scholarly journals Utilization of Dynamic and Physical Properties of Ice in Underground Mining Operations

1977 ◽  
Vol 19 (81) ◽  
pp. 672 ◽  
Author(s):  
Henning Fangel
Keyword(s):  
Underground Mining ◽  
Complete Recovery ◽  
Extraction Process ◽  
Wall Material ◽  
Mining Operations ◽  
Left Behind ◽  
Winter Temperatures ◽  
Extraction Processes ◽  
Natural Freezing ◽  
Lateral Walls

Abstract In sub-level caving mining operations, the lateral walls cave in. This results in dilution of the mineral content of the produced ore by 15%-20% waste rock. Also 15%-20% of the valuable ores are lost in the caved wall material that is left behind in the mined-out rooms. Placing ice, in the form of a small glacier, in the mine-room before the lateral walls start to cave, permit complete recovery of ore reserves without dilution. The glacier will advance at a rate permitted by ore extraction processes, in accordance with glaciological theories and laws. Volumes of ice that are required may be calculated from ore extraction rates, power consumed in the mine, ventilating air volumes and temperatures, specific heat and thermal conductivity of the lateral rock. The required ice volumes can be produced through natural freezing of water, where the winter temperatures regularly fall below 0°C for a predictable period every winter. Use of ice as a mining aid reduces costs of the ore extraction process by about one-third and increases value of the produced ore by about 20%. Thus, the value of a given orebody is increased by about 30% relative to the values experienced in the most efficient mines of today.

scholarly journals Utilization of Dynamic and Physical Properties of Ice in Underground Mining Operations

1977 ◽  
Vol 19 (81) ◽  
pp. 672-672
Author(s):  
Henning Fangel
Keyword(s):  
Underground Mining ◽  
Complete Recovery ◽  
Extraction Process ◽  
Wall Material ◽  
Mining Operations ◽  
Left Behind ◽  
Winter Temperatures ◽  
Extraction Processes ◽  
Natural Freezing ◽  
Lateral Walls

AbstractIn sub-level caving mining operations, the lateral walls cave in. This results in dilution of the mineral content of the produced ore by 15%-20% waste rock. Also 15%-20% of the valuable ores are lost in the caved wall material that is left behind in the mined-out rooms. Placing ice, in the form of a small glacier, in the mine-room before the lateral walls start to cave, permit complete recovery of ore reserves without dilution. The glacier will advance at a rate permitted by ore extraction processes, in accordance with glaciological theories and laws.Volumes of ice that are required may be calculated from ore extraction rates, power consumed in the mine, ventilating air volumes and temperatures, specific heat and thermal conductivity of the lateral rock. The required ice volumes can be produced through natural freezing of water, where the winter temperatures regularly fall below 0°C for a predictable period every winter. Use of ice as a mining aid reduces costs of the ore extraction process by about one-third and increases value of the produced ore by about 20%. Thus, the value of a given orebody is increased by about 30% relative to the values experienced in the most efficient mines of today.

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.

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.

First application of different Chlorella sp. microalgal strains for the treatment of vegetation waters derived from unconventional oil extractions enriched with citrus byproducts

2021 ◽  
Author(s):  
Carolina Chiellini ◽  
Monica Macaluso ◽  
Adriana Ciurli ◽  
Lorenzo Guglielminetti ◽  
Isabella Taglieri ◽  
...  
Keyword(s):  
Phenolic Compounds ◽  
Olive Oil ◽  
Low Cost ◽  
Environmental Pollutants ◽  
Extraction Process ◽  
Total Phenolic ◽  
Mediterranean Countries ◽  
Extraction Processes ◽  
The Mediterranean ◽  
Vegetation Water

The Mediterranean diet has among its cornerstones the use of olive oil for its nutraceutical and organoleptic properties. Despite the numerous merits, olive-oil mill wastewater (OMWW), which is generated by the olive-oil extraction process, is one of the most serious environmental pollutants in the Mediterranean countries. The polluting potential of OMWW is due to its high content of tannins, polyphenols, polyalcohols, pectins and lipids. In this experiment, we tested the ability of five microalgae of the Chlorella group (SEC_LI_ChL_1, CL-Sc, CL-Ch, FB and Idr) in lowering the percentage of total phenolic compounds in vegetation water. In order to close the recovery cycle of a fortified citrus olive oils previously developed, we tested the vegetation wa-ter obtained with three different extraction processes (conventional, lemon and orange peels) at three concentrations each (10%, 25% and 50%). Results showed that strains Idr, FB and CL-Sc from the Lake Massaciuccoli can tolerate vegetation water from conventional and lemon peels extraction up to 25%; these strains can also reduce the phenolic compounds within the tests. The results demonstrate that the application of microalgae for OMWW treatment represent an inter-esting opportunity, and an eco-friendly low-cost solution to be developed within the companies as a full-scale approach.

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.

Analysis on the Steady-state Performance and Losses of a Bent-axis Type Hydraulic Motor Used in Heavy Earth Moving Machinery

2021 ◽  
Author(s):  
Ajit Kumar Pandey ◽  
Amit Kumar ◽  
Nitish Kumar
Keyword(s):  
Steady State ◽  
Electric Motor ◽  
Underground Mining ◽  
Operating Conditions ◽  
Constant Speed ◽  
Working Environment ◽  
Variable Load ◽  
Mining Equipment ◽  
Mining Operations ◽  
Design Guideline

Hydraulic components play a significant role in the mining and construction equipment. It is responsible for smooth change in the output speed, torque, and power of the machine. The hydrostatic drive powered by a constant speed electric motor is widely used in the propel system of the mining equipment. Regulation of the displacements of the pump and the hydro-motor of the drive facilitates the control of the straight running and steering of the machines. In the present scenario, better efficiency and ease of control are the critical aspects to be considered in the design and selection of the hydraulic pump and motor used in underground mining operations. The bent axis hydro-motor is one such equipment that is an electro-hydraulic component that can work in an adverse working environment. The present study deals with the performance analysis of fixed displacement bent axis hydro-motor at different operating parameters such as different temperatures, sizes, viscosity at different loads, and drive speed. For analysis, the hydraulic drive consists of a variable displacement pump rotated by a constant speed electric motor and a fixed displacement hydro-motor. The regulation of the pump displacement controls the speed of the drive. Manually controlled hydrostatic drive propels the said machine against variable load demands. The present work investigates the performances of the hydro-motor used in the mining and construction machine through detailed modeling and experimentations. The steady-state performances are analyzed in terms of slip, torque losses and efficiency of the hydro-motor. The study finds the design guideline to operate the hydrostatic drive using such motors in a reasonable efficiency zone. The model is validated for various operating conditions of the equipment by comparing the predicted results with the test results. The outcome of the present work will be expedient for the preliminary design and assortment of similar hydraulic component used in the mobile, mining equipment.

Life Cycle Assessment of opencast lignite mining

2020 ◽  
Author(s):  
Lukasz Lelek ◽  
Joanna Kulczycka
Keyword(s):  
Life Cycle ◽  
Production Efficiency ◽  
Underground Mining ◽  
Hot Spot ◽  
Electricity Consumption ◽  
Calorific Value ◽  
High Sensitivity ◽  
Cycle Phase ◽  
Mining Operations ◽  
Lignite Mining

Abstract The life cycle phase of fossil fuel extraction is mainly considered in the LCA when evaluating the energy production processes. It is then only one of many unit processes, which contribute to the blurring of mining-relevant results. There are few items in the literature focusing exclusively on the lignite mining phase and analysing the specific mining conditions and associated environmental impacts. The article focuses on the LCA of lignite mining pro-cesses on the basis of data coming from a Polish mine. The technology for opencast lignite mining is noted for its high production efficiency, high level of recovery and lower risk as regards the safety of workers when compared with underground mining systems. However, the need to remove large amounts of overburden to uncover the deposit contributes to a much greater degradation of the landscape. Analysing the results obtained, several key (hot spot) elements of the lignite mining operations were distinguished for modelling the environmental impact, i.e.: calorific value, the amount of electricity consumption, the manner in which waste and overburden are managed. As a result there is a high sensitivity of the final indicator to changes in these impacts.

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.

Quantifying Discrete Seismic Responses to Mining

2020 ◽  
Author(s):  
Laura G Brown
Keyword(s):  
Sensor Array ◽  
Underground Mining ◽  
Complex Nature ◽  
Seismic Responses ◽  
Mining Operations ◽  
Analysis Techniques ◽  
Naturally Occurring ◽  
Single Link ◽  
Rock Mass Failure ◽  
Temporal Windows

Applying analysis techniques developed for naturally occurring earthquakes to mine seismicity is common practice, however, these methodologies rarely consider the influence of blasting on the dynamic rock mass failure processes observed in mines. Due to the complex nature of bulk orebody extraction at depth, quantifying discrete seismic responses to mining can be challenging. This paper identifies seismic responses to mining by pairing single-link clustering with finite temporal windows bound by mine blasting practices. A methodology is presented to quantify the space-time characteristics of these responses using four Seismic Response Parameters (SRP’s): Distance to Blast, Distance to Centroid, Time After Blast and Time Between Events. Using SRP’s, seismic responses to mining can be quantitatively classified as induced, complex or triggered (with respect to discrete mine blasting). Because these response parameters do not require an extensive and/or triaxial dense sensor array, they are applicable to a variety of underground mining operations. In this work, SRP’s are applied to 189 discrete seismic responses occurring over two months of active mining, and a two week shutdown period, at Agnico Eagle’s LaRonde Mine.

scholarly journals Extraction of Antioxidants from Blackberry (Rubus ulmifolius L.): Comparison between Ultrasound- and Microwave-Assisted Extraction Techniques

Agronomy ◽  
2019 ◽  
Vol 9 (11) ◽  
pp. 745 ◽  
Author(s):  
Estrella Espada-Bellido ◽  
Marta Ferreiro-González ◽  
Ceferino Carrera ◽  
Miguel Palma ◽  
José A. Álvarez ◽  
...  
Keyword(s):  
Extraction Process ◽  
Total Phenolic ◽  
Antioxidant Compounds ◽  
Extraction Techniques ◽  
Potential Health ◽  
Assisted Extraction ◽  
Total Anthocyanins ◽  
Precision Study ◽  
Extraction Processes ◽  
High Concentrations

Berries are considered functional food because of their potential health benefits to consumers due to their high concentrations in bioactive compounds. The extraction process of their antioxidant compounds is a crucial step. In this work, ultrasound (UAE) and microwave (MAE) assisted extraction have been evaluated and compared for the recovery of total phenolic compounds (TPC) and total anthocyanins (TA) from blackberry. Since several variables have an influence on the extraction processes efficiency, a response surface method using a Box–Behnken design (BBD) was chosen for the optimization of UAE and MAE variables. Six variables (solvent, temperature, amplitude, cycle, pH, and sample:solvent ratio) were optimized for UAE while the optimization for MAE was performed on four variables (solvent, temperature, pH, and sample:solvent ratio). It has been proven that solvent and temperature have a significant influence on the extraction of both TA and TPC. Only 10 and 5 min were necessary to complete the UAE and MAE procedures, respectively. A precision study was also carried out, and coefficient of variation lower than 5% was determined. Non-significant differences were obtained when using UAE and MAE at their respective optimum conditions. Thus, the results demonstrated a successful potential use of both techniques for the extraction of TA and TPC from blackberry. In conclusion, this work shows interesting perspectives for quality control analytical laboratories for the development of rapid extraction techniques to quantify these antioxidant compounds in blackberries.

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