Wyniki wyszukiwania - BazTech

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Influence of grain size and gas pressure on diffusion kinetics and CH 4 sorption isotherm on coal

Kozieł Katarzyna, Gajda Aleksandra, Skiba Marta, Skoczylas Norbert, Pajdak Anna

Archives of Mining Sciences

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2024

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Vol. 68, no. 1

3--23

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.

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Rock transport after an outburst and the fluidisation phenomenon – can it occur during a dolomite and gas outburst?

Kozieł Katarzyna, Skoczylas Norbert

Archives of Mining Sciences

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2023

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Vol. 68, no. 4

621--638

EN

Rock and gas outburst is a phenomenon in which fragmented rock material is transported deep into a pit. The transport of rock material by gas is a two-phase process. The article deals with the fluidisation of rock material. Considerations on the fluidisation phenomenon were carried out, and experiments were performed to help clarify whether the fluidisation of dolomite is possible. In the last chapter, a discussion was carried out, and the results obtained were analysed regarding the possibility of occurrence in mine conditions.

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Force exerted by gas on material ejected during gas-geodynamic phenomena analysis and experimental verification of theory

Kozieł Katarzyna, Janus Jakub

Archives of Mining Sciences

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2022

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Vol. 67, no. 3

491--508

EN

The analysis of natural hazards, including gas-geodynamic phenomena, requires study of the basic physical processes that take place at each stage of an event. This paper focuses on analysing the transport of fragmented rock material during rock and gas outbursts. Our theoretical considerations and experiments have allowed us to specify and verify the significant forces acting on fragmented rock during its transport, thus determining the speed of grains of each grain class in the stream of expanding gas. The above study may serve as a preface to a wide-ranging quantitative and qualitative energy analysis of the movement of material ejected during Gas-geodynamic phenomena.

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Analiza porównawcza porowatości całkowitej dolomitu wyznaczanej metodą punktowej ilościowej analizy mikroskopowej oraz metodą densymetryczną

Kozieł Katarzyna

Prace Instytutu Mechaniki Górotworu PAN

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2020

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T. 22, nr 1-4

69--73

PL

W artykule przedstawiono wyniki badań porowatości skał, pochodzących z Legnicko-Głogowskiego Okręgu Miedziowego, określonych dwiema metodami: densymetryczną oraz punktową analizą mikroskopową. Do określenia porowatości sposobem densymetrycznym wykorzystano metody piknometrii helowej oraz quasicieczowej a także autorski analizator do rozdrobnienia skał. Porowatość metodą punktowej analizy mikroskopowej zbadana została przy pomocy mikroskopu polaryzacyjnego AXIOPLAN ze sterowanym komputerowo stolikiem mechanicznym XYZ. Analizom poddano 20 próbek dolomitu. Dla wszystkich próbek wyznaczona została porowatość całkowita na dwa sposoby. Każda z próbek w metodzie densymetrycznej uzyskała niższy wynik porowatości całkowitej. Średnia porowatość wyznaczona metodą densymetryczną wyniosła niespełna 3%, zaś w punktowej analizie mikroskopowej wynik ten był na poziomie 8,2%.

XX

The article presents the results of research of porosity of rocks from the Legnica-Głogów Copper District, determined by two methods: densimetric and point microscopic analysis. The helium and quasi-liquid pycnometry methods were used to determine the porosity using the densimetric method, as well as the author’s analyser for rock fragmentation. The porosity was determined by point microscopic analysis using an AXIOPLAN polarizing microscope with a computer-controlled XYZ mechanical table. 20 samples of dolomite were analyzed. For all samples, the total porosity were determined in two ways. Each of the samples in the densimetric method obtained a lower total porosity result. The average porosity determined by the densimetric method was less than 3.0%, while in the point microscopic analysis, this result was at the level of 8.2%.