Island Mine Research Articles

Compound disaster characteristics of rock burst and coal spontaneous combustion in island mining face: A case study

The island mining face in coal mines often encounters stress concentration and significant air leakage, elevating the risk of rock burst and spontaneous combustion of residual coal in the goaf. This study centers on the investigation of the 9305 island mining face within a mine situated in Shandong Province, China. Leveraging the features of coal spontaneous combustion and data from microseismic and gas monitoring throughout the mining process, a novel method for calculating safe mining speeds under compound disasters is introduced. The safe mining speed of the 9305 island mining face is stratified, and a prevention and control technology integrating long distance directional drilling for impact-spontaneous combustion compound disasters is proposed. Findings suggest that to mitigate spontaneous combustion of residual coal, considering the seam's spontaneous combustion tendency, the safe mining speed should exceed 3.7 m per day. Accounting for the distribution of microseismic events during coal seam extraction, the safe mining speed is maintained below 4.8 m per day in the unprotected mining area and capped at 8 m per day in the protected zone. Through a comprehensive analysis considering coal seam spontaneous combustion tendency, impact tendency, and time to coal seam oxidation to critical temperature, the safe mining speed for the island mining face ranges from 3.7 m per day to 4.8 m per day in the unprotected area and from 5.14 m per day to 8 m per day in the protected area. The proposed long distance directional drilling 'one hole, multiple purposes' scheme enables an integrated approach encompassing pressure relief before coal seam extraction, water injection during mining, and grouting post-mining. This method effectively prevents and controls the compound disasters of rock burst and coal spontaneous combustion, presenting innovative technical solutions for the safe extraction of coal resources.

Comprehensive heat extraction performance and fractured reservoir cooling effect analysis of a novel mine enhanced geothermal system

Mining deep metal mines poses significant challenges due to the high-temperature conditions in such environments. However, the vast untapped geothermal energy within these mines holds great prospects for development and application. Herein, we proposed a novel technology for the deep mine cooling and enhanced geothermal system (DMC-EGS), which transforms the relationship between deep mining and geothermal resources from a source of heat harm to heat benefit, while also providing conditions for underground mining environment cooling. Understanding the fluid flow and heat transfer processes in the deep mine thermal reservoir is crucial for developing DMC-EGS. Based on the local thermal equilibrium theory, a three-dimensional thermal–hydraulic coupled model of the thermal reservoir in the Sanshan Island Mine containing multiple fractures was established. The impact of natural fractures and fracture number on the thermal recovery performance and cooling effect of the system was considered, and the optimization scheme of heat recovery wellbore was proposed for the deep thermal reservoir of Sanshan Island Mine. It can be found that fractures play a crucial role in fluid-rock heat exchange. Compared with scenarios without fractures, hydraulic fractures could significantly improve the heat transfer capacity and rock cooling effect, resulting in a 45.7% increase in the amplitude of rock matrix temperature decrease and more than a 1.76-fold increase in overall heat recovery efficiency. In addition, the number of fractures significantly impacted the temperature distribution within the rock formation, and an increased number of fractures was associated with more efficient heat recovery performance. When the number of fractures was 7, the cumulative thermal production could reach 6.767 × 109 J. Among the three thermal exploitation schemes compared, the DMC-EGS under the triple-well mode yielded the best heat recovery performance during the 40-year extraction period, superior to the conventional dual-well mode, while the one injection and two production mode demonstrated better heat recovery capacity and cooling effect.

The Ediacaran record of glaciogenic dropstones, diamictites and cap carbonates associated with non-metamorphosed banded iron formations (BIFs) in Iran

The Ediacaran period is marked by global icehouse episode, greenhouse period, increasing levels of oxygen-carbon dioxide, syn-glaciogenic structures-BIFs, typical Ediacaran biota and a marked negative carbon isotope excursion. On this global point, field glaciogenic structures, petrographic textures, Ediacaran biota, U-Pb zircon ages, C-O isotopes and geochemical data record an Ediacaran glaciogenic BIFs event in Iran. The Ediacaran (578–547 or 578–541.8 Ma) glaciogenic sequences in Bafq and Hormuz Island mining districts include submarine syn-glaciovolcanic rhyolitic rocks, rhyolitic tuffs, shaly tuffaceous carbonates, dropstone-bearing jaspilitic BIFs, salt minerals, ferruginous diamictites, and cap carbonates. The presence of polygonal, bullet-shape and flatiron forms of gneiss, greenschist, quartz schist, quartzite, marble and magnetite-hematite clasts in a matrix of jaspilitic magnetite-hematite, muddy sandstones and muddy dolomitic rocks records an Ediacaran glaciogenic event. The dropstones occur as lone-stones, dump-stones and deflect their underlying layers. The diamictites contain similar clasts to those of the dropstones, are gradationally covered by buff to dark-grey cap carbonates ± dropstones and resemble the Ghaub, Chuos and Kingston Peak Formation diamictites. C-O isotopes, REE+Y diagrams, high Y/Ho ratios, positive Eu-Y anomalies and subtle Ce anomaly possibly reflect a possible hydrothermal origin for the cap carbonates. Delta 13C values (−0.42 to −6.33‰) in cap carbonates show similar negative signatures to the Ediacaran Shuram glaciogenic event. Average delta 18O (−8.34‰) in the least-altered cap carbonates gives a precipitation temperature of 252.7 °C in the waning stage of the glaciogenic BIFs-hydrothermal system.

Pressure Control Technology at the Hard Thick Sandstone Roof in an Island Mining Face with a Large Mining Height

Pressure Control Technology at the Hard Thick Sandstone Roof in an Island Mining Face with a Large Mining Height

Supporting problems at an island mining face in shanxi, China. Case study based on field observation

Abstract In this paper, field observation is conducted in Fujiaao Coal Mine, Linfen city in Shanxi province, China, which is unique because of its island-typed mining layout. Firstly, geology, layout of the coal cutting face, supporting pattern are presented and details are also provided. Then the problems are discussed and analyzed based on existing bolting theories. It finds out the length of the cable bolt is too long, which requires long time to drill boreholes, whilst the effectiveness is limited due to the illogical combination between cable bolt function zone and rock bolt function zone. Also, the face place allocated to rock bolt is very likely to cause line contact between its edge and steel belt, thus the bearing force is tremendously weakened and solely determined by strength of belt. Furthermore, field observation proves the low active supporting effects to roof, thus leading obvious roof sink even without the disturbance of mining activity. Eventually, some solutions are proposed with the intention to improve the situation based on the economic and technical considerations, including bolting in humidity environment, rational cable bolt length, wise choice of face plate, and ways to increase pretension force. The viewpoints and comments of this study can be referred by practitioners in coal mines sharing same difficulties.

Experimental Study on the Pattern of Surrounding Rocks’ Movement under Excavation Activities and Impact Prevention Technologies in Island Mining Face

Based on the structural feature of island mining face’s ‘T’ shape overburden and by using analog material and numerical simulation to analyze the rules of overburden movement and stress distribution, and yield failure characteristics during stoping in island mining face, this paper studies the variation rules of roadway stress, acceleration, displacement and deformation velocity when island mining face’s overburden breaks, producing strong dynamic impact load. The result shows: In the beginning stage of stoping, plastic failure in the surrounding rocks mainly appears in the roof, while in later times, plastic failure in the overburden will gradually move up towards the overlying strata, appearing in symmetrical arcuate; under the dynamic load of mine earthquakes, the left and right ribs suffer slighter deformation than the roof and the floor; the right rib and the roof changes faster than other places; the roof sinks the most; and the vertical stress on the left and right ribs are bigger than that on the roof and the floor. The rules of overburden movement and impact failure in island mining face stated in this paper provide theories for impact prevention in high impact-risk island mining face, impact prevention parameters design and impact prevention measure-making as well as help engineering practice so as to guarantee stoping safety in high impact-risk island mining face.

Fuegian Firestone Quarry: Iron Pyrite on Capitán Aracena Island, Magallanes Archipelago, Southern Chile

Fire was essential for the ancient inhabitants of Tierra del Fuego, at the southernmost end of the Americas. The Fuegians, as these human groups are traditionally known, produced fire primarily by striking a piece of iron pyrite against a flint nodule. Several European chroniclers mention this firestone technology and note its social value, a conclusion based on the fact that it was carefully safeguarded in leather pouches. Anglican missionary Thomas Bridges visited one of these pyrite sources in 1883 with two Yaghan guides and left behind a brief description of its out-of-the-way location. Almost 130 years later, we rediscovered this mine on Capitán Aracena Island in the Strait of Magellan. In this study, we present a brief report focused on the mine’s exact location, archaeological materials, and layout, and we offer the first physical-chemical description of the pyrite source. Comparison of these results to similar analyses of archaeological samples from the Santa Isabel Island settlements in the Magellan Strait suggests that the early inhabitants of the area used different pyrite sources, only one of them corresponding to the Capitán Aracena Island mine.

Football, Place, and Community in a New Zealand Mining Town, 1877–1939

Resource towns (such as lumber camps, power plants, and mining towns) are by their very nature peripheral. They frequently exist in a space of isolation, not only geographically but also culturally as well. The South Island mining town of Kaitangata is a classic example of this process – an industrial, working class, and heavily migrant community positioned within an otherwise agricultural, conservation, and homogenous tract of rural New Zealand. Kaitangata, in the words of one writer, ‘possessed a unique character and pattern of social interaction’ that marked it out from its immediate environment. One way in which these differences manifested themselves was in the sporting activities of the town. In a part of the world where rugby union held absolute hegemony, the town broke the mould by also fielding teams in association football, rugby league, and even Australian Rules football (distinguishing itself as the only town outside of the provincial capital of Dunedin where these three sports obtained a foothold). This paper analyses how these sporting activities contributed to a unique sense of space, addressing themes including class, ethnicity, masculinity, and identity.

Investigation of Intrinsic and External Factors Contributing to the Occurrence of Coal Bumps in the Mining Area of Western Beijing, China

An investigation has been made to relate the occurrence of coal bumps to specific geological and mining conditions to the mining area of western Beijing. This investigation demonstrates that the high frequency of coal bumps in this area is due to four localized conditions, namely intrinsic coal properties, the presence of overturned strata and thrust faults, high in situ stress and the extraction of coal from island mining faces. Laboratory tests of coal samples indicated that the coals have a short duration of dynamic fracture, high bursting energy and high elastic strain energy, indicating that the coal is intrinsically prone to the occurrence of coal bumps. This investigation has also revealed that there are overturned strata and well-developed large- and medium-scale thrust faults in this area, and the presence of these structures results in plastic flow, severe discontinuities, rapid changes in overburden thickness and dipping of the coal seams. Well-developed secondary fold structures are also present in the axes and limbs of the primary folds. The instability of thrust faults, in combination with large-scale intrusion of igneous rocks, is closely associated with sudden roof breaking and induces sharp variations in electromagnetic radiation (EMR) and micro-seismic signals, which could be used to help predict coal bumps. In situ stress tests in the mining area demonstrate that the maximum and minimum principal stresses are nearly horizontal and that the intermediate principal stress is approximately vertical. The in situ stress level in the area is higher than the average in the Beijing area, North China and mainland China. In addition to the presence of overturned strata and thrust faults and high in situ stress levels, another external factor contributing to the frequency of coal bumps is coal extraction from island mining faces in this area. Island mining faces experience intermittent mining-induced abutment stress when a fault exists at one side of the island mining face due to reactivation of the fault, and this stress redistribution increases the likelihood of coal bumps during coal extraction from island mining faces.

‘This Island's Mine’: Ownership of the Island in The Tempest

‘This Island's Mine’: Ownership of the Island in <i>The Tempest</i>

Cyclic Loading Effects on the Creep and Dilation of Salt Rock

The Solution Mining Research Institute (SMRI) has embarked on inquiries into the effect cyclic loading might have on salt. This interest stems from the concept of using salt caverns as a storage medium for renewable energy projects such as compressed air energy storage where daily pressure cycles in the cavern are conceivable as opposed to the seasonal cycles that are typical for natural gas storage projects. RESPEC and the Institut fur Aufbereitung und Deponietechnik at Clausthal University of Technology jointly executed a rock mechanics laboratory study using both facilities for performing triaxial cyclic loading creep tests on rock salt recovered from the Avery Island Mine in Louisiana, USA. The cyclic triaxial creep tests were performed under various load paths including compression, extension, and compression/extension. The tests were performed under both dilative and nondilative stress regimes. The cyclic compression creep data were compared to static creep tests performed under similar conditions to assess the effect of cycling of the applied stress. Furthermore, the cyclic compression tests were compared to a numerically simulated static creep test at the same stress and temperature conditions to determine if the creep behavior was similar under cyclic loading.

This Island's Mine: Mapping the Borders of Shakespeare, Whiteness, and National Belonging in Manhattan's Ethnic Theaters, 1890–1910

By combining performance history's turn to the performativity of archives with rhetorical studies' turn to the rhetoricity of borders, this essay analyzes English-language press coverage of German, Italian, and Yiddish productions of Shakespeare in Manhattan between 1890 and 1910 to show how mainstream journalists articulated Shakespeare as a normative cultural and rhetorical space in which to explore, negotiate, and even resist the increasingly diverse urban population and the shifting reality of what it meant to be American during this period. It also considers the resistive potential, or “border crossings,” of the immigrant performances themselves as they operated within and against the rhetoric of dominant reviewers. Finally, it suggests the utility of performative border rhetorics, specifically “genealogies of bordering,” for future critical cultural histories.

Importance of soil ecology in vegetation rehabilitation on a North Stradbroke Island mine

Importance of soil ecology in vegetation rehabilitation on a North Stradbroke Island mine

&lt;i&gt;The Tempest&lt;/i&gt; and Its Travels

Notes on the Editors and Contributors Preface Prologue: 'After Prospero' I. LOCAL KNOWLEDGE 1. 'Baseless Fabric': London as a 'World City' 2. 'Knowing I loved my books': Reading The Tempest Intertextually 3. The Ship Adrift 4. Wild Waters: Hydraulics and the Forces of Nature 5. Trinculo's Indian: American Natives in Shakespeare's England 6. The Enchanted Island: Vicarious Tourism in Restoration Adaptations of The Tempest II. EUROPEAN AND MEDITERRANEAN CROSSROADS 7. The Italy of The Tempest 8. 'The foul witch' and Her 'freckled whelp': Cricean Mutations in the New World 9. Re-Engineering Virgil: The Tempest and the Printed English Aeneid 10. The Mediterranean and Shakespeare's Geopolitical Imagination 11. Carthage and Tunis, The Tempest and Tapestries 12. Island Logic Cesaire's Une tempete at The Gate Otra Tempestad at The Globe Tempest(s) at Terra Nova Theatre Institute III. TRANSATLANTIC ROUTES 13. The Figure of the New World in The Tempest 14. 'This island's mine': Caliban and Native Sovereignty 15. Arielismo and Anthropophagy: The Tempest in Latin America 16. Reading from Elsewhere: George Lamming and the Paradox of Exile 17. Maintaining the State of Emergence/y: Aime Cesaire's Une tempete 18. H.D.'s 'The Tempest' 19. Hogarth and the Canecutter Envoy: 'The Word-In the Beginning' References Further Reading Acknowledgments Photographic Acknowledgements Index

ABSTRACT: Geologic Mapping of Salt Mines in Salt Diapirs; Approaches and Examples from South Louisiana

Abstract Gulf Coast salt diapirs have complex internal structure, which is shown by light and dark layering. The layering reflects variation in anhydrite content and is interpreted to represent highly stretched and sheared depositional bedding. Structure is dominantly vertical, consisting of repeatedly refolded isoclinal folds having vertical plunge. Geologic mapping is conducted primarily as an aid to mine planning and development; separate maps are produced to record basic structure and display the distribution of clastic stringers, sylvite stringers and lenses, crystal size, wet areas, and gas. The latter characteristics, including coarse salt crystals, are anomalous and tend to be associated (in anomalous areas and trends). Gas is a mining hazard, causing Weeks Island and Cote Blanche Island to be classified by MSHA as gassy mines having many associated regulations. Five miners died in a gas explosion at Belle Isle mine in 1979, and blasting is now normally done while the mines are unoccupied (before the morning shift goes in, for example). Water influx, particularly if derived from outside the mine, is a cause of major concern for obvious reasons; at Avery Island a crew is constantly drilling and grouting to maintain control of leaks, and Jefferson Island mine has been lost as a result of flooding when penetrated by an oil rig. Sand reduces the salability of the commercial product and also increases mining costs. The geologic maps provide structural trend information to help the mine engineers avoid undesirable or potentially dangerous areas including those in proximity to the edge of the diapir. They also cast light on the nature of salt diapirism; linear anomalous zones have routinely been interpreted (sometimes with minimal justification) as boundaries between separate salt spines. Map examples from Weeks Island are included.

Quartz Hill, Alaska: a case history of engineering and environmental requirements for STD in the USA : C. A. Hesse & D. V. Ellis, Marine Georesources & Geotechnology, 13(1–2), 1995, pp 135–182

The Quartz Hill molybdenum prospect, with an estimated tailings disposal rate of up to 80,000 tons per day, was developed through preliminary engineering design, environmental impact assessments, and permit applications during the 1970s and 1980s. The intent was to meet the stringent environmental requirements of several federal and state regulatory agencies. The case history of mine development, extending over two decades, provides a unique set of details usable by future large‐scale coastal and island mine prospects in the U.S. and elsewhere. Two fjords provided options for submarine tailings disposal (STD) with conventional deaeration and seawater mix chamber. An outfall was designed, and would be located, to produce a density current descending to fjord bottom. Innovative modeling of near‐field and far‐field tailings dispersal, and resuspension potential, was developed and applied. Of about $102,000,000 invested on the development, approximately $31,000,000 was given to environmentally related work. F...

Quartz hill, Alaska: A case history of engineering and environmental requirements for STD in the USA

The Quartz Hill molybdenum prospect, with an estimated tailings disposal rate of up to 80,000 tons per day, was developed through preliminary engineering design, environmental impact assessments, and permit applications during the 1970s and 1980s. The intent was to meet the stringent environmental requirements of several federal and state regulatory agencies. The case history of mine development, extending over two decades, provides a unique set of details usable by future large‐scale coastal and island mine prospects in the U.S. and elsewhere. Two fjords provided options for submarine tailings disposal (STD) with conventional deaeration and seawater mix chamber. An outfall was designed, and would be located, to produce a density current descending to fjord bottom. Innovative modeling of near‐field and far‐field tailings dispersal, and resuspension potential, was developed and applied. Of about $102,000,000 invested on the development, approximately $31,000,000 was given to environmentally related work. F...

The Image of the Indo-Caribbean Woman in Olive Senior's "The Arrival of the Snake Woman"

This paper looks at the portrayal of the Indian woman in the contemporary literature of the anglophone Caribbean. It attempts to examine the processes of readjustment and accommodation, acculturation, interculturation and indigenization in its attempt to explore Indo-Caribbean female experience: the psychosocial and spiritual growth and the quest for identity within the context of the Indian diaspora in the Caribbean. It explores the Indian woman's claim to a place as home in the multiracial, multicultural Caribbean vis a vis a tradition of colonial discourse which privileges European possession of the discovered lands of the New World while several culturally discrete groups, displaced by colonialism and indentureship, jostle for ontological space and identity in the colonial social reality. dominant transplanted group in the Caribbean can be seen to have a protest registered against disinheritance and dispossession in Caliban's now famous words of anger hurled at Prospero: island's mine, by Sycorax my mother in Shakespeare's political allegory Tempest. Many West Indian authors have portrayed various aspects of Indo-Caribbean female experience' and I have chosen to examine Olive Senior's short story, The Arrival of the Snake Woman2 because it seems to present a culmination of all the phases of readjustment and accommodation inherent in migration and displacement. It starts at the beginning of the process with the woman as an alien and works its way through the alienation and isolation of the exile, colonial victimization and racial exclusion to the conscious decision to integrate culturally and also to address the issue of her tentative hold on land and home. This paper also reveals that this short story is counterdiscursive: it depicts resistance to the colonial power base and questions the centre/ margin paradigm of dominant discourse in a manner which characterizes post-colonial writing. Ashcroft, Griffiths, and Tiffin address themselves in Empire Writes Back (Routledge, 1989) to the question of the dismantling of the power hierarchy entrenched in colonial texts, the abrogation of European power and its false premises, the reappropriation of indigenous cultural forms and the recognition that hybridity and syncreticity are the most viable means to recuperation and selfhood in the semiotics of postcolonial writing and, although Senior's short story is not itself a rewriting of a colonial text, it is newer writing which intervenes in and resists dominant discourse about the other. It relates how the Indo-Caribbean woman manages in the colonial minefield. Senior's short story depicts a plural society in what is unmistakably colonial Jamaica, the temporal setting estimated at the first half of the twentieth century. At its heart, the work portrays racial antagonisms, cultural differences, alienation, exclu

Rock mechanics program helps improve trona recovery at Stauffer's Big Island Mine in Wyoming : Agapito, J F T; Hunter, R V Min EngngV41, N1, Jan 1989, P24–26

Rock mechanics program helps improve trona recovery at Stauffer's Big Island Mine in Wyoming : Agapito, J F T; Hunter, R V Min EngngV41, N1, Jan 1989, P24–26

Improvements in resource recovery at Stauffer's Big Island Mine

Significant increases in extraction ratio on the order of 6 to 8%, equivalent to as much as 142 t/m of panel advance, have occurred at the Big Island Mine during the last five years with the help of a practical rock mechanics program. This increase in resource recovery has also contributed to improvements in productivity. Both conventional and continuous machine mining have been used to mine two flat-laying trona beds at depths of 250 and 260 m in the Green River Formation in southwestern Wyoming.