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1

Assessing risky behavior based on survey research among mine rescuers

Grodzicka Aneta

Zeszyty Naukowe. Organizacja i Zarządzanie / Politechnika Śląska

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2023

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z. 172

253--269

EN

Purpose: The aim of the paper was to analyze risky behavior in the mining industry on the example of survey research among mine rescuers. Design/methodology/approach: The analysis of risky behaviors concerned the mine rescue service crew in a selected hard coal mine. The author's method of synthetic assessment of risky behaviors was used for the research. The surveys was conducted during rescue training on a group of 30 mine rescuers, which accounted for 25% of the crew's record. Findings: The article presents the results of a study of synthetic assessment of mine rescuers according to six problem areas (assessment parameters). The synthetic assessment of risky behavior is a method that allows individual assessment for each respondent in all areas. If one of the areas receives an abnormal rank, only one selected area can be re-evaluated after applying suggestions for improvement. Survey questionnaires consisting of closed-ended questions were used for each area. All respondents were given an option to give either affirmative or negative responses. Having obtained the sum of the assessment criterion ranks for each area, a synthetic assessment of risky behavior was interpreted for the surveyed mine rescuers. The summative assessment was then interpreted on a four-point scale: outstanding, satisfactory, normal, and abnormal. Out of the entire study group, only two subjects received an abnormal rating, each in one of the areas; the first respondent in the area of risky behavior, the second respondent in the area of risky behavior in situations of unbreathable air. For these two mine rescuers, detailed results for all areas were presented. Research limitations/implications: The research was dedicated to working conditions underground, but they can be adapted to working conditions on the surface, as well as to the specificity of other rescue services (e.g. firefighters, rescuers). Practical implications: The results of the research can be used as criteria for the selection of mine rescuers for the mine rescue service (rescue emergencies, rescue teams). Originality/value: The publication contains original results of research on risky behavior of mine rescuers, and they are addressed to the management of mining plants.

2

Applying Model Studies to Support the Monitoring of Methane Hazard during the Process of Underground Coal Mining

Tutak Magdalena, Brodny Jarosław, Małkowski Piotr, Grebski Wes

Production Engineering Archives

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2023

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Vol. 29, Iss. 3

319-327

EN

The process of underground mining is one of the most complex and hazardous activities. In order to maintain the continuity and efficiency of this process, it is necessary to take measures to reduce this hazard. The paper addresses this issue by presenting a developed methodology for using model studies and numerical simulations to support the process of monitoring methane hazards. Its basis is the developed model of the region of underground mining exploitation along with the ventilation phenomena occurring in it. To develop it, the ANSYS Fluent program was used, based on the finite volume method classified as computational fluid mechanics. The model reflects both the geometries and physical and chemical phenomena occurring in the studied area, as well as the auxiliary ventilation equipment used during operation. The research was conducted for two variants of methane emissions from goaf zones, the first of which concerned the actual state of the mining area, and the second of which concerned increased methane emissions from these goaf zones. The purpose of the study was to determine the distribution of methane concentrations in the most dangerous part of the studied area, which is the intersection of the longwall and the tailgate, as well as the distribution of ventilation air flow velocities affecting them. The studies for both variants made it possible to determine places particularly exposed to the occurrence of dangerous concentrations of methane in this region. The methodology developed represent a new approach to studying the impact of methane emissions from goaf zones into mine workings.

3

Study of Compensation Room Impacts on the Massіf Stability and Mined Ore Mass Quality

Stupnik Mykola, Fedko Mykhaylo, Hryshchenko Mykhaylo, Kalinichenko Olena, Kalinichenko Vsevolod

Inżynieria Mineralna

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2023

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no. 1

129--135

EN

The paper presents the study and a functional analysis of requirements of the world metallurgical industry to the quality of underground iron ores at underground mines of Ukraine. There are found dependencies of the impact of the shape and parameters of compensation spaces on their stability and broken ore quality indicators. It is proved that a vertical trapezoidal compensation room possesses the highest stability and is stable within the range of all the considered depths, even in ores with hardness of 3–5 points. Less atabiity is demonstrated by a vertical compensation room of a vaulted shape with minor falls in the abutment of the room vault in ores with hardness of 3–5 points at the depth of 2000 m, and a tent-shaped one where falls of varying intensity occur in the lower part of inclined exposures of the tent in ores with hardness of 3–5 points at the depth of 1750 m or more. The horizontal compensation room is of the lowest stability; falls occur in ores with hardness of 3–5 points at the depth of 1400 m, and at the depths of 1750–2000 m it remains stable only in harder ores. It is established that the use of compensation rooms of high stability makes it possible to achieve their maximum volume, increase the amount of pure ore extracted, reduce its dilution, enhance the quality of the mined ore mass and concequently increase its price and competitiveness of marketable products.

PL

Artykuł przedstawia studium i analizę funkcjonalną wymagań światowego przemysłu metalurgicznego co do jakości rud żelaza w podziemnych kopalniach Ukrainy. Stwierdzono zależności wpływu kształtu i parametrów przestrzeni kompensacyjnych na ich stateczność i wskaźniki jakości rudy. Udowodniono, że komora wyrównawcza w kształcie trapezu pionowego charakteryzuje się największą stabilnością i jest stabilna w zakresie wszystkich rozważanych głębokości, nawet w rudach o twardości 3–5 punktów. Mniejszą stateczność wykazuje komora kompensacji pionowej o kształcie sklepionym z niewielkimi spadkami w przyczółku sklepienia komory w rudach o twardości 3–5 punktów na głębokości 2000 m. Komora z opadami o rożnym natężeniu występuje w dolnej części nachylonych odsłonięć namiotu w rudach o twardości 3–5 punktów na głębokości 1750 m lub większej. Pomieszczenie kompensacji poziomej ma najmniejszą stateczność; spadki występują w rudach o twardości 3–5 punktów na głębokości 1400 m, a na głębokościach 1750–2000 m pozostają stabilne tylko w rudach twardszych. Stwierdzono, że zastosowanie komór kompensacyjnych o dużej stabilności umożliwia osiągnięcie ich maksymalnej objętości, zwiększenie ilości wydobywanej czystej rudy, zmniejszenie jej rozrzedzenia, poprawę jakości wydobywanej masy rudy, a co za tym idzie, wzrost jej ceny i konkurencyjności rynkowej.

4

Selecting Parameters to Design Auxiliary Ventilation in Underground Mine

Dang Phuong Thao

Inżynieria Mineralna

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2023

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no. 2, vol. 1

267--270

EN

In recent years, Quang Ninh coal mines are continually expanding on size and depth, the total length of the roadway each year amounts about ten thousands meters in order to reach new production zones. The length of new roadways is usually longer, leading to increase to the airflow demand. Ventilation is one of the main factors effecting driving progress of the roadway. The estimation of airflow requirements is usually based on the minimum amount of airflow required at the heading during driving roadways or at the working face, in other words, when the ventilation ductwork is at its maximum length. Therefore, determination of maximum ventilation length of ductwork has been undertaken. This results allow the selection of a reasonable fan to meet the ventilation requirements when driving the roadway. Also, this value is an important parameter for designing auxiliary ventilation system that operates more efficiently on a lower cost.

5

Prediction of Road Subsidence Caused by Underground Mining Activities by Artificial Neural Networks

Nguyen Hung Viet, Le Duyen Quang, Nguyen Long Quoc, Lipecki Tomasz

Inżynieria Mineralna

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2023

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no. 2, vol. 1

335--340

EN

Mining-induced road subsidence is a significant concern in areas with extensive underground mining activities. Therefore, the prediction of road subsidence is crucial for effective land management and infrastructure planning. This paper applies an artificial neural network (ANN) to predict road subsidence caused by underground mining activities in Vietnam. The ANN model proposed in this study is adopted relying on the recursive multistep prediction process, in which the predicted value in the previous step is appended to the time series to predict the next value. The entire dataset of 12 measured epochs covering 12 months with a 1-month repeat time is divided into the training set by the first 9 measured epochs and the test set by the last 3 measured epochs. K-fold cross validation is first applied to the training set to determine the best model’s hyperparameters, which are then adopted to predict land subsidence of the test set. Absolute errors of the predicted road subsidence depend on the separated time between the last measured epoch and the predicted epoch. Those errors at the 10th month of the three tested points are 3.0%, 0.1 %, and 0.1%, which increase to 4.8%, 3.3%, and 1.5% at the 11th month, and 7.2%, 2.5% and 1.3% at the 12th month. The absolute errors are found to be small, which were all ranged with 0.5 mm and demonstrates that the proposed method utilizing ANN in this study can produce good prediction for road subsidence time series at mining areas.

6

Using elastic wave velocity anomaly to predict rockburst hazard in coal mines

Zhou Kunyou, Małkowski Piotr, Dou Linming, Yang Ke, Chai Yanjiang

Archives of Mining Sciences

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2023

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Vol. 68, no. 1

141--164

EN

For the prevention and control of rockburst in underground coal mines, a detailed assessment of a rockburst hazard area is crucial. In this study, the dependence between stress and elastic wave velocity of axially-loaded coal and rock samples was tested in a laboratory. The results show that P-wave velocity in coal and rock is positively related to axial stress and can be expressed by a power function. The relationship showed that high stress and a potential rockburst area in coal mines can be determined by the elastic wave velocity anomaly assessment with passive seismic velocity tomography. The principle and implementation procedure of passive seismic velocity tomography for elastic wave velocity were introduced, and the assessment model of rockburst hazard using elastic wave velocity anomaly was built. A case study of a deep longwall panel affected by rockbursts was introduced to demonstrate the effectiveness of tomography. The rockburst prediction results by passive velocity tomography closely match the dynamic phenomenon in the field, which indicates the feasibility of elastic wave velocity anomaly for rockburst hazard prediction in coal mines.

7

On the merits of modified sublevel caving mining method – a case study

Adams Kenneth K., Chen Tuo, Sainoki Atsushi, Mitri Hani S.

Archives of Mining Sciences

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2023

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Vol. 68, no. 4

543--569

EN

Sublevel caving (SLC) mining method has several features that make it one of the preferred methods for ore extraction due to its high productivity and early access to ore recovery. However, there are some major challenges associated with the SLC method such as ground surface subsidence, high unplanned ore dilution, and the potential for air blast. To remedy these shortcomings, a recent approach has been to modify the SLC method by introducing rockfill into the void atop the production zone to provide continued support for the host rock and prevent it from caving. This paper discusses in detail the merits of the Modified SLC or MSLC. In comparison with other long-hole stoping methods that are predominantly practiced in metal mines, the MSLC method boasts several advantages. Early production achieved from the topmost level helps reduce the payback period. Productivity is enhanced due to multilevel mining without the use of sill pillars. The cost of backfilling is significantly reduced as there is no need for the construction of costly backfill plants. Continuous stoping is achieved without delays as mining and backfilling take place concurrently from separate mining horizons. A significant reduction in underground development costs is achieved as fewer slot raises and crosscuts are required for stope preparation. These merits of the Modified SLC method in steeply dipping orebodies are discussed by way of reference to real-life mine case studies. Dilution issues are addressed, and the benefits of top-down mining are explained. Typical mine design, ventilation, materials handling, and mining schedules are presented. Geomechanics issues associated with different in-situ stress environments are discussed and illustrated with simplified mine-wide 3D numerical modeling study.

8

Computer-aided selection of the stabilising system parameters of the mobile transport and assembly manipulator in mining excavations

Krauze Krzysztof, Klempka Ryszard, Mucha Kamil, Wydro Tomasz

Archives of Mining Sciences

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2023

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Vol. 68, no. 1

3--18

EN

Shifting masses in a confined space in the company of other machines and devices, which limits the manoeuvring and transport area, poses a significant problem in every field of industry, especially with underground mining. The works involved in transporting and manoeuvring masses in underground workings are challenging and are most often performed using various auxiliary machines or manually. Hence the need arose to develop a device carrying out activities related to the shifting of masses with the assumed maximum value. The device was created as a result of cooperation between FAMA sp. z o.o. and the AGH University of Science and Technology in Kraków, Poland. The mining modular transport and assembly unit (MZT-M) enables assembling and transporting various masses, especially the elements of the roadway support in the face. The primary function of this device is its movement in the excavation along with the transported mass and delivering it to a specific place. Therefore, an important issue is to ensure the module’s stability in different phases of its operation (lifting, transport, manoeuvring, feeding, lowering) due to the limited space in the excavation. That is why an analytical model and specialised software were created to determine the design parameters of the device as a function of its operating phases, especially the counterweight’s mass. As previously mentioned, an analytical model (physical, mathematical) with equations and applications written in Microsoft Visual Studio and Matlab was used for this purpose. It is beneficial at the design or construction changes stage. Calculation results are documented in the form of numerical summaries and graphs.

9

Porównanie stosowania kolejek podwieszonych o napędzie akumulatorowym z kolejkami spalinowymi w podziemnych kopalniach węgla kamiennego

Szlązak Nikodem, Korzec Marek

Przegląd Górniczy

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2022

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T. 78, nr 4

36--44

PL

Transport materiałów oraz załogi stanowi ważne ogniwo w procesie produkcyjnym w każdym podziemnym zakładzie górniczym. Pogarszające się warunki klimatyczne związane głównie ze zwiększającą się głębokością eksploatacji oraz obecnością maszyn zmuszają do poszukiwania rozwiązań poprawiających sytuację. Istotnym czynnikiem pogarszającym warunki pracy są także substancje szkodliwe wydzielające się wraz ze spalinami z pracujących silników zasilanych olejem napędowym. W celu utrzymania stężeń gazów na odpowiednim poziomie bardzo często trzeba doprowadzić do miejsc ich pracy powietrze w ilości przekraczającej inne wymagania. Sposobem na rozwiązanie tych problemów może być zastąpienie kolejek podwieszonych spalinowych nowymi rozwiązaniami o napędzie elektrycznym, zasilanymi akumulatorowo. W artykule przeprowadzono analizę spalin kolejek pracujących w kopalni węgla kamiennego oraz określono wymagane strumienie powietrza pozwalające na utrzymanie dopuszczalnych stężeń czynników szkodliwych. Przeprowadzono także analizę porównawczą warunków klimatycznych w drążonym wyrobisku chodnikowym, uwzględniając funkcjonowanie wyrobiska z pracą kolejki spalinowej oraz pracą kolejki elektrycznej. Przeprowadzona analiza pozwoliła wskazać przyrosty ciepła w wyrobisku spowodowane pracą obu rozwiązań kolejek. Na podstawie wykonanych analiz stwierdzono, że stosowanie kolejek elektrycznych może w istotny sposób przyczynić się do poprawy warunków pracy w wyrobiskach.

EN

Materials and mine staff transportation is necessary during production process in underground mines. Worsening climatic conditions, related to the mining depth and the usage of machines, force us to look for solutions to improve the situation. Another essential factor connected with underground working conditions is harmful substances and exhaust fumes emitted from Diesel engines. For maintaining the gas concentration at the appropriate level it is necessary to supply air in quantities exceeding other requirements. Possible way to solve the problems is replacing suspended monorails powered by internal combustion engines with new solutions of electrically battery-powered monorails. In the article were performed the analyzes of the exhaust gas parameters from monorail locomotives operating in a hard coal mine and determines the required airflow to maintain permissible concentrations of harmful gases. I was also done a comparative analysis of climatic conditions in the development heading, considering the roadway’s functioning with and without using Diesel or electric monorail. The obtained results showed that using electric monorails could significantly improve working conditions.

10

Use of InSAR in Linear Discontinuous Ground Deformation Generation analysis: case study of a mine in Poland

Apanowicz Bartosz

Journal of Sustainable Mining

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2022

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Vol. 21, iss. 1

45--53

EN

Linear Discontinuous Ground Deformations are defined as fissures and steps, as well as structural forms composed of them. They occur on the surface as a result of underground mining. Knowledge of LDGDs has been acquired through field observations which are subsequently described in the scientific publication. Records of LDGDs are made by using the classic surveying method. The paper reviews the created LDGDs in the years 2015-2019 in one of the mines of the USCB. The analysis covers the velocity of subsidence as a result of underground mining and the values of horizontal strains determined according to the Knothe-Budryk theory. The InSAR satellite technique was used to measure the subsidence. The subsidence was determined using the small baseline method - SBAS. The combination of the theoretical Knothe-Budryk model with the large-scale capabilities of InSAR may provide valuable material for a better understanding of the genesis of LDGD creation and their prediction.

11

The use of microalgal sourced biodiesel to help underground mines transition to battery electric vehicles

Laamanen Corey A., Moreau Kyle, Desjardins Sabrina M., McLean Shannon H., Scott John A.

Journal of Sustainable Mining

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2022

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Vol. 21, iss. 1

2--14

EN

The use of fossil fuel sourced diesel underground has various associated health and environmental hazards, and additional energy demand and costs associated with necessary ventilation. One way to reduce these impacts is by utilizing a biodiesel-blend, which generates lower levels of harmful emissions from underground equipment and can be produced regionally, reducing the impact of transportation. Furthermore, this would help allow use of existing machinery during transition towards more widespread electrification underground. Therefore, the concept of an integrated supply and use chain within the mining industry is examined based on biodiesel from acidophilic photosynthetic microalgae cultivated using CO 2 in smelter off-gas. A life cycle assessment (LCA) was conducted to compare the environmental impacts of production, transportation, and end-use of fossil fuel sourced diesel to biodiesel-blended fuel across four underground metal ore mine sites (Canada, Poland, Zambia, and Australia). The outcomes from assessing four key environmental impact potentials (global warming, eutrophication, acidification and human toxicity) demonstrate the advantages of using biodiesel-blends. The integration of biodiesel resulted in changes of -22.5 to +22.8% (global warming), -6.1 to +27.3% (eutrophication), -18.9 to +26.3% (acidification), and -21.0 to -3.6% (human toxicity). The results showed reduction across all potentials for two mines and reduction in human toxicity potential for all sites.

12

Effect of mining and geology on mining-induced seismicity – a case study

Khalil Heba, Chen Tuo, Xu Yu-Hang, Mitri Hani

Journal of Sustainable Mining

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2022

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Vol. 21, iss. 3

200--215

EN

Mining-induced seismicity is a commonly occurring phenomenon in underground mines. This poses a greater challenge to the safety of the mining operation. This paper presents a case study of the Young-Davidson mine in northern Ontario, Canada, where seismic events of magnitude Mn 2.0+ have been observed at mining depths of 600 to 800 m below the surface. The occurrence of large seismic events at such shallow depths is the key issue of this study. A comprehensive study of the microseismic database has been conducted to discern the root causes for the unusually strong seismic activities recorded at shallow depths. The effects of mining activities in the vicinity of two dykes intersecting the orebody on the seismic response are investigated. Variation of the b-value derived from the magnitude-frequency distribution is examined, and moment tensor inversion for three large seismic events is carried out to determine the source mechanisms. It is shown from this investigation that the influence of the sill pillar is more critical, leading to high mining-induced stress and the occurrence of large events. While the findings from this research are specific to this case study, they could be used to shed light on the causes of induced seismicity at other mines with similar conditions.

13

Zarządzanie podczas sytuacji awaryjnych na przykładzie podziemnej kopalni rudy miedzi

Zgrzebski Przemysław, Laskowski Mirosław, Danis Marcin

Inżynieria Mineralna

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2022

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no. 1

79--86

PL

Górnictwo stanowi tę gałąź przemysłu, gdzie w trakcie normalnej działalności produkcyjnej mogą występować zdarzenia awaryjne o katastrofalnych skutkach. Podczas nagłych wypadków z udziałem ludzi, akcje ratownicze prowadzone są w ustawowo określonym trybie. Ale to nie jedyne sytuacje kryzysowe, które mogą wystąpić w kopalni. W większości z nich nie mamy narzuconych scenariuszy działań. W artykule opisano wykorzystanie podejścia PCDA z elementami Problem Solving podczas zarządzania sytuacją awaryjną w jednej z podziemnych kopalń rudy miedzi.

EN

Mining is the branch of industry where catastrophic accident events may occur in the course of normal production activities. During emergencies involving people, rescue operations are carried out in a statutory manner. But these are not the only emergencies that may occur in the mine. In most of them we do not have any imposed action plans. e paper describes the use of the PCDA approach with Problem Solving elements when managing an emergency in one of the underground copper ore mines.

14

Methodology development and initial results of CFD simulations of methane distribution in the working of a longwall ventilated in a short “Y” manner

Janoszek Tomasz, Krawczyk Jerzy

Archives of Mining Sciences

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2022

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Vol. 67, no. 1

3--24

EN

The mining in seams with a high methane content by means of a longwall system, under conditions of high extraction concentration, results in exceeding methane concentrations allowed by the regulations at workings of the longwall environment, with the effect of mining machines’ standstill periods. The paper is a part of a study supporting the development of a system for shearing cutting speed control at the longwall, which should substantially reduce the production standstills due to exceeded limits and switching off the supply of electric equipment. Such a control system may be appropriate for longwalls ventilated using “Y” and “short Y” methods. Efficient Computer simulations of the 3D airflow and methane propagation may assist the design and initial evaluation of the control system performance. First chapters present studies that are necessary for a proper formulation of the properties of the longwall model. Synthetic analysis of production during the period of longwall operation allowed one to choose the input assumptions to carry out ventilation-methane computations in a CFD numerical model of longwall Z-11. This study is followed by a description of the model that is used for a case study, considering three variants of the shearer position. Finally, initial simulation results and directions of further studies are discussed.

15

Harmonization of technical requirements in the scope of machines for underground mines

Malec Małgorzata, Zając Romana

Mining Machines

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2021

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no. 2

44--52

EN

In the European Union different methods of harmonizing technical requirements are accepted. The main legal instrument includes, among others, directives and European standards which are a key component of the European Single Market. European Standardization plays an important role in the development and consolidation of the European Single Market. The fact that each European Standard is recognized across the whole of Europe, and automatically becomes the national standard in 34 European countries, makes it much easier for businesses to sell their goods or services to customers throughout the European Single Market. This article presents general principles of implementing uniform technical requirements contained in the harmonized standards following the example of mining machines, in particular powered roof supports. The article concerns the standard EN 1804-Parts:1; 2; 3, i.e. Machines for underground mines - Safety requirements for hydraulic powered roof supports: - Part 1: Support units and general requirements, - Part 2: Power set legs and rams, - Part 3: Hydraulic and electrohydraulic control systems. The authors described the work results of the Technical Committee CEN/TC 196 “Mining machinery and equipment - Safety”, over the years 2017-2020, oriented onto establishing three new edition of standards. These new edition of standards have been prepared under a mandate given to CEN by the European Commission and the European Free Trade Association and supports essential requirements of EU Directives.

16

Cause and Solution to Roadway Deformation in Vietnam Underground Coal Mine

Le Quang Phuc

Inżynieria Mineralna

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2021

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no. 2

381--390

EN

The deformation and support method of roadways have always been important issues in safe mining and production. Vinacomin's statistics show that, by 2021, there will be 64.19 km of roadways that need to be repaired (accounting for 25% of the total new roadways). Thus, the problem of maintaining roadway stability is facing difficulties in underground coal mines in Vietnam. To find out the causes of roadway failures, a case study at roadways of the Khe Cham I and Khe Cham III coal mines, Vietnam, is presented in this paper. Based on the results of a detailed field survey, the deformation characteristics of roadways and the failure mode of support structures were investigated. The results show that the roadway deformation is severe and the main support cannot control surrounding rock mass. Also, the destruction of support structure is frequent on reused roadways, affecting production efficiency and work safety. Therefore, to reduce deformation and increase roadway stability, a new support method called “multistage anchor of rock bolt + cable bolt” has been developed and a new longwall mining system with critical coal pillar width has been proposed. The new findings of the research can provide references for scientific studies, and apply them in Vietnam's underground coal mine practices.

17

Applying Artificial Pillar to Replace the Coal Pillar Protecting Roadway to Increase Production Efficiency and Sustainable Development in the Vietnamese Coal Industry

Dinh Van Cuong, Nguyen Anh Tuan, Tran Van Thanh, Nguyen Thi Hoai Nga, Duong Duc Hai

Inżynieria Mineralna

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2021

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no. 2

587--597

EN

Vietnam's domestic coal production is growing fast and is expected to reach 68.9 million tons in 2030, nearly 1.5 times higher than today. Open-pit mines will gradually reduce production and close, and underground mining coal output will increase progressively year by year and take a leading role. Besides the investment in new mines to achieve these goals, it is necessary to maximize the coal reserve exploited annually of existing underground mine projects, which its coal reserve in pillars protecting roadways currently accounts for 12−15%. The further exploitation of this coal reserve will decrease the costs of preparation of underground mines and granting mining rights and depreciation of infrastructure assets. Moreover, it will help reduce the loss of non-renewable resources and contributing to the sustainable development of Vietnam’s coal industry.

18

Badanie i analiza stanu cieplnego jednostek napędowych przenośnika taśmowego w oparciu o pomiar termowizyjny

Szurgacz Dawid, Więcek Piotr, Stempniak Marta

Bezpieczeństwo Pracy i Ochrona Środowiska w Górnictwie

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2021

|

nr 8

2--7

PL

W artykule przedstawiono badania nad określeniem stanu cieplnego jednostek napędowych przenośnika taśmowego odstawy głównej. W realizowanych badaniach wykorzystano termowizję, którą charakteryzuje bezdotykowy pomiar. W oparciu o uzyskane wyniki wyciągnięto wnioski o stanie technicznym jednostek napędowych.

EN

Underground mining involves natural processes associated with high temperatures generated by rocks as well as the machinery and equipment used in the production. A belt conveyor transporting excavated material from the longwall is one of such elements. The performance of power unit of belt conveyors located in workings where the air temperature i.s high, impacts the efficiency of the overall mining process. A thermal imaging study was performed to determine the thermal condition of such a power unit. Al! the measurements were taken using a thermal imaging camera. The main research task was to detect changes associated with an increase in temperature of an operating conveyor drive unit. A series of measurements have been taken and the results of them have shown the correct thermal condition of the conveyor analysed.

19

Geophysical and analytical determination of overstressed zones in exploited coal seam: a case study

Chlebowski Dariusz, Burtan Zbigniew

Acta Geophysica

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2021

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Vol. 69, no. 2

701--710

EN

A variety of geophysical methods and analytical modeling are applied to determine the rockburst hazard in Polish coal mines. In particularly unfavorable local conditions, seismic profling, active/passive seismic tomography, as well as analytical state of stress calculating methods are recommended. They are helpful in verifying the reliability of rockburst hazard forecasts. In the article, the combined analysis of the state of stress determined by active seismic tomography and analytical mod eling was conducted taking into account the relationship between the location of stress concentration zones and the level of rockburst hazard. A longwall panel in the coal seam 501 at a depth of ca.700 m in one of the hard coal mines operating in the Upper Silesian Coal Basin was a subject of the analysis. The seismic tomography was applied for the reconstruction of P-wave velocity felds. The analytical modeling was used to calculate the vertical stress states basing on classical solutions ofered by rock mechanics. The variability of the P-wave velocity feld and location of seismic anomaly in the coal seam in relation to the calculated vertical stress feld arising in the mined coal seam served to assess of rockburst hazard. The applied methods partially proved their adequacy in practical applications, providing valuable information on the design and performance of mining operations.

20

Charakterystyka głównych geotypów obszarowych ocen podatności wód podziemnych na zanieczyszczenia

Bukowski Przemysław, Krogulec Ewa, Haładus Andrzej

Przegląd Geologiczny

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2020

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Vol. 68, nr 4

226--232

EN

The article presents a proposal of the classification of hydrogeological and environmental conditions in relation to different intensities of the impact of factors affecting groundwater threat in assessments of groundwater vulnerability to pollution. Due to the complexity and high degree of transformation of the natural environment, including aquatic, types of areas subjected to ordinary and strong anthropopressure, the so-called Area Geotypes (GO), are distinguished and discussed. The main factors characterizing the impact of mining activity on the water environment (typical and specific) are discussed, and the mine ’s characteristics are highlighted, emphasizing its role and importance as an influator constituting a large, multifactorial source threatening the groundwater environment. The role of the mine as an influator is presented against the background of the mine ’s "life cycle”(development phases) along with an indication of the desirability of carrying out assessments of groundwater vulnerability to pollution and groundwater threat assessments. The need to develop legal regulations regarding the preparation of vulnerability assessments is indicated.