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1

Eco-efficiency and life cycle assessment of the long reach directionally drilled and cross-measure boreholes methane drainage technologies employed in bituminous coal mine on the basis of the pilot scale experimental data

Jura Bartłomiej, Krawczyk Piotr, Śliwińska Anna, Skiba Jacek, Karbownik Marcin, Howaniec Natalia

Journal of Sustainable Mining

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2025

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Vol. 24, iss. 2

189--202

EN

This paper presents the results of eco-efficiency and life cycle analysis conducted for two methane drainage technologies: cross-measure (CM) and long reach directionally drilled (LRDD) boreholes. In the analyses, data from coal mine methane drainage of two coal panels, I-C and II-C, located at the Staszic-Wujek coal mine in Poland, were used. The results of the life cycle and eco-efficiency assessments showed that employment of long reach directional drilling boreholes method has a lower environmental impact and is more eco-efficient, causing the lower environmental impact and lower construction and operating costs per cubic meter of methane extracted. The results of the sensitivity analysis indicated that the quantity of methane extracted has the greatest impact on the eco-efficiency index. For LRDD technology, the quantities of methane captured are significantly higher than for CM technology. The advantage of LRDD technology results mainly from the possibility of further extraction of methane from the exploited coal panel after coal extraction is completed. This is not possible with CM technology, in case of which the boreholes are being destroyed during coal extraction. CM technology also requires drilling a much larger number of boreholes and of a higher total length than needed in LRDD technology.

2

Coal mine underground positioning algorithm based on RSSI model correction and node cooperation

Qiao Xin, Chang Fei, Wang Jing, Wang Xiuying, Jiang Yun

Archives of Mining Sciences

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2025

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Vol. 70, no. 1

45--62

EN

To address the issues of environmental complexity and low positioning accuracy faced by coal mine underground positioning systems, an improved localisation algorithm based on Received Signal Strength Indication (RSSI) model correction and node collaboration, namely, the RSSI-MCNC (RSSI Model Correction and Node Collaboration) algorithm, is proposed. First, this algorithm employs Kalman filter technology to optimise the collected RSSI values, improving signal stability and range model accuracy. Second, more precise ranging results are achieved by dynamically adjusting the RSSI model parameters to adapt to changes in mining environments. In the localisation stage, the localised unknown nodes are used as cooperative nodes to position other unknown nodes and solve the objective function through the improved weighted centroid algorithm and gradient descent method, precisely locating the unknown nodes. The simulation results indicate that the RSSI-MCNC algorithm can significantly improve the positioning coverage and accuracy of fixed anchor nodes and the random distribution of unknown nodes in mine roadways, especially in the case of limited anchor nodes. This is significant for improving the safety of mine personnel and equipment.

3

Numerical simulation of methane distribution at the longwall working with various stages of shearer advance

Janoszek Tomasz

Archives of Mining Sciences

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2024

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Vol. 69, no. 3

353--373

EN

The article presents a methodology for predicting the impact of the longwall shearer’s control parameter on methane emission rate to the working of a longwall based on computational fluid dynamics (CFD) methods. The methodology was applied to the Z-11a longwall panel conditions at the Jankowice Hard Coal Mine. The results of the methane emissions rate in the working of a longwall for three variations of the position of the longwall shearer are shown and discussed. The modelled issue’s geometry, numerical grid, assumptions, and boundary conditions are presented. The filtration parameters of goafs are discussed. Relationships to estimate the various sources of methane emissions into the air flowing around the longwall panel Z-11a are presented. The results of the model tests were compared with the mining data in the Z-11a longwall panel at the Jankowice Hard Coal Mine.

4

Comprehensive review of haul road design methods: a comparative approach

Gouda Jagdish, Reddy D. Sita Rami, Srinivasan V., Butle Vaibhav

Archives of Mining Sciences

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2024

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Vol. 69, no. 3

529--554

EN

The mining industry, primarily coal mines, has grown significantly, leading to heavy traffic on haul roads. However, inadequately designed haul roads often result in problems. The objective of the present study is to review and design the haul road using existing design methods and analyze their pavement design parameters. The study compares haul road design methods, including empirical California Bearing Ratio (CBR) methods, design charts, mechanistic design approach, and geocell reinforced design. This research enhances understanding of effective haul road design methods considering layer thicknesses, vertical strain, and deflections, thereby ascertaining the overall performance and suitability of each design approach. The mechanistic and reinforced design approaches emphasize pavement safety, significantly reducing vertical compressive strain. By using IITPAVE software, an optimal haul road design was found by finding vertical strains and deflections of various designs. Vertical strains ranged from 1238 to 3700 µε, with 1.5 to 4.5 mm deflections. The outcomes indicate that both the mechanistic and reinforced approaches meet the criteria for critical strain limits (CSL). This study highlights the advantages of different design approaches to ensure cost-effectiveness.

5

Iskrobezpieczne pneumatyczne źródło sejsmiczne do monitorowania i obrazowania górotworu w górnictwie podziemnym

Sierodzki Przemysław, Remiorz Leszek, Ćwiękała Mateusz, Krawiec Krzysztof

Napędy i Sterowanie

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2023

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R. 25, nr 7/8

82--87

PL

Do najbardziej zagrożonych tąpaniami i wyrzutami skał i gazów rejonów kopalń w Polsce należą rejony ścian wydobywczych, w których podejmowane są próby wczesnego wykrywania tych zagrożeń z wykorzystaniem metod aktywnego prześwietlania rejonu ścian wydobywczych. Dotychczas były one realizowane głównie z wykorzystaniem małych ładunków wybuchowych, co nie zawsze jest możliwe ze względu na duże zagrożenie gazowe i obostrzenia z tym związane. Powszechne jest oczekiwanie na umożliwienie w przyszłości bezpiecznego i tańszego prześwietlania górotworu na bieżąco z wykorzystaniem iskrobezpiecznych lekkich mobilnych pneumatycznych wzbudników podczas wydobycia, w celu wczesnego wykrywania miejsc koncentracji naprężeń charakteryzujących się zmianami prędkości rozchodzenia się wzbudzanych fal sejsmicznych, towarzyszących niebezpiecznym odkształceniom górotworu, które mogą prowadzić do zagrożeń. Opracowane w Centrum Transferu Technologii EMAG pneumatyczne, iskrobezpieczne źródło sejsmiczne WZB-2 umożliwia generowanie fal sejsmicznych oraz prowadzenie aktywnych badań sejsmicznych w rejonie zagrożenia. W porównaniu do materiałów wybuchowych wzbudnik pneumatyczny jest źródłem bezpiecznym, mobilnym, tańszym w użyciu i może być również używany w trakcie prowadzenia wydobycia. Wyzwalany z powierzchni w krótkich odstępach czasu, przy współpracy z aparaturą sejsmoakustyczną, może pomóc w uzyskaniu wysoko rozdzielczej informacji o zmianie prędkości fal sejsmicznych w górotworze. W artykule przedstawiono opis rozwiązania oraz charakterystykę techniczną urządzenia. Wykonano pierwsze testy aparatury w warunkach dołowych. Wyniki testów potwierdzają wysoką skuteczność aparatury w prześwietlaniu 200 m ściany pokładu węgla. W rezultacie sumowania rejestracji otrzymanych z 18 uderzeń wzbudnika w ocios uzyskano odpowiedź w przeciwległym chodniku w zakresie do 500 Hz.

EN

The regions of mines in Poland most at risk of rock bursts and rock and gas outbursts include longwall areas where attempts are made to detect these threats early using methods of active scanning of the longwall area. So far, they have been carried out mainly with the use of small explosives, which is not always possible due to the high gas hazard and the related restrictions. It is common to expect safe and cheaper scanning of the rock mass in the future with the use of intrinsically safe lightweight mobile pneumatic exciters during mining in order to early detect stress concentration points characterized by changes in the propagation speed of induced seismic waves accompanying dangerous deformations of the rock mass, which may lead to hazards. The WZB-2 pneumatic intrinsically safe seismic source developed at the CTT EMAG allows seismic waves to be generated and active seismic surveys to be carried out in the hazard region. Compared to explosives, the pneumatic exciter is a safe, mobile, less expensive source and can also be used during mining operations. Triggered from the surface at short intervals, in cooperation with seismoacoustic apparatus, it can help to obtain high-resolution information about the change in seismic wave velocity in the rock mass.The paper presents a description of the solution and the technical characteristics of the apparatus. The first tests of the apparatus in underground conditions were carried out. The test results confirm the high effectiveness of the apparatus in screening a 200 m long coal seam. As a result of the summation of the registrations obtained from the 18 strokes of the exciter in the wall face, a response of up to 500 Hz was obtained in the opposite gallery.

6

Effects of ecological restoration patterns on runoff and sediment in an abandoned coal mine of Southern China

Li Hao, Chen Wenbo, Zhang Cheng, He Lei, Liang Haifen, Li Haifeng, Liu Dingpu

Environment Protection Engineering

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2023

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Vol. 49, nr 4

29--44

EN

Evaluating the ecological economic benefits of different ecological restoration patterns in abandoned mines is important in ecological restoration study. Taking the abandoned coal mine in Luoshi Township of Fengcheng county, Jiangxi province, as a case, 4 different ecological restoration patterns (grapefruit with grass vegetation – Pattern I, pine with grass vegetation – Pattern II, grapefruit – Pattern III, and bare slope – Pattern IV) have been conducted to study the runoff and sediment yield under natural rainfall conditions. The results showed that the ecological restoration patterns and rainfall intensity can significantly affect runoff and sediment yield which increased as rainfall intensity increased: Pattern IV > Pattern III > Pattern II > Pattern I. For the optimal ecological restoration with Pattern I, the average runoff and sediment reduction was 59.01 and 77.1%, respectively, in all rainfall intensities. Multivariate analysis of variance (MANOVA) showed that runoff and sediment were significantly affected by ecological restoration pattern and rainfall intensity (P < 0.05). Correlation analysis of runoff and sediment yields indicated that the reduction effect on sediment yield increased with the decrease of runoff, and the relationships between runoff and sediment at different ecological restoration patterns could be fitted with a linear function. Moreover, the vegetation configuration that combines fruit farming with grass can be not only beneficial to control soil and water conservation but produce considerable economic and ecological benefits.

7

Efficient and reliable prediction of dump slope stability in mines using machine learning: an in-depth feature importance analysis

Singh Sudhir Kumar, Chakravarty Debashish

Archives of Mining Sciences

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2023

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Vol. 68, no. 4

685--706

EN

This study rigorously examines the pressing issue of dump slope stability in Indian opencast coal mines, a problem that has led to significant safety incidents and operational hindrances. Employing machine learning algorithms such as Random Forest (RF), k-Nearest Neighbors (KNN), Support Vector Machine (SVM), Logistic Regression (LR), Decision Tree (DT), and Gaussian Naive Bayes (GNB), the study aims to achieve a scientific goal of predictive accuracy for slope stability under various environmental and operational conditions. Promising accuracies were attained, notably with RF (0.98), SVM (0.98), and DT (0.97). To address the class imbalance issue, the Synthetic Minority Oversampling Technique (SMOTE) was implemented, resulting in improved model performance. Furthermore, this study introduced a novel feature importance technique to identify critical factors affecting dump slope stability, offering new insights into the mechanisms leading to slope failures. These findings have significant implications for enhancing safety measures and operational efficiency in opencast mines, not only in India but potentially globally.

8

Mining operations and geotechnical issues in deep hard rock mining – case of Boukhadra iron mine

Benyoucef Ali Ahmed, Gadri Larbi, Hadji Riheb, Mebrouk Faouzi, Harkati Elhaddi

Geomatics, Landmanagement and Landscape

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2022

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no. 4

27--46

EN

Underground mining operations are a very problematic task, especially in poor geotechnical conditions. The right choice of excavation and support techniques leads to adequate and secure mining operations. This should ensure the overall stability of the underground mine with the best productivity and stability performance. In this paper, an empirical model for obtaining support systems for underground galleries was applied. Then, a numerical model for the evaluation of the performance of support measures for rock masses in the Boukhadra iron mine was introduced. Extensive field and laboratory tests were performed to obtain geological, geotechnical, and mechanical data on the entire geologic formations of the (1105 m) level. The performance of the design is supported by the selection of a common support plan between RMR, Q, and UBC systems for each geotechnical unit. Therefore, the rock masses classification based on the geo-mechanical model has determined the suitable support systems. The finite element model (FEM) was used for the analysis of rock mass behaviour, displacements, stress, and plastic point distribution. The results permit the optimization of the plastic zone thickness around the gallery. The outcomes of this study could improve the stability of the mine by choosing the right direction of excavation in consideration to the direction of the discontinuity planes. In order to choose between the current and the recommended mining operations, an equivalent calculation sequence was verified. Our study demonstrated that the consideration of discontinuity sets in the orientation of excavation highly improves the mining conditions with or without support.

9

Wymagania dla urządzeń i systemów ochronnych przeznaczonych do użytku w atmosferze potencjalnie wybuchowej

Łasak Fryderyk

Elektro Info

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2022

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nr 6

97--99

10

High-Performance Workwear for Coal Miners in Northern China: Design and Performance Evaluation

Ke Ying, Zheng Qing, Wang Faming, Wang Min, Wang Yi

Autex Research Journal

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2022

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Vol. 22, no. 2

155--162

EN

The design of workwear has significant effects on worker performance. However, the current workwear for coal miners in Northern China is poor in fitness and thermal comfort. In this study, new workwear (NEW) for coal miners was developed with the design features providing better cold protection and movement comfort performance, as compared with a commonly worn workwear (CON). To evaluate the effectiveness of NEW, we conducted human trials which were performed using simulated work movements (i.e., sitting, shoveling, squatting, and crawling) in a climate chamber (10°C, 75% RH). Physiological measurements and perceptual responses were obtained. The results demonstrated that the local skin temperatures at chest, scapula, thigh, and calf; mean skin temperatures,; and thermal comfort in NEW were significantly higher than those in CON. NEW also exerted an improvement in enhancing movement comfort. We conclude that NEW could meet well with the cold protective and mobility requirements.

11

Using high level roadway to control gas emission in a longwall mining face – numerical simulation study

Ma Yongzhen, Cheng Jianwei, Zhang Rui, Wang Zui, Ran Dezhi, Sheng Shuping, Zhang Jufeng, Si Junhong, Yu Zhaoyang

Archives of Mining Sciences

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2022

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Vol. 67, no. 4

715--728

EN

With the increase of coal mining depth, the gas content in coal seams could also become larger and larger, which could suddenly cause an inrush of gas into the longwall mining face. It is very dangerous for miners’ safety in the underground. The U-shaped ventilation pattern of longwall mining face that underground coal mines currently use is not enough to deliver sufficient air quantities to dilute gases in mining faces, which could result in the gas concentration over the required celling limit by government laws. Thus, the mine must stop production. In this paper, the high level roadway (HLR) is designed and the U + HLR new ventilation pattern is proposed to control gas emission in a longwall mining face. Using computational fluid dynamics simulation (CFD) software, the flow field and gas transportation in the mine gob are studied. The optimized ventilation parameters are summarized. It is found that the best vertical distance of the HLR is 35 m over the coal seam and the horizontal distance is 25 m from the air return roadway. It is recommended that the negative suction pressure design of the high level roadway should be ranged from 9000 Pa to 10000 Pa. Based on the study outcomes, the gas emission could be well controlled in mining faces and avoid any gas disaster accidents.

12

Failure characteristics of W strap in coal mine support

Feng Xiaowei, Xue Fei, Feng Xiaotian, Zhao Tongyang

Archives of Mining Sciences

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2022

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Vol. 67, no. 2

289--302

EN

W strap is a crucial surface support component for underground coal mine roadways. In this study, the failure characteristics of the W strap in the field are discussed, and the loading characteristics of the strap and the faceplate are numerically and experimentally analysed. Afterwards, a loading apparatus capable of reappearing the loading environment of the strap in the field is fabricated. This loading device, combined support systems consisting of a bolt, faceplate and strap is tested under different simulated strata conditions. Failure patterns of the strap are evaluated by the 3D scanning method, and proper selection of a faceplate is explored. Results indicate that a domed faceplate can achieve a favourable supporting effect on strata, and thus it is favoured compared with a square domed faceplate. In addition, rock cavity and rock integrity beneath the strap are essential factors determining the servicing life of the overall supporting system.

13

Case study of rock bolting in a deep coal mine in Poland

Masny Wojciech, Nita Łukasz, Ficek Jerzy

Archives of Mining Sciences

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2022

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Vol. 67, no. 1

79--94

EN

In 2017, the Central Mining Institute (GIG), Jastrzębska Spółka Węglowa SA (JSW SA), the largest producer of coking coal in Europe, and JOY KOMATSU, the producer of mining machinery, signed a consortium. The project’s main goal was to reduce the costs of driving mine workings by reintroducing the rock bolt support. The works began in November 2019, and for the first time in the history of Polish coal mining, a Bolter Miner machine was used for the purpose. The paper presents the results of measuring the axial forces in rock bolts at the measurement base and their analysis with numerical modelling.

14

Analysis of noise sources and selection of ear protector in a coal mine

Erol Ilknur, Su Okan

Archives of Mining Sciences

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2022

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Vol. 67, no. 3

455--476

EN

In this study, the noise sources to which a coal miner, who works at the Kurul panel of Kilimli Colliery, Zonguldak, was exposed were investigated. These sources were positioned at different points from the surface to the workface. Noise levels were measured according to the working periods of the coal miners around the machines. The results were evaluated under the Turkish Noise Regulation. The critical exposure times in which the coal miners could work without the use of personal protective equipment were examined according to the noise values to which they were exposed. In addition, the personal noise exposure values of the machine operators (boring machine, electro-hydraulic drill, and pick hammer) were determined during the development works. Two different types of noise measurements, with a microphone at the ear level and inside the ear protector, were conducted. The results obtained when the microphone of the personal dosimeter was at ear level, were found to be 15 dBA higher than those when the microphone was inside the ear protector. As a result, the selection methods of ear protectors were analyzed. Recommendations were given for those working on the risky tasks at the panel.

15

The concentration level of PM10 in southern Poland (Katowice, Kraków, and Rzeszów) during the year 2018

Qor-el-aine Achraf, Béres András, Géczi Gábor

Science, Technology and Innovation

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2021

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Vol. 14, no. 3-4

27--34

EN

Human health and food quality are greatly affected by the state of the ambient air. In the European Union, Poland is considered as a country that has the most polluted air. The level of PM10 concentration exceeds the EU limit value in almost all the areas of Poland, but higher concentrations are registered in the southern regions, which are considered as the coal heartlands. Katowice, Kraków, and Rzeszów are three big cities in the southern part of Poland and are surrounded by coal mining industries. High PM10 concentrations are usually registered in these three cities, especially in the winter period. In 2018, the peak PM10 daily concentration occurred in the three cities at the same period (04/03/2018 in Rzeszów, 05/03/2018 in Kraków, and 05/03/2018 in Katowice). The aim was to identify the effect of each of the 8 coal mines that exist in Poland on the level PM10 concentration for the first week and March where the highest daily PM10 concentration for the year 2018 was registered. Using HYSPLIT Frequency analysis, the results showed that 100% of the particles coming from Bełchatów, Bolesław Śmiały, Halemba, Jas-Mos, Pniówek and Marcel Coal Mines hit Katowice region, and 10% from Bogdanka. While for Kraków, it was affected by 100% of the particles that are originated from Bolesław Śmiały, Pniówek, Halemba, and Jas-Mos Coal Mines and 10% Bogdanka, Bełchatów, and Marcel Coal Mines. Moreover, Rzeszów was the least affected city by the coal mines, 10% of the particles coming from Bogdanka, Bełchatów, Jas-Mos and Marcel, Halemba, and Pniówek Coal Mines attributed to high PM10 concentration during the first week of March 2018. Katowice and Kraków are more affected by the coal mines industry, Particulate Matter particles originating from the coal mines sites contribute to the high level of PM10 concentration.

16

Underground mine gas explosion accidents and prevention techniques – an overview

Song Wanting, Cheng Jianwei, Wang Wenhe, Qin Yi, Wang Zui, Borowski Marek, Wang Yue, Tukkaraja Purushotham

Archives of Mining Sciences

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2021

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Vol. 66, no. 2

297--312

EN

Mine gas explosions present a serious safety threat in the worldwide coal mining industry. It has been considered the No.1 killer for underground coal mining workers. The formation of an explosive atmosphere involves various factors. Due to complicated stratified geology and the coal production process, geological conditions and coal production process reasons and particular working sections underground present a high risk of an explosion that would most likely cause casualties and property loss. In this study, the basic conditions, propagation law and hazards analysis of gas explosions are reviewed, followed by a review of the typical locations where an explosion would occur. Finally, current technologies used in the mining industry for preventing gas explosions and suppressing the associated dangers were studied. Preventive gas explosion technologies mainly include gas drainage, gas accumulation prevention and gas and fire source monitoring technologies. The technologies often used to control or mitigate gas explosion hazards are usually divided into active and passive, and the advantages and disadvantages of each method are discussed and compared. This paper aims to summarise the latest technologies for controlling and suppressing gas explosion and guides mining engineers to design risk mitigation strategies.

17

Modeling of methane and air velocity behavior in an auxiliary ventilated coal heading

Daloğlu Gülnaz, Önder Mustafa, Parra Teresa

Archives of Mining Sciences

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2021

|

Vol. 66, no. 1

69--84

EN

It is commonly known that the cause of serious accidents in underground coal mining is methane. Thus, computational fluid dynamics (CFD) becomes a useful tool to simulate methane dispersion and to evaluate the performance of the ventilation system in order to prevent mine accidents related to methane. In this study, numerical and experimental studies of the methane concentration and air velocity behaviour were carried out. The experiment was conducted in an auxiliary ventilated coal heading in Turkish Hard Coal Enterprises (TTK), which is the most predominant coal producer in Turkey. The simulations were modeled using Fluent-Ansys v.12. Significant correlations were found when experimental values and modeling results were compared with statistical analysis. The CFD modeling of the methane and air velocity in the headings especially uses in auxiliary ventilation systems of places where it is hard to measure or when the measurements made are inadequate.

18

Interaction principle of rock-bolt structure and rib control in large deformation roadways

Yuan Xun, Yang Shuangsuo

Archives of Mining Sciences

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2021

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Vol. 66, no. 2

227--248

EN

Large deformation in roadways is an inevitable problem faced by many coal mines, and bolt installation is widely adopted to keep roadway stability. To provide a theoretical basis for bolt supporting scheme design in order to eliminate hazards associated with roadway failure, the interaction principle between bolts and the bolted strata should be studied thoroughly. This research attempts to investigate the above principle through theoretical analysis through a group of selected statistics from fifteen different coal mines. At the same time, the thick board support method was proposed and applied for controlling the ribs deformation in a particular coal mine. It is concluded that the interaction of the rock-bolt entity is subjected to the fluctuation balance law. When deformation increases, the bolted structure experiences periodic equilibrium variation. Both the supporting force needed to stabilise the surrounding rocks and the supporting capability of bolted strata show a trend of decrease in this process. The interaction principle of surrounding rocks and bolts is in essence the mechanical phenomenon caused by their mutual load transformation, and the load-carrying capacity varies with the bolted structure’s deformation, which is subjected to the following law: elastic roadway>plastic roadway> fractured roadway>broken roadway. The designed bolted thickness of the ribs should be more than 1/5 of roadway height to make full use of the self-stability of surrounding rocks. Finite Difference Method simulation and on-site monitoring data showed that the roof subsidence and ribs convergence of 2201 roadway in Shuguang coal mine was reduced by 83.7% and 88.6% respectively after utilising the proposed support method, indicating that the thick-board method was effective. Results of this research can lay a foundation for support design in large deformation roadways.

19

Analysis and application of filling mining technology in China’s mining area: a case study of Yuxing Coal Mine

Huang Dongmei, Xing Daqian, Chang Xikun, Zhu Yingying

Archives of Mining Sciences

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2021

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Vol. 66, no. 4

611--624

EN

According to the requirements of green mine construction and the coordinated development of environmental protection regulations, the existing filling technologies in China are compared and analysed. Several types of technologies are discussed, including the dry filling technology for gangue, grouting and filling for separated strata zones in overburden, grouting and filling technology for caving gangue fissures, paste and paste-like filling, high-water and ultra-high-water filling, and continuous mining and continuous filling. Then, the characteristics of these individual technologies are analysed. Through the analysis and comparison of these technologies, considering the requirements of green mine construction and coordinated development of environmental protection regulations, it was found that continuous mining and continuous filling technology is a feasible mean for constructing green mines and protecting the environment. In this study, the application of continuous mining and continuous filling technology in the Yuxing coal mine is introduced. Results show that surface subsidence was less than 80 mm, and the recovery rate of the working face reached 95%. This indicates that continuous mining and continuous filling technology can solve the problems of surface subsidence, environmental damage, and coal resource waste. Finally, the development prospects of continuous mining and continuous filling technology are proposed, providing theoretical and technical support for similar mining.

20

An investigation into the effect of rockmass properties on mean fragmentation

Chandrahas Sri, Choudhary Bhanwar Singh, Prasad N. S. R. Krishna, Musunuri Venkataramayya, Rao K. K.

Archives of Mining Sciences

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2021

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Vol. 66, no. 4

561--578

EN

Desired rock fragmentation is the need of the hour, which influences the entire mining cycle. Thus, most engineering segments pay attention to rock fragmentation and neglect by-products like ground vibration and fly rock. Structural and mechanical properties of rock mass like joint spacing, joint angle, and compressive strength of rock pose a puzzling impact on both fragmentation and ground vibration. About 80% of explosive energy that gets wasted in producing ill effects can be positively optimised, with a new set of blast design parameters upon identifying the behaviour of rock mass properties. In this connection, this research aims to investigate the influence of joint spacing, joint angle, and compressive strength of rock on fragmentation and induced ground vibration. To accomplish this task, research was carried out at an opencast coal mine. It was discovered from this research that compressive strength, joint spacing, and joint angle have a significant effect on the mean fragmentation size (MFS) and peak particle velocity (PPV). With the increase in compressive strength, MFS explicit both increase and decrease trends whilst PPV increased with a specific increase in compressive strength of the rock. An increase in joint spacing triggers both increase and decrease trends in both MFS and PPV. While there is an increase in joint angle, MFS and PPV decrease.