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Coal is a vital basic energy source in China, and rail serving is its major mode of transportation. Heavy metals in street dust surrounding the coal railway do harm to the environment and pose a potential risk to human health. This paper aims to identify the effects of coal transportation hubs on heavy metals in street dust. The geoaccumulation index and ecological risk index were used to assess the contamination levels of the following elements in Yuanping, Shanxi: arsenic (As), cadmium (Cd), chromium (Cr), copper (Cu), mercury (Hg), nickel (Ni), lead (Pb), and zinc (Zn). The levels of contamination of these heavy metals in soils were compared to those in street dust, and the difference between the railway's and mining's impacts on dust's heavy-metal concentrations was explored. The results indicated that Cr and Pb in street dust were mainly affected by coal railway transportation, and the interaction effect of coal railway transportation and mining was greater than either of them alone. A potential control and prevention zone for Cr and Pb extending 1 km to both sides of the railway was identified. This work proves that coal railway transportation has certain effect on heavy metals in street dust and provides a scientific approach for future environmental impact assessments of coal transportation via railway.

Aiming at the problem of safe mining of coal seam under the condition of hard roof, taking Xiagou coal mine as the background, the expression of coal seam supporting force in isolated island working face mining is derived through the analysis of the "umbrella arch" overlying rock structure mechanism in isolated island working face mining. Combined with the mine geological conditions, it is concluded that the supporting force near the inclined gob of ZF2822 isolated island working face is more than 1.26 times that near the strike gob. Based on the numerical simulation analysis, it is known that the stress and elastic energy of the working face near the inclined gob are obviously greater than that towards the gob, and the peak stress on the side of the transport gateway after the first square and the second square is 1.41 times and 1.55 times that of the return air gateway, respectively. Strata discrimination determines that the key stratum is medium-grained sandstone 22.32 m above the coal seam. The reasonable blasting pressure relief angle is determined according to the field situation. Pressure relief control makes the "high energy-high frequency" feature of mining face change into "low energy-low frequency". After pressure relief, the daily average microseismic energy of working face mining is reduced to below 104 J, which is 27.77% and 39.74% lower than that in March and April before pressure relief. The changes of width and height of transport gateway after pressure relief are 22.73% and 24.75% of those before pressure relief, respectively. The research results provide a scientific basis for the safe mining of isolated island working face under the condition of hard roof. Highlights: The "umbrella arch" overlying strata structure of isolated island working face mining is put forward, and the expression of supporting force of working face mining is deduced. The corresponding relationship between the side close to the gob and the side close to the gob in the isolated island working face is mastered theoretically. The variation law of peak value difference of elastic energy of solid coal side in transportation gateway and return gateway of irregular island mining face is mastered. The asymmetric pressure relief control strategy of roadway surrounding rock in isolated island working face mining is formed. [ABSTRACT FROM AUTHOR]

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The layout of methane sensors in the working face cannot meet the needs for monitoring methane concentrations within confined spaces, and it is challenging to determine the precise locations for manual inspections. Therefore, the working face is firstly divided into different areas and grids. Then combined with the characteristics of methane emissions and the measured data on site, the boundary conditions of simulation experiments are set up and the research is carried out on the diffusion law of methane in the confined space of the working face under different conditions. The experimental results show that methane emission intensity from coal walls affects its distribution. As emission intensity rises, methane nearer the coal wall decreases, while methane further away increases. Among coal mining points, point 2 shows the widest methane diffusion range. Rising wind speeds decrease methane diffusion from the coal wall, increasing vertical diffusion distance. Methane from the coal wall shifts to the air inlet, while methane from the mining point diffuses increasingly to the downwind side. The location of the maximum methane concentration generated from falling coal and its transportation process is only related to the location of the coal mining point. The key areas for methane monitoring in confined spaces of the working face should be the overlapping locations of the vertical‐3 and vertical‐4 areas and the horizontal‐1 and horizontal‐3 areas. The key areas for manual inspection should be the overlapping locations of the vertical‐2 and vertical‐3 areas and the horizontal‐1 area. [ABSTRACT FROM AUTHOR]

Copyright of China Mining Magazine is the property of China Mining Magazine Co., Ltd. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In the face of the increasing complexity of risk factors in the coal mining transportation system (CMTS) during the process of intelligent transformation, this study proposes a method for analyzing accidents in CMTS based on fault tree analysis (FTA) combined with Bayesian networks (BN) and preliminary hazard analysis (PHA). Firstly, the fault tree model of CMTS was transformed into a risk Bayesian network, and the inference results of the fault tree and Bayesian network were integrated to identify the key risk factors in the transportation system. Subsequently, based on the preliminary hazard analysis of these key risk factors, corresponding rectification measures and a risk control system construction plan are proposed. Finally, a case study was carried out on the X coal mine as a pilot mine to verify the feasibility of the method. The application of this method effectively identifies and evaluates potential risk factors in CMTS, providing a scientific basis for accident prevention. This research holds significant importance for the safety management and decision making of coal mine enterprises during the process of intelligent transformation and is expected to provide strong support for enhancing the safety and reliability of CMTS. [ABSTRACT FROM AUTHOR]

Copyright of Clean Coal Technology is the property of Clean Coal Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

As one of the most important coal-producing provinces of China, Shanxi Province has been concerned about soil potentially toxic elements (PTEs) contamination in recent years. The study aimed to determine the status and sources of PTEs contamination and evaluate the quality of the soil ecology. This study investigated the degree of 13 PTEs contamination. The sources and contributions of PTEs were traced by the absolute principal component score followed by a multiple linear regression model (APCS–MLR). And the status of the soil ecosystem was verified by evaluating the soil nematode community around the coal mining areas in Jinzhong. The results showed that the mean PTEs concentration of 5 trace elements were higher than the background values of Shanxi, and safe to considerable was indicated by the pollution and ecological risk values. Soil Hg was the most contaminated element, followed by Cd. The distribution of PTEs was determined by coal mining activities (44.72%) followed by agricultural practice (32.37%) and coal transportation (21.37%). The nematode genera Acrobeloides (4.01%), Aphelenchus (20.30%), Meloidogyne (11.95%) and Aporcelaimus (2.74%) could be regarded as bioindicators of soil PTEs contamination by their tolerance. Concentrations of soil Cr, Mn, Ti and Cd showed remarkable influences on the total nematode abundance, maturity index, enrichment index, structural index, Shannon–Wiener diversity index and Pielou index of soil nematode. It is an appropriate method to evaluate the status of soil PTEs contamination combining the response of a single nematode genus and the nematode community evaluation index. [ABSTRACT FROM AUTHOR]

Copyright of Machine Tool & Hydraulics is the property of Guangzhou Mechanical Engineering Research Institute (GMERI) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This study clarifies the formation mechanism of attentional bias toward safety (ABS) of coal mine transportation drivers to reduce related accidents. It proposes a theoretical model of the formation mechanism of ABS based on the Stressor-Emotion Model and the following trait theory. We collected 360 questionnaires on Chinese coal transport drivers using multi-point data to explore the psychological cognitive mechanism and boundary conditions of role stress and abusive supervision affecting coal transport drivers' ABS, and found them to have a significant negative impact on their ABS. Both factors affect ABS through the mediating effect of emotional exhaustion. Additionally, positive followership trait regulates the positive effects of role stress and abusive supervision, and the mediating effect of emotional exhaustion. [ABSTRACT FROM AUTHOR]

Copyright of Coal Science & Technology (0253-2336) is the property of Coal Science & Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The analysis of the particle size of suspended solids in snow samples from various areas near the coal-mining enterprise “Razrez Arshanovsky” LLC in the Republic of Khakassia. Snow sampling sites of the snow cover were located in the area of the road along which coal is transported, and at a distance of 0,5 km from the village of Arshanovo in accordance with the wind rose. Particle size analysis was performed using a LaskaTD device. It was found that in the samples under study, the main proportion of suspended particles, regardless of the point of study, had sizes from 5 to 20 microns, which numerically amounted from 63.8 to 81,3 % of the total weight of suspended substances. The site located in the western direction at a distance of 0,5 km from the Arshanovo had such low values of suspended solids that it was not possible to determine them using the Laska-TD device. The average particle size, depending on the point of study, had the following values (μm): № 1 - 11,2 ± 0,4; № 2 - 11 ± 1,6; № 3 - 9,3 ± 0,2; № 4 - 7,3 ± 0,9; № 5 - 13,5 ± 0,3; № 6 - 11,5 ± 0,2; № 8 - 11,6 ± 0,3. The obtained results of the study allow to conclude that there is a large amount of fine dust in the snow cover, which can accumulate in the environment and negatively affect its biological component, including humans.

WC55-Y hydraulic support transporters allow an efficient transport of support equipment in fully mechanized mining faces. However, the diesel particulate matter (DPM) emitted by these transporters seriously pollutes the air environment along mine roadways, endangering the health of coal mine workers. In this paper, we simulated the diffusion dispersion of DPM during the functioning of a WC55-Y hydraulic support transporter (emitting high amounts of exhaust pollutants) by computational fluid dynamics, identifying high DPM concentration zones. While the transporter was driven along a coal auxiliary transportation roadway, the diffusion–dispersion characteristics of DPM changed: DPM reached a long horizontal diffusion distance and a high concentration. We found that to avoid the inhalation of DPM and reduce its potential harm, coal mine workers should keep a distance of at least 21.27 m from the hydraulic support transporter while the vehicle runs along the roadway. Moreover, according to our simulation, the operators responsible for disassembling the hydraulic support transporter should wear protective equipment with good filterability while unloading it. Overall, the findings of this study can be applied to outline new work practice guidelines and design new optimum auxiliary ventilation for reducing underground miner exposure to DPM. [ABSTRACT FROM AUTHOR]

Unmanned driving technology has always been one focus of mine smart transportation, which is a crucial component of smart mines. However, the descriptions of both the intelligent transportation system and its industrial application are not comprehensive. In order to have an all-encompassing and comprehensive understanding of both the intelligent coal mine transportation system and its industrial application with the intelligent system, this paper summarizes and analyzes the current research status of unmanned driving technology in mines and the industrial application of current mining transportation vehicles. It begins by outlining the current research state of unmanned driving technology in mines and then assesses the advancement of unmanned driving technology. The unmanned transportation system in mines is also introduced, together with its components for perception, location, path planning, vehicle control, and multi-vehicle scheduling. In addition, each component is described in combination with the current artificial intelligent unmanned technology individually. Then, some typical categories of intelligent industrial vehicles are introduced for learning about the conditions of their actual application. There are almost four hundred coal mines that have researched unmanned driving technology, and some companies have applied the unmanned technology to realize transportation with an efficiency enhancement of 70~80%. Finally, currently existing challenges and future research are analyzed and proposed. This review may provide more comprehensive knowledge of the intelligent coal mine, accelerating the development of intelligent technology and helping to build a new management and control model. [ABSTRACT FROM AUTHOR]

Several performance metrics to measure the effectiveness of manufacturing equipment have been studied, and one of the most used is overall equipment effectiveness (OEE). However, its application and development in the road transportation sector remains little studied. The purpose of this paper is to establish a new metric derived from OEE to measure the overall effectiveness of coal mining transportation and apply this metric to actual operation. This study employed in-depth interviews and Delphi techniques to explore the specific metrics. Three rounds of Delphi involving mining experts, academia, and consultants identified six potential metrics to measure coal mining transportation operations that contributed to a new metric to measure mining transportation overall vehicle effectiveness. This paper also discusses a case study of how this newly developed metric was tested and applied to the actual operation of the truck fleet at a coal-hauling company in Indonesia. According to the case study, this metric accommodated the important factors in coal mining transportation operations and reflected operational performance. This study contributes to measuring the effectiveness of coal-hauling transportation by providing an effective metric that will help the managerial team make better decisions for process improvement. [ABSTRACT FROM AUTHOR]

This paper applies the CenterNet target detection algorithm to the foreign object detection of coal conveying belts in coal mines. Given the fast running speed of coal conveying belts and the influence of background and light sources on the objects to be inspected, an improved algorithm of CenterNet is proposed. First, the depth separable volume is introduced. The product replaces the standard convolution, which improves the detection efficiency. At the same time, the normalization method is optimized to reduce the consumption of computer memory. Finally, the weighted feature fusion method is added so that the features of each layer are fully utilized, and the detection accuracy is improved. The experimental results show that the improved algorithm has improved speed and accuracy compared with the original CenterNet algorithm. The foreign object detection algorithm proposed in this paper mainly detects coal gangue and can also detect iron tools such as bolts, drill bits, and channel steel. In the experimental environment, the average detection rate is about 20fps, which can meet the needs of real-time detection. [ABSTRACT FROM AUTHOR]

With the increase in the production scale of open-pit coal mines, the safety management, economic benefits, and sustainable development of open-pit coal mines are constantly being challenged. A new optimization method for the internal circulation transportation was proposed to improve the transportation benefit of the open-pit coal mine and reveal its temporal and spatial evolution laws in such a mine. The applicable conditions of the proposed transportation were described. The applicable conditions of the two internal circulation transportations, single and double bridges, were also compared and analyzed. The adaptability, key parameters, and space-time benefits of the introduced method were verified through the Hongshaquan opencast coal mine. Results show that the saving cost of internal circulation transportations increases as the working line length L rises. Critical internal circulation length L1 and critical doublebridge length L2 are also observed. The proposed transportation can be constructed when L is larger than L1, and the transportation scheme with double bridges can be profitable when L is larger than L2. The Hongshaquan opencast coal mine has the following conditions for building internal circulation transportation: the critical internal transportation length L1 = 430.8 m and the critical double-bridge length L1 = 515 m. This study can provide a reference for the open-pit coal mine transportation system and improve the benefits of the transportation system. [ABSTRACT FROM AUTHOR]

In the process of coal mining and transportation, it is inevitable to produce a large number of coal powder, which has many adverse effects, causing pneumoconiosis and even explosion, bringing huge hidden dangers to the safety of people's lives and property. In order to reduce the occurrence of this kind of engineering disaster, surfactant is often used for wetting and dust reduction. In this study, the coal powder of the left 2 working face at No.65 layer in Xinxing Coal Mine is taken as the object, and four kinds of surfactants are used to study the osmotic effect. The comparative analysis is carried out from the penetration forms, the change of contact angle, and the unit cost. The method of selecting reagents under different engineering conditions and requirements is obtained, which provides an effective way for reduction of coal powder in coal mine, and has a certain reference value. [ABSTRACT FROM AUTHOR]

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Copyright of Coal Science & Technology (0253-2336) is the property of Coal Science & Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Coal Science & Technology (0253-2336) is the property of Coal Science & Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

To reduce gas disasters in low permeability and high gas coal seams and improve gas predrainage efficiency, conventional deep hole presplitting blasting permeability increasing technology was refined and perfected. The damage degree of coal and rock blasting was quantitatively evaluated by using the value range of the damage variable D. According to the actual field test parameters of coal seam #3 in the Sanyuan coal mine, Dlim = 0.81 ~ 1.0 was the coal rock crushing area, Dlim = 0.19 ~ 0.81 was the coal rock crack area, and Dlim = 0 ~ 0.19 was the coal rock disturbance area. The blasting models under different blasting parameters were established by ANSYS/LS-DYNA software. The influence radius of single-hole blasting was 3.1 m, the hole diameter of double-hole blasting was 113 mm, the hole spacing was 5.5 m, and the delayed blasting time was 25 ms. According to the numerical simulation results, the determined parameters were tested on the working face of the 1312 transportation roadway in coal seam #3 of the Sanyuan coal mine. The results show that after blasting, the permeability of the original coal seam was increased by more than 30 times, the gas concentration was increased by 2.16 times, and the single hole purity and mixing volume were increased by 4.73 and 4.27 times, respectively. The positive effects of deep hole presplitting blasting permeability enhancement technology on the pressure relief and permeability enhancement of a low pressure and high gas coal seam were determined. [ABSTRACT FROM AUTHOR]

The scraper conveyor is the key coal transportation equipment on the coal mining face. The conveyor often encounters the influence of abnormal working conditions, such as stuck chains, broken chains, and impact loads, which have a great effect on the smooth operation of the scraper chain and seriously affect the safety of coal production. If the chain breaks during the test, the broken link may fly out and hurt the tester. The test risk of the scraper conveyor under abnormal working conditions is relatively large; hence, the test research is impossible to carry out. The combination of experiment and simulation is used to carry out the research. The dynamic characteristic test bed of the chain drive system is created to collect the speed of the sprocket and the acceleration of the scraper. The two groups of data are obtained by simulation, and the accuracy of the simulation is verified by comparing the test data with the simulation data. The dynamic characteristics of the chain drive system under abnormal working conditions are analyzed by simulation. Results show that the longitudinal velocity of the link dramatically changes, the contact force increases by 5.4 times, and the link vibrates under impact loads. When the chain is stuck, the speed of the running direction suddenly changes, and the chainring vibrates. The contact force between the chainrings increases by 7.2 times compared with the smooth operation. When the chain is broken, the acceleration in the running direction of the link dramatically changes. This study provides a basis and reference for the further optimization design of the chain drive system and detection of the abnormal working conditions. [ABSTRACT FROM AUTHOR]

We consider an integrated planning and scheduling problem motivated by the coal supply chains in Australia. The problem considers production planning of several independent mines. The mines need trains to complete delivery of coal by the arrival of ships at the terminal. The trains, on the other hand, are in limited supply and therefore the mines need to share this common resource. For this problem, we present a mixed integer programming formulation which minimises total weighted earliness, tardiness and operational costs. We also present a distributed algorithm based on the Lagrangian relaxation, which incorporates the volume and Wedelin algorithms. The strength of our distributed algorithm is demonstrated by an extensive computational experiment on several randomly generated instances. [ABSTRACT FROM PUBLISHER]

According to the failure law of the 1070 main roadway, this paper proposes a reasonable position for large section roadways under small coal mines and a design for seven roadway positions. RS2 software was used to establish a numerical model to select a reasonable position for the roadway. The influences of roadway positions on roof separation amount, roof subsidence, lateral displacement on the ribs, vertical stress on ribs and roadway failure areas were revealed. On the basis of influence laws, reasonable positions for the roadway could be determined. In this study, a center distance of 5 m was deemed a reasonable position. Finally, an industrial test was conducted at the original roadway. The experimental results indicate that the deformation of the roadway could be well controlled and the roadway position is reasonable. [ABSTRACT FROM AUTHOR]

Copyright of Coal Science & Technology (0253-2336) is the property of Coal Science & Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Coal Science & Technology (0253-2336) is the property of Coal Science & Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Through in-situ stress measurements, stress data were obtained from an auxiliary transportation roadway in a coal mine in Shanxi Province, China. Based on the principles of elastic mechanics and using a generalized plane strain model, the mechanical effects of the in-situ stresses on an idealized roadway were calculated and the distributions of stresses, displacements, and plastic zones determined. Building on this model, the vulnerable zones in the roadway cross section were identified. Ground support specifications were developed and during specification design, comprehensive consideration was given to factors affecting the stability of the rock surrounding the roadway. A scientific and reasonable support scheme was put forward. Practical experience in the coal mine shows the normal forces of anchor bolt and cable, the minimal convergence of roof to floor, and a generally good support in the auxiliary transportation roadway. The support should ensure safe production during its service life. This study provides a new method for designing roadway support systems that can be particularly valuable for high-stress roadways. [ABSTRACT FROM AUTHOR]

Copyright of Coal Science & Technology (0253-2336) is the property of Coal Science & Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The flowchart of multispectral visual detection method • Image acquisition sensor captures visible, mid-infrared and far infrared images. • Dual-thread image processing is adopted for the double fused images. • The method can identify longitudinal tear and other states of the conveyor belt. As an important part of modern coal mine production, conveyor belts are widely used in the coal collection and transportation. In order to ensure the safe operation of the coal mine conveyor belt and solve the drawbacks of the existing conveyor belt longitudinal tear detection technology, a multispectral visual detection method for conveyor belt longitudinal tear is proposed in this paper. The experimental results show that the multispectral visual detection method not only can identify the conveyor belt longitudinal tear, but also accurately classifies and identify other states of the conveyor belt. The accuracy of multispectral visual detection method is over 90.06%, and the precision of longitudinal tearing recognition is over 92.04%. The proposed method is verified to meet the requirements of reliability and real-time in the industrial field. [ABSTRACT FROM AUTHOR]

Abstract Belt conveying is largely used in the area of coal mining in the surface and underground mining operations. It is primarily applied for transporting of extracted coal from the mining site for further processing. Effectiveness of the coal extraction process depends on high reliability and durability of the conveyor belts. In addition to the technology itself, the material composition of the conveyor belts has a significant impact on ensuring of the above-mentioned requirements. Material properties of the conveyor belts markedly impact their operational properties. In their design stage, the desired conveyor belt properties must be carefully considered. This paper is focused on the effect of several properties of conveyor belts from the aspect of tension-deformation relations. Tensional deformations occurred in conveyor belts are significantly affecting their operation. They affect the extent of dynamic resistance and the conveyor belt's lifetime. More detailed research and analysis, which saves experimental measurements, is also possible by means of the FEM-based simulation tools. The presented research work proved a direct dependence among the modulus of elasticity values and the contact press values, whereby there was applied the elasticity modulus range from 382 MPa to 427 MPa and the consequential differences of the contact press values were identified in the range from 3.95 MPa to 4.399 MPa. These obtained results are significant with regard to failures of the conveyor belt. Highlights • Dependence of the stretch of transport belt with different mass density on the width of transport belt. • Dependence of the stretch of each types of transport belt by changes of Young's modulus. • Dependence of contact forces by changes of Young's modulus in the transverse direction on the width of transport belt. • Dependence of the contact forces of several types of transport belts by the changes of the Young's modulus. [ABSTRACT FROM AUTHOR]

The exact determination of the height of fractured zones in overlying sedimentary strata is important in coal mining performed underneath water bodies and for a safe production. To prevent the inrush of water and sand during strip Wongawilli mining, we studied the height of fractured zones in shallow coal seams underlying a hard roof. Based on the geological setting and mining conditions at the Zhaowu coal mine, the height of the fractured zones in overlying strata was measured using the loss of drilling fluid method and by numerical simulation. The height of the fractured zones and its development characteristics during strip Wongawilli mining in shallow buried coal seam underlying a hard roof were obtained. The results demonstrate that the disturbance of the overlying strata during strip Wongawilli mining is reduced and the height of the fractured zones is smaller relative to that occurring during critical mining. The height of fractured zones increases with mining width in a steppedfinger line, and it manifests stable in each stage, but turns into the next stage by sudden increase. The existing method of calculation and the traditional empirical formula to obtain the height of the fractured zones are not suitable for strip Wongawilli mining. The calculation should be based on the size of mining. [ABSTRACT FROM AUTHOR]

Coal has many applications for fuel and energy production; therefore, coal mining has always been taken into consideration. When the coal is transported by trucks, it falls on the mine haul road and influence on the geotechnical properties of road pavement. Since, there have been scarce researches on the effects of coal on mine haul road pavement, the aim of this study is to investigate experimentally and numerically the effects of coal on the physical and geotechnical properties of the mine haul road pavement. Therefore, coal was sampled from 'Hojedk' coal mine located in Kerman- Iran and was added to the sandy gravel surface layer with weight percentages of 2, 4, 6, and 8%, and its geotechnical properties were examined in compaction, California Bearing Ratio (CBR), unconfined compression strength, direct shear, permeability, sand equivalent, and liquid limit tests. The results indicate that with increase of coal from 0 to 8%, the maximum dry density, CBR, and coefficient of permeability increased to 362, 361, and 132%, respectively, and the sand equivalent decreased by 20%. Also, with increase the percentages of coal from 0 to 4%, unconfined compressive strength and cohesion increased up to 102 and 194%, respectively and with increase the percentages of coal from 4 to 8%, these values decreased by 31 and 43%, respectively. According to scanning electron micrograph test, the sample without coal had more pores than the sample with coal which led to increase the soil permeability and reduction in strength of soil. According to numerical analysis of mine haul road with finite element software OpenSees, it was found that by subjecting the standard wheel load (850 kPa), the least maximum settlement of pavement was observed in the pavement containing 4% coal at 4.4 cm. [ABSTRACT FROM AUTHOR]

Since the reform and opening up, with the development of continuous mining technology and scale expansion of open pits, the design philosophy of current mining procedure and mining technology has gradually lagged behind. For the development of large-scale opencast coal clusters in china, the paper analyzed the backward design philosophy of traditional industrial square-centered mining procedure under the original shovel-truck technology, and put forward a new design idea of banded subarea mining. On this basis, for large-scale open pits, the paper further proposed the stripping technology of shovel -- self advancing crusher -- double-face belt conveyor in combination with the raw coal transport technology of shovel -- truck -- simple mobile crushing station -- end slope belt conveyor. These new technologies have already been applied to Pingshuo East surface mines, providing references for future development of China's large-scale opencast coal mines. [ABSTRACT FROM AUTHOR]

The article presents information on the wholesale coal trade in the United States. The author describes the history of coal mining in the U.S. and the production units that must be built to process and distribute raw materials from the mine. The expansion of coal facilities and the market of individual wholesale companies is detailed. A discussion is presented about changes in the methods of wholesalers brought on by the practice of selecting one wholesaler to act as the sole distributor of a producer's products. Details related to the storage and transportation of bulk coal are presented.

The paper analyses the reliability of the belt conveyors used for the transport of coal in the underground mines from the Jiu Valley, based on the information about faults, recorded between June 2012 and March 2013. The analysis was performed for each main part of the belt conveyor system, in order to highlight the type of defect, the damaged part and the occurrence of defects for each sub-assembly. [ABSTRACT FROM AUTHOR]

The effective production of high-quality anthracite has attracted increasing global attention. Based on the coal occurrence in Yongxia Mining Area and mining conditions of a coalface in Xinqiao Coal Mine, we proposed a systematic study on the technical support for the production of high-quality anthracite. Six key steps were explored, including coal falling at the coalface, transport, underground bunker storage, main shaft hoisting, coal preparation on the ground, and railway wagon loading. The study resulted in optimized running parameters for the shearers, and the rotating patterns of the shearer drums was altered (one-way cutting was employed). Mining height and roof supporting intensity were reduced. Besides, loose presplitting millisecond blasting and mechanized mining were applied to upgrade the coal quantity and the lump coal production rate. Additionally, the coalface end transloading, coalface crush, transport systems, underground storage, and main shaft skip unloading processes were improved, and fragmentation-prevention techniques were used in the washing and railway wagon loading processes. As a result, the lump coal production rate was maintained at a high level and fragmentation was significantly reduced. Because of using the parameters and techniques determined in this research, high-quality coal production and increased profits were achieved. The research results could provide theoretical guidance and methodology for other anthracite production bases. [ABSTRACT FROM AUTHOR]

The article presents a study on the relationship between the amount of coal particle breakdown obtained and vertical vehicle acceleration. An in-service rail transport company Transnet Freight Rail (TFR) coal train was examined with accelerometers when travelling between Vryheid and Ermelo in South Africa to record forces experienced by a coal wagon. The study reveals that the track section between railway stations is retained well because only isolated acceleration spikes were recorded.

The article focuses on the construction of third baloon line of the coal railway from Blackhill to the export terminal in Richards Bay, South Africa in response to the increasing transport capacity of the coal line in the area. It offers overview of concept and description of the project which was started in 2008. It also offers information of design and construction challenges encountered by the contractors of the project, as well as the completion of its overall aspects.

This study describes international coal transportation from a coal mining site in the South Gobi, Mongolia to Japan, which is located approximately 8,000 km to the west. The logistics of transportation from the origin to the final destination comprises of four stages: transportation by truck, Mongolian railway, Russian railway, and coal vessel. Specifically, performance measures such as the total transportation time and inventory levels at transshipment between two consecutive means of transportation are examined. A procedure to improve the efficiency of performance measures is proposed. [ABSTRACT FROM AUTHOR]