Analysis of the Thermophysical Properties and Influencing Factors of Various Rock Types From the Guizhou Province

Song, X.; Jiang, Ming; Peiwen, Xiong

doi:10.1051/e3sconf/20185303059

Cited by 11 publications

(5 citation statements)

References 6 publications

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“…The first step in establishing the nature of the transformation was to determine the specific heat of the studied dolomite, for which a value of 932.74 J/kg∙K was obtained. This result is in agreement with values reported in the literature [ 34 , 35 , 36 , 37 , 38 ]. The fundamental problem addressed in the study was the determination of the rate of heat exchange between the rock and the gas.…”

Section: Discussionsupporting

confidence: 93%

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The Intensity of Heat Exchange between Rock and Flowing Gas in Terms of Gas-Geodynamic Phenomena

Koziel

Topolnicki

Skoczylas

2021

Entropy

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Gas-induced geodynamic phenomena can occur during underground mining operations if the porous structure of the rock is filled with gas at high pressure. In such cases, the original compact rock structure disintegrates into grains of small dimensions, which are then transported along the mine working space. Such geodynamic events, particularly outbursts of gas and rock, pose a danger both to the life of miners and to the functioning of the mine infrastructure. These incidents are rare in copper ore mining, but they have recently begun to occur, and have not yet been fully investigated. To ensure the safety of mining operations, it is necessary to determine parameters of the rock–gas system for which the energy of the gas will be smaller than the work required to disintegrate and transport the rock. Such a comparison is referred to as an energy balance and serves as a starting point for all engineering analyses. During mining operations, the equilibrium of the rock–gas system is disturbed, and the rapid destruction of the rock is initiated together with sudden decompression of the gas contained in its porous structure. The disintegrated rock is then transported along the mine working space in a stream of released gas. Estimation of the energy of the gas requires investigation of the type of thermodynamic transformation involved in the process. In this case, adiabatic transformation would mean that the gas, cooled in the course of decompression, remains at a temperature significantly lower than that of the surrounding rocks throughout the process. However, if we assume that the transformation is isothermal, then the cooled gas will heat up to the original temperature of the rock in a very short time (<1 s). Because the quantity of energy in the case of isothermal transformation is almost three times as high as in the adiabatic case, obtaining the correct energy balance for gas-induced geodynamic phenomena requires detailed analysis of this question. For this purpose, a unique experimental study was carried out to determine the time required for heat exchange in conditions of very rapid flows of gas around rock grains of different sizes. Numerical simulations reproducing the experiments were also designed. The results of the experiment and the simulation were in good agreement, indicating a very fast rate of heat exchange. Taking account of the parameters of the experiment, the thermodynamic transformation may be considered to be close to isothermal.

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Section: Discussionsupporting

confidence: 93%

“…The averaged result obtained in the experiments is very close to the values for the specific heat of dolomite reported in the literature, which range from approximately 850 to 950 J/(kg·K) [ 34 , 35 , 36 , 37 , 38 ].…”

Section: Resultssupporting

confidence: 86%

The Intensity of Heat Exchange between Rock and Flowing Gas in Terms of Gas-Geodynamic Phenomena

Koziel

Topolnicki

Skoczylas

2021

Entropy

View full text Add to dashboard Cite

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“…In addition, the rocks should have different thermal behaviour because of their different characteristics. For example, there is an appreciable difference in the specific heat of limestone (0.515 ± 0.015 kJ/kg • C) and dolostone (0.553 ± 0.082 kJ/kg • C) [56], which suggests that there is different thermal behaviour between the two lithologies.…”

Section: Resultsmentioning

confidence: 99%

Mining Exploration with UAV, Low-Cost Thermal Cameras and GIS Tools—Application to the Specific Case of the Complex Sulfides Hosted in Carbonates of Udías (Cantabria, Spain)

et al. 2022

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The depletion of natural resources implies the need for a constant search for new reserves to satisfy demand. In the mining sector, Unmanned Aerial Vehicles (UAVs) have revolutionised geo-information capture and modelling to allow the use of low-cost sensors for prospecting and exploration for potentially exploitable resources. A very powerful alternative for managing the huge volume of data is the Geographic Information System (GIS), which allows storage, visualisation, analysis, processing and map creation. The research in this paper validates a new quasi-automatic identification of mining resources using GIS thermal-image analysis obtained from UAVs and low-cost sensors. It was tested in a case that differentiated limestone from dolostone with varying iron content, and different thermal behaviour from solar radiation, thereby ensuring that the thermal image recorded these differences. The objective is to discriminate differences in an image in a quasi-automatic way using GIS tools and ultimately to determine outcrops that could contain mineralisation. The comparison between the proposed method with traditional precision alternatives offered differences of only 4.57%, a very small deviation at this early stage of exploration. Hence, it can be considered very suitable.

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“…If these measurements were performed in a vertical line scan along the center of a typical 60 mm long, 12.5 g returned Mars sample, ~0.76 J maximum would be transferred in total, equivalent to a maximum dose of ~61 Gy. If all this energy was absorbed as heat, assuming a lower end heat capacity for a basalt of 400 J kg −1 K −1 (Xiaoqing et al., 2018), this would result in a sample temperature increase of 0.15 K. This upper limit is much lower than required to avoid effects on amino acid content (Friedrich et al., 2016).…”

Section: Methodsmentioning

confidence: 99%

Synchrotron x‐ray diffraction for sealed Mars Sample Return sample tubes

Adam,

Bridges,

Bedford

et al. 2023

Meteorit & Planetary Scien

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The joint NASA‐ESA Mars sample return campaign aims to return up to 31 sample tubes containing drilled sedimentary and igneous cores and regolith. The titanium alloy tubes will initially still be sealed when they are retrieved. Several types of measurement will be carried out on sealed samples in the pre‐basic characterization phase of scientific investigation. We show that powder x‐ray diffraction (XRD) analysis can be successfully carried out on sealed samples using an x‐ray source at the I12 beamline of Diamond Light Source synchrotron. Our experiment used an analog sample tube and a Martian regolith analog (Icelandic basaltic sand). The titanium walls of the tube analog give strong but few diffraction peaks, making identification of the major constituent mineral phases feasible. A more significant constraint on quantification of mineral phase abundances by this XRD technique is likely to be the grain size of the sample. This technique opens up the possibility of initial mineralogical analysis of samples returned from Jezero crater without opening the sample tubes and the potential changes to the sample that entails.

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Analysis of the Thermophysical Properties and Influencing Factors of Various Rock Types From the Guizhou Province

Cited by 11 publications

References 6 publications

The Intensity of Heat Exchange between Rock and Flowing Gas in Terms of Gas-Geodynamic Phenomena

The Intensity of Heat Exchange between Rock and Flowing Gas in Terms of Gas-Geodynamic Phenomena

Mining Exploration with UAV, Low-Cost Thermal Cameras and GIS Tools—Application to the Specific Case of the Complex Sulfides Hosted in Carbonates of Udías (Cantabria, Spain)

Synchrotron x‐ray diffraction for sealed Mars Sample Return sample tubes

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