scholarly journals Occurrence Forms, Composition, Distribution, Origin and Potential Hazard of Natural Hydrogen–Hydrocarbon Gases in Ore Deposits of the Khibiny and Lovozero Massifs: A Review

Minerals ◽  
2019 ◽  
Vol 9 (9) ◽  
pp. 535 ◽  
Author(s):  
Valentin A. Nivin
Keyword(s):  
Underground Mining ◽  
Carbon Oxide ◽  
Ore Deposits ◽  
Gas Content ◽  
Potential Hazard ◽  
Mining Operations ◽  
Hydrocarbon Gases ◽  
Distinctive Features ◽  
Igneous Complexes ◽  
Main Component

The Khibiny and Lovozero massifs—the world’s largest alkaline massifs—contain deposits with unique reserves of phosphorus and rare metals, respectively. The reduced gas content in the rocks and, especially, the ore deposits of these massifs is unusually high for igneous complexes, thus representing both geochemical and practical interests. There are three morphological types (or occurrence forms) of the gas phase in these deposits: occluded (predominantly in vacuoles of micro-inclusions in minerals), diffusely dispersed, and free. All three morphological types have the same qualitative chemical gas composition. Methane is the main component, and molecular hydrogen (which sometimes dominates) and ethane are the subordinate constituents. Heavier methane homologs (up to and including pentanes), alkenes, helium, and rarely carbon oxide and dioxide are present in minor or trace amounts. All three morphological types of gases are irregularly distributed in space to various degrees. Free gases also show a release intensity that varies in time. The majority of researchers recognize that the origin of these gases is abiogenic and mostly related to the formation of the massifs and deposits. However, the relative time and mechanism of their generation are still debated. Emissions of combustible and explosive hydrogen–hydrocarbon gases pose hazards during the underground mining of ore deposits. Therefore, the distinctive features of gas-bearing capacity are an essential part of the mining and geological characterization of such deposits because they provide a basis for establishing and implementing special measures of the gas regime during mining operations.

A Review of Technical Potential for Coal Production and Coal Degasification – A Conventional Source of Methane – In Nigeria

2003 ◽  
Vol 14 (1) ◽  
pp. 59-67
Author(s):  
Adepo Jepson Olumide ◽  
Ayodele Charles Oludare ◽  
Balogun Olufemi
Keyword(s):  
Coal Seam ◽  
Fossil Fuels ◽  
Underground Mining ◽  
Simple Calculation ◽  
Gas Content ◽  
Gelling Agent ◽  
Coal Bed ◽  
Natural State ◽  
Mining Operations ◽  
Inorganic Matter

Coal, a solid fuel in its natural state has been identified as one of the world's major fossil fuels. It is a compact, stratified mass of mummified plant debris interspersed with smaller amounts of inorganic matter buried in sedimentary rocks. The use of coal as an energy source can be dated back to the prehistoric times. Methane is associated with many if not all coal seams, and is the dreaded “fire damp” responsible for many pit explosions. Coal mines are designed to vent as much methane as possible. It is present in the pores of coal under pressure, released during mining operations and can be extracted through vertical well bores. This paper highlights the fact that pipeline- quality methane can be extracted economically from coal seems before and during underground mining operations. The stimulation method involves hydraulic fracturing of the coal seam by using water, sand and, a gelling agent in a staged and alternating sand/and no sand sequence. The purpose is to create new fractures in the coal seam(s). The cleating of the coal helps to determine the flow characteristics of the coal formation and is vital in the initial productivity of a coal-methane well. The simple calculation of gas-in-place is achieved by multiplying the gas content of the coal by net coal thickness, the density, and the aerial extent of the drainage. The method is claimed to be suitable for use in Nigeria and potential sites for coal bed methane extraction in Nigeria are identified.

scholarly journals Influence of structural and textural features of ores and rocks on mine dust explosion hazard during development of pyrite deposits

2020 ◽  
Vol 192 ◽  
pp. 03017
Author(s):  
Marina Rylnikova ◽  
Viktor Fedotenko ◽  
Natalia Mitishova
Keyword(s):  
Sulfur Content ◽  
Underground Mining ◽  
Environmental Safety ◽  
Ore Deposits ◽  
Dust Explosion ◽  
Explosion Hazard ◽  
Mining Operations ◽  
Mine Dust ◽  
Mining Works ◽  
Explosive Properties

In the practice of mining works, sulfide-dust explosions often occur during underground development of pyrite ore deposits: copper-zinc, lead-zinc, copper-nickel, antimony, and others. This makes it necessary to conduct researches aimed at improvement of methods for studying the explosive properties of sulfide dust and development of industrial and environmental safety requirements for mining operations. Currently, there is no generally accepted state-approved regulatory procedure for assessment of sulfide dust explosion hazards during underground mining operations in Russia. Assessment of the type and concentration of mine sulfide dust in the underground mine atmosphere is vitally important for solving this problem. In practice, ores even with a sulfur content of less than 35% can constitute a sulfide dust explosion hazard, although mine dust with a sulfur content of less than 35% does not explode in laboratory conditions. To identify the cause of this phenomenon and develop technical solutions for ensuring safety of underground mining operations, change in the sulfur content of various mine dust fractions obtained from primary disintegration of sulfides was studied.

Gas content of the D6 coal seam

2021 ◽  
Vol 101 (1) ◽  
pp. 18-25
Author(s):  
S.B. Imanbaeva ◽  
◽  
A.D. Mausymbaeva ◽  
V.M. Yurov ◽  
V.S. Portnov ◽  
...  
Keyword(s):  
Coal Seam ◽  
Coalbed Methane ◽  
Underground Mining ◽  
Lower Layer ◽  
Complex Structure ◽  
Gas Content ◽  
Mining Operations ◽  
Coal Particles ◽  
The Difference ◽  
External Forces

The article deals with the issues of gas content of the most thick and stable D6 coal seam in the Tentek region. This complex structure seam is dangerous in underground mining for gas and dust outbursts, it consists of coal packs separated by interlayers of mudstones, while the lower layer 0.5-1.5 m thick is very soft, has a strong shear disturbance and is most saturated with methane. Extraction of coalbed methane is a necessary process to ensure the safety of mining operations, to reduce its emissions into the atmosphere, and to utilize it as a fuel and a product for obtaining synthetic materials. The regularity of changes in the particle size distribution of the upper thick pack and the lower thin pack indicates the difference in small coal particles in them, while there are much more of them in the lower layer therefore, the specific surface is larger, which is an important factor of the adsorption processes intensity in the accumulation of methane, and during the gas drainage from the seam. The activation energy of methane from carbohydrate has been determined. A quadratic relationship between methane gas evolution and its initial concentration has been shown. In carbohydrate, it depends on the energy of external forces. A complex relationship has been established between the gas pressure in the coal seam and its concentration and characteristics of the «coal-methanenatural moisture» system. Regularities of changing the methane content of the coal seam depending on its fracturing formed due to the effect of the energy of destruction and the energy appearing with increasing the area of a crack in the coal, have been obtained. The effect of the coal mineral composition on the gas content has been shown.

scholarly journals Influence of the parameters of the layer of ore being brought down on its freezing and losses during the face ore draw

2020 ◽  
Vol 192 ◽  
pp. 01014
Author(s):  
Vladimir Zubkov ◽  
Dmitrii Petrov ◽  
Dosanbai Bekbergenov
Keyword(s):  
Physical Simulation ◽  
Underground Mining ◽  
Experimental Studies ◽  
Thermal Conditions ◽  
Ore Deposits ◽  
Underground Mines ◽  
Mining Operations ◽  
Cryolithic Zone ◽  
The Impact ◽  
Broken Ore

Application of mining systems with ore caving and adjacent strata, which do not entail high expenditures on delivery of freed ore and rock pressure management, allows to considerably increase efficiency of underground mining of ore deposits in the cryolithic zone. However, their use where permafrost formations are prevalent, requires taking into account factors complicating mining operations, in particular, the congealing of broken ore in the stoping zone. In order to assess the impact of thermal and humidity conditions on the completeness of reserves recovery, a study was carried out to determine the dependence between the volume of losses of broken ore prone to congealing and the width and height of the layer being brought down. Experimental studies were conducted by physical simulation in a cryo chamber on a laboratory bench. The ore drawing was conducted in a uniform sequence at the temperature in the stoping zone of minus 5 ˚C. The final parameter to be determined the loss of ore prone to congealing, was defined as the difference between the mass of ore in the block and the mass of ore drawn. It has been established that the losses of the broken ore due to congealing increase significantly when the depth of the layer being freed decreases and the width increases. The established patterns of influence of parameters of a beaten layer on losses of ore mass will be used during development of recommendations on technology of drawing of ore mass prone to congealing in the negative thermal conditions of underground mines of a cryolithic zone.

scholarly journals The influence of extensive caving zones on the state and behavior of the surface as a result of underground mining works

2020 ◽  
Vol 192 ◽  
pp. 03009
Author(s):  
Evgeny Fedorov ◽  
Khaini-Kamal Kassymkanova ◽  
Gulnar Jangulova ◽  
Natalia Miletenko
Keyword(s):  
Underground Mining ◽  
Ore Deposits ◽  
The State ◽  
Mining Operations ◽  
Applied Development ◽  
Urgent Task ◽  
Mine Workings ◽  
Mining Works ◽  
The Stability ◽  
And Behavior

The article discusses the features of the development of the Donskoy chromite deposit and the improvement of the applied development system with self-caving of ore. For a system with self-destruction of ore, as well as for other similar systems, the weakest point is mining under the collapsed massif, which largely affects the stability of mine workings, their safety for the entire period of stope excavation, the effect of extensive zones of collapse on the state and behavior surface. This problem is one of the most important and urgent, especially with the transition of mining operations to deeper horizons, where the technological features of the mine field are significantly complicated. Therefore, the formation of extensive zones of collapsed rocks in the process of stope excavation leads to the development of negative processes for the formation of extremely high loads on the support of mine workings, and in certain geotechnical situations, the collapse zones affect the state of the day surface, where subsidence is possible up to the formation of craters. All this can lead to disastrous consequences, both in mine conditions and on the surface. The study of the formation of caving zones during the development of ore deposits is an urgent task.

scholarly journals The assessment of the impact of natural and anthropogenic factors on the current stressstrain state of rock massif of burst-hazardous ore deposits in the East of Russia

2018 ◽  
Vol 56 ◽  
pp. 02011
Author(s):  
Igor Rasskazov ◽  
Boris Saksin ◽  
Vitaly Usikov ◽  
Alexander Sidlyar
Keyword(s):  
Underground Mining ◽  
Ore Deposits ◽  
Anthropogenic Factors ◽  
Mining Operations ◽  
Tectonic Plates ◽  
Radar Images ◽  
Rock Structure ◽  
Zone Of Influence ◽  
Space Data ◽  
The Impact

This paper does a case study of endogenous deposits located in the zone of influence of convergent (converging, colliding) boundaries of tectonic plates in the zone of the continent-ocean transition, where there is increased present seismic and geodynamic activity, covers the issues of the ratio of natural and anthropogenic components of the stress-strain state (SSS) in rock massifs. It has been shown that, despite the confinement of the studied deposits to a single rock structure, as well as the proximity of their common neotectonic position, the SSS of the rock massifs containing them varies significantly. Based on a comprehensive analysis of geological and geophysical data with the use of space data about the Earth (GRACE mission data for calculation of stress fields and radar images of the Earth's surface), the kinematics of the process of modern deformation of the upper part of the Earth's crust within the studied area is specified. It is established that the peculiarity of the region is the pronounced contribution of the natural component to the general present SSS of rock massifs of impactthreatening deposits. On a real example, the possibility of a predictive assessment of SSS has been shown, which is important at the stages of designing and conducting underground mining operations in severe mining-geological and burst -hazardous conditions.

scholarly journals Geological CO2 quantified by high-temporal resolution stable isotope monitoring in a salt mine

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Alexander H. Frank ◽  
Robert van Geldern ◽  
Anssi Myrttinen ◽  
Martin Zimmer ◽  
Johannes A. C. Barth ◽  
...  
Keyword(s):  
Temporal Resolution ◽  
Underground Mining ◽  
Stable Carbon Isotope ◽  
Underground Mines ◽  
Background Concentration ◽  
High Temporal Resolution ◽  
Salt Mine ◽  
Gas Migration ◽  
Mining Operations ◽  
Anthropogenic Contributions

AbstractThe relevance of CO2 emissions from geological sources to the atmospheric carbon budget is becoming increasingly recognized. Although geogenic gas migration along faults and in volcanic zones is generally well studied, short-term dynamics of diffusive geogenic CO2 emissions are mostly unknown. While geogenic CO2 is considered a challenging threat for underground mining operations, mines provide an extraordinary opportunity to observe geogenic degassing and dynamics close to its source. Stable carbon isotope monitoring of CO2 allows partitioning geogenic from anthropogenic contributions. High temporal-resolution enables the recognition of temporal and interdependent dynamics, easily missed by discrete sampling. Here, data is presented from an active underground salt mine in central Germany, collected on-site utilizing a field-deployed laser isotope spectrometer. Throughout the 34-day measurement period, total CO2 concentrations varied between 805 ppmV (5th percentile) and 1370 ppmV (95th percentile). With a 400-ppm atmospheric background concentration, an isotope mixing model allows the separation of geogenic (16–27%) from highly dynamic anthropogenic combustion-related contributions (21–54%). The geogenic fraction is inversely correlated to established CO2 concentrations that were driven by anthropogenic CO2 emissions within the mine. The described approach is applicable to other environments, including different types of underground mines, natural caves, and soils.

Experience in the development of innovative underground geotechnologies for mining of ore deposits

2020 ◽  
pp. 338-350
Author(s):  
I. V. Sokolov ◽  
Y. G. Antipin ◽  
N. V. Gobov ◽  
I. V. Nikitin
Keyword(s):  
Systematic Approach ◽  
Underground Mining ◽  
Mineral Resources ◽  
Environmental Safety ◽  
Ore Deposits ◽  
Operating Costs ◽  
Processing Waste ◽  
Ore Preparation ◽  
Additional Value

Based on an analysis of the design principles and practice of underground mining of ore deposits, the most significant features, trends to develop and directions to enhance of underground geotechnology in the field of opening and preparation, mining systems, filling works and ore preparation have been established. The main signs of innovation - scientific research and implementation in production in order to obtain additional value, are highlighted. Various approaches to the development of innovative underground geotechnologies are shown and a methodology for their justification is formulated based on a systematic approach implemented in the framework of the concept of integrated development of mineral resources and on the principles of economic efficiency, industrial and environmental safety, completeness of subsoil development. The experience of the IM UB RAS on the development and implementation of innovative underground geotechnologies in the design and industrial operation of a number of ore deposits is given, which significantly increased the completeness and quality of ore extraction from the subsoil, increased labor productivity in sinking and stoping works, reduced capital and operating costs for ore mining and to utilize mining and processing waste in the mined-out space.

Comprehensive Assessment of Working Conditions and Occupational Disease Rates at Mining and Metallurgical Enterprises

2021 ◽  
pp. 114-119
Author(s):  
A.G. Chebotarev ◽  
D.D. Sementsova
Keyword(s):  
Ferrous Metallurgy ◽  
Working Conditions ◽  
Occupational Diseases ◽  
Underground Mining ◽  
Working Environment ◽  
Aluminum Production ◽  
Dump Truck ◽  
Mining Operations ◽  
Production Factors ◽  
Aluminum Smelters

The paper presents the results of hygienic assessment of the working environment and work process factors at surface and underground ore mining operations, ferrous metallurgy plants and aluminum production facilities. It has been established that workers are affected by a complex of production factors (dust, toxic substances, noise, vibration, unfavorable micro climate, etc.), the level of which often exceeds the hygienic standards. The workplace conditions of the primary jobs at these enterprises in 60-80% of cases are classified as hazardous, i.e. Class 3 of various hazard degrees. The incidence of occupational diseases remains high, especially in underground mining and at aluminum production plants. The specific features of mining and metallurgical operations and the severity of unfavorable production factors determine the structure of occupational morbidity. Occupational respiratory diseases are most common among workers in the ferrous metallurgy industry and account for 70.3% in total. Vibration-induced pathologies are most frequently diagnosed among excavator, bulldozer and dump truck operators, and account for 52.9% of all the diagnosed occupational diseases. Hearing organ pathology in the form of neurosensory loss of hearing among workers of mining and metallurgical enterprises ranges from 10.2% (aluminum smelters) to 22.7% (ferrous metallurgy plants) in the occupational morbidity structure. Chronic intoxication with fluorine compounds at aluminum smelters was diagnosed in 68.1% of cases. The results obtained confirm the pressing need to improve the working conditions, introduce preventive measures based on the primary prevention principles, and reduce the risk factors of health problems among the workers.

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