. The western part of the country is mantled by the Kalahari beds, a top layer of unconsolidated sands masking bedrock geology. Although coal seams have been intersected in boreholes in this western area, most exploration activity has taken place in the eastern part of the country where the Morupule and Mmamabula coal fields are located. It is in the east that most of the population is concentrated and infrastructure has been developed

Effect of part replacement of silica sand with carbon black on composite properties

International Nuclear Information System (INIS)

Adeosun, B.F.; Olaofe, O.

2003-01-01

We have reported the properties of natural rubber filled with locally available materials (Adu et al 2000). The effect of local clay, limestone, silica sand and charcoal on the properties of natural rubber has been examined. Results have shown detrimental effects of silica sand on the properties of natural rubber compound. It has been reported that when silica is used as a part for part replacement of carbon black, the heat build up the composite decreased whilst tear resistance improved. Results revealed that within the filler content range used in the present work, the hardness, modulus, and tensile strength of composites loaded with silica sand/carbon black showed enhanced magnitude over the composite loaded singly with silica sand. These parameters generally increased with increasing carbon black content in the composite. New area of use requiring moderate level of tensile strength, hardness and modulus (as in soles of shoes and engine mounts) is therefore opened up for silica sand.(author)

The effect of clay amendment on substrate properties and growth of woody plants

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Tomáš Meisl

2012-01-01

Full Text Available This work deals with the effect of two clay products differing in particle size distribution on properties of growing substrate and on growth of containerized woody plants in substrates amended with these clay products. Fine and coarse clay were added to a peat substrate, each at two rates. The peat substrate without clay was used as a control. The substrates were tested in experiments with two woody ornamentals (Thuja occidentalis ’Smaragd’ and Prunus cistena. Chemical and physical properties of the substrates were measured according to European Standards before planting. Proportion of water categories differing in availability to the plants were calculated from retention curves measured on the sand box. Properties of substrates in containers with and without plants were evaluated in the same way at the end of the culture. Clay addition changed chemical and physical properties of the tested substrates in terms: available nutrients content, particle density, bulk density, total pore volume, easy available water, water buffering capacity, air capacity, and shrinkage. The effect of fine clay was much stronger. In comparison with the clear effect of clay addition on the substrate chemical and physical properties, the effect on the growth and quality of model woody plants was not so explicit.

Neoformation of clay in lateral root catchments of mallee eucalypts: a chemical perspective

Science.gov (United States)

Verboom, William H.; Pate, John S.; Aspandiar, Mehrooz

2010-01-01

Background and Aims A previous paper (Annals of Botany 103: 673–685) described formation of clayey pavements in lateral root catchments of eucalypts colonizing a recently formed sand dune in south-west Western Australia. Here chemical and morphological aspects of their formation at the site are studied. Methods Chemical and physical examinations of soil cores through pavements and sand under adjacent heath assessed build-up of salts, clay and pH changes in or below pavements. Relationships of root morphology to clay deposition were examined and deposits subjected to scanning electron microscopy and energy-dispersive X-ray analysis. Xylem transport of mineral elements in eucalypt and non-eucalypt species was studied by analysis of xylem (tracheal) sap from lateral roots. Key Results The columns of which pavements are composed develop exclusively on lower-tier lateral roots. Such sites show intimate associations of fine roots, fungal filaments, microbiota and clay deposits rich in Si, Al and Fe. Time scales for construction of pavements by eucalypts were assessed. Cores through columns of pavemented profiles showed gross elevations of bulk density, Al, Fe and Si in columns and related increases in pH, Mg and Ca status in lower profiles. A cutting through the dune exhibited pronounced alkalinity (pH 7–10) under mallee woodland versus acidity (pH 5–6·5) under proteaceous heath. Xylem sap analyses showed unusually high concentrations of Al, Fe, Mg and Si in dry-season samples from column-bearing roots. Conclusions Deposition of Al–Fe–Si-rich clay is pivotal to pavement construction by eucalypts and leads to profound chemical and physical changes in relevant soil profiles. Microbial associates of roots are likely to be involved in clay genesis, with parent eucalypts supplying the required key mineral elements and carbon sources. Acquisition of the Al and Fe incorporated into clay derives principally from hydraulic uplift from ground water via deeply

Parametric study of the physical properties of hydrate-bearing sand, silt, and clay sediments: 1. Electromagnetic properties

Science.gov (United States)

Lee, J.Y.; Santamarina, J.C.; Ruppel, C.

2010-01-01

The marked decrease in bulk electrical conductivity of sediments in the presence of gas hydrates has been used to interpret borehole electrical resistivity logs and, to a lesser extent, the results of controlled source electromagnetic surveys to constrain the spatial distribution and predicted concentration of gas hydrate in natural settings. Until now, an exhaustive laboratory data set that could be used to assess the impact of gas hydrate on the electromagnetic properties of different soils (sand, silt, and clay) at different effective stress and with different saturations of hydrate has been lacking. The laboratory results reported here are obtained using a standard geotechnical cell and the hydrate-formed tetrahydrofuran (THF), a liquid that is fully miscible in water and able to produce closely controlled saturations of hydrate from dissolved phase. Both permittivity and electrical conductivity are good indicators of the volume fraction of free water in the sediment, which is in turn dependent on hydrate saturation. Permittivity in the microwave frequency range is particularly predictive of free water content since it is barely affected by ionic concentration, pore structure, and surface conduction. Electrical conductivity (or resistivity) is less reliable for constraining water content or hydrate saturation: In addition to fluid-filled porosity, other factors, such as the ionic concentration of the pore fluid and possibly other conduction effects (e.g., surface conduction in high specific surface soils having low conductivity pore fluid), also influence electrical conductivity.

Analysis of the eukaryotic community and metabolites found in clay wall material used in the construction of traditional Japanese buildings.

Science.gov (United States)

Kitajima, Sakihito; Kamei, Kaeko; Nishitani, Maiko; Sato, Hiroyuki

2010-01-01

Clay wall (tsuchikabe in Japanese) material for Japanese traditional buildings is manufactured by fermenting a mixture of clay, sand, and rice straw. The aim of this study was to understand the fermentation process in order to gain insight into the ways waste biomass can be used to produce useful materials. In this study, in addition to Clostridium, we suggested that the family Nectriaceae and the Scutellinia sp. of fungi were important in degrading cell wall materials of rice straw, such as cellulose and/or lignin. The microorganisms in the clay wall material produced sulfur-containing inorganic compounds that may sulfurate minerals in clay particles, and polysaccharides that give viscosity to clay wall material, thus increasing workability for plastering, and possibly giving water-resistance to the dried clay wall.

Sedimentological and Scanning Electron Miscroscopic Descriptions of Afowo Oil Sand Deposits, South Western Nigeria

Directory of Open Access Journals (Sweden)

Akinmosin A

2017-12-01

Full Text Available Sedimentological and scanning electron microscopic analyses of some shallow reservoir tar sand samples in parts of Southwestern Nigeria were carried out with the aim of characterizing the reservoir properties in relation to bitumen saturation and recovery efficiency. The production of impregnated tar from the sands requires the reservoir to be of good quality. A total of thirty samples were collected at different localities within the tar sand belt (ten out of these samples were selected for various reservoir quality analyses based on their textural homogeneity. The result of particle size distribution study showed that bulk of the sands is medium – coarse grained and moderately sorted. The grain morphologies are of low to high sphericity with shapes generally sub-angular to sub-rounded, implying that the sands have undergone a fairly long transportation history with depositional energy having a moderate to high velocity. The quartz content was made up of about 96% of the total mineralogical components; the sediments of the Afowo Formation can be described to be mineralogically and texturally stable. The result of the scanning electron microscopy (SEM analysis revealed that the oil sands contained minerals which had been precipitated and occurred as pore filling cement; these minerals include sheet kaolinite, block kaolinite, vermiform kaolinite, pyrite crystals and quartz. The SEM images also showed micro-pores ranging from 0.057µm to 0.446µm and fractures. The study showed that the clay minerals contained in the Afowo reservoir rocks were mainly kaolinite. Kaoline unlike some other clays (e.g Montimorillonite does not swell with water, hence it is not expected to have any negative effects on the reservoir quality, especially during enhanced oil recovery operations.

Use of x-ray radiographic methods in the study of clay liners

International Nuclear Information System (INIS)

Malone, P.G.; May, J.H.; Brown, K.W.; Thomas, J.C.

1986-01-01

X-ray radiography has been widely used in soil investigation to study the distribution of layers in soil cores and the effects of changing conditions (loading or impact) on soil structure. X-ray radiographic techniques also can be useful in studying clays or clay soils used in liners. Laboratory investigations were undertaken to demonstrate that X-ray radiographic techniques could be used to detect density and soil structure changes that usually accompany variations in hydraulic conductivity of clay liners. An example of a real-time test of a simulated bentonite and sand, liner attacked with acid lead nitrate and examples of radiographic examination of clay soil (non-calcareous smectite) samples that have been permeated by lead acetate or lead nitrate are presented. The changes in density and structure can be related to changes observed in hydraulic conductivity during permeation. X-ray radiography easily can be applied to field samples of soil or clay liner materials to detect density and structural changes that occur as the liner and permeating fluid interact. X-ray techniques have applications in both understanding failure mechanisms and forecasting liner performance

Study on Type C Coal Fly ash as an Additive to Molding Sand for Steel Casting

Science.gov (United States)

Palaniappan, Jayanthi

2017-04-01

Study of physio-chemical properties studies such as granulometric analysis, moisture, X ray fluorescence etc. were performed with Type C coal—combustion fly ash to investigate their potential as a distinct option for molding sand in foundry, thereby reducing the dependency on latter. Technological properties study such as compressive strength, tensile strength, permeability and compaction of various compositions of fly ash molding sand (10, 20 and 30 % fly ash substitute to chemically bonded sand) were performed and compared with silica molding sand. Steel casting production using this fly ash molding sand was done and the casting surface finish and typical casting parameters were assessed. It was noted that a good quality steel casting could be produced using type C fly ash molding sand, which effectively replaced 20 % of traditional molding sand and binders thereby providing greater financial profits to the foundry and an effective way of fly ash utilization (waste management).

Laboratory-scale study of possible use of residual sludge from glass sand beneficiation

Science.gov (United States)

Prikryl, Richard; Weishauptova, Zuzana; Zach, Jaroslav; Kozlovcev, Petr

2016-04-01

Beneficiation of quartz sand from sedimentary deposits for glass sands results in significant amounts of under-size fraction, a sludge rich in clay minerals. This sludge is considered as a waste and is returned in mined-out spaces for a simple rehabilitation, which is also the case of one of the largest glass sand production areas in the Czech Republic. The amount of produced waste sludge in the studied area (glass sand works in Provodín area, Bohemian Cretaceous Basin) is about 20 kt per year. In the recent study, we have focused on possible employment of this waste material for three applications: (1) a clay component in a raw material mixture for making of hydraulic lime, (2) a kaolinite absorbent, and (3) a geotechnical material. The sampled sludge was primarily analysed for mineralogical and chemical composition, mechanical and physical properties, the specific surface area, and parameters of pore space. X-ray analysis proved the presence of kaolinite, illite (both WCI and PCI), quartz, and accessory microcline. According to silicate analysis, the material is composed of SiO2 (80.52 wt. %), Al2O3 (11.36 wt. %), and K2O (2.14 wt. %). For its potential use as an artificial admixture for hydraulic lime production, the studied material was mixed with pure limestone in ratio of 10, 15, 20, and/or 25 wt. %. The experimental mixtures were burnt in the temperature range from 850 to 1,200°C. XRD was employed for the detection of newly formed phases showing formation of hydraulic phase such as C2S, C3A, C4AF starting from the 1050°C burning temperature. Peak burning temperature significantly influenced amount of individual phases in the burnt product. Second possible mode of use of the investigated waste material focused on its application as a sorbent. Pore space and specific surface area characteristics (SBET 7.4 sq. m/g) range this material to the group of low grade kaolinite-dominated adsorbents. Thermal treatment (burning of raw waste material at temperatures of

Non-cohesive silt turbidity current flow processes; insights from proximal sandy-silt and silty-sand turbidites, Fiordland, New Zealand

Science.gov (United States)

Strachan, Lorna J.; Bostock, Helen C.; Barnes, Philip M.; Neil, Helen L.; Gosling, Matthew

2016-08-01

Silt-rich turbidites are commonly interpreted as distal marine deposits. They are associated with interlaminated clay and silt deposition from the upper and rear portions of turbidity currents. Here, multibeam bathymetry and shallow sediment core data from the intra-slope Secretary Basin, Fiordland, New Zealand, located laminar) flows that have undergone a variety of up-dip flow transformations. Most flows were initially erosive followed by deposition of partitioned 2- or 3- phase mixed mode flows that include high-density transitional and laminar flows that can be fore- or after-runners to low-density turbulent flow sections. Turbulence is inferred to have been suppressed in high-density flows by increasing flow concentration of both sands and silts. The very fine and fine sand modal grain sizes of sandy-silt and silty-sand turbidites are significantly coarser than classical abyssal plain silt turbidites and are generally coarser than overbank silt turbidites. While the low percentage of clays within Secretary Basin sandy-silt and silty-sand turbidites represents a fundamental difference between these and other silt and mud turbidites, we suggest these beds represent a previously undescribed suite of proximal continental slope deposits.

Energy options and the role of coal: an integrated approach

Energy Technology Data Exchange (ETDEWEB)

Isaacs, E. [Alberta Energy Research Institute, Edmonton, AB (Canada)

2006-07-01

Considers energy goals and options with particular regard to providing affordable energy to Canada. Gasification of coal and carbon to provide a reliable source of clean power and heat to the oil sand industry and for feedstocks for the production of fertilizer, methanol, petrochemicals, and ultra-clean fuels is examined. The layout for integrated gasification polygeneration with carbon feed and plans for Canada's first commercial gasification plant (the Nexen Long Lake Project) are shown in diagrams. Progress in coal gasification at a clean coal Luscar/Sherritt pilot plant is outlined. Clean coal technology is part of a strategy to provide integration across energy systems, generate value for all hydrocarbon resources, and minimize emissions. 15 figs., 2 tabs.

Gasification of oil sand coke: review

Energy Technology Data Exchange (ETDEWEB)

Furimsky, E. [IMAF Group, Ottawa, ON (Canada)

1998-08-01

The production of synthetic crude from the tar sands in Western Canada has been steadily increasing. Most of the delayed coke produced by Suncor is combusted on site, whereas all fluid coke produced by Syncrude is stockpiled.The database on the chemical and physical properties of the oil sand coke, including the composition and fusion properties of the mineral matter, has been established. The reactivity of the coke was determined by oxygen chemisorption, fixed bed and fluid bed bench scale gasification and pilot plant gasification. The reactivity of the oil sand coke for gasification is rather low and comparable to high rank coals, such as anthracite. Slurrability tests revealed that a solid concentration in water, approaching 70 wt%, can be achieved. Gasification is the front runner among clean technologies for the conversion of carbonaceous solids to useful products. Several commercial gasifiers are available to cover the wide range of severity. Because of the low reactivity of oil sands coke, high severity conditions are required to achieve high gasification conversion. Such conditions can be attained in entrained bed gasifiers. Gasifiers employing both dry and slurry feeding systems are suitable. A high efficiency, low SO{sub x} and NO{sub x} emissions, as well as a low solid waste production are among the key advantages of the gasification technology compared with thecompeting technologies. Commercial gasification of oil sands coke is delayed because of the availability of natural gas on the site of the upgrading plants. Potential for the transportation of the oil sand coke to USA for electricity generation using the integrated gasification combined-cycle (IGCC) technology was evaluated. 27 refs., 17 figs., 9 tabs.

Development of clay characterization methods for use in repository design with application to a natural Ca bentonite clay containing a redox front

International Nuclear Information System (INIS)

Karnland, O.; Pusch, R.

1990-12-01

Natural smectite clays in the form of 'true' bentonites formed from volcanic ash, or resulting from in-situ weathering of rock, are suitable for a number of sealing options in repositories, both as tightening component of sand/clay backfills and as highly efficient buffer for embedment of canisters, as well as for fracture sealing. The price and quality, in terms of smectite content and type of smectite, vary considerably and an optimum choice of clay for use in repositories has to be based on quantitative quality data. This requires characterization of the clay material for which a test scheme has been worked out. It comprises determination of the granulometrical, chemical, and mineralogical compositions, as well as of certain physical properties. Recent research shows the importance of the type of smectite for the longevity of buffers in repository environment, beidellite being less favourable and saponite superior to montmorillonite, which is the most common smectite species. The test scheme hence includes means of distinguishing between various smectite minerals. The influence of accessory minerals on the chemical integrity of both the smectite and the canister material requires identification also of such minerals, for which the scheme is useful as well. The report summarizes the various test procedures and gives data from application of the scheme to samples from a natural Ca bentonite containing a redox front. This study suggests that a significant part of the iron in the clay fraction is in the form of Fe 2+ in octahedral positions of the montmorillonite of unoxidized natural clay and that it is converted to Fe 3+ on oxidation. Part of the iron is probably in the form of the Fe 2+ Fe 3+ hydroxy compounds that give the unoxidized clay its bluish colour, while they can be assumed to be transformed to yellowish FeOOH forms on oxidation. (author)

Distribution and correlation of the natural radionuclides in a coal mine of the West Macedonia Lignite Center (Greece).

Science.gov (United States)

Tsikritzis, L I; Fotakis, M; Tzimkas, N; Kolovos, N; Tsikritzi, R

2008-02-01

The distribution and correlation of six natural nuclides in the West Macedonia Lignite Center, Northern Greece were studied. Fifty-five samples of lignite, aged from 1.8 to 5 million years, and corresponding steriles, beds of marls, clays and sands alternating with the lignite, were collected perpendicular to the mine benches and measured spectroscopically. The mean concentrations of (238)U and (226)Ra in lignites were found to be higher than that in steriles since these nuclides are associated with the organic material of lignite, whereas (238)U/(226)Ra equilibrium was not observed in either lignites or steriles. Finally, the ratio (226)Ra/(228)Ra in lignites was approximately double of that in steriles, confirming the affinity of the (238)U series with the coal matrix in contrast to the (232)Th series. No correlation was found between radionuclide concentrations and the depth of the sample, nor with the ash content of lignite.

Biochemical Removal of HAP Precursors from Coal

Energy Technology Data Exchange (ETDEWEB)

Olson, Gregory J

1997-05-12

Column biooxidation tests with Kentucky coal confirmed results of earlier shake flask tests showing significant removal from the coal of arsenic, selenium, cobalt, manganese, nickel and cadmium. Rates of pyrite biooxidation in Kentucky coal were only slightly more than half the rates found previously for Indiana and Pittsburgh coals. Removal of pyrite from Pittsburgh coal by ferric ion oxidation slows markedly as ferrous ions accumulate in solution, requiring maintenance of high redox potentials in processes designed for removal of pyrite and hazardous air pollutant (HAP) precursors by circulation of ferric solutions through coal. The pyrite oxidation rates obtained in these tests were used by Unifield Engineering to support the conceptual designs for alternative pyrite and HAP precursor bioleaching processes for the phase 2 pilot plant. Thermophilic microorganisms were tested to determine if mercury could be mobilized from coal under elevated growth temperatures. There was no evidence for mercury removal from coal under these conditions. However, the activity of the organisms may have liberated mercury physically. It is also possible that the organisms dissolved mercury and it readsorbed to the clay preferentially. Both of these possibilities are undergoing further testing. The Idaho National Engineering and Environmental Laboratory's (INEEL) slurry column reactor was operated and several batches of feed coal, product coal, waste solids and leach solutions were submitted to LBL for HAP precursor analysis. Results to date indicate significant removal of mercury, arsenic and other HAP precursors in the combined physical-biological process.

The geochemistry of environmentally important trace elements in UK coals, with special reference to the Parkgate coal in the Yorkshire-Nottinghamshire Coalfield, UK

Science.gov (United States)

Spears, D.A.; Tewalt, S.J.

2009-01-01

The Parkgate coal of Langsettian age in the Yorkshire-Nottinghamshire coalfield is typical of many coals in the UK in that it has a high sulphur (S) content. Detailed information on the distribution of the forms of S, both laterally and vertically through the seam, was known from previous investigations. In the present work, 38 interval samples from five measured sections of the coal were comprehensively analysed for major, minor and trace elements and the significance of the relationships established using both raw and centered log transformed data. The major elements are used to quantify the variations in the inorganic and organic coal components and determine the trace element associations. Pyrite contains nearly all of the Hg, As, Se, Tl and Pb and is also the major source of the Mo, Ni, Cd and Sb. The clays contain the following elements in decreasing order of association: Rb, Cs, Li, Ga, U, Cr, V, Sc, Y, Bi, Cu, Nb, Sn, Te and Th. Nearly all of the Rb is present in the clay fraction, whereas for elements such as V, Cu and U, a significant amount is thought to be present in the organic matter, based on the K vs trace element regression equations. Only Ge, and possibly Be, would appear to have a dominant organic source. The trace element concentrations are calculated for pyrite, the clay fraction and organic matter. For pyrite it is noted that concentrations agree with published data from the Yorkshire-Nottinghamshire coalfield and also that Tl concentrations (median of 0.33 ppm) in the pyrite are greater than either Hg or Cd. Unlike these elements, Tl has attracted less attention and possibly more information is needed on its anthropogenic distribution and impacts on man and the environment. A seawater source is thought to be responsible for the high concentrations of S, Cl and the non-detrital trace elements in the Parkgate coal. Indicative of the seawater control is the Th/U ratio, which expresses the detrital to non-detrital element contributions. Using

Catalysis of metal-clay intercalation compound in the low temperature coal hydrogasification

Energy Technology Data Exchange (ETDEWEB)

Fuda, Kiyoshi; Kimura, Mitsuhiko; Miyamoto, Norimitsu; Matsunaga, Toshiaki

1986-10-23

Focusing the hydrogenating methanation by gaseous phase catalytic reactions of low temperature volatile components, the catalytic effects of Ni metal and the effects of carriers having sensitive effects on the catalytic activities of Ni metal were studied. Sample coals were prepared from Shin-Yubari coal, and Ni hydride-montmorillonite complex catalysts and the catalysts produced by carring Ni nitrate on alumina and burning in hydrogen gas flows were prepared. The hydrogasification were carried out in a reaction tube. As a result, the montmorillonite-Ni compounds catalysts had high catalitic effects and high conversion ratio of 90% or more in the low temperature coal gasification. The catalitic effects of carried Ni metal strongly depended on the carrier substances, and the rank of effects for the carriers was montmorillonite>zeorite>TiO/sub 2/>alpha-Al/sub 2/O/sub 3/>MgO>SiO/sub 2/=gamma-Al/sub 2/O/sub 3/. (3 figs, 3 tabs, 3 refs)

A Study of Clay-Epoxy Nanocomposites Consisting of Unmodified Clay and Organo Clay

Directory of Open Access Journals (Sweden)

Graham Edward

2006-04-01

Full Text Available Clay-epoxy nanocomposites were synthesized from DGEBA resin and montmorillonite clay with an in-situ polymerization. One type of untreated clay and two types of organo clay were used to produce the nanocompsoites. The aims of this study were to examine the nanocomposite structure using different tools and to compare the results between the unmodified clay and modified clays as nanofillers. Although diffractogram in reflection mode did not show any apparent peak of both types of materials, the transmitted XRD (X-Ray Difraction graphs, DSC (Differential Scanning Calorimeter analysis and TEM (Transmission Electron Microscope images revealed that the modified clay-epoxy and unmodified clay-epoxy provides different results. Interestingly, the micrographs showed that some of the modified clay layers possessed non-exfoliated layers in the modified clay-epoxy nanocomposites. Clay aggregates and a hackle pattern were found from E-SEM images for both types of nanocomposite materials. It is shown that different tools should be used to determine the nanocomposite structure.

Distillation, destructive

Energy Technology Data Exchange (ETDEWEB)

Newton, A V

1856-04-22

In order to obtain, at the first distillation, from coal, shale, and bituminous substances an oil sufficiently pure for illuminating and other purposes, the material broken into very small pieces and placed on the bottom of the retort, is evenly covered with common sand, about four times greater in weight than the weight of the coal. The coal and sand are then gradually raised to a temperature of 212/sup 0/F. Steam containing carbonaceous impurities first passes to the condenser, and subsequently oil, which rises to the surface of the water in the receiving-vessel. When some bituminous substances are employed, the temperature, after oil ceases to come over, may be gradually raised until the oil produced ceases to be pure. Most kinds of clay and earth, chalk, gypsum, black oxide of manganese, plumbago, or charcoal may be used separately, in combination, or with added chemicals, instead of sand as the medium for filtering the gas or vapor from which the oil is formed. Either the oil obtained by the first distillation or oils obtained by other means may be rectified by distilling with sand.

The Suitability Of Local Quartz Sand In The Production Of Bath Crucibles.

Directory of Open Access Journals (Sweden)

C. O. Okpanachi

2017-03-01

Full Text Available The suitability of local quartz sand in the production of bath crucibles is a study that was carried out in order to impart overall strength on bath crucibles hence reduce breakages during fettling. Therefore this research constitutes a study to enhance the efficiency of production of bath crucibles by addition of quartz sand in slip preparation. The steps taken in the beneficiation of quartz sand for the production of bath crucibles are comminution which entails crushing and milling classification washing liquid dispersion sizing and reduction of iron content by magnetic separation. The slip contains materials like plastic clay feldspar kaolin talc sodium silicate water quartz sand etc. These were all milled in the ball mill for slip production casting and fettling glazing and sintering to get final bath crucibles as the end products. Quartz sand is used in a variety of products essentially as raw material for the foundry casting and glass industries and also in chemicals water filtration and ceramics the heat resistance nature of quartz sand makes it an excellent refractory substance for these industrial processes. Slip can be prepared for production of bath crucibles without the inclusion of quartz sand however the addition of quartz sand is needed to improve the mechanical performance of the slip in the production of bath crucibles.

Rapid pyrolysis of Serbian soft brown coals

Directory of Open Access Journals (Sweden)

Jankes Goran

2009-01-01

Full Text Available Soft brown coals of the open coal fields of Kolubara and Kostolac are the main domestic energy sources of Serbia. This paper presents the results of investigations on rapid devolatilization of these two coals which have covered kinetics of devolatilization (based on total volatile yield, forms of sulphur and petrographic analysis of coal and char. Experiments of devolatilization were performed in inert gas (N2 at atmospheric pressure and in batch-type hot-wire screen reactor. The mass-loss values of both coals at selected final reaction temperatures (300-900°C and retention times (3-28 s were obtained. Anthony and Howard's kinetic model was applied over two temperature ranges (300-500 and 700-900°C. The types of sulphur as monosulphide, sulphate, pyritic, and organic sulphur were determined for chars and original coals. Strong transformation of pyrite was evident even at low temperatures (300°C. Devolatilization of all types of sulphur has started over 600 and at 900°C the content of sulphur in char remained only 66% of total sulphur in original coal. Microscopic investigations were carried out on samples prepared for reflected light measurements. The petrographic analysis included: the ratio of unchanged and changed coal, maceral types, the share of cenosferes, isotropic mixed carbonized grains, mixed grains, small fragments, clay, and pyrite. The change of the structure of devolatilized coal was also observed.

Geochemistry of Toxic Elements and Their Removal via the Preparation of High-Uranium Coal in Southwestern China

Directory of Open Access Journals (Sweden)

Piaopiao Duan

2018-02-01

Full Text Available High-uranium (U coal is the dominant form of coal in Southwestern China. However, directly utilizing this resource can also harm the environment because this element is radioactive; it is, therefore, necessary to clean this kind of coal before burning. This research studied the geochemistry of toxic elements and their partitioning during the preparation of high-U coal in China. The results show that high-U coals are mainly distributed in Southwestern China and are characterized by a high organic sulfur (S content and vanadium (V-chromium (Cr-molybdenum (Mo-U element assemblage. These elements are well-correlated with one another, but are all negatively related to ash yield, indicating that all four are syngenetic in origin and associated with organic materials. A mineralogical analysis shows that U in Ganhe and Rongyang coal occurs within fine-grained anatase, clay minerals, guadarramite, and pyrite, while V occurs in clay minerals, pyrite, and dolomite, and Cr occurs in dolomite. Other elements, such as fluorine (F, lead (Pb, selenium (Se, and mercury (Hg, mainly occur in pyrite. By applying a gravity separation method to separate minerals from coal, the content of the enrichment element assemblage of V-Cr-Mo-U in Rongyang coal is still shown to be higher than, or close to, that of the original feed because this element assemblage is derived from hydrothermal fluids during syngenetic or early diagenetic phases, but other elements (beryllium [Be], F, manganese [Mn], zinc [Zn], Pb, arsenic [As], Se, Hg can be efficiently removed. Once cleaned, the coal obtained by gravity separation was subject to a flotation test to separate minerals; these results indicate that while a portion of V and Cr can be removed, Mo and U remain difficult to extract. It is evident that the two most commonly utilized industrialized coal preparation methods, gravity separation and flotation, cannot effectively remove U from coal where this element occurs in large

Physico-chemical properties of clay deposits of Bina and Jhingurdah mines of Singrauli coalfield, District Sidhi (MP)

Energy Technology Data Exchange (ETDEWEB)

Singh, V B; Joshi, V C

1980-01-01

Clay samples exposed over Baraker and Raniganj coal seams of Lower Gondwana System in Bina and Jhingurdah mines respectively are studied. The chemical and rational analyses of the samples indicate that range of variation of the different constituents. Infra-red, X-ray diffraction, differential thermal analysis and thermal gravimetric analysis were used to determine clay and other minerals. The deposits may be suitable for manufacture of triaxial wares, e.g. ordinary porcelain sanitary ware, stoneware, etc.

Distilling coal, etc

Energy Technology Data Exchange (ETDEWEB)

Nelson, J

1917-12-21

Coals of various kinds such as shales, bitumens, and oil sand, peat, etc. are distilled at 350 to 450/sup 0/C and in the presence of vapors and gases obtained by cracking hydrocarbon oils, or the gases obtained by separating the condensable hydrocarbons therefrom, and, if desired, with the addition of superheated steam. The hydrocarbons are properly cracked by passing through molten lead as described in Specification 116,304. According to the Provisional Specification, superheated steam alone may be used to effect the distillation.

An Investigation into the Use of Manufactured Sand as a 100% Replacement for Fine Aggregate in Concrete

Directory of Open Access Journals (Sweden)

Martins Pilegis

2016-06-01

Full Text Available Manufactured sand differs from natural sea and river dredged sand in its physical and mineralogical properties. These can be both beneficial and detrimental to the fresh and hardened properties of concrete. This paper presents the results of a laboratory study in which manufactured sand produced in an industry sized crushing plant was characterised with respect to its physical and mineralogical properties. The influence of these characteristics on concrete workability and strength, when manufactured sand completely replaced natural sand in concrete, was investigated and modelled using artificial neural networks (ANN. The results show that the manufactured sand concrete made in this study generally requires a higher water/cement (w/c ratio for workability equal to that of natural sand concrete due to the higher angularity of the manufactured sand particles. Water reducing admixtures can be used to compensate for this if the manufactured sand does not contain clay particles. At the same w/c ratio, the compressive and flexural strength of manufactured sand concrete exceeds that of natural sand concrete. ANN proved a valuable and reliable method of predicting concrete strength and workability based on the properties of the fine aggregate (FA and the concrete mix composition.

An Investigation into the Use of Manufactured Sand as a 100% Replacement for Fine Aggregate in Concrete.

Science.gov (United States)

Pilegis, Martins; Gardner, Diane; Lark, Robert

2016-06-02

Manufactured sand differs from natural sea and river dredged sand in its physical and mineralogical properties. These can be both beneficial and detrimental to the fresh and hardened properties of concrete. This paper presents the results of a laboratory study in which manufactured sand produced in an industry sized crushing plant was characterised with respect to its physical and mineralogical properties. The influence of these characteristics on concrete workability and strength, when manufactured sand completely replaced natural sand in concrete, was investigated and modelled using artificial neural networks (ANN). The results show that the manufactured sand concrete made in this study generally requires a higher water/cement (w/c) ratio for workability equal to that of natural sand concrete due to the higher angularity of the manufactured sand particles. Water reducing admixtures can be used to compensate for this if the manufactured sand does not contain clay particles. At the same w/c ratio, the compressive and flexural strength of manufactured sand concrete exceeds that of natural sand concrete. ANN proved a valuable and reliable method of predicting concrete strength and workability based on the properties of the fine aggregate (FA) and the concrete mix composition.

Sand-RAPG combination simulating fertile clayey soil (Part I to IV)

International Nuclear Information System (INIS)

Azzam, R.; El-Hady, O.A.; Lotfy, A.A.; Hegela, M.

1983-01-01

I. Radiation Preparation of RAPG. Sites of co-ordination and reinforcement are dominated in reclaimer ameliorator polymeric gel (RAPG). It is a modified acrylonitrile base multifunction polymer grafted upon a binder of worthless cellulosic agricultural discard. It varies chemically from non-ionic through anionic and cationic to ampholite. The hydroproperty of the gel is similarly controlled. Thus, RAPG can be tailored for any soil texture under various climatic conditions. II. Structure Stability and Maintenance. Sinai dune sand is treated with non-ionic and anionic RAPGs at rates varying from 0.05 to 0.2 wt.%. The stability increased with RAPG anionicity and application rate. The structure formed maintained three cycles of complete destruction and re-formation without significant changes in erosion index. The resistance of sand-RAPG combination to breakdown by tillage, as well as to wind and water erosion, is practically proved. This is in addition to the beneficial changes in bulk density, void ratio and microporosity, which were also achieved. III. Water Preservation. Inshas sandy soil treated by RAPG is compared with fertile clayey soil. The water-holding capacity and retention at different suctions are increased. The available water to plants in treated sand has reached 15 times that of the control, and even exceeded clay by 11%. Water losses by evaporation and leaching as well as deep percolation are all reduced to a minimum. IV. Plantation and Nutritional Status. Pepper seed germination, growth and dry matter are increased in the sand-RAPG combination relative to fertile clayey soil. The optimum rate and anionicity of RAPG are determined. This increases water-use efficiency to twice that of the fertile clayey soil. Macro- and micro-nutrient uptake have also increased. Thus, fertilizer use efficiency is increased by almost three times over that of clay. These factors lead convincingly to the conclusion that RAPG furnishes adequate conditions for sandy soil

Impact of organic-mineral matter interactions on thermal reaction pathways for coal model compounds

Energy Technology Data Exchange (ETDEWEB)

Buchanan, A.C. III; Britt, P.F.; Struss, J.A. [Oak Ridge National Lab., TN (United States). Chemical and Analytical Sciences Div.

1995-07-01

Coal is a complex, heterogeneous solid that includes interdispersed mineral matter. However, knowledge of organic-mineral matter interactions is embryonic, and the impact of these interactions on coal pyrolysis and liquefaction is incomplete. Clay minerals, for example, are known to be effective catalysts for organic reactions. Furthermore, clays such as montmorillonite have been proposed to be key catalysts in the thermal alteration of lignin into vitrinite during the coalification process. Recent studies by Hatcher and coworkers on the evolution of coalified woods using microscopy and NMR have led them to propose selective, acid-catalyzed, solid state reaction chemistry to account for retained structural integrity in the wood. However, the chemical feasibility of such reactions in relevant solids is difficult to demonstrate. The authors have begun a model compound study to gain a better molecular level understanding of the effects in the solid state of organic-mineral matter interactions relevant to both coal formation and processing. To satisfy the need for model compounds that remain nonvolatile solids at temperatures ranging to 450 C, model compounds are employed that are chemically bound to the surface of a fumed silica (Si-O-C{sub aryl}linkage). The organic structures currently under investigation are phenethyl phenyl ether (C{sub 6}H{sub 5}CH{sub 2}CH{sub 2}OC{sub 6}H{sub 5}) derivatives, which serve as models for {beta}-alkyl aryl ether units that are present in lignin and lignitic coals. The solid-state chemistry of these materials at 200--450 C in the presence of interdispersed acid catalysts such as small particle size silica-aluminas and montmorillonite clay will be reported. Initial focus will be on defining the potential impact of these interactions on coal pyrolysis and liquefaction.

Replacing coal by tire powder in ceramic industry

Energy Technology Data Exchange (ETDEWEB)

Mothe, C.G. [Dept. de Processos Organicos, Escola de Quimica/CT/UFRJ, Rio de Janeiro, RJ (Brazil); Mothe Filho, H.F. [Dept. de Geociencias, Inst. de Agronomia/UFRRJ, Seropedica, RJ (Brazil)

2005-07-01

Nowadays preserving nature, recycling or reusing materials are good policies. Around ten million tires are put out by year in Brazil, and it is not known for how long they will remain in environment till their complete degradation. This research used tires to replace coal in ceramic processing. In this way it helps to protect environment, to reduce the consumption of mineral deposits and to save money. Results show that tire powder can replace coal to obtain ceramic material, using one percent of tire. Experiments were carried out using TA instruments SDT 2960, in air or nitrogen atmospheres, at heating rate of 10 C/min., flow 120 ml/min. TG/DTA curves of tire and coal have exothermic events at close temperatures between 450-600 C. At range of temperatures clay have endothermic events. (orig.)

Mineral processing and characterization of coal waste to be used as fine aggregates for concrete paving blocks

Directory of Open Access Journals (Sweden)

C. R. Santos

Full Text Available Commercial coal production in the southern region of Brazil has been occurring since the beginning of the twentieth century. Due to the geological characteristics of the region, large amounts of solid wastes are generated. The aim of this work was to evaluate the use of coal waste to produce concrete paving blocks. A procedure to process the coal waste with the purpose of reducing the sulfur content and changing the particle size distribution of the material to meet the specification of fine aggregates was developed. The methodology considered the following steps: (a sampling of a coal mining waste; (b gravity separation of the fraction with specific gravity between 2.4 and 2.8; (c comminution of the material and particle size analysis; (d technological characterization of the material and production of concrete paving blocks; and (e acidity generation prediction (environmental feasibility. The results showed that the coal waste considered in this work can be used to replace conventional sand as a fine aggregate for concrete paving blocks in a proportion of up to 50%. This practice can result in cleaner coal production and reduce the demand for exploitation of sand deposits.

Soil Microbes and soil microbial proteins: interactions with clay minerals

International Nuclear Information System (INIS)

Spence, A.; Kelleher, B. P.

2009-01-01

Bacterial enumeration in soil environments estimates that the population may reach approximately 10 1 0 g - 1 of soil and comprise up to 90% of the total soil microbial biomass. Bacteria are present in soils as single cells or multicell colonies and often strongly adsorb onto mineral surfaces such as sand and clay. The interactions of microbes and microbial biomolecules with these minerals have profound impacts on the physical, chemical and biological properties of soils. (Author)

Heat-resistant agent used for control sand of steam huff and puff heavy oil well

Science.gov (United States)

Zhang, F. S.; Liu, G. L.; Lu, Y. J.; Xiong, X. C.; Ma, J. H.; Su, H. M.

2018-01-01

Heat-resistant agent containing hydroxymethyl group was synthesized from coal tar, which has similar structure with phenolic resin and could improve the heat resistance of phenolic resin sand control agent. The results showed that the heat resistance of the sand control agent was improved by adding 10% to 30% heat-resistant agent, after 280°C high temperature treatment for 7d, the compressive strength of consolidated core was increased to more than 5MPa. The compressive strength of consolidation core was not decreased after immersion in formation water, crude oil, acid or alkaline medium, which showed good resistance to medium immersion. The sand control agent had small core damage and the core permeability damage ratio of sand control agent consolidation was only 18.7%.

Synthesis of anion clay starting from flying ash and its application in the removal of Chromium VI

International Nuclear Information System (INIS)

Gil, E.

1998-01-01

The present study shows a simple and economic method for the removal of Cr (VI) of the liquid waste. The study was carried out in two stages, a first stage consisted on the synthesis of the anion clay, using fly ash as matter prevails, which is a waste material coming from the ovens of combustion of the coal; in the other stage it was carried out the process of removal of Cr (VI), using the anion clay like absorption, throwing satisfactory results

Study on the basic properties of Indonesian oil sands

Energy Technology Data Exchange (ETDEWEB)

Wang, Qing; Jiang, Qian-qian; Bai, Jing-ru; Sun, Jian; Liu, Hong-peng [Northeast Dianli Univ., Jilin (China). Inst. of Energy and Power Engineering

2013-07-01

The basic properties of three Indonesian oil sands have been investigated. The results show that since the high content of volatile, heating value and oil yield, Indonesian oil sands could be combusted for power generation and retorting for oil refining. Moreover, oil sand ash with the low content of fixed carbon and high content of CaO, could not only be used as solid heat carrier during retorting, but also comprehensively used as construction material. Based on the thermogravimeric analysis (TGA), pyrolysis and combustion behaviors have been identified. As for pyrolysis, 350-520 C could be regarded as the major oil-producing region, the apparent activation energy E is not a constant obtained by distributed activation energy model (DAEM). For combustion, 620-800 C is the high-temperature oxidation (HTO) stage. TG-DTG extrapolation method was applied to determine the combustion characteristics parameters such as ignition temperature, burn-out temperature, combustion stability and combustion reactivity, and finally gave a comparison with those of oil shale and coal.

Compressive strength performance of OPS lightweight aggregate concrete containing coal bottom ash as partial fine aggregate replacement

Science.gov (United States)

Muthusamy, K.; Mohamad Hafizuddin, R.; Mat Yahaya, F.; Sulaiman, M. A.; Syed Mohsin, S. M.; Tukimat, N. N.; Omar, R.; Chin, S. C.

2018-04-01

Concerns regarding the negative impact towards environment due to the increasing use of natural sand in construction industry and dumping of industrial solid wastes namely coal bottom ash (CBA) and oil palm shell (OPS) has resulted in the development of environmental friendly lightweight concrete. The present study investigates the effect of coal bottom ash as partial fine aggregate replacement towards workability and compressive strength of oil palm shell lightweight aggregate concrete (OPS LWAC). The fresh and mechanical properties of this concrete containing various percentage of coal bottom ash as partial fine aggregate replacement were investigated. The result was compared to OPS LWAC with 100 % sand as a control specimen. The concrete workability investigated by conducting slump test. All specimens were cast in form of cubes and water cured until the testing age. The compressive strength test was carried out at 7 and 28 days. The finding shows that integration of coal bottom ash at suitable proportion enhances the strength of oil palm shell lightweight aggregate concrete.

Mode of occurrence of chromium in four US coals

Science.gov (United States)

Huggins, Frank E.; Shah, N.; Huffman, G.P.; Kolker, A.; Crowley, S.; Palmer, C.A.; Finkelman, R.B.

2000-01-01

The mode of occurrence of chromium in three US bituminous coals and one US subbituminous has been examined using both X-ray absorption fine structure (XAFS) spectroscopy and a selective leaching protocol supplemented by scanning electron microscopy (SEM) and electron microprobe measurements. A synthesis of results from both methods indicates that chromium occurs principally in two forms in the bituminous coals: the major occurrence of chromium is associated with the macerals and is not readily leached by any reagent, whereas a second, lesser occurrence, which is leachable in hydrofluoric acid (HF), is associated with the clay mineral, illite. The former occurrence is believed to be a small particle oxyhydroxide phase (CrO(OH)). One coal also contained a small fraction (<5%) of the chromium in the form of a chromian magnetite, and the leaching protocol indicated the possibility of a similar small fraction of chromium in sulfide form in all three coals. There was little agreement between the two techniques on the mode of occurrence of chromium in the subbituminous coal; however, only a limited number of subbituminous coals have been analyzed by either technique. The chromium in all four coals was trivalent as no evidence was found for the Cr6+ oxidation state in any coal.

Identification and Purification of Nyalo River Silica Sand as Raw Material for the Synthesis of Sodium Silicate

Science.gov (United States)

Aini, S.; Nizar, U. K.; NST, A. Amelia; Efendi, J.

2018-04-01

This research is on identification and purification of silica sand from Nyalo River. It will be used as a raw material for synthesis of sodium silicate. Silica sand was separated from clay by washing it with water, and then the existing alumina and iron oxide were removed by soaking the silica sand with 1 M HNO3 solution. Qualitative and quantitative analysis of the silica sand with X-ray diffraction and X-ray fluorescence revealed that, silica sand existed in quartz form and contained a small amount of impurity oxide such as Al2O3, K2O, MgO, CaO, Fe2O3 with percentage below the minimum threshold. The percentages of silica were 80.59% before purification. After three purificationsteps the silica percentage become 98.38%. It exceedsthe minimum threshold of silica percentage for industry.So, the silica sand from Nyalo River has high potency as a raw material for sodium silicate synthesizing.

Characterization of Malaysian coals for carbon dioxide sequestration

Science.gov (United States)

Abunowara, M.; Bustam, M. A.; Sufian, S.; Eldemerdash, U.

2016-06-01

Coal samples from Mukah-Balingian and Merit-Pila coal mines were characterized with ultimate, approximate, petrographic analysis, FT-IR spectra patterns, FESEM images and BET measurements to obtain information on the chemical composition and chemical structure in the samples. Two coal samples were obtained from Merit-Pila coal mine namely sample1 (S1) and sample2 (S2). The other two coal samples were obtained from Mukah-Balingian coal mine namely sample3 (S3) and sample4 (S4), Sarawak, Malaysia. The results of ultimate analysis show that coal S1 has the highest carbon percentage by 54.47%, the highest hydrogen percentage by 10.56% and the lowest sulfur percentage by 0.19% and the coal S4 has the highest moisture content by 31.5%. The coal S1 has the highest fixed carbon percentage by 42.6%. The coal S4 has BET surface area by 2.39 m2/g and Langmuir surface area by 3.0684 m2/g respectively. Fourier-Transform Infrared (FT-IR) spectroscopy analysis of all coal samples shows a presence of oxygen containing functional groups which considered are as active sites on coal surface. The oxygen functional groups are mainly carboxyl (-COOH), hydroxyl (-OH), alkyl (-CH, -CH2, -CH3), aliphatic (C-O-C stretching associated with -OH), amino (-NH stretching vibrations), (-NH stretching vibrations), aromatic (C=C), vinylic (C=C) and clay minerals. In all FE-SEM images of coal samples matrix, it can be seen that there are luminous and as non luminous features which refer to the existence of various minerals types distributed in the coal organic matrix. The bright luminosity is due to the presence of sodium, potassium or aluminium. According to petrographic analysis, all coal sample samples are range in vitrinite reflectance from 0.38% to 56% (VRr) are sub-bituminous coals.

Creating a soil-like profile for plant growth using tailings sand and fine tails

International Nuclear Information System (INIS)

Li, X.; Fung, M. P. Y.

1996-01-01

Development of a technology to create stable aggregates with a soil-like profile capable of supporting a stable plant community, was discussed as the major challenge and primary task in restoring oil sands processing wastes, and in re-creating a self-sustaining ecosystem. A procedure for creating a soil-like profile using oil sands mining wastes, was described. Clay and water content were critical factors in the aggregation procedure. A study to evaluate the physical, chemical and biological properties of these soils and their suitability as a plant growth medium is currently underway. 6 refs., 3 figs

Study on the technology of decreasing ash and sulfur in coking coal concentrate by deep-cleaning

Energy Technology Data Exchange (ETDEWEB)

Li, A.; Li, P.; Chen, S. [Hefei Design and Research Institute of Coal Industry, Hefei (China)

2007-06-15

Middling fractions of coking coal, a rare resource in China, were analysed for their embedded minerals both in kind and distribution. Observation with a microscope shows that most are clay minerals of very small particle size. The embedded minerals can be liberated from middling by grinding. Clean coal can be obtained from ground middling by the flocculation-flotation process. The yield of clean coal could thus be increased and its ash and sulfur content decreased. 3 refs., 2 figs., 4 tabs.

Effect of substitution of sand stone dust for quartz and clay in triaxial ...

Indian Academy of Sciences (India)

Few quartz grains (20–40μm) are associated with circumferential cracks around them. Keywords. Environmental pollutant; sand stone dust; ceramic tiles; pavement block; vitrification; ... increased risk of tuberculosis. Moreover, exposure ..... Health. 14 94. Hamano K, Nakagawa Z and Hasegawa M 1992 J. Ceram. Soc. Jap.

Productivity of clay tailings from phosphate mining: 3. Grain crops

International Nuclear Information System (INIS)

Mislevy, P.; Blue, W.G.; Roessler, C.E.; Martin, F.G.

1991-01-01

A split-fold field experiment was conducted to study forage and grain yield, forage quality, plant nutrient concentrations, changes in soil nutrients, and 226 Ra contents of four grain crops in various rotations. The crop rotations (1) corn (Zea mays L. Jacques 247)-sunflower (Helianthus annuus L. Cargil 205), (2) sunflower-grain sorghum (Sorghum bicolor L, Moench Northrup King Savanna 5), (3) soybean (Glycine max L. Merr. Williams 80)-grain sorghum, and (4) grain sorghum-soybean (University of Florida V-1) were grown on a dry phosphatic clay with and without a 50-mm surface layer of quartz-sand tailings. Results show that corn and grain sorghum produced highest forage yields and highest grain yields per harvest, respectively. Soybean harvested for forage (Crop 1) contained the highest crude protein and in vitro organic matter digestibility. Concentrations of P, K, Ca, Mg, and Fe in most of the forages were adequate for the diets of beef cattle, while those of Mn, Cu and Zn were low. Mehlich I-extractable soil, Ca, and Mg were considered very high and changed little over the 4-yr production period. Application of 50 mm of sand tailings tended to increase Mehlich I-extractable P, Ca, Mn, Cu, Zn, and Fe. Radium-226 concentration in the forage of all grain crops averaged 8.5 Bq kg -1 , which was about 17 times higher than that in the grain of the same crops. Concentrations of 226 Ra in the forage and grain were 1.1% and 0.09% of the concentration in clay respectively. These data indicate that phosphatic clays can be a valuable resource for the production of corn and sorghum grain that contain low concentrations of 226 Ra

Suitability of a South African silica sand for three-dimensional printing of foundry moulds and cores

Directory of Open Access Journals (Sweden)

Nyembwe, Kasongo

2016-11-01

Full Text Available Applications of three-dimensional printing (3DP to metal casting include, among other things, the direct manufacturing of foundry moulds and cores in refractory materials such as silica sand. The main properties of silica sand that are essentially related to the traditional moulding and core-making processes are: size distribution, clay content, pH, acid demand, and refractoriness. The silica sand used for 3DP must also be appropriately selected for the layer-based manufacturing process involved in 3DP. Properties such as grain size distribution, grain surface morphology, angularity, flowability, and recoating abilities have a particular importance when determining sand suitability. Because of these extra requirements, only a limited range of available foundry silica sands can be used for 3DP processes. The latter situation explains the scarcity and high cost of suitable silica sands, thus contributing to the relatively high operational costs of the 3DP processes for the production of sand moulds and cores. This research paper investigates the suitability of a locally-available silica sand for use in a Voxeljet VX1000 3DP machine. The local silica sand was assessed and compared with an imported silica sand recommended by the manufacturer of 3DP equipment in terms of foundry characteristics and recoating behaviour. The study shows that, despite the differences between the characteristics of the two silica sands, the local sand could be considered a suitable alternative to imported sand for rapid sand casting applications.

Petrology, Palynology, and Geochemistry of Gray Hawk Coal (Early Pennsylvanian, Langsettian in Eastern Kentucky, USA

Directory of Open Access Journals (Sweden)

James C. Hower

2015-09-01

Full Text Available This study presents recently collected data examining the organic petrology, palynology, mineralogy and geochemistry of the Gray Hawk coal bed. From the Early Pennsylvanian, Langsettian substage, Gray Hawk coal has been mined near the western edge of the eastern Kentucky portion of the Central Appalachian coalfield. While the coal is thin, rarely more than 0.5-m thick, it has a low-ash yield and a low-S content, making it an important local resource. The Gray Hawk coal palynology is dominated by Lycospora spp., and contains a diverse spectrum of small lycopods, tree ferns, small ferns, calamites, and gymnosperms. The maceral assemblages show an abundance of collotelinite, telinite, vitrodetrinite, fusinite, and semifusinite. Fecal pellet-derived macrinite, albeit with more compaction than is typically seen in younger coals, was observed in the Gray Hawk coal. The minerals in the coal are dominated by clay minerals (e.g., kaolinite, mixed-layer illite/smectite, illite, and to a lesser extent, pyrite, quartz, and iron III hydroxyl-sulfate, along with traces of chlorite, and in some cases, jarosite, szomolnokite, anatase, and calcite. The clay minerals are of authigenic and detrital origins. The occurrence of anatase as cell-fillings also indicates an authigenic origin. With the exception of Ge and As, which are slightly enriched in the coals, the concentrations of other trace elements are either close to or much lower than the averages for world hard coals. Arsenic and Hg are also enriched in the top bench of the coal and probably occur in pyrite. The elemental associations (e.g., Al2O3/TiO2, Cr/Th-Sc/Th indicate a sediment-source region with intermediate and felsic compositions. Rare metals, including Ga, rare earth elements and Ge, are highly enriched in the coal ashes, and the Gray Hawk coals have a great potential for industrial use of these metals. The rare earth elements in the samples are weakly fractionated or are characterized by heavy

Discriminating silt-and-clay from suspended-sand in rivers using side-looking acoustic profilers

Science.gov (United States)

Wright, Scott A.; Topping, David J.; Williams, Cory A.

2010-01-01

techniques rely on measurements of ancillary properties that correlate with suspended-sediment concentration and particle size and thus require the collection of traditional samples for calibration. Through in situ deployments, these methods can provide the high temporal resolution that cannot be achieved through traditional sampling. Here we focus on the evaluation of acoustic profiling techniques (e.g. acoustic-Doppler sideways-looking profilers, or ADPs). One major advantage of acoustic profiling is the ability to concurrently measure water velocity (using Doppler-shift methods) and suspended-sediment concentration such that suspended-sediment flux can be directly computed using data from a single instrument. Acoustic-Doppler profilers have become popular for measuring water velocity and discharge in rivers, through both moving-boat operations and from fixed deployments such as bank-mounted sideways-looking instruments (Hirsch and Costa, 2004, Muste et al., 2007). The method presented herein is most suited to sideways-looking applications as a complement to the "index velocity" technique, whereby an index velocity from a sideways-looking instrument is related to the cross-section average velocity (determined from moving-boat discharge measurements) as a means for developing a continuous water-discharge record (Ruhl and Simpson, 2005). Topping et al. (2007) presented a method for discriminating silt-and-clay from suspended sand, using single frequency ADPs. This method takes advantage of the relations among acoustic backscatter, sediment-induced acoustic attenuation, suspended-sediment concentration (SSC), and particle size distribution (PSD). Backscatter is the amount of sound scattered back and received at the transducer while sediment-induced attenuation is the amount of sound scattered in other directions and absorbed by the sediment particles. Both of these parameters can be measured with an ADP, and their different dependencies on SSC and PSD allow for the

Occurrence of trace elements in respirable coal dust

International Nuclear Information System (INIS)

Sahoo, B.N.

1991-01-01

Inhalation of fine particles of coal dust contributes significantly to the occurrence of the disease, pneumoconiosis, prevailing in coal mining community. It is not presently known whether only the coal dust or specific chemical compounds or synergistic effects of several compounds associated with respirable coal dust is responsible for the disease, pneumoconiosis. The present paper describes the quantitative determination of ten minor and trace elements in respirable coal dust particles by atomic absorption spectrophotometric methods. The respirable coal dust samples are collected at the mine atmosphere during drilling in coal scams by using Messrs. Casella's Hexlet apparatus specially designed and fitted with horizontal elutriator to collect the respirable coal dust fraction simulating as near as possible to the lung's retention of the coal miners. After destruction of organic matter by wet oxidation and filtering off clay and silica, Fe, Ca, Mg, Na, K, Mn, Cu, Zn, Cd, and Ni were determined directly in the resulting solution by atomic absorption spectrophotometric procedures. The results show that the trace metals are more acute in lower range of size spectrum. Correlation coefficient, enrichment factor and linear regression values and their inverse relationship between the slope and EF values suggest that, in general, the trace metals in respirable particulates are likely to be from coal derived source if their concentrations are likewise high in the coal. The trace metal analytical data of respirable particulates fitted well to the linear regressive equation. The results of the studies are of importance as it may throw some light on the respirable lung disease 'pneumoconiosis' which are predominant in coal mining community. (author). 13 refs., 6 tabs

Potential effects of surface coal mining on the hydrology of the Corral Creek area, Hanging Woman Creek coal field, southeastern Montana

Science.gov (United States)

McClymonds, N.E.

1984-01-01

The Corral Creek area of the Hanging Woman Creek coal field, 9 miles east of the Decker coal mines near the Tongue River, contains large reserves of Federal coal that have been identified for potential lease sale. A hydrologic study was conducted in the area to describe existing hydrologic systems and to study assess potential impacts of surface coal mining on local water resources. Hydrogeologic data collected indicate that aquifers are coal and sandstone beds within the Tongue River Member of the Fort Union Formation (Paleocene age) and sand and gravel in valley alluvium (Pleistocene and Holocene age). Surface-water resources are limited to a few spring-fed stock ponds in the higher parts of the area and the intermittent flow of Corral Creek near the mouth. Most of the stock ponds in the area become dry by midsummer. Mining of the Anderson coal bed would remove three stock wells and would lower the potentiometric surface within the coal and sandstone aquifers. The alluvial aquifer beneath Corral Creek and South Fork would be removed. Although mining would alter the existing hydrologic systems and remove several shallow wells, alternative ground-water supplies are available that could be developed to replace those lost by mining. (USGS)

Transient Electromagnetic Soundings Near Great Sand Dunes National Park and Preserve, San Luis Valley, Colorado (2006 Field Season)

Science.gov (United States)

Fitterman, David V.; de Sozua Filho, Oderson A.

2009-01-01

Time-domain electromagnetic (TEM) soundings were made near Great Sand Dunes National Park and Preserve in the San Luis Valley of southern Colorado to obtain subsurface information of use to hydrologic modeling. Seventeen soundings were made to the east and north of the sand dunes. Using a small loop TEM system, maximum exploration depths of about 75 to 150 m were obtained. In general, layered earth interpretations of the data found that resistivity decreases with depth. Comparison of soundings with geologic logs from nearby wells found that zones logged as having increased clay content usually corresponded with a significant resistivity decrease in the TEM determined model. This result supports the use of TEM soundings to map the location of the top of the clay unit deposited at the bottom of the ancient Lake Alamosa that filled the San Luis Valley from Pliocene to middle Pleistocene time.

Application of Coal Ash to Postmine Land for Prevention of Soil Erosion in Coal Mine in Indonesia: Utilization of Fly Ash and Bottom Ash

Directory of Open Access Journals (Sweden)

Shinji Matsumoto

2016-01-01

Full Text Available The increase in the number of coal-fired power plants with the increase in coal production and its consumption has caused the problem of the treatment of a large amount of coal ash in Indonesia. In the past studies, coal ash was applied to postmine land with the aim of improving soil conditions for plant growth; however, heavy rain in the tropical climate may cause soil erosion with the change in soil conditions. This study presents the effects of application of coal ash to postmine land on soil erosion by performing the artificial rainfall test as well as physical testing. The results indicate that the risk of soil erosion can be reduced significantly by applying the coal ash which consists of more than 85% of sand to topsoil in the postmine land at the mixing ratio of over 30%. Additionally, they reveal that not only fine fractions but also microporous structures in coal ash enhance water retention capacity by retaining water in the structure, leading to the prevention of soil erosion. Thus, the risk of soil erosion can be reduced by applying coal ash to topsoil in consideration of soil composition and microporous structure of coal ash.

Description of the physical environment an coal-mining history of West-Central Indiana, with emphasis on six small watersheds

Science.gov (United States)

Martin, Jeffrey D.; Crawford, Charles G.; Duwelius, Richard F.; Renn, Danny E.

1990-01-01

This report describes the physical and human environment and coal-mining history of west-central Indiana, with emphasis on six small watersheds selected for study of the hydrologic effects of surface coal mining. The report summarizes information on the geology, geomorphology, soils, climate, hydrology, water use, land use, population, and coal-mining history of Clay, Owen, Sullivan, and Vigo Counties in Indiana. Site-specific information is given on the morphology, geology, soils, land use, coal-mining history, and hydrologic instrumentation of the six watersheds, which are each less than 3 square miles in area.

[Analysis of XRD spectral characteristics of soil clay mineral in two typical cultivated soils].

Science.gov (United States)

Zhang, Zhi-Dan; Luo, Xiang-Li; Jiang, Hai-Chao; Li, Qiao; Shen, Cong-Ying; Liu, Hang; Zhou, Ya-Juan; Zhao, Lan-Po; Wang, Ji-Hong

2014-07-01

The present paper took black soil and chernozem, the typical cultivated soil in major grain producing area of Northeast, as the study object, and determinated the soil particle composition characteristics of two cultivated soils under the same climate and location. Then XRD was used to study the composition and difference of clay mineral in two kinds of soil and the evolutionary mechanism was explored. The results showed that the two kinds of soil particles were composed mainly of the sand, followed by clay and silt. When the particle accumulation rate reached 50%, the central particle size was in the 15-130 microm interval. Except for black soil profile of Shengli Xiang, the content of clay showed converse sequence to the central particle in two soils. Clay accumulated under upper layer (18.82%) in black soil profile while under caliche layer (17.41%) in chernozem profile. Clay content was the least in parent material horizon except in black profile of Quanyanling. Analysis of clay XRD atlas showed that the difference lied in not only the strength of diffraction peak, but also in the mineral composition. The main contents of black soil and chernozem were both 2 : 1 clay, the composition of black soil was smectite/illite mixed layer-illite-vermiculite and that of chernozem was S/I mixture-illite-montmorillonite, and both of them contained little kaolinite, chlorite, quartz and other primary mineral. This paper used XRD to determine the characteristics of clay minerals comprehensively, and analyzed two kinds of typical cultivated soil comparatively, and it was a new perspective of soil minerals study.

Paleocene coal deposits of the Wilcox group, central Texas

Science.gov (United States)

Hook, Robert W.; Warwick, Peter D.; SanFilipo, John R.; Schultz, Adam C.; Nichols, Douglas J.; Swanson, Sharon M.; Warwick, Peter D.; Karlsen, Alexander K.; Merrill, Matthew D.; Valentine, Brett J.

2011-01-01

Coal deposits in the Wilcox Group of central Texas have been regarded as the richest coal resources in the Gulf Coastal Plain. Although minable coal beds appear to be less numerous and generally higher in sulfur content (1 percent average, as-received basis; table 1) than Wilcox coal deposits in the Northeast Texas and Louisiana Sabine assessment areas (0.5 and 0.6 percent sulfur, respectively; table 1), net coal thickness in coal zones in central Texas is up to 32 ft thick and more persistent along strike (up to 15 mi) at or near the surface than coals of any other Gulf Coast assessment area. The rank of the coal beds in central Texas is generally lignite (table 1), but some coal ranks as great as subbituminous C have been reported (Mukhopadhyay, 1989). The outcrop of the Wilcox Group in central Texas strikes northeast, extends for approximately 140 mi between the Trinity and Colorado Rivers, and covers parts of Bastrop, Falls, Freestone, Lee, Leon, Limestone, Milam, Navarro, Robertson, and Williamson Counties (Figure 1). Three formations, in ascending order, the Hooper, Simsboro, and Calvert Bluff, are recognized in central Texas (Figure 2). The Wilcox Group is underlain conformably by the Midway Group, a mudstone-dominated marine sequence, and is overlain and scoured locally by the Carrizo Sand, a fluvial unit at the base of the Claiborne Group.

The influence of clay minerals on acoustic properties of sandstones

Energy Technology Data Exchange (ETDEWEB)

Hansen, Olav

1997-12-31

This thesis aims to provide better understanding of the relationship between the acoustic properties and the petrophysical/mineralogical properties in sand-prone rock. It emphasizes the influence of clay minerals. The author develops a method to deposit clay minerals/mineral aggregates in pore space of a rigid rock framework. Kaolinite aggregates were flushed into porous permeable Bentheimer sandstone to evaluate the effect of pore filling minerals on porosity, permeability and acoustic properties. The compressional velocity was hardly affected by the clay content and it was found that the effect of minor quantities of pore filling minerals may be acoustically modelled as an ideal suspension, where the pore fluid bulk modulus is modified by the bulk modulus of the clay minerals. The influence of clays on acoustic velocities in petroleum reservoir rocks was investigated through ultrasonic measurements of compressional- and shear-waves on core material from reservoir and non-reservoir units on the Norwegian Continental Shelf. The measured velocities decrease as the porosity increases, but are not strongly dependent on the clay content. The measured velocities are less dependent on the petrophysical and lithological properties than indicated by previous authors and published mathematical models, and stiffness reduction factors are introduced in two of the models to better match the data. Velocities are estimated along the wellbores based on non-sonic well logs and reflect well the actual sonic log well measurements. In some wells the compressional velocity cannot be modelled correctly by the models suggested. Very high compressional wave anisotropy was measured in the dry samples at atmospheric conditions. As the samples were saturated, the anisotropy was reduced to a maximum of about 30% and decreases further upon pressurization. Reservoir rocks retrieved from 2500 m are more stress dependent than those retrieved from less than 200 m depth. 168 refs., 117 figs., 24

Geochemical Characteristics of Trace Elements in the No. 6 Coal Seam from the Chuancaogedan Mine, Jungar Coalfield, Inner Mongolia, China

Directory of Open Access Journals (Sweden)

Lin Xiao

2016-03-01

Full Text Available Fourteen samples of No. 6 coal seam were obtained from the Chuancaogedan Mine, Jungar Coalfield, Inner Mongolia, China. The samples were analyzed by optical microscopic observation, X-ray diffraction (XRD, scanning electron microscope equipped with an energy-dispersive X-ray spectrometer (SEM-EDS, inductively coupled plasma mass spectrometry (ICP-MS and X-ray fluorescence spectrometry (XRF methods. The minerals mainly consist of kaolinite, pyrite, quartz, and calcite. The results of XRF and ICP-MS analyses indicate that the No. 6 coals from Chuancaogedan Mine are higher in Al2O3, P2O5, Zn, Sr, Li, Ga, Zr, Gd, Hf, Pb, Th, and U contents, but have a lower SiO2/Al2O3 ratio, compared to common Chinese coals. The contents of Zn, Sr, Li, Ga, Zr, Gd, Hf, Pb, Th, and U are higher than those of world hard coals. The results of cluster analyses show that the most probable carrier of strontium in the coal is gorceixite; Lithium mainly occurs in clay minerals; gallium mainly occurs in inorganic association, including the clay minerals and diaspore; cadmium mainly occurs in sphalerite; and lead in the No. 6 coal may be associated with pyrite. Potentially valuable elements (e.g., Al, Li, and Ga might be recovered as byproducts from coal ash. Other harmful elements (e.g., P, Pb, and U may cause environmental impact during coal processing.

Hydraulic fracture considerations in oil sand overburden dams

Energy Technology Data Exchange (ETDEWEB)

Cameron, R.; Madden, B.; Danku, M. [Syncrude Canada Ltd., Fort McMurray, AB (Canada)

2008-07-01

This paper discussed hydraulic fracture potential in the dry-filled temporary dams used in the oil sands industry. Hydraulic fractures can occur when reservoir fluid pressures are greater than the minimum stresses in a dam. Stress and strain conditions are influenced by pore pressures, levels of compaction in adjacent fills as well as by underlying pit floor and abutment conditions. Propagation pressure and crack initiation pressures must also be considered in order to provide improved hydraulic fracture protection to dams. Hydraulic fractures typically result in piping failures. Three cases of hydraulic fracture at oil sands operations in Alberta were presented. The study showed that hydraulic fracture failure modes must be considered in dam designs, particularly when thin compacted lift of dry fill are used to replace wetted clay cores. The risk of hydraulic fractures can be reduced by eliminating in situ bedrock irregularities and abutments. Overpressure heights, abutment sloping, and the sloping of fills above abutments, as well as the dam's width and base conditions must also be considered in relation to potential hydraulic fractures. It was concluded that upstream sand beaches and internal filters can help to prevent hydraulic fractures in dams in compacted control zones. 5 refs., 16 figs.

Sulfur biogeochemistry of oil sands composite tailings

Energy Technology Data Exchange (ETDEWEB)

Warren, Lesley; Stephenson, Kate [Earth Sciences, McMaster University (Canada)], email: warrenl@mcmaster.ca; Penner, Tara [Syncrude Environmental Research (Canada)

2011-07-01

This paper discusses the sulfur biogeochemistry of oil sands composite tailings (CT). The Government of Alberta is accelerating reclamation activities on composite tailings. As a CT pilot reclamation operation, Syncrude is currently constructing the first freshwater fen. Minor unpredicted incidents with H2S gas released from the dewatering process associated with these reclamations have been reported. The objective of this study is to ascertain the connection between microbial activity and H2S generation within CT and to assess the sulfur biogeochemistry of untreated and treated (fen) CT over seasonal and annual timescales. The microbial geochemical interactions taking place are shown using a flow chart. CT is composed of gypsum, sand, clay and organics like naphthenic acids and bitumen. Sulfur and Fe cycling in mining systems and their microbial activities are presented. The chemistry and the processes involved within CT are also given along with the results. It can be said that the diverse Fe and S metabolizing microorganisms confirm the ecology involved in H2S dynamics.

Validating Experimental Bedform Dynamics on Cohesive Sand-Mud Beds in the Dee Estuary

Science.gov (United States)

Baas, Jaco H.; Baker, Megan; Hope, Julie; Malarkey, Jonathan; Rocha, Renata

2014-05-01

Recent laboratory experiments and field measurements have shown that small quantities of cohesive clay, and in particular 'sticky' biological polymers, within a sandy substrate dramatically reduce the development rate of sedimentary bedforms, with major implications for sediment transport rate calculations and process interpretations from the sedimentary record. FURTHER INFORMATION Flow and sediment transport predictions from sedimentary structures found in modern estuaries and within estuarine geological systems are impeded by an almost complete lack of process-based knowledge of the behaviour of natural sediments that consist of mixtures of cohesionless sand and biologically-active cohesive mud. Indeed, existing predictive models are largely based on non-organic cohesionless sands, despite the fact that mud, in pure form or mixed with sand, is the most common sediment on Earth and also the most biologically active interface across a range of Earth-surface environments, including rivers and shallow seas. The multidisciplinary COHBED project uses state-of-the-art laboratory and field technologies to measure the erosional properties of mixed cohesive sediment beds and the formation and stability of sedimentary bedforms on these beds, integrating the key physical and biological processes that govern bed evolution. The development of current ripples on cohesive mixed sediment beds was investigated as a function of physical control on bed cohesion versus biological control on bed cohesion. These investigations included laboratory flume experiments in the Hydrodynamics Laboratory (Bangor University) and field experiments in the Dee estuary (at West Kirby near Liverpool). The flume experiments showed that winnowing of fine-grained cohesive sediment, including biological stabilisers, is an important process affecting the development rate, size and shape of the cohesive bedforms. The ripples developed progressively slower as the kaolin clay fraction in the sandy substrate

Siemens fuel gasification technology for the Canadian oil sands industry

Energy Technology Data Exchange (ETDEWEB)

Morehead, H. [Siemens Energy Inc., Orlando, FL (United States). IGCC and Gasification Sales and Marketing

2010-07-01

The Siemens fuel gasification (SFG) technology can be used to gasify a range of feedstocks, including petcoke, hard coal, lignite, and low-ranking fuels such as biomass and refinery residuals. The technology has recently been applied to a number of projects over the last 3 years. This paper discussed some of the issues related to the technology and it's use at a start-up facility in China. Five entrained-flow gasifiers with a thermal capacity of 500 MW are being installed at a coal gasification plant in northwestern China. The technology's use in hydrogen, steam and power production applications for the oil sands industry was also discussed. Issues related to feedstock quality, process characteristics, and equipment requirements for commercial gasifier systems were reviewed. The paper concluded by observing that improvements in gasification technology will make coal and petcoke gasification feasible options for power generation. IGCC is the most advanced and cost-effective technology for reducing emissions from coal-fired power plants. Gasification-based plants are also able to capture carbon dioxide (CO{sub 2}) for storage and sequestration. Details of the Siemens gasification test center in Germany were also included. 1 tab., 4 figs.

Flow dynamics at the origin of thin clayey sand lacustrine turbidites: Examples from Lake Hazar, Turkey

KAUST Repository

Hage, Sophie

2017-04-18

Turbidity currents and their deposits can be investigated using several methods, i.e. direct monitoring, physical and numerical modelling, sediment cores and outcrops. The present study focuses on thin clayey sand turbidites found in Lake Hazar (Turkey) occurring in eleven clusters of closely spaced thin beds. Depositional processes and sources for three of those eleven clusters are studied at three coring sites. Bathymetrical data and seismic reflection profiles are used to understand the specific geomorphology of each site. X-ray, thin sections and CT-scans imagery combined with grain-size, geochemical and mineralogical measurements on the cores allow characterisation of the turbidites. Turbidites included in each cluster were produced by remobilization of surficial slope sediment, a process identified in very few studies worldwide. Three types of turbidites are distinguished and compared with deposits obtained in flume studies published in the literature. Type 1 is made of an ungraded clayey silt layer issued from a cohesive flow. Type 2 is composed of a partially graded clayey sand layer overlain by a mud cap, attributed to a transitional flow. Type 3 corresponds to a graded clayey sand layer overlain by a mud cap issued from a turbulence-dominated flow. While the published experimental studies show that turbulence is damped by cohesion for low clay content, type 3 deposits of this study show evidence for a turbulence dominated mechanism despite their high clay content. This divergence may in part relate to input variables such as water chemistry and clay mineralogy that are not routinely considered in experimental studies. Furthermore, the large sedimentological variety observed in the turbidites from one coring site to another is related to the evolution of a sediment flow within a field scale basin made of a complex physiography that cannot be tackled by flume experiments.

Clay membrane made of natural high plasticity clay

DEFF Research Database (Denmark)

Foged, Niels; Baumann, Jens

1998-01-01

Leachate containment in Denmark has through years been regulated by the DIF Recommendation for Sanitary Landfill Liners (DS/R 466). It states natural clay deposits may be used for membrane material provided the membrane and drainage system may contain at least 95% of all leachate created throughout...... ion transport as well as diffusion.Clay prospection for clays rich in smectite has revealed large deposits of Tertiary clay of very high plasticity in the area around Rødbyhavn on the Danish island Lolland. The natural clay contains 60 to 75% smectite, dominantly as a sodium-type. The clay material...... has been evaluated using standardised methods related to mineralogy, classification, compaction and permeability, and initial studies of diffusion properties have been carried out. Furthermore, at a test site the construction methods for establishing a 0.15 to 0.3m thick clay membrane have been tested...

Clay membrane made of natural high plasticity clay:

DEFF Research Database (Denmark)

Foged, Niels; Baumann, Jens

1999-01-01

Leachate containment in Denmark has throughout the years been regulated by the DIF Recommendation for Sanitary Landfill Liners (DS/R4669. It states that natural clay deposits may be used as membrane material provided the membrane and drainage system contains at least 95% of all leachate created...... into account advective ion transport as well as diffusion. Clay prospecting for clays rich in smectite has revealed large deposits of Tertiary clay of very high plasticity in the area around Rødbyhavn on the Danish island of Lolland. The natural clay contains 60-75% smectite, dominantly as a sodium......-type. The clay material has been evaluated using the standardized methods related to mineralogy, classification, compaction and permeability, and initial studies of diffusion properties have been carried out. Furthermore, at a test site the construction methods for establishing a 0.15-0.3 m thick clay membrane...

Thermal volume changes in clays and clay-stones

International Nuclear Information System (INIS)

Delage, P.; Sulem, J.; Mohajerani, M.; Tang, A.M.; Monfared, M.

2012-01-01

Document available in extended abstract form only. The disposal of high activity exothermic radioactive waste at great depth in clay host rocks will induce a temperature elevation that has been investigated in various underground research laboratories in Belgium, France and Switzerland through in-situ tests. Thermal effects are better known in clays (in particular Boom clay) than in clay-stone (e.g. Opalinus clay and Callovo-Oxfordian clay-stone). In terms of volume changes, Figure 1 confirms the findings of Hueckel and Baldi (1990) that volume changes depend on the over-consolidation ratio (OCR) of the clay. In drained conditions, normally consolidated clays exhibit plastic contraction when heated, whereas over-consolidated clay exhibit elastic dilation. The nature of thermal volume changes in heated clays obviously has a significant effect on thermally induced pore pressures, when drainage is not instantaneous like what occurs in-situ. Compared to clays, the thermal volume change behaviour of clay-stones is less well known than that of clays. clay-stone are a priori suspected to behave like over-consolidated clays. In this paper, a comparison of recent results obtained in the laboratory on the drained thermal volume changes of clay-stones is presented and discussed. It is difficult to run drained mechanical tests in clay-stones like the Opalinus clay and the Callovo-Oxfordian clay-stone because of their quite low permeability (10 -12 - 10 -13 m/s). This also holds true for thermal tests. Due to the significant difference in thermal expansion coefficient between minerals and water, it is necessary to adopt very slow heating rate (0.5 - 1 C/h) to avoid any thermal pressurization. To do so, a new hollow cylinder apparatus (100 mm external diameter, 60 mm internal diameter) with lateral drainages reducing the drainage length to half the sample thickness (10 mm) has been developed (Monfared et al. 2011). The results of a drained cyclic thermal test carried out on

Nano-mineralogical investigation of coal and fly ashes from coal-based captive power plant (India): An introduction of occupational health hazards

International Nuclear Information System (INIS)

Oliveira, Marcos L.S.; Marostega, Fabiane; Taffarel, Silvio R.; Saikia, Binoy K.; Waanders, Frans B.; DaBoit, Kátia; Baruah, Bimala P.

2014-01-01

Coal derived nano-particles has been received much concern recently around the world for their adverse effects on human health and the environment during their utilization. In this investigation the mineral matter present in some industrially important Indian coals and their ash samples are addressed. Coal and fly ash samples from the coal-based captive power plant in Meghalaya (India) were collected for different characterization and nano-mineralogy studies. An integrated application of advanced characterization techniques such as X-ray diffraction (XRD), High Resolution-Transmission Electron microscopy (HR-TEM)/(Energy Dispersive Spectroscopy) EDS/(selected-area diffraction pattern) SAED, Field Emission-Scanning Electron Microscopy (FE-SEM)/EDS analysis, and Mössbauer spectroscopy were used to know their extent of risks to the human health when present in coal and fly ash. The study has revealed that the coals contain mainly clay minerals, whilst glass fragments, spinel, quartz, and other minerals in lesser quantities were found to be present in the coal fly ash. Fly ash carbons were present as chars. Indian coal fly ash also found to contain nanominerals and ultrafine particles. The coal-fired power plants are observed to be the largest anthropogenic source of Hg emitted to the atmosphere and expected to increase its production in near future years. The Multi Walled Carbon Nano-Tubes (MWCNTs) are detected in our fly ashes, which contains residual carbonaceous matter responsible for the Hg capture/encapsulation. This detailed investigation on the inter-relationship between the minerals present in the samples and their ash components will also be useful for fulfilling the clean coal technology principles. - Highlights: • We research changes in the level of ultrafine and nanoparticles about coal–ash quality. • Increasing dates will increase human health quality in this Indian coal area. • Welfare effects depend on ex-ante or ex-post assumptions about

Process for separating and recovering oil from oil-sands, etc

Energy Technology Data Exchange (ETDEWEB)

Preller, H

1921-02-24

A process for separating and recovering oil from oil-sands, bitumen from oil-chalk, oil-shale, and coal, according to Patent 400,122, is described. It is characterized in that the mined material falling on account of its weight is exposed to the running hot water in circulation through the wash-chamber and the clarifying chamber arranged separate or built on (circulation) being obtained by pumps or injectors in a regulatable motion.

Process water treatment in Canada's oil sands industry : 2 : a review of emerging technologies

International Nuclear Information System (INIS)

Allen, E.W.

2008-01-01

This review was conducted to identify candidate treatment technologies for treating oil sands process water. The oil sands industry in Canada uses large volumes of fresh water in order to extract bitumen deposits. The development of process water treatment technologies has become a critical issue for the industry, particularly as oil sand production is expected to triple in the next decade. However, treatment technologies must be adapted to consider the fouling potential of bitumens and fine clays as well as the effect of alkaline process water on treatment performance. The review included developments in chemical modifications to membranes and adsorbents designed to improve pollutant removal and reduce fouling; hybridization technologies designed to enhance the biological treatment of toxic feedwaters; recent advances in photocatalytic oxidation technologies for organic compounds; and new designs for large-scale treatment wetlands for polluted waste waters. It was concluded that major knowledge gaps must be optimized and preliminary studies must be conducted in order to understand how the treatment technologies will be affected by the chemical and physical characteristics of oil sands process water. 188 refs., 8 tabs

Specific Energy of Hard Coal Under Load

Directory of Open Access Journals (Sweden)

Bogusz Anna

2015-03-01

Full Text Available The article presents results of experimental tests of energy parameters of hard coals under loading, collected from research sites located within five main geologic structures of Upper Silesian Coal Basin (GZW - Main Trough, Main Anticline, Bytom Trough, Rybnik Trough and Chwałowice Trough. Coals from12 mines were analysed, starting with seams of group 200, through groups 400, 500, 600 and, finally, seams of group 700. Coal of each of the groups of seams underwent uniaxial compression stress of the energy parameters, in a servo-controlled testing machine MTS-810NEW, for the full range of strain of the tested coal samples. Based on the tests the dependence of different types of specific energy of longitudinal strain of coals on the value of uniaxial compression strength was determined. The dependence of the value of dissipated energy and kinetic energy of coals on the uniaxial compression strength was described with a linear function, both for coals which due to their age belong to various bed sand for various lithotypes of coal. An increase in the value of dissipated energy and in kinetic energy was observed, which was correlated with an increase in uniaxial compression strength of coal. The share of dissipated energy is dominant in the total energy of strain. Share of recoverable energy in the total energy of strain is small, independent of the compression strength of coals and is at most a few per cent high. In coals of low strength and dominant share of dissipated energy, share of recoverable energy is the biggest among the tested coals. It was shown that following an increase in compression strength the share of recoverable energy decreases, while the share of dissipated energy in the total energy increases. Further studies of specific energy of longitudinal strain of rocks in the full-range strain will be the next step inperfecting methodology of research into natural rock burst susceptibility of Carboniferous rock mass and changes in the

Influence green sand system by core sand additions

Directory of Open Access Journals (Sweden)

N. Špirutová

2012-01-01

Full Text Available Today, about two thirds of iron alloys casting (especially for graphitizing alloys of iron are produced into green sand systems with usually organically bonded cores. Separation of core sands from the green sand mixture is very difficult, after pouring. The core sand concentration increase due to circulation of green sand mixture in a closed circulation system. Furthermore in some foundries, core sands have been adding to green sand systems as a replacement for new sands. The goal of this contribution is: “How the green sand systems are influenced by core sands?”This effect is considered by determination of selected technological properties and degree of green sand system re-bonding. From the studies, which have been published yet, there is not consistent opinion on influence of core sand dilution on green sand system properties. In order to simulation of the effect of core sands on the technological properties of green sands, there were applied the most common used technologies of cores production, which are based on bonding with phenolic resin. Core sand concentration added to green sand system, was up to 50 %. Influence of core sand dilution on basic properties of green sand systems was determined by evaluation of basic industrial properties: moisture, green compression strength and splitting strength, wet tensile strength, mixture stability against staling and physical-chemistry properties (pH, conductivity, and loss of ignition. Ratio of active betonite by Methylene blue test was also determined.

Mineralogical and Micro-fabric investigation of the Sandy Facies of Opalinus Clay (Mont Terri)

International Nuclear Information System (INIS)

Kaufhold, Annette; Siegesmund, Siegfried; Dohrmann, Reiner; Graesle, Werner; Plischke, Ingo

2013-01-01

In the field of geological disposal of radioactive waste in many countries argillaceous formations are considered as potential host rock. For the understanding of the long-term behaviour of clay host rock, it is important to understand the interaction between mechanical behaviour, micro-fabric, and mineral composition. Previous publications showed that particularly the carbonate content and the arrangement of the carbonate grains (as cement in the matrix or as shells) determines the mechanical strength of Opalinus Clay and Callovo-Oxfordian Clay specimens, respectively. Klinkenberg et al. (2009) studied the shaly facies of Opalinus Clay, however, the actual deposit is planned to be built in the sandy facies of Opalinus Clay. The aim of the present study is to investigate the relation between micro-fabric, mineral composition, and mechanical properties of different samples derived from the sandy facies (BLT-A2). Image analysis showed that the carbonates in the sandy facies mainly occur as 1) matrix which in turn acts as cement. Carbonates also occur 2) in the fine sand fraction and 3) biogenic carbonates as traces. The carbonates of the sandy facies, therefore, appear to be similar to the carbonates of the Callovo-Oxfordian Clay with respect to their possible influence on failure strength. The mechanical testing showed that the shear strength increases with increasing carbonate content. This phenomenon was also observed for the samples of the Callovo-Oxfordian Clay, while the opposite relation was found for the shaly facies of the Opalinus Clay. Preliminary results presented here, indicate that the sandy facies (drilling BLT-A2) and Callovo-Oxfordian Clay show similar mechanical properties - in detail: 1) Micro-fabric: carbonates predominate in the matrix, 2) Mineralogy: high carbonate content and 3) Mechanical testing: shear strength increases with increasing carbonate content, where the type of carbonates which controls the increase of strength has to be

Loadings of polynuclear aromatic compounds and metals to the Athabasca River watershed by oil sands mining and processing

International Nuclear Information System (INIS)

Hodson, P.V.

2010-01-01

The contribution of oil sands operations to pollution in the Athabasca River has not yet been determined. Wastes from oil sands processes include recycled water, sand, silt, clay, bitumen, and polycyclic aromatic compounds (PAC) and metals. Upgrading processes can also release significant quantities of PAC and heavy metals. This paper discussed a study in which PAC and metals in the snow pack and river water of the Athabasca watershed were assessed. The study showed that the oil sands industry is a significant source of contamination. The equivalent of 600 T of bitumen was observed at sites within 50 km of oil sands upgrading facilities. The strongest contamination signals occurred during the summer months, which suggested that the surface run-off of contaminated water was related to recent oil sands developments. Samples taken from tributaries in watersheds with little or no development indicated that increased concentrations of oil sands related contaminants were not caused by natural erosion. The contaminants may contribute to higher levels of mercury (Hg) and cadmium (Cd) in the flesh of fish and wildlife and increase toxicity to the embryos of spring-spawning fish.

Interaction of petroleum mulching, vegetation restoration and dust fallout on the conditions of sand dunes in southwest of Iran

Science.gov (United States)

Azoogh, Liela; Khalili moghadam, Bijan; Jafari, Siroos

2018-06-01

In the past half-century, petroleum mulching-biological fixation (PM-BF) practices have been employed to stabilize sand dunes in Iran. However, the effects of PM-BF practices on the attributes of sand dunes and the dispersion of heavy metals of mulch have been poorly understood. To this end, three regions treated with PM-BF for 5, 20, and 40 years and a control region with no PM-BF were studied. Samples of soil properties were taken at the depths of 0-10 cm and 10-50 cm, with three replications, in Khuzestan Province. The results showed that PM-BF practices promoted the restoration of vegetation cover in the sand dunes. In addition, these practices increased the deposition of dust particles, gradually increasing the magnitudes of palygorskite and smectite clays over time. The interactions between dust deposition and PM-BF practices significantly altered the chemical and physical properties of the dunes. PM-BF practices increased soil organic matter (184-287%), cation exchangeable capacity (142-209%), electrical conductivity (144-493%), clay content (134-196%), and penetration resistance (107-170%) compared to the region with no PM-BF practices. Furthermore, petroleum mulching significantly increased the amount of Ni (1.19%), Cd (1.55%), Pb (1.08%), Cu (1.34%), Zn (1.38%), Mn (1.66%), and Fe (1.15%). However, in the long term, these elements will probably leach linearly as a consequence of an increase in organic matter and soil salinity in the light texture of sand dunes.

Nibelung-Kaoline-Black band fluit clay - the new key-horizon in the carboniferous system of the Ruhr coal field

Energy Technology Data Exchange (ETDEWEB)

Burger, K.; Otte, M.U. (Bergbau A.G. Lippe, Gelsenkirchen (Germany, F.R.). Abt. Markscheidewesen); Pfisterer, W. (Bergbau A.G. Lippe, Herne (Germany, F.R.). Hauptlaboratorium)

1979-10-01

Based upon the stratigraphic distribution of the kaoline-black-band flint clay in the carbon strata of the Ruhr, the Nibelung-Kaoline-black-band flint clay found in the upper Westphal C (Dorsten strata) is defined to be the new keyhorizon. The position of the discoveries of the kaoline-black-band flint clay, its stratigraphic positions as well as its macroscopic and microscopic characteristics together with the chemical composition are given. Investigations of the structure and minerals content show that the Nibelung-Kaolin-black-band flint clay is a new keyhorizon and is of great importance for the stratigraphy of the upper Westfal C. Its position within the system is represented by strata sections.

Compressive and tensile strength for concrete containing coal bottom ash

Science.gov (United States)

Maliki, A. I. F. Ahmad; Shahidan, S.; Ali, N.; Ramzi Hannan, N. I. R.; Zuki, S. S. Mohd; Ibrahim, M. H. W.; Azmi, M. A. Mohammad; Rahim, M. Abdul

2017-11-01

The increasing demand in the construction industry will lead to the depletion of materials used in construction sites such as sand. Due to this situation, coal bottom ash (CBA) was selected as a replacement for sand. CBA is a by-product of coal combustion from power plants. CBA has particles which are angular, irregular and porous with a rough surface texture. CBA also has the appearance and particle size distribution similar to river sand. Therefore, these properties of CBA make it attractive to be used as fine aggregate replacement in concrete. The objectives of this study were to determine the properties of CBA concrete and to evaluate the optimum percentage of CBA to be used in concrete as fine aggregate replacement. The CBA was collected at Tanjung Bin power plant. The mechanical experiment (compressive and tensile strength test) was conducted on CBA concrete. Before starting the mechanical experiment, cubic and cylindrical specimens with dimensions measuring 100 × 100 × 100 mm and 150 × 300 mm were produced based on the percentage of coal bottom ash in this study which is 0% as the control specimen. Meanwhile 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90% and 100% of CBA were used to replace the fine aggregates. The CBA concrete samples were cured for 7 days and 28 days respectively to maintain the rate of hydration and moisture. After the experimental work was done, it can be concluded that the optimum percentage of CBA as fine aggregate is 60% for a curing period of both 7 days and 28 days with the total compressive strength of 36.4 Mpa and 46.2 Mpa respectively. However, the optimum percentage for tensile strength is at 70% CBA for a curing period of both 7 days and 28 days with a tensile strength of 3.03 MPa and 3.63 MPa respectively.

Evaluating process origins of sand-dominated fluvial stratigraphy

Science.gov (United States)

Chamberlin, E.; Hajek, E. A.

2015-12-01

Sand-dominated fluvial stratigraphy is often interpreted as indicating times of relatively slow subsidence because of the assumption that fine sediment (silt and clay) is reworked or bypassed during periods of low accommodation. However, sand-dominated successions may instead represent proximal, coarse-grained reaches of paleo-river basins and/or fluvial systems with a sandy sediment supply. Differentiating between these cases is critical for accurately interpreting mass-extraction profiles, basin-subsidence rates, and paleo-river avulsion and migration behavior from ancient fluvial deposits. We explore the degree to which sand-rich accumulations reflect supply-driven progradation or accommodation-limited reworking, by re-evaluating the Castlegate Sandstone (Utah, USA) and the upper Williams Fork Formation (Colorado, USA) - two Upper Cretaceous sandy fluvial deposits previously interpreted as having formed during periods of relatively low accommodation. Both units comprise amalgamated channel and bar deposits with minor intra-channel and overbank mudstones. To constrain relative reworking, we quantify the preservation of bar deposits in each unit using detailed facies and channel-deposit mapping, and compare bar-deposit preservation to expected preservation statistics generated with object-based models spanning a range of boundary conditions. To estimate the grain-size distribution of paleo-sediment input, we leverage results of experimental work that shows both bed-material deposits and accumulations on the downstream side of bars ("interbar fines") sample suspended and wash loads of active flows. We measure grain-size distributions of bar deposits and interbar fines to reconstruct the relative sandiness of paleo-sediment supplies for both systems. By using these novel approaches to test whether sand-rich fluvial deposits reflect river systems with accommodation-limited reworking and/or particularly sand-rich sediment loads, we can gain insight into large

EXPERIMENTAL RESEARCH OF PROCESSING OF DUMP SAND-CLAY MIXES BY THE CENTRIFUGAL AND SHOCK CRUSHING

Directory of Open Access Journals (Sweden)

V. V. Vorobev

2015-01-01

Full Text Available Results of experimental research of processing of centrifugal and shock crushing of dump sandy-clay mixes are given. Use of products of processing of received mixes in foundry production and in production of asphalt concrete mixes allows to exclude transportation of the mix to dumping.

Clay Play

Science.gov (United States)

Rogers, Liz; Steffan, Dana

2009-01-01

This article describes how to use clay as a potential material for young children to explore. As teachers, the authors find that their dialogue about the potential of clay as a learning medium raises many questions: (1) What makes clay so enticing? (2) Why are teachers noticing different play and conversation around the clay table as compared to…

Utilization of fly ash as partial sand replacement in oil palm shell lightweight aggregate concrete

Science.gov (United States)

Nazrin Akmal, A. Z. Muhammad; Muthusamy, K.; Mat Yahaya, F.; Hanafi, H. Mohd; Nur Azzimah, Z.

2017-11-01

Realization on the increasing demand for river sand supply in construction sector has inspired the current research to find alternative material to reduce the use of natural sand in oil palm shell lightweight aggregate concrete (OPS LWAC) production. The existence of fly ash, a by-product generated from coal power plant, which pose negative impact to the environment when it is disposed as waste, were used in this research. The effect of fly ash content as partial sand replacement towards workability and compressive strength of OPS lightweight aggregate concrete were investigated. Four concrete mixes containing various percentage of fly ash that are 0%, 10%, 20% and 30% by weight of sand were used in the experimental work. All mixes were cast in form of cubes before subjected to water curing until the testing age. Compressive strength test were conducted at 1, 3, 7 and 28 days. The finding shows that the workability of the OPS LWAC decreases when more fly ash are used as sand replacement. It was found that adding of 10% fly ash as sand replacement content resulted in better compressive strength of OPS LWAC, which is higher than the control mix.

Ball clay

Science.gov (United States)

Virta, R.L.

2001-01-01

Part of the 2000 annual review of the industrial minerals sector. A general overview of the ball clay industry is provided. In 2000, sales of ball clay reached record levels, with sanitary ware and tile applications accounting for the largest sales. Ball clay production, consumption, prices, foreign trade, and industry news are summarized. The outlook for the ball clay industry is also outlined.

Experimental use of road header (AM-50) as face cutting machine for extraction of coal in longwall panel

Energy Technology Data Exchange (ETDEWEB)

Passi, K.K.; Kumar, C.R.; Prasad, P. [DGMS, Dhanbad (India)

2001-07-01

The scope of this paper has been limited to the use of available machines and techniques for attaining higher and more efficient production in underground coal mines. Under certain conditions of strata and higher degree of gassiness, the longwall method with hydraulic sand stowing is the only appropriate method of work for extraction of thick seam. In Moonidih Jitpur Colliery of M/S IISCO, No. 14 seam, Degree III gassy seam, 9.07 m thick, is extracted in multilift system with hydraulic sand stowing. In general, the bottom lift is extracted by Single Ended Ranging Arm Shearer and the middle and top lift are extracted by conventional method. However, in one of the panels spare road header machine was used as face cutting machine in bottom lift, on an experimental basis. This paper presents a successful case study of extraction of bottom lift coal by the longwall method with hydraulic sand stowing using road header (AM 50) as the face cutting machines. 9 figs.

Fluidized bed combustion of low-grade coal and wastes: Research and development

Energy Technology Data Exchange (ETDEWEB)

Borodulya, V.A.; Dikalenko, V.I.; Palchonok, G.I.; Vinogradov, L.M. [Academy of Sciences of Belarus, Minsk (Belarus). A.V. Luikov Heat and Mass Transfer Inst.; Dobkin, S.M.; Telegin, E.M. [Special Design Office, Brest (Belarus)

1994-12-31

Experimental studies were carried out to investigate devolatilization of fuel as single spherical particles of wood, hydrolytic lignin, leather sewage sludge and Belarussian brown coals in a fluidized bed of sand. It is found that the devolatilization process depends on moisture and ash contents in fuel and on the external heat and mass transfer rate. The char combustion occurs largely in the intermediate region. Kinetic parameters of the devolatilization and char combustion are obtained. A low-capacity fluidized bed boiler suitable for combustion of coal and different wastes is described.

Dressing coals, shales, and the like

Energy Technology Data Exchange (ETDEWEB)

Osawa, H

1938-12-28

A process for dressing coals, shales, and like carbonaceous substances with the use of floating and sinking phenomena caused by differences in the specific gravities of the substances to be separated in the dressing operation is characterized by the use as the dressing medium of an aqueous suspension of clay and finely ground pyrite or iron ore cinder, or finely ground easily pulverizable iron ore, such as earthy or granular limonite. The aqueous suspension has a low viscosity and a specific gravity between 1.35 and 1.70.

Depositional environments of the Jurassic Maghara main coal seam in north central Sinai, Egypt

Science.gov (United States)

Edress, Nader Ahmed Ahmed; Opluštil, Stanislav; Sýkorová, Ivana

2018-04-01

Twenty-eight channel samples with a cumulative thickness of about 4 m collected from three sections of the Maghara main coal seam in the middle Jurassic Safa Formation have been studied for their lithotype and maceral compositions to reconstruct the character of peat swamp, its hydrological regime and the predominating type of vegetation. Lithotype composition is a combination of dully lithotypes with duroclarain (19% of total cumulative thickness), clarodurain (15%), black durain (15%), and shaly coal (15%) and bright lithotypes represented by clarain (23%), vitrain (12%) and a small proportion of wild fire-generated fusain (1%). Maceral analyses revealed the dominance of vitrinite (70.6% on average), followed by liptinite (25.2%) and inertinite (8.1%). Mineral matter content is ∼9% on average and consists of clay, quartz and pyrite concentrate mostly at the base and the roof of the seam. Dominantly vitrinite composition of coal and extremely low fire- and oxidation-borne inertinite content, together with high Gelification Indices imply predomination of waterlogged anoxic conditions in the precursing mire with water tables mostly above the peat surface throughout most of the time during peat swamp formation. Increases in collotelinite contents and Tissue Preservation Index up the section, followed by a reversal trend in upper third of the coal section, further accompanied by a reversal trend in collodetrinite, liptodetrinite, alginite, sporinite and clay contents records a transition from dominately limnotelmatic and limnic at the lower part to dominately limnotelmatic with increase telmatic condition achieved in the middle part of coal. At the upper part of coal seam an opposite trend marks the return to limnic and limnotelmatic conditions in the final phases of peat swamp history and its subsequent inundation. The proportion of arborescent (mostly coniferous) and herbaceous vegetation varied throughout the section of the coal with tendency of increasing

The mine where extracting coal is a bonus

Energy Technology Data Exchange (ETDEWEB)

NONE

1993-07-01

Bowmans Harbour opencast mine is probably unique. Here Clay Colliery is mining an area that was derelict and contaminated land, which became a landfill site. When standards for landfill were raised the Black Country Development Corporation decided to redeposit the waste in a new repository on the same site, using higher standards. New cells for waste are being constructed. In creating these new cells coal is being extracted and sold. Four excavators are involved in this project.

Impact of clay mineral on air oxidation of PAH-contaminated soils.

Science.gov (United States)

Biache, Coralie; Kouadio, Olivier; Lorgeoux, Catherine; Faure, Pierre

2014-09-01

This work investigated the impact of a clay mineral (bentonite) on the air oxidation of the solvent extractable organic matters (EOMs) and the PAHs from contaminated soils. EOMs were isolated from two coking plant soils and mixed with silica sand or bentonite. These samples, as well as raw soils and bentonite/soil mixtures, were oxidized in air at 60 and 100 °C for 160 days. Mineralization was followed by measuring the CO2 produced over the experiments. EOM, polycyclic aromatic compound (PAC), including PAH, contents were also determined. Oxidation led to a decrease in EOM contents and PAH concentrations, these diminutions were enhanced by the presence of bentonite. Transfer of carbon from EOM to insoluble organic matter pointed out a condensation phenomenon leading to a stabilization of the contamination. Higher mineralization rates, observed during the oxidation of the soil/bentonite mixtures, seem to indicate that this clay mineral had a positive influence on the transformation of PAC into CO2.

Influence of shaly sands on continuous steam injection oil recovering method; Influencia de areias argilosas na recuperacao de petroleo por injecao de vapor

Energy Technology Data Exchange (ETDEWEB)

Barbosa, J.M.D.; Rodrigues, M.A.F.; Galvao, E.R.V.P.; Barillas, J.L.M.; Mata, W.; Dutra Junior, T.V. [Universidade Federal do Rio Grande do Norte (UFRN), Natal, RN (Brazil)

2008-07-01

Steam flooding is one of the most used thermal recovery methods in Northeast Brazil, because of high occurrence of heavy oil reservoir. In this process, the oil into the reservoir is heated while reduces, substantially, its viscosity and improves the production. This process can be affected by various parameters, including reservoir heterogeneity and the presence of clay. This work studied the influence of the presence of shaly sand layers in the reservoir for this type of recovery. The studied models were synthetics, but the used reservoir data can be extrapolated to real situations of Potiguar Basin. The influence of reservoir parameters in this process is quite important to the oil industry, and some of them were tested, such as the horizontal permeability of the reservoir and clay, the vertical/horizontal permeability ratio, the influence of capillary pressure of shaly sand and how all heterogeneities are allowed to affect in the oil productivity. In this study the parameter of greater influence in the oil recovery was the horizontal permeability, and the configuration of the layer of clay and other parameters affected least the process. (author)

Shaft-retort for treating waste materials, like washery waste, bituminous shale, oil-bearing sands and the like

Energy Technology Data Exchange (ETDEWEB)

Koppers, H

1916-10-29

A shaft-retort for converting waste materials, like washery waste, bituminous shale, oil-bearing sands, brown coal and non-coking mineral coal to oil and tar by supplying heat through the shaft wall formed of an iron-sheet to the material, which is forced through a feeding member perforated for the removal of gases and vapors, and moved downward in a thin layer on the shaft wall; that is characterized by the fact that the iron heating sheet is made rotatable for the purpose of equalizing overheating of itself and the material to be treated.

Leaching and soil/groundwater transport of contaminants from coal combustion residues

International Nuclear Information System (INIS)

Hjelmar, O.; Hansen, E.A.; Larsen, F.; Thomassen, H.

1992-01-01

In this project the results of accelerated laboratory leaching tests on coal fly ash and flue gas desulfurization (FGD) products from the spray dryer absorption process (SDA) were evaluated by comparison to the results of large scale lysimeter leaching tests on the same residues. The mobility of chromium and molybdenum - two of the kev contaminants of coal combustion residue leachates - in various typical soil types was investigated by batch and column methods in the laboratory. Some of the results were confirmed by field observations at an old coal fly ash disposal site and by a lysimeter attenuation test with coal fly ash leachate on a clayed till. A large number of groundwater transport models and geochemical models were reviewed, and two of the models (Gove-Stollenwerk and CHMTRNS) were modified and adjusted and used to simulate column attenuation tests performed in the laboratory. One of the models (Grove-Stollenwerk) was used to illustrate a recommended method of environmental impact assessment, using lysimeter leaching data and laboratory column attenuation data to describe the emission and migration of Mo from a coal fly ash disposal site

Identification of discontinuous sand pulses on the bed of the Colorado River in Grand Canyon

Science.gov (United States)

Mueller, E. R.; Grams, P. E.; Buscombe, D.; Topping, D. J.

2017-12-01

Decades of research on alluvial sandbars and sand transport on the Colorado River in Grand Canyon has contributed to in-depth understanding of the sand budget and lead to management actions designed to rebuild eroded sandbars. However, some basic, but difficult to address, questions about the processes and rates of sand movement through the system still limit our ability to predict geomorphic responses. The coarse fraction of the bed is heterogeneous and varies among boulders, cobble, gravel, and bedrock. Sand covers these substrates in patches of variable size and thickness, fills interstices to varying degrees, and forms mixed sand/coarse bed configurations such as linear stripes. Understanding the locations of sand accumulation, the quantities of sand contained in those locations, and the processes by which sand is exchanged among depositional locations is needed to predict the morphological response of sandbars to management actions, such as the controlled flood releases, and to predict whether sandbars are likely to increase or decrease in size over long (i.e. decadal) time periods. Here, we present evidence for the downstream translation of the sand component of tributary sediment inputs as discontinuous sand pulses. The silt and clay (mud) fraction of sediment introduced episodically by seasonal floods from tributary streams is transported entirely in suspension and moves through the 400 km series of canyons in a few days. The sand fraction of this sediment, which is transported on the bed and in suspension, moves downstream in sand pulses that we estimate range in length from a few km to tens of km. Owing to the complex geomorphic organization, the sand pulses are not detectable as coherent bed features; each individual sand pulse is comprised of many isolated storage locations, separated by rapids and riffles where sand cover is sparse. The presence of the sand pulses is inferred by the existence of alternating segments of sand accumulation and depletion

Casing drilling TM : a viable technology for coal bed methane?

Energy Technology Data Exchange (ETDEWEB)

Madell, G.; Muqeem, M. [Tesco Corp., Calgary, AB (Canada)

2001-07-01

This paper highlighted the experience that Tesco has gained by drilling more than 30 wells using only casings as the drill stem, suggesting that such technology could be advantageous for Coal Bed Methane (CBM) exploration and development. Tesco has manufactured a mobile and compact hydraulic drilling rig that is ideal to meet the great demand for CBM development in Canada. The Casing Drilling TM system, when used in conjunction with the drilling rig, could be very effective and efficient for exploration and development of CBM reserves which typically require extensive coring. Continuous coring while drilling ahead and wire line retrieval can offer time savings and quick core recovery of large diameter core required for exploration core desorption tests. The proposed system may also have the potential to core or drill typically tight gas sands or coal beds under balanced with air or foam. This would reduce drilling fluid damage while finding gas at the same time. Compared to conventional drill pipes, Casing Drilling TM could also be effective with water production from shallow sands because of the smaller annual clearance which requires less air volumes to lift any produced water. 8 refs., 3 tabs., 9 figs.

Report for the coal type committee in fiscal 1992; 1992 nendo tanshu iinkai hokokusho

Energy Technology Data Exchange (ETDEWEB)

NONE

1993-03-01

This paper reports the activities of the coal type committee in fiscal 1992, and summarizes the main technological achievements. In the Chinese coal liquefaction test, fiscal 1991 has performed liquefaction tests on Fushun coal by using a small continuous testing facility (0.1 t/d) at the Coal Chemistry Research Institute in Beijing. Fiscal 1992 has completed the liquefaction tests on Shengli coal. In October, a liquefaction test was carried out by using Tianzhu coal according to the NEDOL process. This paper reports the result of the liquefaction test on the Shengli coal, and the result of the analysis on the Fushun coal liquefied oil. The coal type selection and investigation having been performed to date reveals close correlation among the maceral composition of coal, coal rank and liquefied oil yield. Coals having good reactivity and suitable for liquefaction are generally suitable also for gasification. In the pretreatment of coal as a gasification material for hydrogen manufacture, a test was performed by using A heavy oil and tar sand bitumen plus A heavy oil as the granulating agents. With Montana coal, the highest de-ashing rate was achieved when the oil was added at 35% by weight. Both of the reaction rate and oil yield were improved. A handling test was carried out up to 72.5 degrees C, wherein Tatung coal presented no problems in both of the discharging and sticking tendencies. (NEDO)

In-situ remediation of TCE by ERD in clay tills. Feasibility and performance of full-scale application insights gained through an integrated investigative approach for 2 sites

OpenAIRE

Broholm, Mette Martina; Damgaard, Ida; Chambon, Julie Claire Claudia; Manoli, Gabriele; Pade, Dorte Moon; Christiansen, Camilla Maymann; Binning, Philip John; Westergaard, Claus; Tsitonaki, Aikaterini; Christophersen, Mette; Kerrn-Jespersen, Henriette; Bjerg, Poul Løgstrup

2012-01-01

Background/Objectives. Remediation of trichloroethene (TCE) in clay and other low permeabil-ity geologic media, where groundwater flow occurs preferentially in higher permeability sand lenses or fractures, is a significant challenge. At older sites, much of the contaminant mass is pre-sent as a sorbed phase in the matrix due to matrix diffusion. The principal challenge for in situ remediation in clay is to achieve effective contact between contaminant and bioremediation addi-tives (e.g., orga...

Physico-chemistry and geochemistry of Balengou clay deposit (West Cameroon) with inference to an argillic hydrothermal alteration

Science.gov (United States)

Tassongwa, Bernard; Eba, François; Njoya, Dayirou; Tchakounté, Jacqueline Numbem; Jeudong, Narcisse; Nkoumbou, Charles; Njopwouo, Daniel

2017-09-01

Field description and sampling along two pits, granulometry, Atterberg limits, mineralogical (XRD, FTIR, DSC & TGA) and geochemical analyses of the Balengou clays help to determine their characteristics and the genesis of the deposit. The mineralogical composition is comprised of halloysite-kaolinite, quartz, montmorillonite, hematite, anatase, feldspar, zircon, chromite, and apatite. Gibbsite and illite occur at the shallow and deep depth, respectively. Dikes of sand-poor clays contain also cristobalite and tridymite. Pairs of elements Rb-Ba, Rb-Sr, Nb-Ta, Ta-Zr, TiO2-Zr display good positive correlations (R2 > 0.85). REE patterns are highly fractionated (LaN up to 3312, LaN/YbN: 19-10) and are marked by deep Ce and Eu negative anomalies. Immobile element canonical ratios indicate that the protoliths were commendite/pantelerite, rhyolite and dacite, or their plutonic equivalents. Mineralogical and geochemical features lead to the suggestion that the clays derived from an advanced argillic hydrothermal alteration.

Briquetting of coal fines and sawdust. Part 1: binder and briquetting-parameters evaluations

Energy Technology Data Exchange (ETDEWEB)

D. Taulbee; D.P. Patil; Rick Q. Honaker; B.K. Parekh [University of Kentucky, Lexington, KY (United States). Center for Applied Energy Research

2009-01-15

Various technical and economic aspects relating to the briquetting of fine coal with sawdust have been evaluated with the results for two segments of that study presented here: binder and briquetting-parameter evaluations. Approximately 50 potential binder formulations were subjected to a series of screening evaluations to identify three formulations that were the most cost effective for briquetting fine coal with sawdust. Two of the binders, guar gum and wheat starch, were selected as most suitable for the pulverized coal market while the third formulation, lignosulfonate/lime, was targeted for the stoker market. Following binder selection, a number of briquetting parameters including binder and sawdust concentration, sawdust type, briquetting pressure and dwell time, coal and sawdust particle size, clay content, moisture content, and cure temperature and cure time were evaluated. Briquetting pressure and dwell time have the least impact while binder and sawdust concentrations, sawdust type, and curing conditions exerted the greatest influence on briquette quality. 7 refs.

Ecofriendly bricks elaborated from coal waste of Moroccan Jerrada Mining

Directory of Open Access Journals (Sweden)

Ez-zaki H.

2018-01-01

Full Text Available Solid waste generated during mining is one of the major environmental problems associated with this industrial activity. The best solution to overcome the environmental impact of this waste is to find recycling facilities in mass-produced products that can absorb the large quantities of these available byproducts. The present study shows the feasibility of using the coal waste of Moroccan Jerrada mining in the production of ecological brick. The first step consists of consecutive stages of crushing, grinding and heating at 650°C of the coal waste with a small amount of lime in order to promote the reactive products of elaborated binders. The second step of the process consists of mixing treated coal waste with a small amount of marble dust, sand, gravel, and water, then pressed and dried at room temperature to manufacture a laboratory ecofriendly bricks. The mechanical strength and thermal conductivity are investigated.

Comparaison de diverses méthodes de dosage des argiles d'un sable de gisement. Dosage des argiles Comparison of Different Methods of Determining Clays in a Reservoir Sand. Quantitative Analysis of Clays

Directory of Open Access Journals (Sweden)

Yvon J.

2006-11-01

Full Text Available Les argiles d'un sable de gisement, concentrées dans la fraction de diamètre Phi Oil, gas and geothermal reservoirs all contain clayey fractions no matter how small they may be. This has been blamed whenever operating or producing problems arise. It may be revealed by phenomena of mechanical resistance, permeability or interfacial properties (ion exchange, adsorption, etc. . Tests to understand such phenomena then go via the quantitative mineralogical analysis of the clays present. This analysis must also be looked at in terms of methods. It is subjected to constraints of cost, instrumentation, competence or deadlines. This article proposes:(a A so-called conventional route (Dejou et al, 1977 based on chemical and weighted analyses. (b An overall assessment method of the clay phase by difference (determination of two nonclay species. (c A method based on the statistical processing of microanalytic data obtained by an electronic microprobe. The material examined was a quartzose arenite made up mainly of quartz, jarosite, orthoclase, plagioclases, calcite, dolomite, muscovite, kaolinite, illite, montmorillonite, interstratified illite-montmorillionite, iron oxyhydroxides and accessory minerals such as rutile, zircon, garnet, tourmaline and hydroxylapatite. The arenite was subjected to an ultrasonic treatment (Letelier, 1986 to recover pellicular or weakly cemented clays. After this treatment, all the free clays were found in the < 40 m fraction which were used for the measurements. The so-called conventionalmethod is based on the associating of multiple techniques that are normally used for analyzing clays. They include X-ray diffraction, TDA, TGA, selective dissolution, CEC, adsorption of various reagents and gravimetric separations. They have been reviewed by Dejou et al (1977. The results they give depend on the grain size, chrystallochemistry, presence of amorphous elements and especially the typical chemical compositions assigned to the

Sorption of activation products on London clay and Dungeness aquifer gravel

International Nuclear Information System (INIS)

Baston, G.M.N.; Berry, J.A.; Littleboy, A.K.; Pilkington, N.J.

1992-01-01

The sortpion of a series of activation-product radionuclides onto London clay and Dungeness aquifer gravel from the nuclear reactor sites at Bradwell and Dungeness, has been examined. Batch sorption and through-diffusion experiments with clay determined chlorine as the chloride ion to be effectively non-sorbing; calcium to be weakly sorbing, whereas cobalt, nickel, niobium and samarium were moderately to strongly sorbing and silver was strongly sorbing. Distribution ratios (R D values) for Nb, Sm and Ag were found to have a strong dependence on the liquid-solid separation technique employed. The presence of high concentrations of calcium hydroxide led to lower values of R D for radioactive Ca but higher R D values for Sm and Ag. The sorption of Ni showed no apparent dependence on groundwater composition at low levels of dissolved organic carbon (DOC). The values of R D for Co decreased as the DOC content was increased by addition of humic materials. Batch sorption studies with aquifer gravel demonstrated that Ca is weakly sorbing whereas Nb, Ag and Eu are moderately to strongly sorbing. R D values for Ca and for Ag under neutral pH conditions show little sensitivity to the liquid/solid separation technique used. However, R D values for Nb and Eu under neutral pH conditions and for Ag in alkaline solution (pH = 11 - 12) show a marked effect. The aquifer gravel was found to be highly inhomogeneous unlike the clay and sorption was greatest on samples with a high proportion of sand, reflecting the clay mineral content. (orig.)

Investigation of Water Holding Capacity of Sugarcane Mulch for Sand Dune Stabilization in Ahvaz

Directory of Open Access Journals (Sweden)

T. Jamili

2017-01-01

Full Text Available Introduction: Wind erosion is one of the most serious problems in southwest Iran. Fine-grained structure of sand dunes with not enough strong composition and their low moisture retention property make them susceptible to wind erosion. They lack organic matter and are considered inherently of low fertility (Ahmadi, 2002. Studies have shown that non-erodible materials which include bentonite clay (Diouf et al., 1990, ureamelamine formaldehyde and urea–formaldehyde with 0.25% sodium chloride (Lahalih and Ahmed, 1998, acids, enzymes, lignosulfonates, polymers, tree resins (Santoni et al., 2001, waterborne polymer emulsion (Al-Khanbashi and Abdalla, 2006, polyvinyl alcohol and a polyvinyl acetate emulsion (Newman et al., 2005; Han et al., 2007, ash and polyacrylamide (Yang and Zejun, 2012.have significant potential in reducing wind erosion The area under farming of sugarcane in Khuzestan, Iran, is more than 130,000, ha. Vinasse and Filter Kike are two organic ingredients of sugarcane residues which are generated as byproduct materials insugarcane processing. In recent years these residues have been released into the environment and cause it regarded as water pollutant. Over 800,000 m3 of Vinasse is annually stored in each agro-industry. Vinasse also is rich in K, Ca, and Mg with moderate amounts of P and N,and non toxic complexes or heavy metals. Filter Kike is another residue produced in huge amounts by the agro-industry that is composed of cellulosic substances, CaCO3, N, P, K, organic matter, and clay. Therefore, the objective of this research is to investigate the effect of sugarcane mulch on water holding capacity in soil. This study is performed to evaluate the feasibility of using sugarcane residues inproduce of ecofriendly mulches for environmental use. In order of achieving these goals, Vinase, Filter Cake, and clay soil from near the sand dunes were used as sugarcane mulches. Further comparison between traditional oil mulches and

Interplay of salt dynamics, sea-level change and climate on the depositional evolution of a Paleogene economic coal bearing salt rim syncline, Schoeningen, Germany

Energy Technology Data Exchange (ETDEWEB)

Osman, A.; Pollok, L.; Brandes, C.; Winsemann, J. [Leibniz Univ. Hannover (Germany). Inst. fuer Geologie

2013-08-01

The Paleogene basin fill (maximum 300 m thick) of the Schoeningen rim syncline in northern Germany is well known for its economic lignitic coal deposits. The fill provides an example of the interaction of basin subsidence, sea-level, and climate changes on depositional environment and gives insight into the development of the coal seams within a sequence stratigraphic context. The rim syncline records thirteen Lower to Middle Eocene coal seams with intervening clastic layers that were deposited during a long-lived transgression of the Central German Estuary, which lasted until the Late Oligocene (Standke, 2008). The previous analysis of the rim syncline fill has primarily focused on coal deposits, their lateral extent and paleo-botanical habitat. In this work, 357 lithologic logs were calibrated to outcrop profiles and integrated with previous studies to provide a facies analysis and sequence stratigraphy interpretation of the syncline fill. This improves understanding of the depositional environments of the lesser-studied clastics that intervene the coals (Osman et al., in review). Four 3{sup rd} order sequences are recorded in the Lower to Middle Eocene basin fill. Sequences 1 and 2 document the interplay of sands and coals within a transgressive estuarine phase. The sands show a regime change from tide- to more wave-dominated estuarine conditions before a turnaround to a regressive deltaic phase. This succession typifies an incised valley fill. However, the accommodation space generated for the initial estuary development is thought to have originated via continual salt withdrawal (Brandes et al. 2012) instead of by incision during relative sea-level fall. The observed tide to wave estuary regime change is linked to increased subsidence rates at 57 Ma that generated a higher tidal prism. As the subsidence rates slowed and the syncline broadened, the tidal prism decreased, leading to the development of more wave-dominated facies. The intervening coal seams

Clay Houses

Science.gov (United States)

Pedro, Cathy

2011-01-01

In this article, the author describes a project designed for fourth-graders that involves making clay relief sculptures of houses. Knowing the clay houses will become a family heirloom makes this lesson even more worth the time. It takes three classes to plan and form the clay, and another two to underglaze and glaze the final products.

Laboratory studies of dune sand for the use of construction industry in Sri Lanka

Science.gov (United States)

de Silva Jayawardena, Upali; Wijesuriya, Roshan; Abayaweera, Gayan; Viduranga, Tharaka

2015-04-01

With the increase of the annual sand demand for the construction industry the excessive excavation of river sand is becoming a serious environmental problem in Sri Lanka. Therefore, it is necessary to explore the possibility for an alternative to stop or at least to minimize river sand mining activities. Dune sand is one of the available alternative materials to be considered instead of river sand in the country. Large quantities of sand dunes occur mainly along the NW and SE coastal belt which belong to very low rainfall Dry Zone coasts. The height of dune deposits, vary from 1m to about 30 meters above sea level. The objective of this paper is to indicate some studies and facts on the dune sand deposits of Sri Lanka. Laboratory studies were carried out for visual observations and physical properties at the initial stage and then a number of tests were carried out according to ASTM standards to obtain the compressive strength of concrete cylinders and mortar cubes mixing dune sand and river sand in different percentages keeping a constant water cement ratio. Next the water cement ratio was changed for constant dune sand and river sand proportion. Microscopic analysis shows that the dune sand consist of 95 % of quartz and 5 % of garnet, feldspar, illmenite and other heavy minerals with clay, fine dust, fine shell fragments and organic matters. Grains are sub-rounded to angular and tabular shapes. The grain sizes vary from fine to medium size of sand with silt. The degree of sorting and particle size observed with dune sands are more suited with the requirement of fine aggregates in the construction industry. The test result indicates that dune sand could be effectively used in construction work without sieving and it is ideal for wall plastering due to its'-uniformity. It could also be effectively used in concrete and in mortars mixing with river sand. The best mixing ratio is 75% dune sand and 25% river sand as the fine aggregate of concrete. For mortar the mixing

Novel foraging in the swash zone on Pacific sand crabs (Emerita analoga, Hippidae) by mallards

Science.gov (United States)

Lafferty, Kevin D.; McLaughlin, John P.; Dugan, Jenifer E.

2013-01-01

Mallards (Anas platyrhynchos) have been observed foraging on intertidal Pacific sand crabs (Hippidae, Emerita analoga) in the swash zone of sandy beaches around Coal Oil Point Reserve, California, and several other beaches on the west coast since at least November 2010. Unlike foraging shorebirds, Mallards do not avoid incoming swashes. Instead, the incoming swash lifts and deposits them down the beach. Shorebirds and diving ducks commonly feed on sand crabs, but sand crabs appear to be a novel behavior and food source for Mallards. Previous surveys of beaches did not report foraging Mallards on regional beaches, whereas foraging Mallards were common in contemporary (recent) surveys and anecdotal reports. Observations of this potentially new behavior were separated by as much as 1,300 km, indicating that this was not a local phenomenon. Mallards foraged singly, in pairs, and in flocks. An expansion of diet to sand crabs carries risks of exposure to surf, human disturbance, high salt intake, and transmission of acanthocephalan and trematode parasites for Mallards but has the benefit of providing a dependable source of animal protein.

Petrographic characteristics and depositional environment of Miocene Can coals, Canakkale-Turkey

Energy Technology Data Exchange (ETDEWEB)

Guerdal, Guelbin; Bozcu, Mustafa [Canakkale Onsekiz Mart University, Engineering and Architecture Faculty (Turkey)

2011-01-01

In this study, petrographic examinations along with proximate, calorific value, ultimate, sulphur form and XRD analyses were performed in order to determine the coal characteristics and the depositional environment of the Miocene Can coals. Seventy coal samples were taken from cores and open pit mines. The investigated Can coals are humic coals and classified as lignite to sub-bituminous coal based on the random huminite reflectance (0.38-0.54% R{sub r}), volatile matter (45.50-62.25 wt.%, daf) and calorific value (3419-6479 kcal/kg, maf). The sulphur content of the Can coals changes from 0.30 up to 12.23 wt.%, and a broad range of ash contents was observed varying between 2.46 wt.% and 41.19 wt.%. Huminite is the most abundant maceral group (74-95 vol.% mmf) consisting of mostly humocollinite (gelinite) which is followed by relatively low liptinite (2-18 vol.% mmf) and inertinite content (2-13 vol.% mmf). In general, major mineral contents of coal samples are clay minerals, quartz, mica, pyrite and feldspar. The Can-Etili lignite basin consists of mainly volcano-clastics, fluviatile and lacustrine clastic sediments and contains only one lignite seam with 17 m average thickness. In order to assess the development of paleo-mires, coal facies diagrams were obtained from maceral composition. According to the Vegetation Index (VI) and Ground Water Index (GWI), the Can coal accumulated in inundated marsh, limnic and swamp environments under a rheotrophic hydrological regime. In general, the facies interpretations are in accordance with the observed sedimentalogical data. (author)

Instrumental neutron activation analysis of coal and its combustion residues from a power plant

International Nuclear Information System (INIS)

Lim, J.M.; Jeong, J.H.; Lee, J.H.

2013-01-01

A growing demand of electrical energy derived from coal combustion led to a significant increase of coal ash as residues. Approximately 70 % of the fly ashes are recycled, while most of the bottom ashes have been land-filled in the ash pond in Korea. In this work, to evaluate the potential impacts of the residues from a coal power plant on the environment, its inorganic elemental components were determined by INAA and PGAA. Coal ash samples were collected from the biggest power plant complex in Korea. These samples were analyzed by using the NAA facilities in the HANARO research reactor of the Korea Atomic Energy Research Institute. A total of 31 elements were analyzed in the samples, and certified reference materials were used for the analytical quality control. The enrichment status of a given metal in fuel coal and ashes was investigated by its concentration ratio. In order to assess the impact of the coal combustion residues on ecosystem, their concentrations determined for each respective type of the samples were compared to both reference data and nearby beach sand samples. (author)

Overview of the evolution of clay mineralogy in the Gulf of Mexico: implications for regional climate and drainage history of the Mississippi and Brazos-Trinity Rivers

Science.gov (United States)

Adatte, T.; John, C. M.; Flemings, P. B.; Behrmann, J.

2005-12-01

In this paper we present the overview and preliminary results of the analysis of clay minerals in two mini basins drilled during IODP Expedition 308. The goal of our project is to explore the vertical and temporal trends in clay mineralogy in the Ursa Basin and the Brazos-Trinity basin #4. The Brazos-Trinity basin was the sink for sands and clays carried by the Brazos and Trinity Rivers, while the Ursa basin was the sink for sediments carried by the Mississippi river. Reconstructing clay minerals (phyllosilicates turbidity current deposition (controlled mainly by sea-level changes and thus glacio-eustasy). Finally, a major focusing point of Expedition 308 was sediment physical properties in an overpressured basin. Because each clay mineral specie has a specific average grain sizes, physical properties and cation exchange capacity, the clay mineral composition of the sediment investigated here (dominated by clay-sized particles) may partly control how these sediments react to changes in pressure and temperature. Thus, clay mineral data could contribute to our understanding of the physical properties of the sediments in overpressured basins, and collaborations with geotechnical scientist are planned.

The systems containing clays and clay minerals from modified drug release: a review.

Science.gov (United States)

Rodrigues, Luís Alberto de Sousa; Figueiras, Ana; Veiga, Francisco; de Freitas, Rivelilson Mendes; Nunes, Lívio César Cunha; da Silva Filho, Edson Cavalcanti; da Silva Leite, Cleide Maria

2013-03-01

Clays are materials commonly used in the pharmaceutical industry, either as ingredients or as active ingredients. It was observed that when they are administered concurrently, they may interact with drugs reducing their absorption. Therefore, such interactions can be used to achieve technological and biopharmaceutical advantages, regarding the control of release. This review summarizes bibliographic (articles) and technological (patents) information on the use of systems containing clays and clay minerals in modified drug delivery. In this area, formulations such natural clay, commercial clay, synthetic clay, composites clay-polymers, nanocomposites clay-polymers, films and hidrogels composites clay-polymers are used to slow/extend or vectorize the release of drugs and consequently they increase their bioavailability. Finally, this review summarizes the fields of technology and biopharmaceutical applications, where clays are applied. Copyright © 2012 Elsevier B.V. All rights reserved.

Provenance of sands from the confluence of the Amazon and Madeira rivers based on detrital heavy minerals and luminescence of quartz and feldspar

Science.gov (United States)

do Nascimento, Daniel R.; Sawakuchi, André O.; Guedes, Carlos C. F.; Giannini, Paulo C. F.; Grohmann, Carlos H.; Ferreira, Manuela P.

2015-03-01

Source-to-sink systems are poorly known in tropical rivers. For the Amazonian rivers, the majority of the provenance studies remain focused on the suspended load, implying a poor understanding of the processes governing production and distribution of sands. In this study, we perform heavy mineral and optically stimulated luminescence (OSL) analysis to cover the entire spectrum (heavy and light minerals fraction) of 29 sand samples of the Lower Madeira river region (Amazon and Madeira rivers), of which the main goal was to find provenance indicators specific to these rivers. Despite the tropical humid climate, the sands of the Amazon and Lower Madeira rivers are rich in unstable heavy minerals as augite, hypersthene, green hornblende and andalusite. The Madeira river is highlighted by its higher content of andalusite, with source attributed to the Amazon Craton (medium-to-high grade metamorphic rocks), while the Amazon river, upstream of the Madeira river mouth, has a signature of augite and hypersthene, that suggests an Andean provenance (volcanic rocks). Sands from the Madeira river can be tracked in the Amazon river by the increasing concentration in andalusite. OSL analysis of the light minerals fraction was used as an index of feldspar concentration and sedimentary history of quartz grains. Lower feldspar concentration and quartz grains with longer sedimentary history (higher OSL sensitivity) also point to a major contribution of cratonic sources for the sands in the Madeira river. While the sands from the Lower Madeira would be mainly supplied by cratonic rocks, previous work recognised that suspended sediments (silt and clay) are derived from Andean rocks. Therefore, we interpret a decoupling between the sources of sand and mud (silt and clay) under transport in the Madeira river. Andean sands (rich in augite and hypersthene) would be trapped in the foreland zones of the Beni and Mamoré tributaries. In the Amazon river sands, the low OSL sensitivity of the

Impact on indoor air quality during burning of Pakistani coal briquettes

International Nuclear Information System (INIS)

Gammage, R.B.; Wachter, E.A.; Wade, J.; Wilson, D.L.; Ahmad, N.; Sibtain, F.; Raza, M.Z.

1993-01-01

A comparison was made of airborne emissions from combustion of new types of Pakistani coal briquettes and traditional fuels. A mud-lined Angethi stove was operated under the standard nominal conditions of burning 200 g charges of fuel inside a 12 m 3 shed with a forced rate of air exchange of 14/hr. Coal was cold briquetted with lime, clay, and oxidant. Traditional fuels were wood, charcoal, and animal dung. Compared to raw coal, the amended coal gave fourfold reduced emission of respirable-size particles (RSP) while dramatically reducing overall SO 2 release. Initial burning was restricted to the outer layers of the briquettes during which time reaction of SO 2 with lime was incomplete and early emissions of SO 2 were substantial. The measurements overall indicated that, with respect to CO, SO 2 , NO x , and RSP, substitution of amended coal briquettes for traditional fuels will not worsen indoor air quality during domestic cooking. The traditional fuels and coal briquettes emit elevated peak amounts of CO (100-250μL/L), SO 2 (2-5 μL/L), and NO x (1-5 μL/L) in the early phase of volatiles burning with much reduced emissions in the later char-burning phase. Stove operators can substantially lower exposures by lighting the fuel outside and later moving the stove inside

Composites Based on Fly Ash and Clay

International Nuclear Information System (INIS)

Fidancevska, E.; Jovanov, V.; Angusheva, B.; Srebrenkoska, V.

2014-01-01

Fly ash is a waste generated from the coal combustion during the production of electricity in the thermal power plants. It presents industrial by-product containing Technologically Enhanced Natural Occurring Radioactive Materials (TENORM) with the great potential for valorisation. Fly ash is successfully utilized in cement and concrete industry, also in ceramics industry as component for manufacturing bricks and tiles, and recently there are many investigations for production of glass-ceramics from fly ash. Although the utilization of fly ash in construction and civil engineering is dominant, the development of new alternative application for its further exploitation into new products is needed. This work presents the possibility for fly ash utilization for fabricating dense composites based on clay and fly ash with the potential to be used in construction industry

Transient electromagnetic soundings in the San Luis Valley, Colorado, near the Great Sand Dunes National Park and Preserve and the Alamosa National Wildlife Refuge (field seasons 2007, 2009, and 2011)

Science.gov (United States)

Fitterman, David V.

2017-06-13

Transient electromagnetic (TEM) soundings were made in the San Luis Valley, Colorado, to map the location of a blue clay unit as well as to investigate the presence of suspected faults. A total of 147 soundings were made near and in Great Sand Dunes National Park and Preserve, and an additional 6 soundings were made near Hansen Bluff on the eastern edge of the Alamosa National Wildlife Refuge. The blue clay is a significant hydrologic feature in the area that separates an unconfined surface aquifer from a deeper confined aquifer. Knowledge of its location is important to regional hydrological models. Previous analysis of well logs has shown that the blue clay has a resistivity of 10 ohm-meters or less, which is in contrast to the higher resistivity of sand, gravel, and other clay units found in the area, making it a very good target for TEM soundings. The top of the blue clay was found to have considerable relief, suggesting the possibility of deformation of the clay during or after deposition. Because of rift activity, deformation is to be expected. Of the TEM profiles made across faults identified by aeromagnetic data, some showed resistivity variations and (or) subsurface elevation relief of resistivity units, suggestive of faulting. Such patterns were not associated with all suspected faults. The Hansen Bluff profile showed variations in resistivity and depth to conductor that coincide with a scarp between the highlands to the east and the floodplain of the Rio Grande to the west.

Natural Radioactivities due to Coal Mining in Gabal El-Maghara, North Sinai, Egypt

International Nuclear Information System (INIS)

Seddeek, M.K.; Ragab, H.S.; Sharshar, T.; Badran, H.M.

2005-01-01

Natural radioactivity concentrations due to the coal mining in Gabal El-Maghara, North Sinai, Egypt, were determined using gamma-ray spectroscopy. Coal, water and soil samples were investigated in this study. The 226 R a, 232 T h and 40 K activity concentrations for coal before extraction were 18.5±0.5, 29.5±1.2 and 149.0±8.4 Bq/kg, respectively. These concentrations were reduced to 18-22% after extraction due to the clay subtraction from the ore. The activity contents of the water and soil samples collected from the surrounding area did not show any evidence of enhancement due to the mining activities. Absorbed dose rate and effective dose equivalent in the mine environment were 29.4±1.0 n Gy/h and 139.2±4.7 mSv/y, respectively

Environmental Impacts of Sand Exploitation. Analysis of Sand Market

Directory of Open Access Journals (Sweden)

Marius Dan Gavriletea

2017-06-01

Full Text Available Sand is an indispensable natural resource for any society. Despite society’s increasing dependence on sand, there are major challenges that this industry needs to deal with: limited sand resources, illegal mining, and environmental impact of sand mining. The purpose of this paper is twofold: to present an overview of the sand market, highlighting the main trends and actors for production, export and import, and to review the main environmental impacts associated with sand exploitation process. Based on these findings, we recommend different measures to be followed to reduce negative impacts. Sand mining should be done in a way that limits environmental damage during exploitation and restores the land after mining operations are completed.

1170-MW(t) HTGR-PS/C plant application study report: tar sands oil recovery application

International Nuclear Information System (INIS)

Rao, R.; McMain, A.T. Jr.

1981-05-01

This report summarizes a study to apply an 1170-MW(t) high-temperature gas-cooled reactor - process steam/cogeneration (HTGR-PS/C) to tar sands oil recovery and upgrading. The raw product recovered from the sands is a heavy, sour bitumen; upgrading, which involves coking and hydrodesulfurization, produces a synthetic crude (refinable by current technology) and petroleum coke. Steam and electric power are required for the recovery and upgrading process. Proposed and commercial plants would purchase electric power from local utilities and obtain from boilers fired with coal and with by-product fuels produced by the upgrading. This study shows that an HTGR-PS/C represents a more economical source of steam and electric power

Assessing the role of coal in the world energy future

International Nuclear Information System (INIS)

Hibbard Junior, W.R.

1981-01-01

Ten recent extensive studies of long range energy futures were evaluated and a consensus of findings developed. Progress toward the consensus was determined. In the next 20 years the United States will need all of the coal, nuclear, oil shale and tar sands that public consensus and the legislatures will permit. Concerns include the cost and availability of OPEC oil, energy efficiency, acid rain, and carbon dioxide build-up. (Author) [pt

Agglomeration of coal fines for premium fuel application

International Nuclear Information System (INIS)

Atalay, A.; Zaman, M.D.

1992-01-01

This paper reports on fine coal in liquid suspension, which can be agglomerated in a number of ways. One of the oldest procedures involves the addition of electrolyte to the suspension to cause a reduction in the zeta potential and allow colliding particles to agglomerate. A second method involves the use of polymeric flocculants to bridge between particles. Both of these technologies are being used in the wastewater treatment plants for removal of fine waste particles from contaminated water. A third method involves the addition of a second immiscible liquid preferentially to wet the particles and cause adhesion by capillary interfacial forces. While the bonding forces in the first two methods are small and result in rather weak and voluminous agglomerates, the third method is postulated to produce more dense and much stronger agglomerates. In the case of fine coals, the carbonaceous constituents can be agglomerated and recovered from the aqueous suspension with many different coagulants. Inorganic or ash-forming constituents are also agglomerated along with the fine coal particles. As the froth floatation, agglomeration using coal and colloidal dust to effect a separation. Froth floatation, however, becomes less effective where extremely fine particles of cal must be treated or if there is considerable clay-size particle present. In contrast, there appears to be virtually no lower limit on the particle size suitable for agglomeration uses

Deposit model for heavy-mineral sands in coastal environments: Chapter L in Mineral deposit models for resource assessment

Science.gov (United States)

Van Gosen, Bradley S.; Fey, David L.; Shah, Anjana K.; Verplanck, Philip L.; Hoefen, Todd M.

2014-01-01

This report provides a descriptive model of heavy-mineral sands, which are sedimentary deposits of dense minerals that accumulate with sand, silt, and clay in coastal environments, locally forming economic concentrations of the heavy minerals. This deposit type is the main source of titanium feedstock for the titanium dioxide (TiO2) pigments industry, through recovery of the minerals ilmenite (Fe2+TiO3), rutile (TiO2), and leucoxene (an alteration product of ilmenite). Heavy-mineral sands are also the principal source of zircon (ZrSiO4) and its zirconium oxide; zircon is often recovered as a coproduct. Other heavy minerals produced as coproducts from some deposits are sillimanite/kyanite, staurolite, monazite, and garnet. Monazite [(Ce,La,Nd,Th)PO4] is a source of rare earth elements as well as thorium, which is used in thorium-based nuclear power under development in India and elsewhere.

Interaction between clay-based shaft seal components and crystalline host rock

International Nuclear Information System (INIS)

Priyanto, D.; Dixon, D.; Man, A.

2010-01-01

Document available in extended abstract form only. The Government of Canada has accepted the Nuclear Waste Management Organization's (NWMO) recommendation of Adaptive Phased Management (APM) as the long-term management approach for Canada's used nuclear fuel. APM ultimately involves the isolation and containment of used nuclear fuel deep in a Deep Geological Repository (DGR). On completion of waste emplacement operation and during repository closure, shaft seals, comprising clay-based shaft seal components, will be installed at strategic locations, such as where significant fracture zones (FZs) are located. The primary function of a shaft seal is to limit and prevent short-circuiting of the groundwater flow regime via the shaft. Currently, at Atomic Energy of Canada Limited's Underground Research Laboratory (URL) a full-scale shaft seal is being constructed at the intersection of a low dipping thrust fault called FZ 2 as part of the overall URL decommissioning activities. Both crystalline rock and sedimentary rock are considered potentially suitable host rocks formations for a DGR. This paper presents the results of numerical simulation of a shaft seal installed in moderately to sparsely fractured crystalline rock (MFR). The shape and thickness of the shaft seal modelled for a DGR in this exercise are similar to the shaft seal at the URL, but in the modelling exercise it is given a larger diameter (i.e. 7.30 m) equal to the assumed diameter of a production shaft of a repository. The seal consists of a blended bentonite-sand (BS) component that is constrained between two massive concrete seals. Dense backfill (DBF) materials are installed above and below the concrete seals (CS). The concrete seals are keyed into the access shaft to better anchor the concrete units in place and in order to restrain the swelling of the bentonite-sand component of the seal as it hydrates. The reference geosphere in the proposed work is MFR similar to the rock conditions

Oil sands mine pit wall design and performance at Syncrude

Energy Technology Data Exchange (ETDEWEB)

Cameron, R.; Danku, M; Purhar, G. [Syncrude Canada Ltd., Fort McMurray, AB (Canada)

2008-07-01

This study conducted slope stability analyses in order to compare pit performance at an oil sands mine with results from computerized simulations using conventionally known soil parameters. Ranges included fully-drained to fully-saturated piezometric conditions; full-peak strength conditions; fully-softened peak conditions; residual shear strength conditions; and undrained shear strength considerations. Pit wall designs were reviewed and a history of marine clay layers at the mine was presented. Assumed overburden fall-down limits were considered. Shovel overburden slope angles were calculated. An analysis of the review suggested that steeper pit walls provide less room for error and have a higher rate of failures. Incised pleistocene channels, joint and fracture areas as well as higher piezometric level areas also impacted on slope performance. Failed areas influenced ore volumes and led to productivity reductions below 50 per cent. It was concluded that the overburden portions of the oil sands mine ranged between 4H:1V to 5H:1V due to haul roads and the timing of top-bench pushbacks. Future plans for the mine must consider ore inventories, haul road requirements; running surface requirements; and ramping accesses. Future slopes at the oil sands mine will be buttressed with overburden and tailings storage areas, while longer-term slopes will be flattened. 6 refs., 2 tabs., 11 figs.

Coal background paper. Coal demand

International Nuclear Information System (INIS)

1997-01-01

Statistical data are presented on coal demands in IEA and OECD member countries and in other countries. Coal coaking and coaking coal consumption data are tabulated, and IEA secretariat's coal demand projections are summarized. Coal supply and production data by countries are given. Finally, coal trade data are presented, broken down for hard coal, steam coal, coking coal (imports and export). (R.P.)

Modelling of the thermomechanical behaviour of saturated clays: application to the radioactive wastes disposal

International Nuclear Information System (INIS)

Rahbaoui, A.

1995-01-01

During the waste disposal of containers, the clay barriers of backfill and the confining medium, which is essentially composed of clay, are submitted to heavy thermal stresses which induce volume change and can result in material failure. The clay, composed of solid skeleton, adsorbed water, and free water, is submitted to physico-chemical interactions which influence its thermomechanical behaviour, itself quits different from granular media such as sand. The principal factor responsible for this response is the effect of temperature on the clays water. Thus, the loss of special structure of adsorbed water and the increase in thickness of the diffused double-layer provoke microstructural rearrangement mechanisms of particles. Those mechanisms are strongly correlated with the mechanical state of material. When it is highly over-consolidated, an irreversible swelling occurs during thermal cycle, accompanied by a breaking up of the particles and a permanent expansion of meso-pores. The greater the OCR, the more important the thermal swelling. When the material is normally consolidated, the particles settle during heating under the external stress, which results in a denser rearrangement of the material. With a slight over-consolidated material, all the intermediate stages between the above mechanisms can be reached. However, cooling produces only a weak reversible compression characterising the thermal contraction of the components. Those microscopic phenomena have been used to elaborate a macroscopic thermomechanical model based on the Cam-Clay and the Hujeux Models. The model formulation includes a thermal softening, on one hand, by the reduction of the mechanical yield surface f c and the translation of the thermal yield surface f T (PTL), and, on the other hand, an irreversible thermal expansive volumetric strain. This approach of the problem was tested along various thermomechanical paths and especially on the laboratory tests, on the expansive and non expansive

Geochemistry of environmentally sensitive trace elements in Permian coals from the Huainan coalfield, Anhui, China

Science.gov (United States)

Chen, J.; Liu, Gaisheng; Jiang, M.; Chou, C.-L.; Li, H.; Wu, B.; Zheng, Lingyun; Jiang, D.

2011-01-01

To study the geochemical characteristics of 11 environmentally sensitive trace elements in the coals of the Permian Period from the Huainan coalfield, Anhui province, China, borehole samples of 336 coals, two partings, and four roof and floor mudstones were collected from mineable coal seams. Major elements and selected trace elements were determined by inductively coupled plasma optical emission spectrometry (ICP-OES), inductively coupled plasma mass spectrometry (ICP-MS), and hydride generation atomic absorption spectrometry (HAAS). The depositional environment, abundances, distribution, and modes of occurrence of trace elements were investigated. Results show that clay and carbonate minerals are the principal inorganic constituents in the coals. A lower deltaic plain, where fluvial channel systems developed successively, was the likely depositional environment of the Permian coals in the Huainan coalfield. All major elements have wider variation ranges than those of Chinese coals except for Mg and Fe. The contents of Cr, Co, Ni, and Se are higher than their averages for Chinese coals and world coals. Vertical variations of trace elements in different formations are not significant except for B and Ba. Certain roof and partings are distinctly higher in trace elements than underlying coal bench samples. The modes of occurrence of trace elements vary in different coal seams as a result of different coal-forming environments. Vanadium, Cr, and Th are associated with aluminosilicate minerals, Ba with carbonate minerals, and Cu, Zn, As, Se, and Pb mainly with sulfide minerals. ?? 2011 Elsevier B.V.

Geochemical of clay formations : study of Spanish clay REFERENCE

International Nuclear Information System (INIS)

Turrero, M. J.; Pena, J.

2003-01-01

Clay rocks are investigated in different international research programs in order to assess its feasibility for the disposal of high level radioactive wastes. This is because different sepcific aspects: they have low hydraulic conductivity (10''-11-10''-15 m/s), a high sorption capacity, self-sealing capacity of facults and discontinuities and mechanical resistance. Several research programs on clay formations are aimed to study the chemistry of the groundwater and the water-rock reactions that control it: e. g. Boom Clay (Mol, Belgium), Oxford Clay /Harwell, United Kingdom), Toarcian Clay (Tournemire, France), Palfris formation (Wellenberg, Switzerland), Opalinus Clay (Bure, France). Based on these studies, considerable progress in the development of techniques for hydrologic, geochemical and hydrogeochemical characterization of mudstones has been accomplished (e. g. Beaufais et al. 1994, De Windt el al. 1998. Thury and Bossart 1999, Sacchi and Michelot 2000) with important advances in the knowledge of geochemical process in these materials (e. g. Reeder et al. 1993, Baeyens and Brandbury 1994, Beaucaire et al. 2000, Pearson et al., 2003).Furtermore, geochemical modeling is commonly used to simulate the evolution of water chemistry and to understand quantitatively the processes controlling the groundwater chemistry (e. g. Pearson et al. 1998, Tempel and Harrison 2000, Arcos et al., 2001). The work presented here is part of a research program funded by Enresa in the context of its R and D program. It is focused on the characterization of a clay formation (reference Argillaceous Formation, RAF) located within the Duero Basin (north-centralSpain). The characterisation of th ephysical properties,, fluid composition, mineralogy, water-rock reaction processes, geochemical modelling and sorption properties of the clays from the mentioned wells is the main purpose of this work. (Author)

Depositional environment of the San Miguel lignite deposit in Atascosa and McMullen Counties, Texas

Energy Technology Data Exchange (ETDEWEB)

Gowan, S.W.

1985-01-01

An analysis of the environment of deposition of the San Miguel lignite deposit was carried out in order to understand newly discovered characteristics of the deposit. The environment of deposition of the overburden and underburden was evaluated through an interpretation of three continuous cores. Four coal cores and a highwall section were carefully described to determine the depositional environmental of the coal seams and partings. These studies were supplemented by the construction of seam and parting isopachs, and the analysis of the distribution of sulfur isotopes, sulfur, forms, and total sulfur within the coal. The sedimentary package is composed of a basal prograding barrier that beach, dune, and back-barrier sands. This unit correlates with a downdip sand that was also interpreted as a prograding barrier by other authors. The barrier is overlain by a series of slit and clay deposits of lagoonal, tidal flat, and tidal channel origin. These deposits are capped by restricted lagoon sediments composed of green, calcareous clays that occasionally contain shell layers. The restricted lagoon deposits formed when the barrier closed the lagoon off from the sea. Peat forming freshwater swamps eventually became established behind the barrier and on top of the restricted lagoon sediments. The parting isopachs reveal a reticulate morphology similar to the mangrove swamps located lateral to the modern Niger River Delta. The partings represent vegetated tidal flat deposits that formed during periodic invasions by the sea that killed the swamp and inundated the peat with sulfate rich water. The lignite interval is capped by open lagoon and tidal flat sediments.

Fate(s) of injected CO2 in a coal-bearing formation, Louisiana, Gulf Coast Basin: Chemical and isotopic tracers of microbial-brine-rock-CO2 interactions

Science.gov (United States)

Shelton, Jenna L.

2013-01-01

Coal beds are one of the most promising reservoirs for geologic carbon dioxide (CO₂) sequestration, as CO₂ can strongly adsorb onto organic matter and displace methane; however, little is known about the long-term fate of CO₂ sequestered in coal beds. The "2800' sand" of the Olla oil field is a coal-bearing, oil and gas-producing reservoir of the Paleocene–Eocene Wilcox Group in north-central Louisiana. In the 1980s, this field, specifically the 2800' sand, was flooded with CO₂ in an enhanced oil recovery (EOR) project, with 9.0×10⁷m³ of CO₂ remaining in the 2800' sand after injection ceased. This study utilized isotopic and geochemical tracers from co-produced natural gas, oil and brine from reservoirs located stratigraphically above, below and within the 2800' sand to determine the fate of the remaining EOR-CO₂, examining the possibilities of CO₂ migration, dissolution, mineral trapping, gas-phase trapping, and sorption to coal beds, while also testing a previous hypothesis that EOR-CO₂ may have been converted by microbes (CO₂-reducing methanogens) into methane, creating a microbial "hotspot". Reservoirs stratigraphically-comparable to the 2800' sand, but located in adjacent oil fields across a 90-km transect were sampled to investigate regional trends in gas composition, brine chemistry and microbial activity. The source field for the EOR-CO₂, the Black Lake Field, was also sampled to establish the δ¹³C-CO₂ value of the injected gas (0.9‰ +/- 0.9‰). Four samples collected from the Olla 2800' sand produced CO₂-rich gas with δ¹³C-CO₂ values (average 9.9‰) much lower than average (pre-injection) conditions (+15.9‰, average of sands located stratigraphically below the 2800' sand in the Olla Field) and at much higher CO₂ concentrations (24.9 mole %) than average (7.6 mole %, average of sands located stratigraphically below the 2800' sand in the Olla Field), suggesting the presence of EOR-CO₂ and gas-phase trapping as

Sorption of activation products on London clay and Dungeness aquifer gravel

Energy Technology Data Exchange (ETDEWEB)

Baston, G.M.N.; Berry, J.A.; Littleboy, A.K.; Pilkington, N.J. (AEA Decommissioning and Radwaste, Harwell Lab. (United Kingdom))

1992-01-01

The sortpion of a series of activation-product radionuclides onto London clay and Dungeness aquifer gravel from the nuclear reactor sites at Bradwell and Dungeness, has been examined. Batch sorption and through-diffusion experiments with clay determined chlorine as the chloride ion to be effectively non-sorbing; calcium to be weakly sorbing, whereas cobalt, nickel, niobium and samarium were moderately to strongly sorbing and silver was strongly sorbing. Distribution ratios (R[sub D] values) for Nb, Sm and Ag were found to have a strong dependence on the liquid-solid separation technique employed. The presence of high concentrations of calcium hydroxide led to lower values of R[sub D] for radioactive Ca but higher R[sub D] values for Sm and Ag. The sorption of Ni showed no apparent dependence on groundwater composition at low levels of dissolved organic carbon (DOC). The values of R[sub D] for Co decreased as the DOC content was increased by addition of humic materials. Batch sorption studies with aquifer gravel demonstrated that Ca is weakly sorbing whereas Nb, Ag and Eu are moderately to strongly sorbing. R[sub D] values for Ca and for Ag under neutral pH conditions show little sensitivity to the liquid/solid separation technique used. However, R[sub D] values for Nb and Eu under neutral pH conditions and for Ag in alkaline solution (pH = 11 - 12) show a marked effect. The aquifer gravel was found to be highly inhomogeneous unlike the clay and sorption was greatest on samples with a high proportion of sand, reflecting the clay mineral content. (orig.).

Characterization of Moroccan coal waste: valorization in the elaboration of the Portland clinker

Directory of Open Access Journals (Sweden)

Belkheiri D.

2014-04-01

Full Text Available Coal exploited in the mine of Jerada (northeast of Morocco was accompanied by large quantities of waste. The purpose of this work is to characterize this waste with the aim of its use as a material for civil engineering. Mineral and chemical investigations on this waste in the raw state, and at different temperature of heat treatments, were carried out by various methods: X-ray fluorescence, X-ray diffraction, infrared spectroscopy. These analyzes showed that the studied waste, contain essentially a mineral part formed by silica and various clays, as well as coal’s residues. The thermal investigation of waste, by differential scanning calorimetry (DSC, revealed an exothermic phenomenon attributed to the combustion of coal residues. Other phenomena were noted on the thermograms due to the mineral part transformations. In this analysis a comparison was also made with pure coal. These characteristics of coal waste encourage studying its development in reducing energy consumption in the Portland cement manufacture. Mixtures of waste with limestone or with raw cement materials were studied, and the resulting products were analyzed by different methods.

Removing heavy metals from wastewaters with use of shales accompanying the coal beds.

Science.gov (United States)

Jabłońska, Beata; Siedlecka, Ewa

2015-05-15

A possibility of using clay waste rocks (shales) from coal mines in the removal of heavy metals from industrial wastewaters is considered in this paper. Raw and calcined (600 °C) shales accompanying the coal beds in two Polish coal mines were examined with respect to their adsorptive capabilities for Pb, Ni and Cu ions. The mineralogical composition of the shales was determined and the TG/DTG analysis was carried out. The granulometric compositions of raw and calcined shales were compared. Tests of adsorption for various Pb(II), Ni(II) and Cu(II) concentrations were conducted and the pH before and after adsorption was analyzed. The results indicate that the shales from both coal mines differ in adsorptive capabilities for particular metal ions. The calcination improved the adsorptive capabilities for lead, but worsened them for nickel. The examined shales have good adsorptive capabilities, and could be used as inexpensive adsorbents of heavy metal ions, especially in the regions where resources of shale are easy accessible in the form of spoil tips. Copyright © 2015 Elsevier Ltd. All rights reserved.

Hydrometric characterization of the clays used in the manufacture of ceramic products in Ocaña, Norte de Santander

Directory of Open Access Journals (Sweden)

Ricardo Andrés García León

2017-01-01

Full Text Available Introduction: Currently in Ocaña, Norte de Santander exists a great variety of natural deposits that can be used to manufacture products of masonry as they are blocks, tiles, bricks, tiles, among others; But the manufacturing companies obtain a lot of waste due to the lack of technological analysis of the raw material to forecast the behavior of the ceramic pastes and to improve the quality of the final product. Objective: In the present work the physical characterization by hydrometry of the clays used in one of the companies dedicated to the manufacture of H-10 blocks in Ocaña, Norte de Santander, was carried out. Methodology: The development of the research was carried out by performing physical tests on samples of clays with which the percentages of sands, silts, and clays were determined; Which were located in the Winkler diagram to identify the types of existing clays according to their texture and the type of product that can be made to be able to formulate a paste of ceramic material. Results: The results obtained show that the clays currently used by the company are in the minimum indexes for the elaboration of blocks, reason why the addition of other clays with which the adequate level of quality with which they comply the requirements established by current standards. Conclusions: It is indispensable to characterize the clays to optimize the production pulp and to avoid imperfections in the final product (Block H-10, thus evidently improving the environmental and economic resources of the company.

Sorption of Cesium on smectite-rich clays from the Bohemian Massif (Czech Republic) and their mixtures with sand

Czech Academy of Sciences Publication Activity Database

Vejsada, J.; Jelínek, E.; Řanda, Z.; Hradil, David; Přikryl, R.

2005-01-01

Roč. 62, č. 1 (2005), s. 91-96 ISSN 0969-8043 Institutional research plan: CEZ:AV0Z40320502 Keywords : cesium * sorption * batch method * distribution ratios * clays Subject RIV: CA - Inorganic Chemistry Impact factor: 0.757, year: 2005

[Dust concentration analysis in non-coal mining. Exposure evaluation based on measurements performed by occupational hygiene laboratories in the years 2001-2005 in Poland].

Science.gov (United States)

Bujak-Pietrek, Stella; Mikołajczyk, Urszula; Szadkowska-Stańczyk, Irena

2011-01-01

Non-coal mining includes the extraction of materials for construction (stone, gravel, sand and clay), chemical industry (salt and sulfur), metallurgy (metal ores, uranium and thorium) and other mining and quarrying. Regardless of the type of mining company one of the most common health hazards in this sector is exposure to high concentrations of dust occurring during the extraction of materials. Such activities as drilling, use of blasting agents, processing of raw material, its transportation and loading are the source of large amounts of dust containing crystalline silica. Data on exposure to dust, collected by industrial hygiene laboratories on the basis of dust concentration measurements in the work environment, were obtained from the sanitary inspection service. The analysis of dust concentrations at workplaces in non-coal mining covered the years 2001-2005. The average concentration of inhalable and respirable dust and the degree of results dispersion at workposts in different branches of non-coal mining (according to NACE rev1.1) were evaluated. Also there was estimated the percentage of surveys indicating dust concentrations above hygiene standards. Almost 5000 measurements of dust concentrations were performed in the years under study. The highest concentration of inhalable dust was noted for the production of salt (5.51 mg/m3), other mining and quarrying (4.30 mg/m3) and quarrying of slate (3.77 mg/m3). For respirable dust the highest concentrations were noted in other mining and quarrying (1.10 mg/m3), quarrying of slate (1.09 mg/m3) and quarrying of stone (0.81 mg/m3). Exposure to high concentrations of dust during the extraction of non-carbon is still an important hazard to human health. Almost for all workposts under study the excess of hygiene standards were observed.

Process for separating and recovering oil from oil-sands, etc

Energy Technology Data Exchange (ETDEWEB)

Preller, H

1920-07-14

A process for separating and recovering oil from oil-sands, bitumen from oil-chalk, oil shale, and coal is characterized in that the material to be separated feeds, by a self-acting feeding arrangement, to a system with slowly rotating drums alternating in different directions and thereby it is exposed to the action of hot water running opposite to the rotation, direction of the drum, with addition of extraction-medium, so that the light material is washed out and rises to the top. It is carried off, while the heavy material sinks to the bottom and, by bucket-conveyor is removed.

Injury experience in sand and gravel mining, 1991

Energy Technology Data Exchange (ETDEWEB)

1993-10-01

This Mine Safety and Health Administration (MSHA) informational report reviews in detail the occupational injury and illness experience of sand and gravel mining in the United States for 1991. Data reported by operators of mining establishments concerning work injuries are summarized by work location, accident classification, part of body injured, nature of injury, and occupation. Related information on employment, worktime, and operating activity also is presented. Data reported by independent contractors performing certain work at mining locations are depicted separately in this report. For ease of comparison with other metal and nonmetallic mineral mining industries and with coal mining, summary reference tabulations are included at the end of both the operator and the contractor sections of this report.

Comprehensive review of geosynthetic clay liner and compacted clay liner

Science.gov (United States)

Shankar, M. Uma; Muthukumar, M.

2017-11-01

Human activity inevitably produces waste materials that must be managed. Some waste can be reused. However many wastes that cannot be used beneficially must be disposed of ensuring environmental safety. One of the common methods of disposal is landfilling. The most common problems of the landfill site are environmental degradation and groundwater contamination caused by leachate produced during the decomposition process of organic material and rainfall. Liner in a landfill is an important component which prevent leachate migration and prevent groundwater contamination. Earthen liners have been widely used to contain waste materials in landfill. Liners and covers for municipal and hazardous waste containment facilities are often constructed with the use of fine-grained, low plasticity soils. Because of low permeability geosynthetic clay liners and compacted clay liners are the main materials used in waste disposal landfills. This paper summaries the important geotechnical characteristics such as hydraulic conductivity, liquid limit and free swell index of geosynthetic clay liner and compacted clay liner based on research findings. This paper also compares geosynthetic clay liner and compacted clay liner based on certain criteria such as thickness, availability of materials, vulnerability to damage etc.

Overview of the Malaysian mineral industry

Energy Technology Data Exchange (ETDEWEB)

Dahan, A.R.B. (Department of Mines (Malaysia))

1992-08-01

The article describes the status of the mining industry in Malaysia. Tin dominated the industry until a price fall caused closure of many mines in 1987-1990. Other minerals mined include copper, gold, iron ore, bauxite, barite, kaolin, limestone, clays, sand and gravel. Coal production in Malaysia resumed when an opencast mine was opened in July 1988 in Sarawak. Another started operation in early 1989 by the underground method. At the end of 1990 there was a total of 53 exploration rights granted for gold, coal, base metals and industrial minerals. A few coalfields have been identified. Generally the industry has suffered a decline because of lack of new investment. 1 fig.

Clay dispersibility and soil friability – testing the soil clay-to-carbon saturation concept

OpenAIRE

Schjønning, P.; de Jonge, L.W.; Munkholm, L.J.; Moldrup, P.; Christensen, B.T.; Olesen, J.E.

2011-01-01

Soil organic carbon (OC) influences clay dispersibility, which affects soil tilth conditions and the risk of vertical migration of clay colloids. No universal lower threshold of OC has been identified for satisfactory stabilization of soil structure. We tested the concept of clay saturation with OC as a predictor of clay dispersibility and soil friability. Soil was sampled three years in a field varying in clay content (~100 to ~220 g kg-1 soil) and grown with different crop rotations. Clay ...

Sugarcane Yield Response to Furrow-Applied Organic Amendments on Sand Soils

Directory of Open Access Journals (Sweden)

J. Mabry McCray

2015-01-01

Full Text Available Organic amendments have been shown to increase sugarcane yield on sand soils in Florida. These soils have very low water and nutrient-holding capacities because of the low content of organic matter, silt, and clay. Because of high costs associated with broadcast application, this field study was conducted to determine sugarcane yield response to furrow application of two organic amendments on sand soils. One experiment compared broadcast application (226 m3 ha−1 of mill mud and yard waste compost, furrow application (14, 28, and 56 m3 ha−1 of these materials, and no amendment. Another experiment compared furrow applications (28 and 56 m3 ha−1 of mill mud and yard waste compost with no amendment. There were significant yield (t sucrose ha−1 responses to broadcast and furrow-applied mill mud but responses to furrow applications were not consistent across sites. There were no significant yield responses to yard waste compost suggesting that higher rates or repeated applications of this amendment will be required to achieve results comparable to mill mud. Results also suggest that enhancing water and nutrient availability in the entire volume of the root zone with broadcast incorporation of organic amendments is the more effective approach for low organic matter sands.

Sand transportation and reverse patterns over leeward face of sand dune

Science.gov (United States)

Jiang, Hong; Dun, Hongchao; Tong, Ding; Huang, Ning

2017-04-01

Sand saltation has complex interactions with turbulent flow and dune form. Most models of wind-blown sand consider ideal circumstances such as steady wind velocity and a flat surface, and the bulk of data on wind flow and sand transport over an individual dune has focused mostly on the influence of dune shape or inter-dune space on the wind flow, neglecting the effect of morphology on sand saltation, particularly airflow and sand transportation over the leeward slope. Wind flow structures over the leeward slope of sand dunes have a fundamental influence on the organization of sand dunes. In order to understand sand dune dynamics, lee face airflow and sediment transportation should be paid more attention. Previous field observations could not measure turbulent flow structure well because of the limited observation points and the influence of experiment structure on wind field. In addition, the reverse sand particles over leeward face could not be collected by sand trap in field. Numerous field observations could not measure turbulent flow structure because of the limited observation points and the influence of experimental structures on the wind field. In addition, the reverse transport of sand particles over leeward face could not be collected by sand traps in field. Therefore, this paper aims to investigate the turbulent flow structure and sand transport pattern over the leeward slope. A numerical model of sand saltation over slope terrain is constructed, which also considers the coupling effects between air flow and sand particles. The large eddy simulation method is used to model turbulent flow. Sand transport is simulated by tracking the trajectory of each sand particle. The results show that terrain significantly alters the turbulent air flow structure and wind-blown sand movement, especially over the leeward slope. Here, mass flux increases initially and then decreases with height in the reversed flow region in the direction of wind flow, and the mass flux

Pengaruh Penambahan Limbah Padat Abu Terbang Batubara(fly Ash) Terhadap Kekuatan Tekan Dan Porositas Genteng Tanah Liat Kabupaten Pringsewu

OpenAIRE

Febriyansyah, Puji; Tarkono,; Zulhanif,

2013-01-01

Fly ash, chemicallyis analumino-silicamineral containing Ca, K, and Na elements, fly ash has amoderate to high bonding capacity characteristic , and has acement-forming properties. In this study the authors use the industrial fly ash coal waste as an alternative mixture of tile manufacture. The tiles manufactured by mixing clay, sand, water and fly ash. Then smoothed with ekstuder machine and forming kuweh then aerate for 3 days, before do the dieing process . Tile dried for 4 days, then do f...

Dynamic behavior of tobacco waste in the coal-fired fluidized-bed boiler

Energy Technology Data Exchange (ETDEWEB)

Zhang, Kai; Chang, Jian; Chen, Honggang; Yang, Yongping [North China Electric Power Univ., Beijing (China). National Eng Lab for Biomass Power Generation Equipment; Yu, Bangting [China Univ. of Petroleum, Beijing (China). State Key Lab. of Heavy Oil Processing

2013-07-01

Circulating fluidized bed (CFB) technology is an advanced method for utilizing coal and other solid fuels in an environmentally acceptable manner. During the processing procedure in the nicotiana tabacum plants, lots of tobacco stem wastes are produced, which are normally being dumped to the landfill field. If this kind of waste can be used as a part of the fuel to be added into the coal in a CFB combustor, it will reduce the use of coal and then cut the net carbon emissions. To understand the complicated fluid dynamics of nicotiana tabacum wastes in the coal-fired CFB boiler, the mixing and segregation behavior of tobacco stalk are preliminary measured in a cylindrical fluidized bed. Obvious segregation behavior is found due to distinct differences in density and shape between tobacco stem and coal, which results in poor fluidization quality and bad combustion efficiency. To overcome this disadvantage, a jet with high gas velocity is introduced through the air distributor and a detailed experimental study is conducted in a fluidized bed made up of stem-sand mixture with different solid components at various jet velocities, which greatly improve the mixing performance of stem in the fluidized bed. The above findings are helpful for the technological upgrading of small- or middle-sized CFB boiler with adding tobacco stem into coal.

Multiscale Micromechanical Modeling of Polymer/Clay Nanocomposites and the Effective Clay Particle

Science.gov (United States)

Sheng, Nuo; Boyce, Mary C.; Parks, David M.; Manovitch, Oleg; Rutledge, Gregory C.; Lee, Hojun; McKinley, Gareth H.

2003-03-01

Polymer/clay nanocomposites have been observed to exhibit enhanced mechanical properties at low weight fractions (Wp) of clay. Continuum-based composite modeling reveals that the enhanced properties are strongly dependent on particular features of the second-phase ¡°particles¡+/-; in particular, the particle volume fraction (fp), the particle aspect ratio (L/t), and the ratio of particle mechanical properties to those of the matrix. However, these important aspects of as-processed nanoclay composites have yet to be consistently and accurately defined. A multiscale modeling strategy was developed to account for the hierarchical morphology of the nanocomposite: at a lengthscale of thousands of microns, the structure is one of high aspect ratio particles within a matrix; at the lengthscale of microns, the clay particle structure is either (a) exfoliated clay sheets of nanometer level thickness or (b) stacks of parallel clay sheets separated from one another by interlayer galleries of nanometer level height. Here, quantitative structural parameters extracted from XRD patterns and TEM micrographs are used to determine geometric features of the as-processed clay ¡°particles¡+/-, including L/t and the ratio of fp to Wp. These geometric features, together with estimates of silicate lamina stiffness obtained from molecular dynamics simulations, provide a basis for modeling effective mechanical properties of the clay particle. The structure-based predictions of the macroscopic elastic modulus of the nanocomposite as a function of clay weight fraction are in excellent agreement with experimental data. The adopted methodology offers promise for study of related properties in polymer/clay nanocomposites.

Role of non-ferrous coal minerals and by-product metallic wastes in coal liquefaction. Technical progress report, June 1, 1980-August 31, 1980

Energy Technology Data Exchange (ETDEWEB)

Garg, D; Givens, E N; Schweighardt, F K; Clinton, J H; Tarrer, A R; Guin, J A; Curtis, C W; Huang, W J; Shridharani, K

1980-09-01

Additional data on the pyrite catalysis of liquefaction of Elkhorn number 3 coal are presented. The liquefaction of Elkhorn number 3 coal was significantly catalyzed by the presence of pyrite. Coal conversion, oil yield and preasphaltene conversion all increased when pyrite was added. An increase in hydrocarbon gas make accompanied by a higher hydrogen consumption were also observed. The higher activity in the presence of pyrite could be utilized by running the liquefaction step at milder conditions which would mean a lower gas make. Although we had heard reports that sulfur elimination from the SRC was improved by use of pyrite, our data showed only very small changes. Nitrogen removal from the solvent, however, was definitely observed. At 850/sup 0/F nitrogen in the oil product went from 1.61 to 1.12 on adding pyrite. This increased nitrogen removal was also seen in the added ammonia yields. Kentucky number 9 coal also responded very well to the presence of pyrite. Conversions and oil yields increased while the hydrocarbon yields decreased at both temperatures that were tested, i.e., 825 and 850/sup 0/F. Hydrogen consumptions also increased. In the screening program the results from testing a number of materials are reported. None of the zeolites gave any significant improvement over coal itself. The iron, molybdenum, nickel, and cobalt rich materials had significant activity, all 85 to 90% conversion with high oil yields.Among materials specifically reported this period the clays failed to show any significant catalytic effect.

Usability of Clay Mixed Red Mud as Building Material in Transdanubian (Hungary) Region

International Nuclear Information System (INIS)

Sas, Z.; Somlai, J.J.; Szeiler, G.; Kovacs, T.

2014-01-01

The most commonly used building materials in Hungary and in numerous country of the world are the bricks, which made from clays. Due to the congenial internal structure properties of the clays these raw materials can be mixed with other materials, provides great possibility to reuse industrial by-products as additive material. The production and inbuilt of new types of synthetic building materials based on NORM (naturally occurring radioactive materials) by-products is raising concerns among authorities, public and scientists. Several NORM residues produced in large quantity, such as: phospogypsum (phosphate industry), red mud (aluminium processing industry), fly ash, coal slag (coal burning and steelworks) and so on are presently under investigation. The aluminum manufacturing in Ajka (Hungary) started in 1943. As a result of the bauxite refining activities up to now approximately 30 Mt of red mud has been produced in Hungary, stored in reservoirs. The radionuclide content of the bauxite usually exceeds the world average in soils (WA), which entirely remains in the by-product during Bayer process. The exposure pathways in case of application of NORM residues have to be explored in order to reveal the potential risks of NORMs on residents. The gamma radiation originated from the primordial radionuclides (K-40; U-238; Th-232) and their daughter elements found in nature and in building materials as well increase the external dose of the human body. In the EU the Radiation Protection 112 (RP 112) guideline serves for classification of building material, wherein the gamma exposure is limited by I-index

Clay intercalation and influence on crystallinity of EVA-based clay nanocomposites

International Nuclear Information System (INIS)

Chaudhary, D.S.; Prasad, R.; Gupta, R.K.; Bhattacharya, S.N.

2005-01-01

Various polymer clay nanocomposites (PCNs) were prepared from ethylene vinyl acetate copolymer (EVA) with 9, 18 and 28% vinyl acetate (VA) content filled with different wt.% (2.5, 5 and 7.5) of a Montmorillonite-based organo-modified clay (Cloisite[reg] C15A and C30B). The PCNs were prepared using melt blending techniques. Morphological information regarding intercalation and exfoliation were determined by using wide-angle X-ray scattering (WAXS) and transmission electron microscopy (TEM). WAXS and TEM confirmed that increasing the VA content was necessary to achieve greater clay-polymer interaction as seen from the comparatively higher intercalation of clay platelets with 28% VA. The effect of addition of clay on the development and the modification of crystalline morphology in EVA matrix was also studied using WAXS and temperature-modulated differential scanning calorimetry (MDSC). Results are presented showing that the addition of clay platelets does not increase the matrix crystallinity but the morphology was significantly modified such that there was an increase in the 'rigid' amorphous phase. Mechanical properties were also evaluated against the respective morphological information for each specimen and there are indications that the level of clay-polymer interaction plays a significant role in such morphological modification, and in such a way that affects the final PCN mechanical properties which has wide and significant applications in the packaging industries

Assessment of harmfulness of green sand with additions of dust from dry dedusting

Directory of Open Access Journals (Sweden)

M. Holtzer

2010-07-01

Full Text Available Recently, in the literature about the problems cause to the environment by foundry industry, attention has been paid to the presence and harmful effect of aromatic hydrocarbons: benzene, toluene, ethylbenzene and isomers of xylenes (BTEX and polycyclic aromatic hydrocarbons (PAHs. The growing interest in these pollutants of the environment is a result of their biological activity; some of them are characterized by mutagenic and carcinogenic action. In foundries these hydrocarbons are emitted during the contact between mould or core sands and liquid metal.This article discusses the results of the studies made on the elution rate of some harmful compounds include polycyclic aromatic hydrocarbons (PAHs (Table 3 and 4 from waste mould sand with bentonite and coal dust M1 (mixture Kormix 75 and this one with addition of dust from dry dedusting of sand M2 preparing station (partial replacement of bentonite and emission of BTEX gases from this moulds poured with molten cast iron. From the results given in these tables it follows that both mould sands are characterized by low values of the concentration of investigation substances and haven’t negative influence for environment during casting or management in other means. Tests were done according to the methodology developed at Faculty of Foundry Engineering University of Science and Technology in Cracow.

Interaction between bacteriophage and pyrophyllite clay in aqueous solution

Science.gov (United States)

Park, Jeong-Ann; Kim, Jae-Hyun; Kang, Jin-Kyu; Son, Jeong-Woo; Yi, In-Geol; Kim, Song-Bae

2014-05-01

Viral contamination results in a degradation in drinking water quality and a threat to public health. Toprovide safe drinking water, water treatment alternatives using various adsorbents and filter media such as activated carbon, bituminous coal, quartz sand and clay have been considered. Pyrophyllite is a 2:1 clay mineral having dioctahedral layer structure with octahedrally coordinated Al ion sheets between two sheets of SiO4 tetrahedra. It is a hydrous aluminosilicate clay with the chemical composition AlSi2O5(OH). Pyrophyllite has recently been investigated as a potential low-cost and environmental friendly adsorbent for removing various contaminants. The aim of this study was to investigate the removal of the bacteriophage MS2 from aqueous solution using pyrophyllite. Batch experiments were conducted to examine the MS2 sorption to pyrophyllite. The influence of fluoride, a groundwater contaminant, on the removal of MS2 was also observed. Batch results demonstrated that pyrophyllite was effective in MS2 removal. The percent removal increased from 5.26% to 99.99% (= 4.0 log removal) as the pyrophyllite concentrations increased from 0.2 to 20 g/L. More than 99% of MS2 could be removed with a pyrophyllite concentration of ≥ 4 g/L. The sorption of MS2 to pyrophyllite was rapid. Within 15 min, approximately 99.98% (= 3.7 log removal) of MS2 was attained. More than 4.0 log removal was achieved after 180 min. The experimental data were analyzed with the pseudo first-order and pseudo second-order kinetic models. The correlation coefficient showed that pseudo second-order model was better than pseudo first-order model at describing the kinetic data. The amount of MS2 removed at equilibrium was determined to be 1.43 × 108 pfu/g from the pseudo second-order model. The experimental data were also analyzed with the Freundlich and Langmuir isotherm models. The correlation coefficients showed that the Langmuir model was more suitable than the Freundlich model for MS2

Clay Dispersibility and Soil Friability-Testing the Soil Clay-to-Carbon Saturation Concept

DEFF Research Database (Denmark)

Schjønning, Per; de Jonge, Lis Wollesen; Munkholm, Lars Juhl

2012-01-01

Soil organic carbon (OC) influences clay dispersibility, which affects soil tilth conditions and the risk of vertical migration of clay colloids. No universal lower threshold of OC has been identified for satisfactory stabilization of soil structure. We tested the concept of clay saturation with OC...... as a predictor of clay dispersibility and soil friability. Soil was sampled 3 yr in a field varying in clay content (∼100 to ∼220 g kg−1 soil) and grown with different crop rotations. Clay dispersibility was measured after end-over-end shaking of field-moist soil and 1- to 2-mm sized aggregates either air......-dried or rewetted to −100 hPa matric potential. Tensile strength of 1- to 2-, 2- to 4-, 4- to 8-, and 8- to 16-mm air-dried aggregates was calculated from their compressive strength, and soil friability estimated from the strength–volume relation. Crop rotation characteristics gave only minor effects on clay...

SBR Brazilian organophilic/clay nanocomposites

International Nuclear Information System (INIS)

Guimaraes, Thiago R.; Valenzuela-Diaz, Francisco R.; Morales, Ana Rita; Paiva, Lucilene B.

2009-01-01

The aim of this work is the obtaining of SBR composites using a Brazilian raw bentonite and the same bentonite treated with an organic salt. The clays were characterized by XRD. The clay addition in the composites was 10 pcr. The composites were characterized by XRD and had measured theirs tension strength (TS). The composite with Brazilian treated clay showed TS 233% higher than a composite with no clay, 133% higher than a composite with Cloisite 30B organophilic clay and 17% lower than a composite with Cloisite 20 A organophilic clay. XRD and TS data evidence that the composite with Brazilian treated clay is an intercalated nanocomposite. (author)

Field test of plutonium and thorium contaminated clay soils from the Mound Site using the ACT*DE*CON Process

International Nuclear Information System (INIS)

Johnson, J.O.; Swift, N.A.; Church, R.H.; Neff, R.A.

1998-01-01

A treatability test was run during the summer and fall of 1997 to demonstrate the effectiveness of ACT*DE*CON for removing plutonium and thorium from the clay soils around Mound. ACT*DE*CON is a proprietary solution patented by Selentec. The process utilized a highly selective dissolution of the contaminants by the use of a chemical wash. The pilot scale process involved pretreatment of the soil in an attrition scrubber with ACT*DE*CON solution. This blended solution was then passed through a counter-current extraction chamber where additional contact with ACT*DE*CON solution occurred, followed by a rinse cycle. During this process sand was added to aid contact of the solution with the soil particles. The sand is removed during the rinse step and reused. The chelating agent is separated from the contaminant and recycled back into the process, along with the reverse osmosis permeate. The resulting solution can be further treated to concentrate the contaminant. Three different types of environmental soils were tested -- plutonium and thorium contaminated soils with the natural clay content, and plutonium contaminated soils with a high percentage of fine clay particles. The goal of these tests was to reduce the plutonium levels from several hundreds of pCi/g to between 25 and 75 pCi/g and the thorium from a couple hundred pCi/g to less than 5 pCi/g. The results of these four tests are presented along with a discussion of the operating parameters and the lessons learned relating to full scale implementation at Mound as well as other potential applications of this process

Atrazine biodegradation modulated by clays and clay/humic acid complexes

International Nuclear Information System (INIS)

Besse-Hoggan, Pascale; Alekseeva, Tatiana; Sancelme, Martine; Delort, Anne-Marie; Forano, Claude

2009-01-01

The fate of pesticides in the environment is strongly related to the soil sorption processes that control not only their transfer but also their bioavailability. Cationic (Ca-bentonite) and anionic (Layered Double Hydroxide) clays behave towards the ionisable pesticide atrazine (AT) sorption with opposite tendencies: a noticeable sorption capacity for the first whereas the highly hydrophilic LDH showed no interactions with AT. These clays were modified with different humic acid (HA) contents. HA sorbed on the clay surface and increased AT interactions. The sorption effect on AT biodegradation and on its metabolite formation was studied with Pseudomonas sp. ADP. The biodegradation rate was greatly modulated by the material's sorption capacity and was clearly limited by the desorption rate. More surprisingly, it increased dramatically with LDH. Adsorption of bacterial cells on clay particles facilitates the degradation of non-sorbed chemical, and should be considered for predicting pesticide fate in the environment. - The biodegradation rate of atrazine was greatly modulated by adsorption of the pesticide and also bacterial cells on clay particles.

Behavior of catalyst and mineral matter in coal liquefaction; Sekitan ekika hannochu no kobusshitsu to shokubai no kyodo

Energy Technology Data Exchange (ETDEWEB)

Iwasaki, K.; Wang, J.; Tomita, A. [Tohoku University, Sendai (Japan). Institute for Chemical Reaction Science

1996-10-28

Mineral matter in coals is important in various senses for coal liquefaction. It is possible that the catalytic activity is affected by the interaction between catalyst and mineral matter. Iron-based catalyst forms pyrrhotite in the process of liquefaction, but the interaction between it and mineral matter is not known in detail. In this study, the interaction between mineral matter and catalyst and the selective reaction between them were investigated. Tanito Harum coal was used for this study. This coal contains a slight amount of siderite and jarosite besides pyrite as iron compounds. Liquefaction samples were obtained from the 1 t/d NEDOL process PSU. The solid deposits in the reactor mainly contained pyrrhotite and quartz. A slight amount of kaolinite was observed, and pyrite was little remained. It was found that the catalyst (pyrrhotite) often coexisted with quartz, clay and calcite. 8 figs., 2 tabs.

Influence of Polymer-Clay Interfacial Interactions on the Ignition Time of Polymer/Clay Nanocomposites.

Science.gov (United States)

Zope, Indraneel S; Dasari, Aravind; Yu, Zhong-Zhen

2017-08-11

Metal ions present on smectite clay (montmorillonite) platelets have preferential reactivity towards peroxy/alkoxy groups during polyamide 6 (PA6) thermal decomposition. This changes the decomposition pathway and negatively affects the ignition response of PA6. To restrict these interfacial interactions, high-temperature-resistant polymers such as polyetherimide (PEI) and polyimide (PI) were used to coat clay layers. PEI was deposited on clay by solution-precipitation, whereas PI was deposited through a solution-imidization-precipitation technique before melt blending with PA6. The absence of polymer-clay interfacial interactions has resulted in a similar time-to-ignition of PA6/PEI-clay (133 s) and PA6/PI-clay (139 s) composites as neat PA6 (140 s). On the contrary, PA6 with conventional ammonium-based surfactant modified clay has showed a huge drop in time-to-ignition (81 s), as expected. The experimental evidences provided herein reveal the role of the catalytic activity of clay during the early stages of polymer decomposition.

The influence of sand content on swelling pressures and structure developed in statically compacted Na-bentonite

International Nuclear Information System (INIS)

Gray, M.N.; Cheung, S.C.H.; Dixon, D.A.

1984-09-01

A laboratory investigation of the vertical and lateral swelling pressures developed in statically compacted, air-dry specimens of sodium (Na)-bentonite:silica sand mixtures as they are saturated in confined conditions with double-distilled, deionized water is described. The results are interpreted with the aid of observations of the compacted soil structures made in a scanning electron microscope. It is shown that the sand acts as an inert filler material and vertical swelling pressures are controlled by a parameter termed the effective clay dry density (qsub(c)). A limiting value of qsub(c) exists below which vertical and lateral swelling pressures do not differ and are theoretically predictable. Above this value, vertical pressures exceed lateral ones. This is related to a change from an isotropic to an anisotropic soil fabric as qsub(c) is increased above the limiting value

On the freezing of clay soil and water migration into the pavement design

Directory of Open Access Journals (Sweden)

Sergeev Andrey Sergeevich

2014-03-01

Full Text Available The freezing of the surface layers of the Earth’s crust causes the volume deformation of soil and is expressed in the increase of volume and differential movement of their surface due to freezing of water and formation of ice inclusions. Underestimation of the frost heaving of soils, as well as the untimely application of anti — heaving measures cause the enormous damage to the national economy. All of this results in life reduction and condition deterioration of auto-road operation, as well as increase in non-manufacturing labor costs, building materials and financial means. During the experimental studies we have found that after four stages of freezing and defrosting the physical properties of clay soil change, i.e. the formation of 2-3 mm ice lenses is taking place at the junction of clay soil and sand. The number and dimensions of ice lenses increase with a further tightening of moisture up to 5-6 mm, and 3 zones related to the intensity of freezing are formed.

International Coal Report's coal year 1991

Energy Technology Data Exchange (ETDEWEB)

McCloskey, G [ed.

1991-05-31

Following introductory articles on factors affecting trade in coal and developments in the freight market, tables are given for coal exports and coal imports for major countries worldwide for 1989 and 1990. Figures are also included for coal consumption in Canada and the Eastern bloc,, power station consumption in Japan, coal supply and demand in the UK, electric utility coal consumption and stocks in the USA, coal production in Australia, Canada and USA by state, and world hard coal production. A final section gives electricity production and hard coal deliveries in the EEC, sales of imported and local coal and world production of pig iron and steel.

Phosphonium modified clay/polyimide nanocomposites

International Nuclear Information System (INIS)

Ceylan, Hatice; Çakmakçi, Emrah; Beyler-Çiǧil, Asli; Kahraman, Memet Vezir

2014-01-01

In this study, octyltriphenylphosphonium bromide [OTPP-Br] was prepared from the reaction of triphenylphosphine and 1 -bromooctane. The modification of clay was done by ion exchange reaction using OTPP-Br in water medium. Poly(amic acid) was prepared from the reaction of 3,3',4,4'-Benzophenonetetracarboxylic dianhydride (BTDA) and 4,4'-Oxydianiline (ODA). Polyimide(PI)/clay hybrids were prepared by blending of poly(amic acid) and organically modified clay as a type of layered clays. The morphology of the Polyimide/ phosphonium modified clay hybrids was characterized by scanning electron microscopy (SEM). Chemical structures of polyimide and Polyimide/ phosphonium modified clay hybrids were characterized by FTIR. SEM and FTIR results showed that the Polyimide/ phosphonium modified clay hybrids were successfully prepared. Thermal properties of the Polyimide/ phosphonium modified clay hybrids were characterized by thermogravimetric analysis (TGA)

Relationship of bifenthrin sediment concentrations to grain size and total organic carbon in California waterbodies: implications for ecological risk.

Science.gov (United States)

Hall, Lenwood W; Anderson, Ronald D

2014-12-01

A summary analysis of data sets from six California waterbodies was conducted to determine the relationship of bifenthrin sediment concentrations to: % sand/gravel; % silt; % clay; % silt/clay and % total organic carbon (TOC). The relationship of TOC to % sand/gravel, % silt, % clay, and % silt/clay was also analyzed. Statistically significant and meaningful direct relationships were reported between bifenthrin and % TOC, % silt, % clay and % silt/clay while a significant and meaningful inverse relationship was reported between bifenthrin and % sand/gravel. A significant and meaningful inverse relationship was reported between % TOC and % sand/gravel, while a significant and meaningful direct relationship was reported between % TOC and % silt, % clay and % silt/clay. Significant bifenthrin sediment concentrations would not be expected in non-depositional (sand/gravel) areas which have been reported to be dominant in various streams in California's Central Valley and are also the preferred habitat for many benthic macroinvertebrate taxa.

Coupled Effect of Elevated Temperature and Cooling Conditions on the Properties of Ground Clay Brick Mortars

Science.gov (United States)

Ali Abd El Aziz, Magdy; Abdelaleem, Salh; Heikal, Mohamed

2013-12-01

When a concrete structure is exposed to fire and cooling, some deterioration in its chemical resistivity and mechanical properties takes place. This deterioration can reach a level at which the structure may have to be thoroughly renovated or completely replaced. In this investigation, four types of cement mortars, ground clay bricks (GCB)/sand namely 0/3, 1/2, 2/1 and 3/0, were used. Three different cement contents were used: 350, 400 and 450 kg/m3. All the mortars were prepared and cured in tap water for 3 months and then kept in laboratory atmospheric conditions up to 6 months. The specimens were subjected to elevated temperatures up to 700°C for 3h and then cooled by three different conditions: water, furnace, and air cooling. The results show that all the mortars subjected to fire, irrespective of cooling mode, suffered a significant reduction in compressive strength. However, the mortars cooled in air exhibited a relativity higher reduction in compressive strength rather than those water or furnace cooled. The mortars containing GCB/sand (3/0) and GCB/sand (1/2) exhibited a relatively higher thermal stability than the others.

Preparation and Characteristics of Porous Ceramics by a foaming Technology at Low Temperature

Science.gov (United States)

Zhang, H. Q.; Wang, S. P.; Wen, J.; Wu, N.; Xu, S. H.

2017-12-01

Recycling and converting coal gangue and red mud into porous ceramics with good performance is a feasible disposal route. In this present work, porous foam ceramics was prepared using coal gangue and red mud as main raw materials at low sintering temperature, The amount of coal gangue and red mud were up to 70 wt%. To regulate the forming and sintering performance of the product, quartz sands and clay material were added to the formula. The green body was formed by a foaming technology using aluminum powders as foaming agents at room temperature. After foamed, the specimens were dried at 60-80 °C, and then calcined at 1060°C. Effects of concentration of NaOH and amount of aluminum powders on the phase, mechanical properties and microstructure were investigated here. Such study is expected to provide a new utilization route of the coal gangue and red mud, and brings both intensive environmental and economic benefits.

Investigation of the selected properties of dusts from the reclamation of spent sands with bentonite

Directory of Open Access Journals (Sweden)

J. Kamińska

2011-10-01

Full Text Available The investigation results of the selected properties of dusts generated during the mechanical reclamation of spent sands with bentonite as well as dusts from the dedusting system of sand processing plant are presented in the hereby paper. Investigations were performed with regard to determination conditions allowing to pelletise dusts in the bowl granulator. The verified methods of testing physical and chemical dust properties such as: specific density, bulk density of loosely put materials and apparent density of compacted materials together with their corresponding porosity, ignition losses and pH values, were applied. Granular composition of dusts generated during abrasion of spent binding materials in mechanical dry reclamation processes of spent sands with bentonite and coal dusts were performed by the laser diffraction analysis, allowing to broaden the measuring range of particle diameters. The optimal wetting agent content (in this case water at which the dust-water mixture obtains the best strength properties – after compacting by means of the standard moulder’s rammer – was determined.

Factors influencing the natural regeneration of the pioneering shrub Calligonum mongolicum in sand dune stabilization plantations in arid deserts of northwest China.

Science.gov (United States)

Fan, Baoli; McHugh, Allen David; Guo, Shujiang; Ma, Quanlin; Zhang, Jianhui; Zhang, Xiaojuan; Zhang, Weixing; Du, Juan; Yu, Qiushi; Zhao, Changming

2018-03-01

Calligonum mongolicum is a successful pioneer shrub to combat desertification, which is widely used for vegetation restoration in the desert regions of northwest China. In order to reveal the limitations to natural regeneration of C. mongolicum by asexual and sexual reproduction, following the process of sand dune stabilization, we assessed clonal shoots, seedling emergence, soil seed bank density, and soil physical characteristics in mobile and stabilized sand dunes. Controlled field and pot experiments were also conducted to assess germination and seedling emergence in different dune soil types and seed burial depths. The population density of mature C. mongolicum was significantly different after sand dune stabilization. Juvenile density of C. mongolicm was much lower in stabilized sand dunes than mobile sand dune. There was no significant difference in soil seed bank density at three soil depths between mobile and stabilized sand dunes, while the emergence of seedlings in stabilized dunes was much lower than emergence in mobile dunes. There was no clonal propagation found in stabilized dunes, and very few C. mongolicum seedlings were established on stabilized sand dunes. Soil clay and silt content, air-filled porosity, and soil surface compaction were significantly changed from mobile sand dune to stabilized dunes. Seedling emergence of C. mongolicm was highly dependent on soil physical condition. These results indicated that changes in soil physical condition limited clonal propagation and seedling emergence of C. mongolicum in stabilized sand dunes. Seed bank density was not a limiting factor; however, poor seedling establishment limited C. mongolicum's further natural regeneration in stabilized sand dunes. Therefore, clonal propagation may be the most important mode for population expansion in mobile sand dunes. As a pioneer species C. mongolicum is well adapted to propagate in mobile sand dune conditions, it appears unlikely to survive naturally in

In situ radionuclide migration studies in a shallow sand aquifer (Part 1)

International Nuclear Information System (INIS)

Williams, G.M.; Alexander, L.S.; Hitchman, S.P.; Hooker, P.J.; Noy, D.J.; Ross, C.A.M.; Stuart, A.; West, J.M.

1985-07-01

As a result of a study of the geology of the British Nuclear Fuels premises at Drigg, Cumbria, the British Geological Survey identified a shallow glacial sand deposit approximately 1.5m thick, interbedded between two clay horizons. An array of boreholes has been contructed in this sand in order to study the migration of radionuclides introduced into the formation under controlled conditions of groundwater flow. Conservative tracers used in the field test include chloride (as NaCl, detected using a specific ion electrode) and iodine-131 (as NaI, detected radiometrically using a NaI (T1) crystal). Strontium-85 (as the chloride) has been used as a chemically reactive tracer in conjuction with 131 I. The principal research objectives of the programme are as follows:- (1) to undertake laboratory batch sorption experiments using core material from the field site in order to choose those nuclides of radiological interest that would migrate sufficiently quickly for their behaviour to be studied in a field experiment within a reasonable time period. (2) to identify and quantify the mechanisms for nuclide/sediment interaction by determination of the geochemical distribution of 85 Sr in contaminated cores using a sequential leaching procedure. (3) to obtain appropriate data on the hydraulic characteristics of the sand formation in order to construct a mathematical model to describe groundwater flow and reactive mass transport. (author)

Common clay and shale

Science.gov (United States)

Virta, R.L.

2000-01-01

Part of the 1999 Industrial Minerals Review. The clay and shale market in 1999 is reviewed. In the U.S., sales or use of clay and shale increased from 26.4 million st in 1998 to 27.3 million st in 1999, with an estimated 1999 value of production of $143 million. These materials were used to produce structural clay products, lightweight aggregates, cement, and ceramics and refractories. Production statistics for clays and shales and for their uses in 1999 are presented.

Effects of modified Clay on the morphology and thermal stability of PMMA/clay nanocomposites

International Nuclear Information System (INIS)

Tsai, Tsung-Yen; Lin, Mei-Ju; Chuang, Yi-Chen; Chou, Po-Chiang

2013-01-01

The potential to improve the mechanical, thermal, and optical properties of poly(methyl methacrylate) (PMMA)/clay nanocomposites prepared with clay containing an organic modifier was investigated. Pristine sodium montmorillonite clay was modified using cocoamphodipropionate, which absorbs UVB in the 280–320 nm range, via ion exchange to enhance the compatibility between the clay platelets and the methyl methacrylate polymer matrix. PMMA/clay nanocomposites were synthesized via in situ free-radical polymerization. Three types of clay with various cation-exchange capacities (CEC) were used as inorganic layered materials in these organic–inorganic hybrid nanocomposites: CL42, CL120, and CL88 with CEC values of 116, 168, and 200 meq/100 g of clay, respectively. We characterized the effects of the organoclay dispersion on UV resistance, effectiveness as an O 2 gas barrier, thermal stability, and mechanical properties of PMMA/clay nanocomposites. Gas permeability analysis demonstrated the excellent gas barrier properties of the nanocomposites, consistent with the intercalated or exfoliated morphologies observed. The optical properties were assessed using UV–Visible spectroscopy, which revealed that these materials have good optical clarity, UV resistance, and scratch resistance. The effect of the dispersion capability of organoclay on the thermal properties of PMMA/clay nanocomposites was investigated by thermogravimetric analysis and differential scanning calorimetry; these analyses revealed excellent thermal stability of some of the modified clay nanocomposites. - Highlights: ► We control the dispersion morphology by protonation of K2 into the clay. ► The CL120 and CL88, with the higher CEC, are more random intercalated by K2. ► We report these materials have good optical clarity, and UV resistance

Selective Clay Placement Within a Silicate-Clay Epoxy Blend Nanocomposite

Science.gov (United States)

Miller, Sandi G (Inventor)

2013-01-01

A clay-epoxy nanocomposite may be prepared by dispersing a layered clay in an alkoxy epoxy, such as a polypropylene oxide based epoxide before combining the mixture with an aromatic epoxy to improve the nanocomposite's thermal and mechanical properties.

Clay nanoparticles for regenerative medicine and biomaterial design: A review of clay bioactivity.

Science.gov (United States)

Mousa, Mohamed; Evans, Nicholas D; Oreffo, Richard O C; Dawson, Jonathan I

2018-03-01

Clay nanoparticles, composites and hydrogels are emerging as a new class of biomaterial with exciting potential for tissue engineering and regenerative medicine applications. Clay particles have been extensively explored in polymeric nanocomposites for self-assembly and enhanced mechanical properties as well as for their potential as drug delivery modifiers. In recent years, a cluster of studies have explored cellular interactions with clay nanoparticles alone or in combination with polymeric matrices. These pioneering studies have suggested new and unforeseen utility for certain clays as bioactive additives able to enhance cellular functions including adhesion, proliferation and differentiation, most notably for osteogenesis. This review examines the recent literature describing the potential effects of clay-based nanomaterials on cell function and examines the potential role of key clay physicochemical properties in influencing such interactions and their exciting possibilities for regenerative medicine. Copyright © 2018 Elsevier Ltd. All rights reserved.

Eastern Scheldt Sand, Baskarp Sand No. 15

DEFF Research Database (Denmark)

Andersen, A. T; Madsen, E. B.; Schaarup-Jensen, A. L.

The present data report contains data from 13 drained triaxial tests, performed on two different sand types in the Soil Mechanics Laboratory at Aalborg University in March, 1997. Two tests have been performed on Baskarp Sand No. 15, which has already ken extensively tested in the Soil Mechanics...... Laboratory. The remaining 11 triaxial tests have ben performed on Eastern Scheldt Sand, which is a material not yet investigated at the Soil Mechanics Laboratory. In the first pari of this data report, the characteristics of the two sand types in question will be presented. Next, a description...... will described. In this connection, the procedure for preparation of the soil specimens will be presented, and the actual performance of the tests will be briefly outlined. Finally, the procedure for processing of the measurements from the laboratory in order to obtain usable data will be described. The final...

Thixotropic Properties of Latvian Clays

OpenAIRE

Lakevičs, Vitālijs; Stepanova, Valentīna; Ruplis, Augusts

2015-01-01

This research studies Latvia originated Devon (Tūja, Skaņkalne), quaternary (Ceplīši), Jurassic, (Strēļi) and Triassic (Vadakste) deposit clays as well as Lithuania originated Triassic (Akmene) deposit clays. Thixotropic properties of clay were researched by measuring relative viscosity of clay in water suspensions. Relative viscosity is measured with a hopper method. It was detected that, when concentration of suspension is increased, clay suspension’s viscosity also increases. It happens un...

Identifying sources of respirable quartz and silica dust in underground coal mines in southern West Virginia, western Virginia, and eastern Kentucky

Energy Technology Data Exchange (ETDEWEB)

Schatzel, Steven J. [National Institute for Occupational Safety and Health, Pittsburgh Research Laboratory, 626 Cochrans Mill Road, PO Box 18070, Pittsburgh, PA 15236 (United States)

2009-04-01

Prior research has suggested that the source of respirable silica dust in underground coal mines is typically the immediate top or bottom lithology adjacent to the mined seam, not mineral matter bound within the mined coal bed. Geochemical analyses were applied in an effort to identify the specific source rock of respirable quartz dust in coal mines. The analyses also demonstrate the compositional changes that take place in the generation of the respirable dust fraction from parent rock material. All six mine sites were mining coal with relatively low mineral matter content, although two mines were operating in the Fire Clay coal bed which contains a persistent tonstein. Interpretations of Ca, Mg, Mn, Na, and K concentrations strongly suggest that the top strata above the mined seam is the primary source of mineral dust produced during mining. One site indicates a mixed or bottom source, possibly due to site specific conditions. Respirable dust compositional analyses suggest a direct relationship between the quantity of mineral Si and the quantity of quartz Si. A similar relationship was not found in either the top or bottom rocks adjacent to the mined seam. An apparent loss of elemental Al was noted in the respirable dust fraction when compared to potential parent rock sources. Elemental Al is present in top and bottom rock strata within illite, kaolinite, feldspar, and chlorite. A possible explanation for loss of Al in the respirable dust samples is the removal of clays and possibly chlorite minerals. It is expected that removal of this portion of the Al bearing mineral matter occurs during rock abrasion and dust transport prior to dust capture on the samplers. (author)

Pollutant transport in clayey sands: reactive flows in saturated porous media and unsaturated flows

International Nuclear Information System (INIS)

Cadalen, Sebastien

2008-01-01

In the context of nuclear risk control associated to nuclear waste storage, the french nuclear agency plays an increasing role in terms of research and development in the area of subsurface contamination. This study focuses on an homogeneous porous media constituted of Fontainebleau sand and clay grains (illite) presenting sorption capacities. The modeling of the complex geometry and physical phenomena at different scales enables us to describe the average transport at Darcy's scale. The two main axes developed are the impact of an heterogeneous sorption on transport phenomena and the dispersivity of an unsaturated porous media. (author) [fr

Nanometre-sized pores in coal: Variations between coal basins and coal origin

Science.gov (United States)

Sakurovs, Richard; Koval, Lukas; Grigore, Mihaela; Sokolava, Anna; Ruppert, Leslie F.; Melnichenko, Yuri B.

2018-01-01

We have used small angle neutron scattering (SANS) to investigate the differences in methane and hexane penetration in pores in bituminous coal samples from the U.S., Canada, South Africa, and China, and maceral concentrates from Australian coals. This work is an extension of previous work that showed consistent differences between the extent of penetration by methane into 10–20 nm size pores in inertinite in bituminous coals from Australia, North America and Poland.In this study we have confirmed that there are differences in the response of inertinite to methane and hexane penetration in coals sourced from different coal basins. Inertinite in Permian Australian coals generally has relatively high numbers of pores in the 2.5–250 nm size range and the pores are highly penetrable by methane and hexane; coals sourced from Western Canada had similar penetrability to these Australian coals. However, the penetrability of methane and hexane into inertinite from the Australian Illawarra Coal Measures (also Permian) is substantially less than that of the other Australian coals; there are about 80% fewer 12 nm pores in Illawarra inertinite compared to the other Australian coals examined. The inertinite in coals sourced from South Africa and China had accessibility intermediate between the Illawarra coals and the other Australian coals.The extent of hexane penetration was 10–20% less than CD4 penetration into the same coal and this difference was most pronounced in the 5–50 nm pore size range. Hexane and methane penetrability into the coals showed similar trends with inertinite content.The observed variations in inertinite porosity between coals from different coal regions and coal basins may explain why previous studies differ in their observations of the relationships between gas sorption behavior, permeability, porosity, and maceral composition. These variations are not simply a demarcation between Northern and Southern Hemisphere coals.

Fe(0)-clays interactions at 90°C under anoxic conditions: a comparative study between clay fraction of Callovo-Oxfordian and other purified clays

International Nuclear Information System (INIS)

Rivard, C.; Pelletier, M.; Villieras, F.; Barres, O.; Galmiche, M.; Ghanbaja, J.; Kohler, A.; Michau, N.

2010-01-01

Document available in extended abstract form only. In the context of the geological disposal of high-level radioactive waste it is of prime importance to understand the interactions between the saturated clay formation and steel containers. This can be achieved through an in-depth analysis of iron-clay interactions. Previous studies on the subject investigated the influence of solid/liquid ratio, iron/clay ratio, temperature and reaction time. The aim of the present study is to explain Callovo-Oxfordian-Fe(0) interactions by determining the role of each mineral phases present in the Callovo-Oxfordian (clay minerals, quartz, carbonates and pyrite) on the mechanisms of interaction between metal iron and clay particles. In that context, it is especially important to understand in detail the influence of clay nature and to obtain some insight about the relationships between interaction mechanisms at the molecular scale and crystallographic properties (particle size, TO or TOT layers, amount of edge faces...). The influence of the combination of different clays and the addition of other minerals must also be studied. In a first step, the Callovo-Oxfordian argillite from the Andra's underground research laboratory was purified to extract the clay fraction (illite, illite-smectite, kaolinite and chlorite). Batch experiments were carried out in anoxic conditions at 90 deg. C in the presence of background electrolyte (NaCl 0.02 M.L -1 , CaCl 2 0.04 M.L -1 ) for durations of one, three or nine months in the presence of metallic iron powder. Experiments without iron were used as control. The iron/clay ratio was fixed at 1/3 with a solid/liquid ratio of 1/20. The above mentioned experiments were also carried out in parallel on other purified clays: two smectites (Georgia bentonite and SWy2 from the Clay Minerals Society), one illite (illite du Puy) and one kaolinite (KGa2, from the Clay Minerals society). At the end of the experiments, solid and liquid phases were

Euroclay 95. Clays and clay materials sciences. Book of abstracts

Energy Technology Data Exchange (ETDEWEB)

Elsen, A; Grobet, P; Keung, M; Leeman, H; Schoonheydt, R; Toufar, H [eds.

1995-08-20

The document contains the abstracts of the invited lecturers (18) and posters (247) presented at EUROCLAY `95. Clays and clay materials sciences. 13 items (4 from the invited lecturers and 12 from posters) have been considered within the INIS Subject Scope and indexed separately.

Euroclay 95. Clays and clay materials sciences. Book of abstracts

International Nuclear Information System (INIS)

Elsen, A.; Grobet, P.; Keung, M.; Leeman, H.; Schoonheydt, R.; Toufar, H.

1995-01-01

The document contains the abstracts of the invited lecturers (18) and posters (247) presented at EUROCLAY '95. Clays and clay materials sciences. 13 items (4 from the invited lecturers and 12 from posters) have been considered within the INIS Subject Scope and indexed separately

Clay particles as binder for earth buildings materials: a fresh look into rheology of dense clay suspensions

Science.gov (United States)

Landrou, Gnanli; Brumaud, Coralie; Habert, Guillaume

2017-06-01

In the ceramic industry and in many sectors, clay minerals are widely used. In earthen construction technique, clay plays a crucial role in the processing. The purpose of this research is to understand and modify the clay properties in earth material to propose an innovative strategy to develop a castable earth-based material. To do so, we focused on the modification of clay properties at fresh state with inorganic additives. As the rheological behaviour of clays is controlled by their surface charge, the addition of phosphate anion allows discussing deep the rheology of concentrated clay suspensions. We highlighted the thixotropic and shear thickening behaviour of a dispersed kaolinite clay suspensions. Indeed, by adding sodium hexametaphosphate the workability of clay paste increases and the behaviour is stable during time after a certain shear is applied. Moreover, we stress that the aging and the shift in critical strain in clay system are due to the re-arrangement of clay suspension and a decrease of deformation during time. The understanding of both effect: thixotropy and aging are crucial for better processing of clay-based material and for self-compacting clay concrete. Yet, studies need to pursue to better understand the mechanism.

Migration of uranium in the presence of clay colloids in a sandy aquifer

International Nuclear Information System (INIS)

Le Cointe, P.; Grambow, B.; Piscitelli, A.; Montavon, G.; Van der Lee, J.; Giffaut, E.; Schneider, V.

2010-01-01

Document available in extended abstract form only. In France, low and medium level radioactive waste of short period (nuclides with a half-life less than 31 years and an activity ranging from 100 to 1,000,000 Bq/g) is stored in concrete constructions on a surface site in Soulaines-Dhuys (Aube). The site was chosen for its simple geology: it entirely lays on an aquifer formation, the Upper Aptian sands, above a Lower Aptian impermeable clay formation. The site is surrounded by the Noues d'Amance stream, which serves as the single outlet of the groundwater on the site. The objective of this study is to improve knowledge of radionuclides migration in the aquifer formation to improve safety, using U(VI) as an example and focusing on colloids, capable of transporting U(VI) on long distances. The sediment is composed of two main phases: quartz and clay minerals (glauconite, with a small fraction of kaolinite and smectite), with relative amounts of 91 and 6% in weight, respectively. The aquifer water contains clay colloids, invisible to the eye though observed with SEM and TEM in a non disturbed sample. No signal was measured with usual light diffusion techniques and Asymmetric Flow Field-Flow Fractionation (AF4). Only the Laser Induced Breakdown Detection (LIBD) technique could characterize the size (between 30 and 70 nm) and the concentration (around 10 ppb) of the clay colloids. Batch experiments were carried out to define U(VI)-Quartz and U(VI)-Clay interactions, with U(VI) concentration, pH and pCO 2 being the studied variables. The data were modelled with the Chess geochemistry code developed at the Paris School of Mines and compared to literature. Davis applied model for U(VI)-Quartz interaction and Bradbury and Baeyens applied model for U(VI)-Illite interaction adequately describe the experimental data. To know if clay colloids can move freely in the groundwater, pore size was measured using X-ray microtomography. Nanoparticles tracing was done with

Migration of uranium in the presence of clay colloids in a sandy aquifer

Energy Technology Data Exchange (ETDEWEB)

Le Cointe, P. [Laboratoire SUBATECH, UMR 6457 Ecole des Mines/CNRS/Universite, 4 rue A. Kastler, BP 20722, 44307 Nantes Cedex 03 (France); Centre de Geosciences, Ecole des Mines de Paris, 35 rue St-Honore, 77305 Fontainebleau Cedex (France); ANDRA 1/7 rue Jean Monnet - 92298 Chatenay Malabry Cedex (France); Grambow, B.; Piscitelli, A.; Montavon, G. [Laboratoire SUBATECH, UMR 6457 Ecole des Mines/CNRS/Universite, 4 rue A. Kastler, BP 20722, 44307 Nantes Cedex 03 (France); Van der Lee, J. [EDF R ete D, Site des Renardieres, Route de Sens - Ecuelles, 77250 Moret sur Loing (France); Giffaut, E.; Schneider, V. [ANDRA 1/7 rue Jean Monnet - 92298 Chatenay Malabry Cedex (France)

2010-07-01

Document available in extended abstract form only. In France, low and medium level radioactive waste of short period (nuclides with a half-life less than 31 years and an activity ranging from 100 to 1,000,000 Bq/g) is stored in concrete constructions on a surface site in Soulaines-Dhuys (Aube). The site was chosen for its simple geology: it entirely lays on an aquifer formation, the Upper Aptian sands, above a Lower Aptian impermeable clay formation. The site is surrounded by the Noues d'Amance stream, which serves as the single outlet of the groundwater on the site. The objective of this study is to improve knowledge of radionuclides migration in the aquifer formation to improve safety, using U(VI) as an example and focusing on colloids, capable of transporting U(VI) on long distances. The sediment is composed of two main phases: quartz and clay minerals (glauconite, with a small fraction of kaolinite and smectite), with relative amounts of 91 and 6% in weight, respectively. The aquifer water contains clay colloids, invisible to the eye though observed with SEM and TEM in a non disturbed sample. No signal was measured with usual light diffusion techniques and Asymmetric Flow Field-Flow Fractionation (AF4). Only the Laser Induced Breakdown Detection (LIBD) technique could characterize the size (between 30 and 70 nm) and the concentration (around 10 ppb) of the clay colloids. Batch experiments were carried out to define U(VI)-Quartz and U(VI)-Clay interactions, with U(VI) concentration, pH and pCO{sub 2} being the studied variables. The data were modelled with the Chess geochemistry code developed at the Paris School of Mines and compared to literature. Davis applied model for U(VI)-Quartz interaction and Bradbury and Baeyens applied model for U(VI)-Illite interaction adequately describe the experimental data. To know if clay colloids can move freely in the groundwater, pore size was measured using X-ray microtomography. Nanoparticles tracing was done with

Berau coal in East Kalimantan; Its petrographics characteristics and depositional environment

Directory of Open Access Journals (Sweden)

Nana Suwarna

2014-06-01

Full Text Available http://dx.doi.org/10.17014/ijog.vol2no4.20071To asses the characteristics of the Early to Middle Miocene Berau coal in the Berau Basin, leading to interpretation of coal depositional environments, some fresh outcrop and subcrop samples and also drill cores of the coals have been analyzed microscopically. Coal petrographic analysis was performed on twenty four coal samples from the Middle Miocene Lati Formation. Vitrinite, present in a high value, and ranging between 66.2 - 96.2%, is dominated by vitrinite B. On the other hand, inertinite and exinite, showing a similar value, exist in a low to moderate amount. Vitrinite reflectance, present in a low value, varies from 0.40 - 0.58%. Low mineral matter content is dominated by clay minerals (0.4 - 6.6% with minor pyrite. Transitions from wet and very wet forested swamps to drier conditions with lower tree density are indicated by the higher content of vitrinite B, whilst a reverse trend is indicated by the lower content of vitrinite A. Petrographic indices obtained from facies diagnostic macerals show that an accumulation of the ancient peats under prevailing relatively wet limited influx clastic marsh to very wet forest swamps or moors is considered. The composition of the coal samples supports the interpretation of a system of fluvial to meandering streams in an upper delta plain environment. The original peat-forming vegetation was composed mainly of cellulose rich, shrub-like plants, tree ferns, herbaceous plant communities, with minor amount of trees. Thereby, the organic facies concept is thus applicable in basin studies context and has potential to become an additional tool for depositional environment interpretation.  

Characterization of Candiota (South Brazil) coal and combustion by-product

Energy Technology Data Exchange (ETDEWEB)

Pires, Marcal [Faculty of Chemistry, Pontifical Catholic University of Rio Grande do Sul, Av. Ipiranga 6681 Predio 12B, 90619-900 Porto Alegre-RS (Brazil); Querol, Xavier [Institute of Earth Sciences ' Jaume Almera' , CSIC, c/Marti i Franques s/n, E-08028 Barcelona (Spain)

2004-10-22

Elemental composition and mineralogy of a high ash feed coal (ash: 49.7 wt.%), and its bottom and fly ash from a Brazilian power plant (Presidente Medici Power Plant or UTPM-446 MW) was determined using ICP-MS, ICP-AES, X-ray diffraction (XRD) and scanning electron micrography (SEM). Most trace elements in coal fall in the usual range determined for world coals. However, concentrations of some elements were higher than the expected for coals, including Cs, Rb and heavy rare earth elements (REEs). This might be due to the high content of detrital minerals of the studied coal, given that these elements are usually associated with clay minerals. Elements were classified into three groups based on the analysis of trace element concentrations in fly and bottom ashes, and enrichments or depletions of these concentrations in relation to the coal: Group I (volatile elements with subsequent condensation): As, B, Bi, Cd, Ga, Ge, Mo, Pb, S, Sb, Sn, Tl and Zn; Group II (no volatile elements enriched in bottom ash vs. fly ash): Ca, Fe, Mn, P, Ti and Zr; Group III (low volatile elements with no partitioning between fly and bottom ashes): Al, Ba, Be, Co, Cr, Cs, Hf, K, Li, Mg, Na, Ni, Rb, Sr, Th, U, W, Y and most of REE. The mass balance for trace elements obtained demonstrated that the volatile emission of the trace elements studied is very low. According to the leachable proportion obtained, the elements may be classified as follows: B (40-50%)>Mo>Cu>Ge=Li=Zn=As>, Ni, Sb, Tl, U>Ba, Cd, Sr, V (0.3-2%). For the other elements studied, the leachable fraction is in most cases <1% of the bulk content.

Analysis of recovered solvents from coal liquefaction in a flowing-solvent reactor by SEC and UV-fluorescence

Energy Technology Data Exchange (ETDEWEB)

Li, W.Y.; Feng, J.; Xie, K.C.; Kandiyoti, R. [Taiyuan University of Technology, Taiyuan (China)

2005-08-01

Point of Ayr coal has been extracted using three solvents: tetralin, quinoline and 1-methyl-2-pyrrolidinone (NMP); at two temperatures: 350 {sup o}C and 450{sup o}C, corresponding approximately to before and after the onset of massive covalent bond scission by pyrolysis. These solvents differ in solvent power and the ability to donate hydrogen atoms to stabilize free radicals produced by pyrolysis of the coal. Analysis of the fresh solvents and recovered solvents from coal liquefaction was achieved by size exclusion chromatography and UV-fluorescence spectroscopy. In the blank run, it was testified that the filling material sand and the steel powder did not react with solvent with increasing reaction temperature. The role of hydrogen donation in the tetralin extracts was to increase the proportion of large molecules with increasing extraction temperature. Quinoline and NMP both have the powerful extracting capability to get more materials out of coal with increasing extraction temperature.

Analysis of recovered solvents from coal liquefaction in a flowing-solvent reactor by SEC and UV-fluorescence

Energy Technology Data Exchange (ETDEWEB)

Wen-Ying Li; Jie Feng; Ke-Chang Xie; R. Kandiyoti [Taiyuan University of Technology, Taiyuan (China). Key Laboratory of Coal Science and Technology for Ministry of Education and Shanxi Province

2005-08-01

Point of Ayr coal has been extracted using three solvents: tetralin, quinoline and 1-methyl-2-pyrrolidinone (NMP); at two temperatures: 350{sup o}C and 450{sup o}C, corresponding approximately to before and after the onset of massive covalent bond scission by pyrolysis. These solvents differ in solvent power and the ability to donate hydrogen atoms to stabilize free radicals produced by pyrolysis of the coal. Analysis of the fresh solvents and recovered solvents from coal liquefaction was achieved by size exclusion chromatography and UV-fluorescence spectroscopy. In the blank run, it was testified that the filling material sand and the steel powder did not react with solvent with increasing reaction temperature. The role of hydrogen donation in the tetralin extracts was to increase the proportion of large molecules with increasing extraction temperature. Quinoline and NMP both have the powerful extracting capability to get more materials out of coal with increasing extraction temperature.

Fluidized bed and pulverized coal combustion residues for secondary pavements

International Nuclear Information System (INIS)

Ghafoori, N.; Diawara, H.; Wang, L.

2009-01-01

The United States produced nearly 125 million tons of coal combustion products in 2006. These by-products include fly ash, flue gas desulphurization materials, bottom ash, boiler slag, and other power plant by-products. The expense associated with waste disposal, lack of disposal sites, and significant environmental damage linked with the disposal of coal combustion residues have encouraged innovative utilization strategies such as the fluidized bed combustion (FBC) unit. This paper presented the results of a laboratory investigation that examined the properties of composites developed with different proportions of pre-conditioned FBC spent bed, pulverized coal combustion fly ash, natural fine aggregate, and Portland cement. The purpose of the study was to examine the extent to which the by-product composites could replace currently used materials in secondary roads. The paper presented the research objectives and experimental programs, including matrix constituent and proportions; mixture proportions; and mixing, curing, sampling, and testing. The discussion of results centered around compressive strength and expansion by internal sulfate attack. It was concluded that with proper proportioning, by-products of pulverized and fluidized bed combustion promote binding of sand particles and provide adequate strength under various curing and moisture conditions 4 refs., 6 tabs.

Rare and Rare-Earth Metals in Coal Processing Waste

Science.gov (United States)

Cherkasova, Tatiana; Cherkasova, Elizaveta; Tikhomirova, Anastasia; Bobrovni-kova, Alyona; Goryunova, Irina

2017-11-01

An urgent issue for power plants operating on solid fuels (coal) is the issue of utilization or use of accumulated production waste - ash and slag materials - in the related production. Ash-slag materials are classified as "waste", usually grade 5; tens of millions of tons of them being pro-duced annually in the Kemerovo region, which threatens the ecology of the region. At the same time, ash and slag is a very promising raw material. The use of this material as a base for the final product allows us to signifi-cantly expand the possibilities of using coal. The most widespread is the system of ash and slag involving in construction or as a replacement for sand in road construction, or as an additive to building mixtures. However, there are both industrially valuable and environmentally dangerous ele-ments in ash-slag materials. Ash-slag materials can be considered as inde-pendent ore deposits located on the surface and requiring the costs of their extraction.

In-situ remediation of TCE by ERD in clay tills. Feasibility and performance of full-scale application insights gained through an integrated investigative approach for 2 sites

DEFF Research Database (Denmark)

Broholm, Mette Martina; Damgaard, Ida; Chambon, Julie Claire Claudia

-scale applications of ERD in clay tills were investigated in a research project in-cluding 2 sites in Denmark undergoing remediation since 2006. Site remediation approach. At the Sortebrovej site an emulsified oil donor (EOS) and a bio-augmentation culture (KB1®) with specific degraders Dehalococcoides were injected......Background/Objectives. Remediation of trichloroethene (TCE) in clay and other low permeabil-ity geologic media, where groundwater flow occurs preferentially in higher permeability sand lenses or fractures, is a significant challenge. At older sites, much of the contaminant mass is pre......-sent as a sorbed phase in the matrix due to matrix diffusion. The principal challenge for in situ remediation in clay is to achieve effective contact between contaminant and bioremediation addi-tives (e.g., organic electron donors and bioaugmentation cultures). The feasibility and perfor-mance of full...

Clay particles as binder for earth buildings materials: a fresh look into rheology of dense clay suspensions

Directory of Open Access Journals (Sweden)

Landrou Gnanli

2017-01-01

Full Text Available In the ceramic industry and in many sectors, clay minerals are widely used. In earthen construction technique, clay plays a crucial role in the processing. The purpose of this research is to understand and modify the clay properties in earth material to propose an innovative strategy to develop a castable earth-based material. To do so, we focused on the modification of clay properties at fresh state with inorganic additives. As the rheological behaviour of clays is controlled by their surface charge, the addition of phosphate anion allows discussing deep the rheology of concentrated clay suspensions. We highlighted the thixotropic and shear thickening behaviour of a dispersed kaolinite clay suspensions. Indeed, by adding sodium hexametaphosphate the workability of clay paste increases and the behaviour is stable during time after a certain shear is applied. Moreover, we stress that the aging and the shift in critical strain in clay system are due to the re-arrangement of clay suspension and a decrease of deformation during time. The understanding of both effect: thixotropy and aging are crucial for better processing of clay-based material and for self-compacting clay concrete. Yet, studies need to pursue to better understand the mechanism.

Synthesis of templated carbons starting from clay and clay-derived zeolites for hydrogen storage applications

CSIR Research Space (South Africa)

Musyoka, Nicholas M

2014-10-01

Full Text Available 57 58 59 60 For Peer Review 1 Synthesis of templated carbons starting from clay and clay-derived zeolites for hydrogen storage applications N. M. Musyoka1*, J. Ren1, H. W. Langmi1, D. E. C. Rogers1, B. C. North1, M. Mathe1 and D. Bessarabov2... clear (filtered) extract of cloisite clay, SNC for zeolite from unfiltered cloisite clay extract and SBC for zeolite from unfiltered South African bentonite clay extract. Furfuryl alcohol (Sigma Aldrich, C5H6O2, 98%) and Ethylene gas were used...

Study of Various Techniques for Improving Weak and Compressible Clay Soil under a High Earth Embankment

Directory of Open Access Journals (Sweden)

Zein A.K. M.

2014-04-01

Full Text Available This paper investigates the suitability of three soil improvement techniques for the construction of a high earth embankment on thick weak and highly compressible clay soil. The eastern approach embankment of Alhalfaya Bridge on the River Nile linking Khartoum North and Omdurman cities was chosen as a case study and a comprehensive site investigation program was carried out to determine the properties the subsurface soils. The study results showed that unless the subsurface soils have been improved they may fail or undergo excessively large settlements due to the embankment construction. Three ground improvement techniques based on the principles of the “staged construction method, SCM”, “vertical sand drain, VSD” and “sand compaction piles, SCP” of embankment foundation soil treatment are discussed and evaluated. Embankment design options based on applications of the above methods have been proposed for foundation treatment to adequately support embankment loads. A method performance evaluation based on the improvement of soil properties achieved; the time required for construction and compared estimated costs criteria was made to assess the effectiveness and expected overall performance. Adoption of any of the soil improvement techniques considered depends mainly on the most critical and decisive factor governing the embankment design. Based on the overall performance for the embankment case studied, the sand drains is considered as the most appropriate improvement method followed by the sand compaction piles technique whereas the staged construction method showed the poorest overall performance.

Submarine sand ridges and sand waves in the eastern part of the China Sea

Science.gov (United States)

Wu, Ziyin; Li, Shoujun; Shang, Jihong; Zhou, Jieqiong; Zhao, Dineng; Liang, Yuyang

2016-04-01

Integrated with multi-beam and single-beam echo sounding data, as well as historical bathymetric data, submarine bathymetric maps of the eastern part of the China Sea, including the Bohai Sea, Huanghai Sea, and East China Sea, are constructed to systematically study submarine sand ridges and sand waves in the eastern part of the China Sea, combined with high-resolution seismic, sub-bottom profile and borehole data. Submarine sand ridges are extraordinarily developed in the eastern part of the China Sea, and 7 sand ridge areas can be divided from north to south, that is, the Laotieshan Channel sand ridge area in the Bohai Sea, the Korea Bay sand ridge area in the southern Huanghai Sea, the sand ridge area in the eastern Huanghai islands and the Huanghai Troughs, the Jianggang sand ridge area in the western Huanghai Sea, the sand ridge area in the East China Sea shelf, and the sand ridge and sand wave area in the Taiwan Strait and Taiwan Banks. The distribution area of the sand ridges and sand waves covers more than 450,000 km2, wherein ~10,000 km2 in the Bohai Bay, ~200,000 km2 in the Huanghai Sea, ~200,000 km2 in the East China Sea shelf, and ~40,000 km2 in the Taiwan Strait and Taiwan Banks, respectively. The great mass of sand ridges are distributed within water depth of 5-160 m, with a total length of over 160 km and a main width of 5-10 km. The inner structure of the sand ridges presents features of high-angle inclined beddings, with main lithology of sands, sand-mud alternations partly visible, and a small number of mud cores. Dating results indicate that the sand ridges in the eastern part of the China Sea are mainly developed in the Holocene. Sea-level variation dominates the sand ridge evolution in the eastern part of the China Sea since the LGM, and the sand ridges developed in the area of < 60m water depth are appeared in bad activity, meanwhile sand ridges with good activity are still developed in large scale.

Athabasca tar sand reservoir properties derived from cores and logs

International Nuclear Information System (INIS)

Woodhouse, R.

1976-01-01

Log interpretation parameters for the Athabasca Tar Sand Lease No. 24 have been determined by careful correlation with Dean and Stark core analysis data. Significant expansion of Athabasca cores occurs as overburden pressure is removed. In the more shaly sands the core analysis procedures remove adsorbed water from the clays leading to further overestimation of porosity and free water volume. Log interpretation parameters (R/sub w/ = 0.5 ohm . m and m = n = 1.5) were defined by correlation with the weight of tar as a fraction of the weight of rock solids (grain or dry weight fraction of tar). This quantity is independent of the water content of the cores, whereas porosity and the weight of tar as a fraction of the bulk weight of fluids plus solids (bulk weight fraction) are both dependent on water content. Charts are provided for the conversion of bulk weight fraction of fluids to porosity; grain weight fraction of fluids to porosity; log derived porosity and core grain weight tar to water saturation. Example results show that the core analysis grain weight fraction of tar is adequately matched by the log analyses. The log results provide a better representation of the reservoir fluid volumes than the core analysis data

Production of fines during co-combustion of coal with biomass fuels by fragmentation and attrition

Energy Technology Data Exchange (ETDEWEB)

I. Gulyurtlu; D. Boavida; H. Lopes (and others) [DEECA-INETI, Lisbon (Portugal)

2005-07-01

Results are reported from a project funded by the RFCS Programme of the European Union. The aim is to investigate, experimentally and by modeling, the production of fine char and ash particles during co-combustion of coal with wastes and biofuels in circulating fluidized bed. Work was undertaken at installations of different scales. Polish and Colombian coals were base fuels. The additional fuels were two sewage sludges. Bed temperature, feeding system, sand particle size, devolatilisation behaviour and char burn-out were studied to verify their influence on the fine particle production. Modeling was also carried out to understand the mechanisms of fragmentation and attrition. Samples from bed and cyclone were collected to determine particle size distributions. 11 refs.

Preparation of affordable and multifunctional clay-based ceramic filter matrix for treatment of drinking water.

Science.gov (United States)

Shivaraju, H Puttaiah; Egumbo, Henok; Madhusudan, P; Anil Kumar, K M; Midhun, G

2018-02-01

Affordable clay-based ceramic filters with multifunctional properties were prepared using low-cost and active ingredients. The characterization results clearly revealed well crystallinity, structural elucidation, extensive porosity, higher surface area, higher stability, and durability which apparently enhance the treatment efficiency. The filtration rates of ceramic filter were evaluated under gravity and the results obtained were compared with a typical gravity slow sand filter (GSSF). All ceramic filters showed significant filtration rates of about 50-180 m/h, which is comparatively higher than the typical GSSF. Further, purification efficiency of clay-based ceramic filters was evaluated by considering important drinking water parameters and contaminants. A significant removal potential was achieved by the clay-based ceramic filter with 25% and 30% activated carbon along with active agents. Desired drinking water quality parameters were achieved by potential removal of nitrite (98.5%), nitrate (80.5%), total dissolved solids (62%), total hardness (55%), total organic pollutants (89%), and pathogenic microorganisms (100%) using ceramic filters within a short duration. The remarkable purification and disinfection efficiencies were attributed to the extensive porosity (0.202 cm 3  g -1 ), surface area (124.61 m 2  g -1 ), stability, and presence of active nanoparticles such as Cu, TiO 2 , and Ag within the porous matrix of the ceramic filter.

Acid mine drainage prevention, control and treatment technology development for the Stockett/Sand Coulee area. Topical report, March 1, 1995 - March 31, 1996

International Nuclear Information System (INIS)

Brown, T.

1996-01-01

The project was initiated to assist the State of Montana to develop a methodology to ameliorate acid mine drainage problems associated with the abandoned mines located in the Stockett/Sand Coulee area near Great Falls, Montana. Extremely acidic water is continuously discharging from abandoned coal mines in the Stockett/Sand Coulee area at an estimated rate of greater than 600 acre-feet per year (about 350 to 400 gallons per minute). Due to its extreme acidity, the water is unusable and is contaminating other water supplies. Most of the local alluvial aquifers have been contaminated, and nearly 5% of the private wells that were tested in the area during the mid-1980's showed some degree of contamination. Significant government money has been spent replacing water supplies due to the magnitude of this problem. In addition, millions of dollars have been spent trying to remediate acid mine drainage occurring in this coal field. To date, the techniques used have focused on the management and containment of mine waters, rather than designing technologies that would prevent the formation of acid mine drainage

Evaluation of heavy metal leaching from coal ash-versus conventional concrete monoliths and debris.

Science.gov (United States)

Gwenzi, Willis; Mupatsi, Nyarai M

2016-03-01

Application of coal ash in construction materials is constrained by the potential risk of heavy metal leaching. Limited information is available on the comparative heavy metal leaching from coal ash-versus conventional concrete. The current study compared total and leached heavy metal concentrations in unbound coal ash, cement and sand; and investigated the effect of initial leachant pH on heavy metal leaching from coal-ash versus conventional concrete monoliths and their debris. Total Pb, Mn and Zn in coal ash were lower than or similar to that of other materials, while Cu and Fe showed the opposite trend. Leached concentrations of Zn, Pb, Mn, Cu and Fe in unbound coal ash, its concrete and debris were comparable and in some cases even lower than that for conventional concrete. In all cases, leached concentrations accounted for just leaching data showed that leaching was dominated by diffusion. Overall, the risk of Zn, Pb, Mn, Cu and Fe leaching from coal ash and its concrete was minimal and comparable to that of conventional concrete, a finding in contrast to widely held public perceptions and earlier results reported in other regions such as India. In the current study the coal ash, and its concrete and debris had highly alkaline pH indicative of high acid neutralizing and pH buffering capacity, which account for the stabilization of Zn, Pb, Mn, Cu and Fe. Based on the low risk of Zn, Pb, Mn, Cu and Fe leaching from the coal ash imply that such coal ash can be incorporated in construction materials such as concrete without adverse impacts on public and environmental health from these constituents. Copyright © 2015 Elsevier Ltd. All rights reserved.

Biomechanical responses to changes in friction on a clay court surface.

Science.gov (United States)

Starbuck, Chelsea; Stiles, Victoria; Urà, Daniel; Carré, Matt; Dixon, Sharon

2017-05-01

To examine the influence of clay court frictional properties on tennis players' biomechanical response. Repeated measures. Lower limb kinematic and force data were collected on sixteen university tennis players during 10×180° turns (running approach speed 3.9±0.20ms -1 ) on a synthetic clay surface of varying friction levels. To adjust friction levels the volume of sand infill above the force plate was altered (kg per m 2 surface area; 12, 16 and 20kgm -2 ). Repeated measures ANOVA and Bonferroni's corrected alpha post-hoc analyses were conducted to identify significant differences in lower limb biomechanics between friction levels. Greater sliding distances (η p 2 =0.355, p=0.008) were observed for the lowest friction condition (20kgm -2 ) compared to the 12 and 16kgm -2 conditions. No differences in ankle joint kinematics and knee flexion angles were observed. Later peak knee flexion occurred on the 20kgm -2 condition compared to the 12kgm -2 (η p 2 =0.270, p=0.023). Lower vertical (η p 2 =0.345, p=0.027) and shear (η p 2 =0.396, p=0.016) loading rates occurred for the 20kgm 2 condition compared to the 16kgm 2 . Lower loading rates and greater sliding distances when clay surface friction was reduced suggests load was more evenly distributed over time reducing players' injury risks. The greater sliding distances reported were accompanied with later occurrence of peak knee flexion, suggesting longer time spent braking and a greater requirement for muscular control increasing the likelihood of fatigue. Copyright © 2016 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

Influence of Amang (Tin Tailing) on Geotechnical Properties of Clay Soil

International Nuclear Information System (INIS)

Zulfahmi, A.R.; Zuhairi, W.Y.W.; Raihan, M.T.; Sahibin, A.R.; Razi, I.W.M.; Tukimat, L.; Syakireen, Z.S.N.; Noorulakma, A.

2012-01-01

Amang or tin tailing is commonly found in the vicinity of disused mining area and responsible in downgrading the water quality, landscape and mechanical behaviour of soils. It was generated from extraction process of separating valuable metal from particular ore. This paper presents the geotechnical characteristics of amang-contaminated clay soil. The geotechnical properties of uncontaminated soils were studied in order to compare to that of amang contaminated soils. The base soil used in this study represents completely weathered horizon of meta sedimentary rock. Meanwhile, tin tailing sample was taken from the disused mine at Sungai Lembing, Pahang. The geotechnical characterisations of base soil and contaminated soils were determined based on consistency index, compaction behaviour, hydraulic conductivity and undrained shear strength (UU tests). Contaminated soil samples were prepared by adding 5, 10 and 20 % of tailing, based on dry weigh of the studied base soil. The results from the particle size distribution analysis showed that residual soil from meta sedimentary rock comprised 42.6 % clay, 32.2 % silt and 25.2 % sand whilst tailing was dominated by 98 % of sand fraction. XRD analysis indicated the presence of quartz, kaolinite and muscovite minerals in the studied soil. The specific gravity of soil used is 2.67 and the pH is 3.88. Tailing found to have higher specific gravity of 3.37. The consistency index of contaminated soils showed that liquid limit, wL and plastic limit, wP decreased with the increase in the percentage of tailing added to the soil samples. The value of maximum dry density, ρ dry max increased while optimum moisture content decreased due to the increase in tailing content in soil sample. The permeability of contaminated soil also increased with the increase in tailing contents ranged from 19.8 cm/ hr to 23.8 cm/ hr. The undrained shear strength, Cu, of contaminated soil decreased from 646 kPa (5 % of tailing) to 312 kPa (20 % of

Low-temperature, mineral-catalyzed air oxidation: a possible new pathway for PAH stabilization in sediments and soils.

Science.gov (United States)

Ghislain, Thierry; Faure, Pierre; Biache, Coralie; Michels, Raymond

2010-11-15

Reactivity of polycyclic aromatic hydrocarbons (PAHs) in the subsurface is of importance to environmental assessment, as they constitute a highly toxic hazard. Understanding their reactivity in the long term in natural recovering systems is thus a key issue. This article describes an experimental investigation on the air oxidation of fluoranthene (a PAH abundant in natural systems polluted by industrial coal use) at 100°C on different mineral substrates commonly found in soils and sediments (quartz sand, limestone, and clay). Results demonstrate that fluoranthene is readily oxidized in the presence of limestone and clay, leading to the formation of high molecular weight compounds and a carbonaceous residue as end product especially for clay experiments. As demonstrated elsewhere, the experimental conditions used permitted the reproduction of the geochemical pathway of organic matter observed under natural conditions. It is therefore suggested that low-temperature, mineral-catalyzed air oxidation is a mechanism relevant to the stabilization of PAHs in sediments and soils.

HDPE/clay hybrids: the effect of clay modified with poly(diphenyl siloxanes) on thermal and rheological properties

Energy Technology Data Exchange (ETDEWEB)

Monasterio, Fernanda E.; Carrera, Maria C.; Erdmann, Eleonora; Destefanis, Hugo A., E-mail: ferelenakq@gmail.co [Consejo Nacional de Investigaciones Cientificas y Tecnicas (CONICET), Buenos Aires (Argentina). Inst. de Investigaciones para la Industria Quimica; Pita, Victor J.R.R.; Dias, Marcos L. [Universidade Federal do Rio de Janeiro (IMA/UFRJ), RJ (Brazil). Inst. de Macromoleculas Profa. Eloisa Mano

2009-07-01

Poly(diphenyl siloxanes) (PDPhS) were synthesized in presence of organophilic clay in order to modify its nano structure. Two silane monomers were used: dimethoxydiphenylsilane and dichlorodiphenylsilane. The following characterizations were performed for all clays: XRD, FTIR and TGA/DTG. These siloxane-modified clays were more hydrophobic and had enhanced thermal stability. Solvent extraction was carried out in the siloxane-modified clays and the PDPhS soluble fraction analyzed according the molecular weight via GPC. The presence of free and grafted oligomers on clay surface was identified. The modified clays were added to HDPE by melt processing to obtain HDPE/clay hybrids which exhibited marked differences in the rheological behavior when compared with neat HDPE. (author)

HDPE/clay hybrids: the effect of clay modified with poly(diphenyl siloxanes) on thermal and rheological properties

International Nuclear Information System (INIS)

Monasterio, Fernanda E.; Carrera, Maria C.; Erdmann, Eleonora; Destefanis, Hugo A.; Pita, Victor J.R.R.; Dias, Marcos L.

2009-01-01

Poly(diphenyl siloxanes) (PDPhS) were synthesized in presence of organophilic clay in order to modify its nano structure. Two silane monomers were used: dimethoxydiphenylsilane and dichlorodiphenylsilane. The following characterizations were performed for all clays: XRD, FTIR and TGA/DTG. These siloxane-modified clays were more hydrophobic and had enhanced thermal stability. Solvent extraction was carried out in the siloxane-modified clays and the PDPhS soluble fraction analyzed according the molecular weight via GPC. The presence of free and grafted oligomers on clay surface was identified. The modified clays were added to HDPE by melt processing to obtain HDPE/clay hybrids which exhibited marked differences in the rheological behavior when compared with neat HDPE. (author)

Organic petrography:An approach for identification of maceral groups in Gheshlagh coal area, Eastern Alborz

Directory of Open Access Journals (Sweden)

Tahereh Rabani

2016-07-01

, collotelinite, and corpogelinite macerals. Collodetrinite maceral (20 to 65.6 vol.% is the most abundant maceral in the vitrinite group and is associated with inertodetrinite and microspornite macerals. Callotelinite (8.4 to 46.7 wt% occurs as a structureless, homogeneous mass in the Gheshlagh coal seams. The inertinite group (4.9 to 23.3 vol% includes fusinite, semifusinite, macrinite, secretinite, funginite and inertodetrinite macerals. Fusinite (1.7 to12.7 vol.% is present in all coal seams in the Gheshlagh area. Cell cavities of fusinite are filled mostly by corpogelinite and clay minerals. Semifusinite occurs in appreciable concentrations (2.1to 14.3vol.% and Cell lumens of this maceral are filled with mineral matter, pyrite and clay. The liptinite group (nil to 3.5 vol% includes sporinite, cutinite and resinite macerals. Sporinite is the dominant maceral in the liptinite group (nil to 2.3 vol.% and occurs as elongated thread-like or spindle-shaped bodies and occurs as microspores and megaspores. Resinite (nil to 0.1 vol.% occurs as round to oval bodies and as fillings of the cell cavities of fusinite, semifusinite and funginite. The mineral matter content of most of the Gheshlagh coal seams varies between 3.1 and 24.9 vol.%. Mineral matter occurs in primary ground mass or secondary cavity filling form and includes clay minerals, carbonate and sulphide. Conclusion Based on organic petrographic studies carried out on four active coal mines in the Gheshlagh area, the presence of three maceral groups were determined. The vitrinite group (66.2 to 87.2 vol% is the dominant maceral group, and callodetrinite maceral (20 to 65.6 vol% is also abundant. The inertinite group contenthas a range of 4.9 to 23.3 vol% while the fusinite and semifusinite macerals are the most abundant of this group. The lowest volume percentage of macerals belongs to the liptinite group (0 to 3.5 vol% with 2.3 vol% espornitebeing the most abundant Maceral of this group. The presence of espornite maceral at

Coal-char combustion in a fluidised bed reactor

Energy Technology Data Exchange (ETDEWEB)

Mehrotra, S.P.; Pande, M. [Indian Institute of Technolgy, Kanpur (India)

2001-12-01

Combustion of bituminous coal chars ranging from 0.8 mm to 1.8 mm has been studied in a fluidised bed reactor at temperatures ranging from 500 to 850{sup o}C. The fluidised bed consists of inert sand particles of average size of 0.5 mm and reactive coal char particles. A heat balance has been worked out to calculate the rate of combustion of char from measured incremental changes in the bed temperature during combustion. Investigations on partially burnt particles suggest that the ash layer which builds up around the burning core of char particles is non-flaking and the particles burn in a shrinking core manner. Analysis of rate data indicates that the rate of combustion is controlled by chemical reaction kinetics, though diffusion of oxygen through the bundary layer begins to influence the overall reaction kinetics at higher temperatures. The burnt out time varies linearly with particle size. Activation energy for the chemical reaction control regime is found to be around 68 kJ/mole.

Fontainebleau Sand

DEFF Research Database (Denmark)

Leth, Caspar Thrane

2006-01-01

The report is a summary of results from laboratory tests in the geotechncial research group on Fontainebleau sand.......The report is a summary of results from laboratory tests in the geotechncial research group on Fontainebleau sand....

Preparation and characterization of bentonite clay for formation of nanocomposites

International Nuclear Information System (INIS)

Santos, J.J.M.; Silva, B.L.; Araujo, I.J.C.; Medeiros, A.M.; Melo, J.D.D.; Paskocimas, C.A.

2011-01-01

This study we used the linear medium density polyethylene (PELMD) as polymer matrix and introduced, as reinforcement to increase the mechanical and thermal properties, the green bentonite deposit of Boa Vista/PB, rich montmorillonite (MMT), previously characterized by XRD, that passed by three stages of purification. The first stage was to clean by washing and filtering for removal of coarse material (sand and organic matter), followed by an acid attack. In the second, we used the quaternary ammonium surfactant, in order to increase the distance between the layers of MMT, and the third was removed from the wastewater, using absolute ethanol, finishing the purification of process. Then, the clay was introduced into the polymer matrix by polymerization in solution by intercalation and characterized by XRD. The results showed a partial exfoliation, satisfying the increasing properties. (author)

Crystallite size distribution of clay minerals from selected Serbian clay deposits

Directory of Open Access Journals (Sweden)

Simić Vladimir

2006-01-01

Full Text Available The BWA (Bertaut-Warren-Averbach technique for the measurement of the mean crystallite thickness and thickness distributions of phyllosilicates was applied to a set of kaolin and bentonite minerals. Six samples of kaolinitic clays, one sample of halloysite, and five bentonite samples from selected Serbian deposits were analyzed. These clays are of sedimentary volcano-sedimentary (diagenetic, and hydrothermal origin. Two different types of shape of thickness distribution were found - lognormal, typical for bentonite and halloysite, and polymodal, typical for kaolinite. The mean crystallite thickness (T BWA seams to be influenced by the genetic type of the clay sample.

A case study of long-term geochemical evolution of coal waste rock drainage and its remediation

Energy Technology Data Exchange (ETDEWEB)

Jarvis, A.P.; Gandy, C.J. [Newcastle Univ. (United Kingdom). School of Civil Engineering and Geosciences, Hydrogeochemical Engineering Research and Outreach Group

2010-07-01

The geochemical evolution of drainage from an 35 hectare orphan waste rock pile over a 15-year period was described. Spoil material at the site was generated during coal mining at 2 collieries between 1922 and 1970, and was comprised of grey and black shale, ash, coal, and coal dust. The heap was founded on an impermeable clay layer. Located in northern England, drainage from the rock heap was intercepted by a small compost wetland system installed in 1997. The waste rock heap was selectively capped in 1998. Water samples were collected and analyzed. Anion concentrations were determined using an ion chromatograph. The samples were filtered periodically. Acidity concentrations and flow rates were determined. Results of the study showed measurable improvements in water quality as a result of capping the heap. The study demonstrated that a combination of selective spoil capping and wetland treatment can serve as a low-cost solution to acid mine drainage at some abandoned mine sites. 9 refs., 1 tab., 1 fig.

A case study of long-term geochemical evolution of coal waste rock drainage and its remediation

International Nuclear Information System (INIS)

Jarvis, A.P.; Gandy, C.J.

2010-01-01

The geochemical evolution of drainage from an 35 hectare orphan waste rock pile over a 15-year period was described. Spoil material at the site was generated during coal mining at 2 collieries between 1922 and 1970, and was comprised of grey and black shale, ash, coal, and coal dust. The heap was founded on an impermeable clay layer. Located in northern England, drainage from the rock heap was intercepted by a small compost wetland system installed in 1997. The waste rock heap was selectively capped in 1998. Water samples were collected and analyzed. Anion concentrations were determined using an ion chromatograph. The samples were filtered periodically. Acidity concentrations and flow rates were determined. Results of the study showed measurable improvements in water quality as a result of capping the heap. The study demonstrated that a combination of selective spoil capping and wetland treatment can serve as a low-cost solution to acid mine drainage at some abandoned mine sites. 9 refs., 1 tab., 1 fig.

Aspects of clay/concrete interactions

International Nuclear Information System (INIS)

Oscarson, D.W.; Dixon, D.A.; Onofrei, M.

1997-01-01

In the Canadian concept for nuclear fuel waste management, both clay-based materials and concrete are proposed for use as barriers, seals or supporting structures. The main concern when clays and concrete are in proximity is the generation of a high-pH environment by concrete since clay minerals are relatively unstable at high pH. Here we examine the OH - -generating capacity of two high-performance concretes when in contact with several solutions. We also investigate various aspects of claylconcrete interactions. They are: (1) the alkalimetric titration of clay suspensions, (2) the effect of Ca(OH) 2 (portlandite) on the swelling and hydraulic properties of compacted bentonite, and (3) the influence of cement grout on a backfill clay retrieved from the 900-d Buffer/Container Experiment at the Underground Research Laboratory of AECL. The results indicate that although high-performance concretes establish significantly lower poresolution pH (9 to 10) than does ordinary portland cement, the pH is still somewhat higher than that of clay/groundwater systems of about pH 8. Hence, even if high-performance concrete is used in a disposal vault, the potential still exists for clay minerals to alter over long periods of time if in contact with this concrete. The data show, however, that clays have a substantial buffering capacity, and clay-based barriers can thus neutralize much of the OH - potentially released from concrete in a vault. Moreover, even after reacting for 120 d at 85 o C with up to 5 wt.% Ca(OH) 2 , compacted bentonite (dry density = 1.2 Mg/m 3 ) retains much of its swelling capacity and has a permeability low enough (hydraulic conductivity ≤ 10 -11 m/s) to ensure that molecular diffusion will be the main transport mechanism through compacted clay-based barriers. Furthermore, according to X-ray diffractometry, the clay mineral component of backfill was not altered by contact with a cement grout for 900 d in the Buffer/Container Experiment

Physical Properties of Latvian Clays

OpenAIRE

Jurgelāne, I; Stepanova, V; Ločs, J; Mālers, J; Bērziņa-Cimdiņa, L

2012-01-01

Physical and chemical properties of clays mostly depends on its mineral and chemical composition, particle size and pH value. The mutual influence of these parameters is complex. Illite is the most abundant clay mineral in Latvia and usually used in building materials and pottery. The viscosity and plasticity of Latvian clays from several deposits were investigated and correlated with mineral composition, particle size and pH value. Fractionated and crude clay samples were used. The p...

Coal geopolitics

International Nuclear Information System (INIS)

Giraud, P.N.; Suissa, A.; Coiffard, J.; Cretin, D.

1991-01-01

This book divided into seven chapters, describes coal economic cycle. Chapter one: coals definition; the principle characteristics and properties (origin, calorific power, international classification...) Chapter two: the international coal cycle: coal mining, exploration, coal reserves estimation, coal handling coal industry and environmental impacts. Chapter three: the world coal reserves. Chapter four: the consumptions, productions and trade. Chapter five: the international coal market (exporting mining companies; importing companies; distributors and spot market operators) chapter six: the international coal trade chapter seven: the coal price formation. 234 refs.; 94 figs. and tabs [fr

Enchanted Clays: 44th Annual Meeting of the Clay Minerals Society (June 2007)

Energy Technology Data Exchange (ETDEWEB)

Randall T. Cygan

2007-06-01

“Enchanted Clays: 44th Annual Meeting of the Clay Minerals Society” was held in early June 2007 in beautiful and historic Santa Fe, New Mexico, USA. Santa Fe provided an idyllic location in the southwestern United States for the attendees to enjoy technical and social sessions while soaking up the diverse culture and wonderful climate of New Mexico—The Land of Enchantment. The meeting included a large and varied group of scientists, sharing knowledge and ideas, benefitting from technical interactions, and enjoying the wonderful historic and enchanted environs of Santa Fe. Including significant number of international scientists, the meeting was attended by approximately two hundred participants. The meeting included three days of technical sessions (oral and poster presentations), three days of field trips to clay and geological sites of northern New Mexico, and a full day workshop on the stabilization of carbon by clays. Details can be found at the meeting web site: www.sandia.gov/clay.

Evaluation of the bleaching flux in clays containing hematite and different clay minerals

International Nuclear Information System (INIS)

Silva Junior, E.M.; Lusa, T.; Silva, T.M.; Medeiros, B.B.; Santos, G.R. dos; Morelli, M.R.

2016-01-01

Previous studies have shown that the addition of a synthetic flux in a clay mineral constituted by illite phase in the presence of iron oxide with the hematite, promotes color change of the firing products, making the reddish color firing into whiteness. This flow is constituted of a vitreous phase of the silicates family obtained by fusion/solidification of oxides and carbonates. Thus, the objective of this work was that of studying the interaction of the iron element in the final color mechanism of the different types of mineral crystal phase of the clays. In order to study the phenomenon, we obtained different compositions between the select clays and the synthetic flow, and characterization using X-ray diffraction (XRD) and visual analysis. The results showed that the action of the synthetic flow as a modifying agent for color depends on the mineral crystal phase of the clays. The color firing modification does not occur in the clays content high levels of kaolinite mineral phase. (author)

Columns in Clay

Science.gov (United States)

Leenhouts, Robin

2010-01-01

This article describes a clay project for students studying Greece and Rome. It provides a wonderful way to learn slab construction techniques by making small clay column capitols. With this lesson, students learn architectural vocabulary and history, understand the importance of classical architectural forms and their influence on today's…

The survey and mapping of sand-boil landforms related to the Emilia 2012 earthquakes: preliminary results

Directory of Open Access Journals (Sweden)

Andrea Ninfo

2012-10-01

Full Text Available Sand boils, which are also known as sand blows or sand volcanoes, are among the most common superficial effects induced by high-magnitude earthquakes. These generally occur in or close to alluvial plains when a strong earthquake (M >5 strikes on a lens of saturated and unconsolidated sand deposits that are constrained between silt-clay layers [Ambraseys 1988, Carter and Seed 1988, Galli 2000, Tuttle 2001, Obermeier et al. 2005], where the sediments are converted into a fluid suspension. The liquefaction phenomena requires the presence of saturated and uncompacted sand, and a groundwater table near the ground surface. This geological–geomorphological setting is common and widespread for the Po Plain (Italy [Castiglioni et al. 1997]. The Po Plain (ca. 46,000 km2 represents 15% of the Italian territory. It hosts a population of about 20 million people (mean density of 450 people/km2 and many infrastructures. Thus, the Po Plain is an area of high vulnerability when considering the liquefaction potential in the case of a strong earthquake. Despite the potential, such phenomena are rarely observed in northern Italy [Cavallin et al. 1977, Galli 2000], because strong earthquakes are not frequent in this region; e.g., historical data report soil liquefaction near Ferrara in 1570 (M 5.3 and in Argenta 1624 (M 5.5 [Prestininzi and Romeo 2000, Galli 2000]. In the Emilia quakes of May 20 and 29, 2012, the most widespread coseismic effects were soil liquefaction and ground cracks, which occurred over wide areas in the Provinces of Modena, Ferrara, Bologna, Reggio Emilia and Mantova (Figure 1. […

Preliminary Result of Geophysical Some Studieson the Nariinsukhait Coal Deposit

Science.gov (United States)

Norov, B.; Purevjav, N.; Roy, D. K., Sr.

2017-12-01

Nariinsukhait coal deposit has a strategic importance on Mongolian national economic development. The deposit is located in Gurvan-tes of the Umnu-gobi province, as 849 km south-west away from Ulaanbaatar. The deposit in geographically, belongs to Gobi Altai region region of the Altai mountain region. The area contains Permian, Cretaceous, Jurassic, Triassic age of sediments. Sediments are red or sedimentary cover on some part of area (Minjin. Ch., Batnyam. D., Rentsendorj. S (Baatarkhuyag. A., Altantsetseg. D., 2015). The coal deposit is located in the center portion of the Nariinsukhait basin. The age of coal hosted sedimentary rock is Jurassic estimated by Paleo-botanic methodology, using examination of a total 59 kind of plants, 288 pollen grains (Baatarkhuyag. A., Altantsetseg. D., 2015). The thickness of coal hosted sedimentary sequence is approximately 1105.5m and named as Orgilohbulag formation. In case of geophysical exploration, preliminary interpretation of the coal basin has been done by 3 geophysical methodologies which commonly applying during exploration stage of coal. The interpretations are given below. Natural Gamma Sonde /NGRS 4140/: use to determine natural gamma activation on rock by radionuclides content (238U; 235U; 232Th; 40K). During measurements well contrasted coal bedding and, value indicate between 0-15cps. And depending on the rock type it has been changed, in case of siltstone, argillite, conglomerate value fluctuated between 15-40cps. However, those rocks natural gamma values are difference little, therefore not showing much contrast between rock types. Formation Density Sonde Version B /FDSB 4036/: The Nariinsukhait coal deposit Open holes and protective pipes of density is 0.5-1.5 g/cm3, 1.2-2.3 g/cm3 respectively. Not well contrasted during measurement due to some of sedimentary rock density range is so low as such sandstone, siltstone, and conglomerate. Therefore, applied resistivity methodology and done interpretation. DLL3

Remediation of arsenic-contaminated groundwater using media-injected permeable reactive barriers with a modified montmorillonite: sand tank studies.

Science.gov (United States)

Luo, Ximing; Liu, Haifei; Huang, Guoxin; Li, Ye; Zhao, Yan; Li, Xu

2016-01-01

A modified montmorillonite (MMT) was prepared using an acid activation-sodium activation-iron oxide coating method to improve the adsorption capacities of natural MMTs. For MMT, its interlamellar distance increased from 12.29 to 13.36 Å, and goethite (α-FeOOH) was intercalated into its clay layers. Two novel media-injected permeable reactive barrier (MI-PRB) configurations were proposed for removing arsenic from groundwater. Sand tank experiments were conducted to investigate the performance of the two MI-PRBs: Tank A was filled with quartz sand. Tank B was packed with quartz sand and zero-valent iron (ZVI) in series, and the MMT slurry was respectively injected into them to form reactive zones. The results showed that for tank A, total arsenic (TA) removal of 98.57% was attained within the first 60 mm and subsequently descended slowly to 88.84% at the outlet. For tank B, a similar spatial variation trend was observed in the quartz sand layer, and subsequently, TA removal increased to ≥99.80% in the ZVI layer. TA removal by MMT mainly depended on both surface adsorption and electrostatic adhesion. TA removal by ZVI mainly relied on coagulation/precipitation and adsorption during the iron corrosion. The two MI-PRBs are feasible alternatives for in situ remediation of groundwater with elevated As levels.

Responses of macroinvertebrates and local environment to short-term commercial sand dredging practices in a flood-plain lake.

Science.gov (United States)

Meng, Xingliang; Jiang, Xiaoming; Li, Zhengfei; Wang, Jun; Cooper, Keith M; Xie, Zhicai

2018-08-01

In parts of the developing world, the expansion of industrial sand mining activities has led to serious environmental concerns. However, current understanding of the effects of this activity on an inland water ecosystem remains limited. Herein, we choose the "most affected" lake in China (Dongting Lake), to assess short-term (1year) effects of sand dredging on key environmental parameters and on the structure of the macroinvertebrate assemblage. Within the dredged area we observed increases in water depth (on average 2.17m), turbidity and changes in sediment composition (e.g., increase in % medium sand, and a decrease in % clay). In addition, dredging was associated with a 50 % reduction in taxa richness, Simpson and Shannon-Wiener indices, and a 72 and 99 % reduction in abundance and biomass, respectively. Indirect effects were also observed in the zone surrounding the extraction sites (ca. 500m), most likely as a result of the dredging processes (e.g., sediment screening and overspill) and water flow. No such effects were observed at a nearby reference site. The direct removal of sediment and indirect alteration of physical conditions (e.g., water depth, turbidity and sediment composition) appear to be the most likely cause of variations in the benthic community. Implications of our findings for the planning, management and monitoring of sand dredging in inland waters are discussed. Copyright © 2018 Elsevier B.V. All rights reserved.

Impact of coal and rice husk ash on the quality and chemistry of cement clinker

International Nuclear Information System (INIS)

Nawaz, S.; Kanwal, S.; Rahim, U.; Sheikh, N.; Shahzad, K.

2012-01-01

Utilization of rice husk as an alternative fuel for coal is of interest due to its availability in huge quantities in Pakistan and also because its combustion is environmental pollution friendly as it generates much less SOX due to its much lower sulphur content (0.1-0.3%) compared to sulphur content in coals, particularly indeginous coals ranging from 0.6-14.8%. The purpose of present study was to examine the impact of co-firing of rice husk and coal on the quality of cement clinker so as to substitute expensive imported coal with the abundantly available cheaper rice husk to reduce the cost of production of the cement. For this investigation raw feed mix (mixture of limestone, clay, bauxite and laterite in predetermined proportions) used for cement manufacture was mixed with predetermined varying proportions of coal ash and rice husk ash and placed inside a muffle furnace at 1200 degree C - 1500 degree C i-e the temperatures prevailing in the industrial cement kilns, for various periods of time to obtain cement clinker. The quality and chemistry of cement clinker thus produced in the laboratory was experimentally studied to ensure the quality of cement clinker that would be obtained by co-firing of rice husk and coal in different proportions in industrial cement kilns as the coal ash and rice husk ash produced during combustion will get mixed with cement clinker in industrial kilns. The results indicated that there was decrease in the Lime Saturation Factor, Free Lime and Tricalcium Silicate (C3S) content and increase in the Dicalcium Silicate (C2S) content by increasing the rice husk ash and decreasing the coal ash proportion in the clinker. (author)

Dual inoculation with an Aarbuscular Mycorrhizal fungus and Rhizobium to facilitate the growth of alfalfa on coal mine substrates

Energy Technology Data Exchange (ETDEWEB)

Wu, F.Y.; Bi, Y.L.; Wong, M.H. [China University of Mining & Technology, Beijing (China)

2009-07-01

A pot experiment was conducted to investigate the effects of Glomus mosseae and Rhizobium on Medicago sativa grown on three types of coal mine substrates, namely a mixture of coal wastes and sands (CS), coal wastes and fly ash (CF), and fly ash (FA). Inoculation with Rhizobium alone did not result in any growth response but G. mosseae alone displayed a significant effect on plant growth. G. mosseae markedly increased the survival rate of M. sativa in CS substrate. In CF and FA substrates the respective oven dry weights of M. sativa inoculated with G. mosseae were 1.8 and 5.1 times higher than those without inoculation. Based on nitrogen (N), phosphorus (P) and potassium (K) uptake and legume growth, the results also show that dual inoculation in CS and CF substrates elicited a synergistic effect. This indicates that inoculation with arbuscular mycorrhizal (AM) fungi may be a promising approach for revegetation of coal mine substrates.

Effects of Different Types of Clays and Maleic Anhydride Modified Polystyrene on Polystyrene/Clay Nanocomposites

Directory of Open Access Journals (Sweden)

M. Mehrabzadeh

2013-01-01

Full Text Available Polymer/clay nanocomposites are considered as a new subject of research in Iran and the world. Addition of a minimum amount of clay (2-5wt% can improve the mechanical properties, enhance barrier properties and reduce flammability dramatically. Polystyrene (PS exhibits high strength, high modulus and excellent dimensional stability, but it has poor ductility, elongation, and flexural modulus. By incorporating clay into polystyrene these properties can be improved. In this study preparation of polystyrene/clay nanocomposite, effects of different types of clays (Cloisite 10A andNanomer I.30TC and maleic anhydride modified polystyrene on mechanical properties of the prepared polystyrene/clay nanocomposites were evaluated. Samples were prepared by a twin screw extruder. Transmission electron microscopy (TEM and X-ray diffraction (XRD techniques were employed to evaluate the extent of intercalation and exfoliation of silicate layers in the nanocomposites. Mechanical tests show that by addition of clay and maleic anhydride modified polystyrene the flexural modulus (~30% and elongation-at-break (~40% of prepared nanocomposites have been improved. XRD and TEM results show that nanocomposite have an intercalated structure with ability to change to further exfoliation structure.

Report of base consolidation promotion survey of overseas coal import in FY 1993. Feasibility survey of effective utilization of coal ash; 1993 nendo kaigaitan yunyu kiban seibi sokushin chosa. Sekitanbai yuko riyo jigyo no feasibility chosa

Energy Technology Data Exchange (ETDEWEB)

NONE

1994-03-01

This report describes the effective utilization of coal ash discharged from general industry (general industry ash) as improving material of construction waste soil and deodorant for poultry industry. Coal ash is characterized by the pozzolan and self-hardening properties which are not shown in soil and sand. Coal ash having a large amount of free CaO in its composition has stronger such properties. Coal ash generated from fluidized bed combustor which is a kind of combustor of coal contains a large amount of free CaO, especially, resulting in the stronger such properties. On the other hand, coal ash has water and oil absorbing property due to its porous structure. To utilize these properties, the improving material of soft construction waste soil and deodorant for poultry industry have been selected. As a result of laboratory and field tests for the former, it was found that sufficient supporting force can be obtained. Since the protection of powder splash is required at the site, a humidification system has been developed, which can protect the splash by the humidification of 5%. The price between 500 and 1,000 yen/ton is suitable for the improving material of construction waste soil. The maximum price of the deodorant for poultry industry is 10 yen/kg. 14 refs., 40 figs., 49 tabs.

Thixotropic Properties of Latvian Illite Containing Clays

OpenAIRE

Lakevičs, Vitālijs; Stepanova, Valentīna; Niedra, Santa; Dušenkova, Inga; Ruplis, Augusts

2015-01-01

Thixotropic properties of Latvian Devonian and Quaternary clays were studied. Dynamic viscosity of the water clay suspensions were measured with a rotating viscometer. Influence of concentration, pH and modifiers on the thixotropic clay properties was analyzed. It was found that Latvian clays have thixotropic properties. Stability of clay suspensions is described with the thixotropy hysteresis loop. Increasing the speed of the viscometer rotation, dynamic viscosity of the clay suspension decr...

Clay exfoliation and polymer/clay aerogels by supercritical carbon dioxide

Directory of Open Access Journals (Sweden)

Simona eLongo

2013-11-01

Full Text Available Supercritical carbon dioxide (scCO2 treatments of a montmorillonite (MMT intercalated with ammonium cations bearing two long hydrocarbon tails (organo-modified MMT, OMMT led to OMMT exfoliation, with loss of the long-range order in the packing of the hydrocarbon tails and maintenance of the long-range order in the clay layers. The intercalated and the derived exfoliated OMMT have been deeply characterized, mainly by X-ray diffraction analyses. Monolithic composite aerogels, with large amounts of both intercalated and exfoliated OMMT and including the nanoporous-crystalline δ form of syndiotactic polystyrene (s-PS, have been prepared, by scCO2 extractions of s-PS-based gels. Also for high OMMT content, the gel and aerogel preparation procedures occur without re-aggregation of the exfoliated clay, which is instead observed for other kinds of polymer processing. Aerogels with the exfoliated OMMT have more even dispersion of the clay layers, higher elastic modulus and larger surface area than aerogels with the intercalated OMMT. Extremely light materials with relevant transport properties could be prepared. Moreover, s-PS-based aerogels with exfoliated OMMT could be helpful for the handling of exfoliated clay minerals.

Carbon dioxide sequestration in oil sands tailings streams

Energy Technology Data Exchange (ETDEWEB)

Mikula, R.; Afara, M.; Namsechi, B.; Demko, B.; Wong, P. [Natural Resources Canada, Devon, AB (Canada). CANMET Western Research Centre

2010-07-01

This PowerPoint presentation discussed the use of carbon dioxide (CO{sub 2}) as an oil sands tailings process aid and investigated its role in maximizing recycle water availability by rapid consolidation of the transition zone. The potential for CO{sub 2} sequestration was also investigated. CO{sub 2} composite tailings (CT) pilot plants were discussed and the results of cylinder tests and water chemistry analyses were presented. Issues related to physical entrapment, ionic trapping, and mineral trapping were discussed. The study showed that carbonic acid lowers pH, dissolving calcite and dolomite. Aluminum hydroxide groups on the clay surface reacted to produce water and Al{sup 3+} and Na+. Increased bicarbonate and calcium resulted in precipitated calcite. The reduction of a transition zone from 6 to 3 meters increased the available recycle water by 15 mm{sup 3} in a 5 km{sup 2} recycle water pond. Optimum CO{sub 2} additions to whole tailings are now being investigated. tabs., figs.

Study of Black Sand Particles from Sand Dunes in Badr, Saudi Arabia Using Electron Microscopy

Directory of Open Access Journals (Sweden)

Haider Abbas Khwaja

2015-08-01

Full Text Available Particulate air pollution is a health concern. This study determines the microscopic make-up of different varieties of sand particles collected at a sand dune site in Badr, Saudi Arabia in 2012. Three categories of sand were studied: black sand, white sand, and volcanic sand. The study used multiple high resolution electron microscopies to study the morphologies, emission source types, size, and elemental composition of the particles, and to evaluate the presence of surface “coatings or contaminants” deposited or transported by the black sand particles. White sand was comprised of natural coarse particles linked to wind-blown releases from crustal surfaces, weathering of igneous/metamorphic rock sources, and volcanic activities. Black sand particles exhibited different morphologies and microstructures (surface roughness compared with the white sand and volcanic sand. Morphological Scanning Electron Microscopy (SEM and Laser Scanning Microscopy (LSM analyses revealed that the black sand contained fine and ultrafine particles (50 to 500 nm ranges and was strongly magnetic, indicating the mineral magnetite or elemental iron. Aqueous extracts of black sands were acidic (pH = 5.0. Fe, C, O, Ti, Si, V, and S dominated the composition of black sand. Results suggest that carbon and other contaminant fine particles were produced by fossil-fuel combustion and industrial emissions in heavily industrialized areas of Haifa and Yanbu, and transported as cloud condensation nuclei to Douf Mountain. The suite of techniques used in this study has yielded an in-depth characterization of sand particles. Such information will be needed in future environmental, toxicological, epidemiological, and source apportionment studies.

In situ radionuclide migration studies in a shallow sand aquifer. Part. 1. Part. 2: appendices

International Nuclear Information System (INIS)

Williams, G.M.; Alexander, L.S.; Hitchman, S.P.; Hooker, P.J.; Noy, D.J.; Ross, C.A.M.; Stuart, A.; West, J.M.

1986-01-01

As a result of a study of the geology of the British Nuclear Fuels premises at Drigg, Cumbria, the British Geological Survey identified a shallow glacial sand deposit approximately 1.5m thick, interbedded between two clay horizons. An array of boreholes has been constructed in this sand in order to study the migration of radionuclides introduced into the formation under controlled conditions of groundwater flow. Conservative tracers used in the field test include chloride (as NaCl) and iodine-131 (as NaI). Strontium-85 (as the chloride) has been used as a chemically reactive tracer in conjunction with 131 I. The principal research objectives of the programme are as follows: (1) To undertake laboratory batch sorption experiments using core material from the field site in order to choose those nuclides of radiological interest that would migrate sufficiently quickly for their behaviour to be studied in a field experiment within a reasonable time period. (2) To identify and quantify the mechanisms for nuclide/sediment interaction by determination of the geochemical distribution of 85 Sr in contaminated cores using a sequential leaching procedure. (3) To obtain appropriate data on the hydraulic characteristics of the sand formation in order to construct a mathematical model to describe groundwater flow and reactive mass transport. Part 2 of this report contains the following appendices: (1) Calculation of sorption parameters. (2) A low-cost manifold system for use with multi-level samplers. (3) Radioactivity curves for 131 I and 85 Sr. (4) Results of particle size analysis for sand aquifers

Clay minerals and Sr-Nd isotopes of the sediments along the western margin of India and their implication for sediment provenance

Digital Repository Service at National Institute of Oceanography (India)

Kessarkar, P.M.; Rao, V.P.; Ahmad, S; Babu, G.A.

- gion is occupied by Recent alluvium and the Warkala beds (ferruginised sand stones with inter- calated clays) of Tertiary age. Extensive laterisation of the parent rocks is a characteristic feature in western India. Bauxite- and laterite...^Nd isotopes of the sediments along the western margin of India and their implication for sediment provenance Pratima M. Kessarkar a , V. Purnachandra Rao a;C3 , S.M. Ahmad b , G. Anil Babu b a National Institute of Oceanography, Dona Paula, Goa 403 004, India...

What makes a natural clay antibacterial?

Science.gov (United States)

Williams, Lynda B.; Metge, David W.; Eberl, Dennis D.; Harvey, Ronald W.; Turner, Amanda G.; Prapaipong, Panjai; Port-Peterson, Amisha T.

2011-01-01

Natural clays have been used in ancient and modern medicine, but the mechanism(s) that make certain clays lethal against bacterial pathogens has not been identified. We have compared the depositional environments, mineralogies, and chemistries of clays that exhibit antibacterial effects on a broad spectrum of human pathogens including antibiotic resistant strains. Natural antibacterial clays contain nanoscale (2+ solubility.

Viscosity and Plasticity of Latvian Illite Clays

OpenAIRE

Jurgelāne, I; Vecstaudža, J; Stepanova, V; Mālers, J; Bērziņa-Cimdiņa, L

2012-01-01

Due to viscosity and plasticity, clays and clay minerals are used in civil engineering, pottery and also in cosmetics and medicine as thickening agents and emulsion and suspension stabilizers. The rheological properties of clay suspensions are complex. Mostly it is an interaction between mineral composition, clay particle size and pH value and also depends on clay minerals. Clay-water suspension is non-Newtonian fluid showing thixotropic and pseudoplastic properties. Results showed that plast...

Investigationof Clay Mineralogy, Micromorphology and Evolution of Soils in Bajestan Playa

Directory of Open Access Journals (Sweden)

Mohammad Ghasemzadeh Ganjehie

2017-03-01

, pediment and clay flat. Considering the diversity of geomorphic units, 11 soil profiles were described and diffrenet soil layers and horizons were sampled. Undisturbed soil samples were taken micromorphological studies. Some horizons were selected for clay mineralogy analysis. The mineralogy of clay fraction was determined using X-ray diffraction method. Results and discution: All studied soils except the profiles in the pediment were classified in the Aridisols order. There were two geomorphic surfaces in alluvial fans. In the first geomorphic surface a soil with the Bk horizon buried a soil with red Btk horizon. In the second geomorphic surface, it seems that the erosion has been removed the overlying soil. The Bk horizon showed the maximum soil development in the clay flat and intermediate alluvial fan-clay flat landforms. Clay coating on sand in thin section was the evidence of clay illuviation in Btk horizon. Carbonate nodules associated with clay coating are the compound pedofeature in Btk horizon. These evidences reflect polygenetic nature of the soils and different period of climate change and soil formation. Smectite, mica, chlorite and palygorskite are the clay minerals in the studied soils. Similar to soils in arid regions of Iran, palygorskite was found in Bk, Bt and Bz horizons. The existence of Bk horizon in overlying soils, buried Btk horizon, removal of surface horizon in alluvial fan are the evidences of regressive and progressive of pedogenic processes in the study area. Btk horizon represents a warm and wetter and Bk horizon indicates a relatively wetter period in comparison to present time. Conclusion: Btk was the most developed horizon in the study area that occurred as buried paleosol in alluvial fan. Bk, Bw, By and Bz were the common horizon in other landforms. Clay coating and red color of Btk horizon might seem as indicators of hot and humid conditions in the past, during the argillic horizon formation. Covered carbonate nodules with clay coating

Mineralogical and technology characterization of raw materials of clay used for ceramic blocks fabrication

International Nuclear Information System (INIS)

Campos, N.Q.; Tapajos, N.S.

2012-01-01

In the state of Para, the red ceramic industry has several segments highly generators of jobs and a strong social appeal. With so many companies focused on this productive sector emerge, but many without any administration quality. Therefore, this study focused the technological and mineralogical characterization of the raw material used in the manufacture of ceramic blocks, by Ceramica Vermelha Company, located in the district of Inhangapi-PA. The raw material was obtained by the techniques of X-ray diffraction (XRD) to determine the present crystalline phases through an accurate and efficient procedure, where it was possible to identify the peaks relating to montmorillonite, illite and kaolinite clay in the sample, and kaolinite and quartz in the sample laterite. Another important result was the absorption of water, with average satisfactory according to the standards. According to a sieve analysis, the laterite the sand fraction showed a greater extent compared to the other, while the clay silt exceeding 80% was found to be too plastic material. The resistance to compression, the results were below the required by the standard, suggesting more accurate test methods. (author)

Coal 1992

Energy Technology Data Exchange (ETDEWEB)

1992-01-01

ACR's Coal 1992, the successor to the ACR Coal Marketing Manual, contains a comprehensive set of data on many aspects of the Australian coal industry for several years leading up to 1992. Tables and text give details of coal production and consumption in New South Wales, Queensland and other states. Statistics of the Australian export industry are complemented by those of South Africa, USA, New Zealand, Canada, Indonesia, China, Colombia, Poland and ex-USSR. Also listed are prices of Australian coking and non-coking coal, Australian coal stocks (and those of other major countries), loading port capacities, freight rates and coal quality requirements (analysis of coals by brand and supplier). A listing of Australian coal exporting companies is provided. A description of the spot Coal Screen Dealing System is given. World hard coal imports are listed by country and coal imports by major Asian countries tabulated. A forecast of demand by coal type and country up to the year 2000 is included.