Storage Piles Research Articles

Geomorphology of coal seam fires

Coal fires occur in underground natural coal seams, in exposed surface seams, and in coal storage or waste piles. The fires ignite through spontaneous combustion or natural or anthropogenic causes. They are reported from China, India, USA, South Africa, Australia, and Russia, as well as many other countries. Coal fires lead to loss of a valuable resource (coal), the emission of greenhouse-relevant and toxic gases, and vegetation deterioration. A dangerous aspect of the fires is the threat to local mines, industries, and settlements through the volume loss underground. Surface collapse in coal fire areas is common. Thus, coal fires are significantly affecting the evolution of the landscape. Based on more than a decade of experience with in situ mapping of coal fire areas worldwide, a general classification system for coal fires is presented. Furthermore, coal seam fire geomorphology is explained in detail. The major landforms associated with, and induced by, these fires are presented. The landforms include manifestations resulting from bedrock surface fracturing, such as fissures, cracks, funnels, vents, and sponges. Further manifestations resulting from surface bedrock subsidence include sinkholes, trenches, depressions, partial surface subsidence, large surface subsidence, and slides. Additional geomorphologic coal fire manifestations include exposed ash layers, pyrometamorphic rocks, and fumarolic minerals. The origin, evolution, and possible future development of these features are explained, and examples from in situ surveys, as well as from high-resolution satellite data analyses, are presented. The geomorphology of coal fires has not been presented in a systematic manner. Knowledge of coal fire geomorphology enables the detection of underground coal fires based on distinct surface manifestations. Furthermore, it allows judgments about the safety of coal fire-affected terrain. Additionally, geomorphologic features are indicators of the burning stage of fires. Finally, coal fire geomorphology helps to explain landscape features whose occurrence would otherwise not be understood. Although coal fire-induced thermal anomalies and gas release are also indications of coal fire activity, as addressed by many investigators, no assessment is complete without sound geomorphologic mapping of the fire-induced geomorphologic features.

Influence of Rhizoctonia-Bacterial Root Rot Complex in Storability of Sugarbeet

A Rhizoctonia-bacterial root rot complex can lead to yield loss in the field but rots also have the potential to cause sucrose loss in storage. Thus, studies were conducted to investigate if combining sugarbeet roots suffering from this complex with healthy roots would compromise the ability of the healthy roots to retain sucrose. Over a three year period, root samples from three commercial cultivars were compared in storage as a healthy (eight healthy roots) or mixed (eight healthy roots + one rotted root) treatment inside an outdoor storage pile. The experiment was arranged as a split block (healthy in one half of block and mixed in the other) with the whole blocks arranged in a ran domized complete block design with four replications. Treatments were sampled in December, January, and February and evaluated for discolored and frozen root area, weight loss, and sucrose reduction and recovery. When comparing the healthy to the mixed treatment over the nine year x sampling date combinations, the Wilcoxon signed-rank test indicated the median change for discoloration (7% increase), frozen area (14% increase), sucrose loss (5% loss), and recoverable sucrose (689 kg/ha less or 8% reduction) were signifi cantly different from zero ( P = 0.008, 0.031, 0.007, and 0.008, respectively). These data indicate that the Rhi zoctonia-bacterial root rot complex can negatively af fect neighboring healthy roots in storage leading to additional sucrose losses.

Characterization of PM10 source profiles for fugitive dust in Fushun-a city famous for coal

Abstract A total of 120 fugitive dust samples were collected to acquire chemical source profiles of PM 10 in Fushun including 27 soil dust samples, 32 road dust samples, 19 construction dust samples, 13 coal storage pile samples, 2 cement production samples, 13 coal-fired power plant fly ash samples, 5 fly ash samples from iron smelt plant and 9 samples from industrial raw material and production piles. The samples were classified as 20 subtypes. The dust samples were dried, sieved, resuspended and sampled through a PM 10 inlet onto filters, and then chemically analyzed. Inductively coupled plasma-atomic emission spectrometry, ion chromatograph and thermal/optical reflectance methods were adopted for analyzing twenty elements including Na, Mg, Al, Si, S, K, Ca, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Cd, Pb and Hg and nine ions including Na + , NH 4 + , K + , Mg 2+ , Ca 2+ , F − , Cl − , NO 3 − and SO 4 2− as well as OC and EC, respectively. The chemical compositions were compared for 20 subtypes. Si and Ca were the most abundant elements in all the fugitive dust profiles. Enrichment factors of elements in fly ashes compared to raw coal were calculated with Fe as reference element. The highest enriched elements were Ni, Cu, Zn and Pb. Significant difference existed among PM 10 profiles with the coefficient of divergence values ranging from 0.28 to 0.78. Profiles were compared with others. Si exhibited lower content in this study for soil and road dust while EC and Cr showed much higher content compared to others indicating the influence of coal mining and industries activities in Fushun. This was validated by source signatures analysis which indicated almost all the fugitive dust were relative to coal and may also be influenced by metallurgy. The ratios of Mn/V, V/Ni, Zn/Pb and Zn/Cd were calculated for source identification. Elemental ratios may vary widely even for the same source types with different processing courses. Chemical profiles of fugitive dust should be established based on characteristic sources for a specific region and updated timely.

Diffuse Emissions of Particles from Iron Ore Piles by Wind Erosion

Abstract Industrial air pollution from point and nonpoint sources of steel complexes has drawn increasingly more public attention in the past decades. Previous research efforts have been more concentrated on point sources of particulate emissions from these complexes. However, wind-induced particulate emissions from iron ore storage piles not only result in ambient air pollution but also increase economic adverse effects to the industry by loss of process raw materials. Experiments were conducted to assess the impact of wind speed and humidity on particulate emission rates from iron ore storage piles. A wind-generating system and specific iron ore, experimental piles (L:W:H of 30:11.5:5 cm) were constructed to evaluate emission rates at four different wind velocities (4.3, 5, 7, and 11 m s−1). Optical and electron microscopes were used for determining size distribution of particles at various distances from emission source. Moreover, the decrease in emission rate was evaluated by changing the percentage o...

Experimental and numerical study of fence effects on dust emission into atmosphere from open storage piles

The results obtained from the research on the behaviour of fences (solid and porous) in the protection against particulated material emission to the atmosphere from open storage piles, are presented. This research was carried out through computational fluid dynamics (CFD) simulation by software Ansys CFX-10.0 in 3D, with K-epsilon being considered in the turbulence model. The efficiency of the use of porous fences as a protection against the wind flow, which interacts with an open storage pile, is shown. The use of these fences (when porosity is ɛ=30%) allows the reduction of wind flow velocity which interacts with the pile in comparison with the case of no use of fences (when porosity is 100%). In addition, the use of porous fences makes the velocity vortex, which is formed between the solid fence (ɛ=0%) and the pile, disappear, reducing the particle emission to the atmosphere by 78%.

Research on Solar Energy Underground Seasonal Storage Device and Its Parameters Measuring System

In order to improve the availability of solar energy, this paper introduces a new solar energy storage device and its parameters automatic measuring system. The device puts the heat which was gathered by synchronous tracking solar collector into underground concrete storage pile. Meanwhile, the system could simultaneously measure the temperature, pressure and flow of the device, etc. Some derived parameters such as thermal energy storage and thermal storage effectiveness can be obtained by calculation. According to the experimental results, the device is able to store the solar energy for seasons in the underground, and automatic measuring system could display the parameters and real-time curves on monitor and draw the history curves of all parameters. The data base of parameters could be built during the energy storage process. Furthermore, the energy storage report can be generated to obtain an automatic and digital energy storage process.

Experimental Evaluation of Sugar Cane Bagasse Storage in Bales System

An experimental evaluation was carried out on three bagasse storage piles with the following characteristics: wet baled raw bagasse, wet baled depithed bagasse and pre-dried baled depithed bagasse. In each of these formerly mentioned alternatives, the storage time influence was analyzed on temperature profile, humidity behavior, granulometry and morphology, with and without mechanical treatment, solubility in hot water, NaOH and alcoholbenzene extractives. In the same way, the behavior of brightness in mechanical pulps produced from stored bagasse was studied. Storage losses were calculated for each alternative on the basis of obtained results and it wasdemonstrated that pre-dried bagasse as compared with wet bagasse storage, yields lower losses and better conservation of its characteristics.

Characterization of Brazilian oil shale byproducts planned for use as soil conditioners for food and agro-energy production

The Brazilian oil shale byproducts resulting from the Petrosix pyrolysis (retortage) process were submitted to a set of analytical techniques to evaluate their possible use as agricultural soil conditioners. Liquid dichloromethane extracts from the solid samples were analyzed using capillary column gas chromatography–mass spectrometry. The results showed that of the 16 PAHs designated by the U.S. EPA as priority pollutants, only phenanthrene, fluorene and naphthalene, present in the retorted oil shale sample taken from inside storage piles; benzo[k]fluoranthene, present in the dolomite limestone layer between the two layers of oil shale in the mine structure; and naphthalene, present in powdered raw oil shale, were above the limits established by the EPA. The solid Brazilian oil shale byproduct samples were also analyzed by X-ray diffractometry (XRD), diffuse reflectance ultraviolet–visible spectroscopy (DRUV–VIS), X-ray fluorescence spectroscopy (XRF) and electron paramagnetic resonance (EPR) spectroscopy. The XRD analysis showed that the pyrolysis process produces a “weathering” transformation, for example with the appearance of kaolinite diffraction lines in the retorted samples. The DRUV–VIS and XRF spectroscopy results indicated iron oxide goethite interactions with the PAHs present in the solid samples studied. The EPR spectroscopy showed that the samples row oil shale (g=2.0044) and the powder oil shale (g=2.0035), before the dichloromethane extraction, presented organic free radical signals associated with oxygen atoms. The other Brazilian oil shale byproduct samples, before and after the dichloromethane extraction, showed organic free radical signals associated with carbon atoms (g=2.0022–2.0031).

Numerical and wind tunnel modeling on the windbreak effectiveness to control the aeolian erosion of conical stockpiles

There are many industrial sites where open aggregate conical piles exist to store granular materials, like coal, industrial residuals, or other minerals. Usually these storage piles are placed in open areas, making them susceptible to wind erosion, which can create health, environmental, and/or economical concerns. It is common to minimize the dust emission through the placement of windbreaks in the vicinity of the storage piles, which reduces the wind speed in the vicinity of the pile’s surface. In this work, some experimental results from a wind tunnel study on the erosion of a conical sand pile, exposed or protected by a fence with porosities of 0, 70, and 83%, are shown. For the sheltered cases, the windbreak was placed at several distances from the pile’s leading edge, ranging from H to 4H, where H is the initial height of the non-eroded pile. The evolution of the shape of the sand pile is shown, at different instances in time, and the pile deformation quantified, using a novel experimental setup developed for wind erosion studies. This information might be regarded as a useful dataset for the benchmark of computational models aiming to produce the transient simulation of the aeolian erosion of stockpiles. The CFD results are comprised of the modeling of several experimental scenarios. The computational results for the surface wind velocity show a good correlation with the initial deformation of the pile. Based on the results, the isocontours of (u s /u r ) presented might be regarded as a good basis for the estimation of the pile shear velocity.

Development and Testing of a Solar Greenhouse, with a Transparent-Heat-Insulating Collector Layer, and a Rock Pile Storage Unit

Development and Testing of a Solar Greenhouse, with a Transparent-Heat-Insulating Collector Layer, and a Rock Pile Storage Unit

Sugarbeet Cultivar Evaluation for Bacterial Root Rot

Bacterial root rot of sugarbeet (Beta vulgaris) caused by Leuconostoc mesenteroides subsp. dextranicum is a disease problem recently described in the Intermountain West region of the United States. To ameliorate the impact of bacterial root rot on sucrose loss in the field, storage piles, and factories, studies were conducted to establish an assay for identifying host resistance. In 2006 and 2007, 21 commercial cultivars were evaluated in a petri dish laboratory assay. Root slices were inoculated with L. mesenteroides and the diameter of the rotted area was measured after 72 and 96 h. The cultivars were arranged in a randomized complete block design with 4 replications. With 2006 roots after 96 h, the average rot diameter ranged from 16 to 34 mm (LSD = 5) depending on cultivar. With 2007 roots after 96 h, the average rot diameter ranged from 10 to 48 mm (LSD = 7) depending on cultivar. The cultivar ranking between years was correlated at 72 (r = 0.47, P = 0.03) and 96 (r = 0.43, P = 0.05) h. The assay allowed for reliable cultivar separation regardless of whether one, two, three, or four roots were used per replication. The laboratory assay has the potential to allow host resistance to bacterial root rot caused by L. mesenteroides to be improved in sugarbeet.

Dehydration accelerates respiration in postharvest sugarbeet roots

Sugarbeet ( Beta vulgaris L.) roots lose water during storage and often become severely dehydrated after prolonged storage and at the outer regions of storage piles which have greater wind and sun exposure. Sucrose loss is known to be elevated in dehydrated roots, although the metabolic processes responsible for this loss are unknown. To identify processes that contribute to sucrose loss in dehydrated roots, respiration rate, cellular electrolyte leakage, and sucrolytic enzyme activities were determined in roots of two varieties (VDH 66156 and Beta 4797R) during 4 weeks of 10 °C storage at high (85%) and low (40%) relative humidities. Roots stored at 40% relative humidity dehydrated significantly and lost almost 50% of their weight after 4 weeks of storage. Electrolyte leakage increased in these roots, indicating that dehydration damaged cellular membranes. Respiration rate generally increased in roots stored at 40% relative humidity compared to roots stored at 85% relative humidity. The increase in respiration rate was positively correlated with root weight loss and electrolyte leakage. Respiration rate was most closely associated with electrolyte leakage, however, suggesting that elevations in respiration rate were not due to dehydration, but to the membrane damage that occurred in response to dehydration. Activities of the sucrose-degrading enzymes, sucrose synthase, alkaline invertase and soluble acid invertase, were unaltered by dehydration. Alterations in sucrolytic enzyme activities, therefore, were not needed to provide for the increased demand for respiratory substrates in dehydrated roots. These results suggest that storage at low relative humidity alters the postharvest physiology of sugarbeet roots by increasing the rate of weight loss, reducing membrane integrity, and accelerating root respiration rate.

Dust emission calculations in open storage piles protected by means of barriers, CFD and experimental tests

The importance of open mineral storage piles in bulk solids port terminals have increased considerably in recent years in Europe and USA (in Spain, great extensions of transoceanic ports are being made) to address the increasing demand of raw material importation due to local mining operation closure. These storage piles are affected by the climatologically processes and the dust emission to the atmosphere, causing repercussions to health and environmental, which is intimately related to the air velocity, according to USEPA studies, maximum ratio of dust emission emitted from CFD and software Ansys CFX 10.0 is determined. In addition, an emission variability study based on the pile distance of different height solid barriers is developed, reducing the emission to 66%. The studies have been contrasted by published investigations and industrial measurement.

Multiscale spatial variation of the bark beetle Ips sexdentatus damage in a pine plantation forest (Landes de Gascogne, Southwestern France)

Bark beetles are notorious pests of natural and planted forests causing extensive damage. These insects depend on dead or weakened trees but can switch to healthy trees during an outbreak as mass-attacks allow the beetle to overwhelm tree defences. Climatic events like windstorms are known to favour bark beetle outbreaks because they create a large number of breeding sites, i.e., weakened trees and for this reason, windthrown timber is generally preventively harvested and removed. In December 1999, the southwest of France was struck by a devastating windstorm that felled more that 27 million m 3of timber. This event offered the opportunity to study large-scale spatial pattern of trees attacked by the bark beetle Ips sexdentatus and its relationship with the spatial location of pine logs that were temporally stored in piles along stand edges during the post-storm process of fallen tree removal. The study was undertaken in a pure maritime pine forest of 1300 ha in 2001 and 2002. We developed a landscape approach based on a GIS and a complete inventory of attacked trees. During this study more than 70% of the investigated stands had at least one tree attacked by I. sexdentatus. Spatial aggregation prevailed in stands with n ≥ 15 attacked trees. Patches of attacked trees were identified using a kernel estimation procedure coupled with randomization tests. Attacked trees formed patches of 500–700 m 2 on average which displayed a clumped spatial distribution. Log piles stemming from the sanitation removals were mainly distributed along the large access roads and showed an aggregated spatial pattern as well. The spatial relationship between patches of attacked trees and log pile storage areas was analyzed by means of the Ripley’s statistic that revealed a strong association at the scale of the studied forest. Our results indicated that bark beetle attacks were facilitated in the vicinity of areas where pine logs were stored. The spatial extent of this relationship was >1000 m. Similar results were obtained in 2001 and 2002 despite differences in the number and spatial distribution of attacked trees. The presence of a strong “facilitation effect” suggests that log piles should be removed quickly in order to prevent outbreaks of bark beetles.

Effects of Aphanomyces Root Rot on Carbohydrate Impurities and Sucrose Extractability in Postharvest Sugar Beet.

Sugar beet (Beta vulgaris) roots with rot caused by Aphanomyces cochlioides often are incorporated into storage piles even though effects of disease on processing properties are unknown. Roots with Aphanomyces root rot were harvested from six fields over 2 years. For each field, roots with similar disease symptoms were combined and assigned a root rot index (RRI) value (0 to 100; 0, no rot symptoms; 100, all roots severely rotted). After 20 or 120 days storage at 4°C and 95% relative humidity, concentrations of the major carbohydrate impurities that accumulate during storage and sucrose extractability were determined. Root rot affected carbohydrate impurity concentrations and sucrose extractability in direct relation to disease severity symptoms. Generally, roots with active and severe infection (RRI ≥ 85) exhibited elevated glucose and fructose concentrations 20 and 120 days after harvest (DAH), elevated raffinose concentration 120 DAH, and reduced sucrose extractability 20 and 120 DAH. Roots with minor or moderate disease symptoms (RRI 20 to 69), or damaged roots with no signs of active infection, had similar carbohydrate impurity concentrations and sucrose extractability after 20 and 120 days storage. Processing properties declined when RRIs exceeded 43, as determined by regression analysis, or when storage duration increased from 20 to 120 days. Results indicate that both disease severity and anticipated duration of storage be considered before Aphanomyces-infected roots are incorporated into storage piles.

Simultaneous CFD evaluation of wind flow and dust emission in open storage piles

Dust emission from storage yards is a multivariable problem to be solved not only at any new installation in order to obtain the licenses from the involved authorities but also at existing yards to continue the operation. Engineers have a great variety of methodologies available at the market to estimate such emissions, but in general the process is divided into two independent stages: wind flow analysis and application of emission rates into such wind pattern. This paper summarizes the research developed by this group to link both steps: by using CFX version 10.0, a powerful computational fluid dynamics (CFD) software, the wind flow around the piles is predicted, or even through a complex yard, and at the same time by implementing new subroutines introduced into the standard software, the program is able to give a quantitative evaluation of the total fugitive dust.

Design of Temperature Monitor Device for DC Source Based on 1-Wire Bus

The structure of X6000 DC source system is introduced. A temperature monitor device for its storage pile based on 1-wire bus is designed. Its central processing unit is single chip microcomputer 80296SA in the monitor unit of this DC source. The DS1822 chip, a kind of digital thermometer chip based on 1-wire bus, is used to measure the temperature of the X6000 DC source system storage pile. The hardware, interface and software are designed and the condition description of the interface routine and realization are given. The system possesses of many advantages, including its novel structure, simple circuit and expedient control.

Partial unmixing as a tool for single surface class detection and time series analysis

In this paper we present the results of time series analysis for a coal mining region based on partial unmixing. We test the method also known as mixture tuned matched filtering on an eight image Landsat 5 TM and Landsat 7 ETM+ time series covering the period from 1987 to 2003. Common change detection methods often include the comparison of two interactively generated classification results, such as derived from Maximum Likelihood classification. These approaches often yield highly accurate results. However, disadvantages include a strong analyst bias and hardly repeatable results. For a quantitative monitoring of a single surface class' development over time they are often not recommendable. Our goal was to test an unbiased quantitative way to assess the development of coal surfaces, such as outcropping coal seams, coal storage piles, coal waste piles, and coal washery discard, within multiple date satellite imagery. Partial unmixing approaches were developed to detect one or few target materials surrounded by—or mixed with—an unknown background material. The main advantage is that only the spectral characteristics of the material of interest must be known, and the desired material can furthermore occur with subpixel coverage. Crisp pixel classificators like maximum likelihood on the other hand require knowledge of all classes. They can only map materials which dominate a pixel. Linear unmixing procedures such as partial unmixing require a thorough radiometric pre‐processing of data. Furthermore, the accuracy and representativity of selected input spectra must be granted. In this paper we demonstrate that partial unmixing is a powerful method to detect and extract single landcover classes of interest relatively fast and unbiased. The subpixel fraction percentages should be interpreted in a relative way only. We furthermore show that partial unmixing represents a standardized method for time series analyses and allows for a quantitative assessment of the temporal development of an area. Challenges lie in the validation of partial unmixing results, which we realized through thresholding of unmixing results and accuracy assessment with ground truth polygons mapped in situ. Furthermore, we performed an indirect comparison with results of a multi‐endmember unmixing.

Características nutritivas de los hollejos húmedos de naranja (Citrus sinensis cv. Valencia) mantenidos en estibas

Proximate analysis and chemical characterization were done of humid orange peel (Citrus sinensis cv. Valencia) by-product immediately after industrial processing and during storage in piles for 12 d. Samples of the stored peel were taken on d 1, 4, 6, 8, 10 and 12 of storage from three layers within the piles: 5-15 cm, 15-30 cm and >30 cm. Results were analyzed with a completely randomized design, using a 3 x 6 factorial arrangement for temperature, pH and dry matter, and a 3 x 2 factorial for crude protein, calcium, phosphorus and ash. Analyzed factors were layer of pile, and sampling day. Interaction was found (P<0.01) between layer and day for dry matter, pH and temperature. The 30+ cm layer had the lowest dry matter values. Temperature was highest in the 5-15 cm layer, indicating fermentation to be most active in this layer. Values for pH initially decreased in the stratum 15-30 cm and 30+ cm layers, and then remained below 3.5. Overall, pH did not surpass 3.73. There was interaction (P<0.01) between layer and day for calcium and ash content, the latter indicating mineral loss over time. No interaction existed for crude protein and phosphorus, meaning there were no differences within layer and day. Humid orange peel by-product stored in piles did not exhibit variations in proximate composition or chemical composition that could affect it use as a livestock feed.

Potential for localized groundwater contamination in a porous pavement parking lot setting in Rhode Island

The control of polluted surface runoff and the assessment of possible impacts on groundwater is a concern at the local and regional scale. On this background, a study investigates possible impacts of organic and inorganic pollutants (including bacteria) originating from a permeable asphalt parking lot on the water quality immediately beneath it. The functioning of the permeable pavement, including clogging and restricted vertical percolation, was also evaluated. Four nested sample ports (shallow and deep) were installed below low- and high-traffic areas, including one port outside the parking lot. At least initially there was a good hydraulic connection between the parking surface and the shallow sample ports. The presence of a geotextile layer at the base of the parking lot structure, however, was identified in lab tests as one factor restricting vertical percolation to the deeper ports. Clogging of the permeable surface was most pronounced in heavy traffic areas and below snow pile storage areas. Corroborated by high electric conductivity and chloride measurements, sand brought in by cars during winter was the principal cause for clogging. No bacteria or BOD were found in percolating water. Polycyclic aromatic hydrocarbons (PAH) were present at concentrations near minimum detection limit. Nutrients (nitrate and phosphate) were being leached into the ground via the permeable parking lot surface at annual flux rates of 0.45–0.84 g/m2/year. A multi-species tracer test demonstrated a retention capacity of the permeable parking lot structure of >90% for metals and 27% for nutrients, respectively.