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 ◽  
...  

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.

2021 ◽  
Author(s):  
Alexander H. Frank ◽  
Robert van Geldern ◽  
Anssi Myrttinen ◽  
Martin Zimmer ◽  
Johannes A. C. Barth ◽  
...  

<p>CO<sub>2</sub> emissions from geological sources have been recognized as an important input to the global carbon cycle. In regions without active volcanism, mines provide an extraordinary opportunity to observe dynamics of geogenic degassing close to its source.</p><p>High temporal resolution of stable carbon isotopes allows to outline temporal and interdependent dynamics of geogenic CO<sub>2</sub> contributions. We present data from an active underground salt mine in central Germany that were collected on site with a field-deployed laser isotope spectrometer.</p><p>Throughout the 34-day measurement period, total CO<sub>2</sub> concentrations varied between 805 ppmV (5<sup>th</sup> percentile) and 1370 ppmV (95<sup>th</sup> percentile). With a 400 ppm atmospheric background concentration, an isotope mixing model enabled the separation of geogenic (16–27 %) from highly dynamic contributions from anthropogenic CO<sub>2</sub>-sources (21–54 %). The geogenic fraction was inversely correlated to established CO<sub>2</sub> concentrations that were driven by anthropogenic CO<sub>2</sub> emissions within the mine. This indicates gradient-driven diffusion along microcracks.</p><p>Read more about this work in our open access publication in Scientific Reports at: http://rdcu.be/cblTz</p>


2014 ◽  
Vol 2014 ◽  
pp. 1-20 ◽  
Author(s):  
Chika Yinka-Banjo ◽  
Isaac O. Osunmakinde ◽  
Antoine Bagula

Underground mining operations are carried out in hazardous environments. To prevent disasters from occurring, as often as they do in underground mines, and to prevent safety routine checkers from disasters during safety inspection checks, multirobots are suggested to do the job of safety inspection rather than human beings and single robots. Multirobots are preferred because the inspection task will be done in the minimum amount of time. This paper proposes a cooperative behaviour for a multirobot system (MRS) to achieve a preentry safety inspection in underground terrains. A hybrid QLACS swarm intelligent model based on Q-Learning (QL) and the Ant Colony System (ACS) was proposed to achieve this cooperative behaviour in MRS. The intelligent model was developed by harnessing the strengths of both QL and ACS algorithms. The ACS optimizes the routes used for each robot while the QL algorithm enhances the cooperation between the autonomous robots. A description of a communicating variation within the QLACS model for cooperative behavioural purposes is presented. The performance of the algorithms in terms of without communication, with communication, computation time, path costs, and the number of robots used was evaluated by using a simulation approach. Simulation results show achieved cooperative behaviour between robots.


2019 ◽  
Vol 1 (1) ◽  
pp. 35-46
Author(s):  
Jimmy Bob Suroto ◽  
Ramdhan Rabbani ◽  
Anas Abdul Latif ◽  
Presentia Biserva Aesh

The development of the Toguraci Underground Mine was begun in 2011 with the ore production started in 2012. The amount of water continued to increase in the Underground Mine at the beginning of 2014 which became problem that effected the activities of mining. The increase of hot water Toguraci underground mining effected to the safety for workers who are exposed to hot water, ventilation problems and equipment that are submerged in hot water. Tuguraci mine has two dewatering systems, namely dewatering systems on the surface and dewatering systems in underground mines. The handling of surface water comes from pumping underground to surface where water discharge is around 400 L / s with the temperatures ranging from 70°C while water treatment in underground mines includes decreasing water heading levels and pumping water from underground mines to the surface. The increase water entering heading development and stoping can be overcome by changing the surface dewatering system by using water cooling, while underground mining is done by changing the pipeline from the polypipe to the steel pipe and to reduce water entering the mining front is doned by drill holes for installing submersible pumps and replacing Oddesse pump to the Schlumberger pump which is more resistant to high temperature hot water, as long as mining operations take place 48 borehole drilling has been done with 11 borehole flowrate below 5 l / s and 37 borehole with flow rate above 5 l / s, and a water drop of around 77 meters


2021 ◽  
pp. 92-96
Author(s):  
L. Yu. Levin ◽  
D. S. Kormshchikov ◽  
E. G. Kuzminykh ◽  
A. M. Machеret

Mining operations at potash mines are carried out by heading machines. Setting of a direction and control of the movement of the machines is carried out by the mine surveyor and by the machine operator in the manual mode. The lack of automation of this process during production leads to large labor costs of the mine surveying service, while the experience of the machine operator affects accuracy of maintenance of a specified course. Currently, there are no ready-made technical products for automating the process of setting the course and controlling the movement of heading machines. This paper deals with the implementation of the navigation system for heading machines in the underground mines of Uralkali company. At the mines of Uralkali, the requirements for the accuracy of such a system are dictated by the requirements for the accuracy of mine surveying support for underground mining operations in driving new roadways. Possible ways of constructing navigation systems and the problems of their application are considered. The analysis of the existing methods shows that the most promising option for navigation of heading machines in underground mine openings are the systems based on the principles of inertial navigation. To use such systems in underground mines and to ensure the required accuracy, the technical requirements for the systems are formulated. It is shown that modern strapdown inertial navigation systems satisfy the required accuracy. On their basis, a prototype of the heading machine navigation system was developed, and its ground tests were carried out. The achieved accuracy of the system makes it possible to proceed to testing of a real heading machine in a mine. The study was supported by the Russian Science Foundation, Project No. 19-77-30008.


2020 ◽  
Vol 192 ◽  
pp. 01014
Author(s):  
Vladimir Zubkov ◽  
Dmitrii Petrov ◽  
Dosanbai Bekbergenov

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.


2018 ◽  
Vol 41 ◽  
pp. 01041
Author(s):  
Vladimir Makarov ◽  
Péter Kovacs ◽  
Samuel Dagmar ◽  
Riccardo Paulman

The main sources of environmental pollution are: pollution from the residual effects of working out of mine fields by underground method; pollution from secondary mining of mine fields by the open method. The pollution of the environment from the underground mining of mine fields is mainly due to the erosion of the surface of the ditches caused by collapse of the underground workings, spontaneous combustion of the remaining coal reserves and exit of poison gases SO2 and CO to the surface through the cracks from the lower horizons of the worked-out mine fields. This makes actual the research of technological possibilities of harmful emissions reducing when quarrying underground mines’ fields. The environment deterioration from conducting open pit mining operations in the underground mine fields is caused by the technological processes of quarrying (preparation of rock for excavation, excavation, transportation of rocks and coal, dumping), by the objects of the open pit infrastructure (industrial site, transport communications, trenches and other workings, coal storage and rock dumps). The main direction of eliminating the negative environmental consequences of underground mining is the localization or complete isolation of the underground mines influence’ on the surface.


2022 ◽  
Vol 354 ◽  
pp. 00028
Author(s):  
Adrian Matei ◽  
Nicolae Ianc

According to the new classification method, salt mines and underground work or areas where methane has not been observed but for which methane has been observed in boreholes found in rock massifs are considered to be fire mines / mine areas or mining work. This new classification allows only the effective areas of exploitation to be maintained in the wire regime, the rest of the salt mine being considered non-wire. The purpose of this paper is to determine the rate of methane (explosive gas) and carbon dioxide (oxidizing gas) in the mining operations of the Tg-Ocna salt mine, given its classification.


2021 ◽  
Author(s):  
Purushotham Tukkaraja ◽  
Rahul Bhargava ◽  
Srivatsan Jayaraman Sridharan

Radon, a radioactive noble gas, is a decay product of uranium found in varying concentrations in all soils and rocks in the earth crust. It is colorless, odorless, tasteless, and a leading cause of lung cancer death in the USA. A study of underground miners shows that 40% of lung cancer deaths may be due to radon progeny exposure. In underground mines, radon monitoring and exposure standards help in limiting miners’ exposure to radioactivity. Radon mitigation techniques play an important role in keeping its concentration levels under permissible limits. This chapter presents a review of the radon sources and monitoring standards followed for underground mines in the USA. Also, the different radon prediction and measurement techniques employed in the underground mines and potential mitigation techniques for underground mining operations are discussed.


2015 ◽  
Vol 60 (1) ◽  
pp. 51-61
Author(s):  
Ritesh Kumar Mishra ◽  
Mikael Rinne

Abstract Underground mining activities are prone to major hazards largely owing to geotechnical reasons. Mining combined with the confined working space and uncertain geotechnical data leads to hazards having the potential of catastrophic consequences. These incidents have the potential of causing multiple fatalities and large financial damages. Use of formal risk assessment in the past has demonstrated an important role in the prediction and prevention of accidents in risk prone industries such as petroleum, nuclear and aviation. This paper proposes a classification system for underground mining operations based on their geotechnical risk levels. The classification is done based on the type of mining method employed and the rock mass in which it is carried out. Mining methods have been classified in groups which offer similar geotechnical risk. The rock mass classification has been proposed based on bulk rock mass properties which are collected as part of the routine mine planning. This classification has been subdivided for various stages of mine planning to suit the extent of available data. Alpha-numeric coding has been proposed to identify a mining operation based on the competency of rock and risk of geotechnical failures. This alpha numeric coding has been further extended to identify mining activity under ‘Geotechnical Hazard Potential (GHP)’. GHP has been proposed to be used as a preliminary tool of risk assessment and risk ranking for a mining activity. The aim of such classification is to be used as a guideline for the justification of a formal geotechnical risk assessment.


2017 ◽  
Vol 39 (2) ◽  
pp. 25-34
Author(s):  
Kajetan D’Obyrn ◽  
Antoni Tajduś

Abstract Salt was excavated at the “Wieliczka” Salt Mine for over 700 years. Underground mining operations terminated in 1996, by which time almost 2,400 chambers and 245 km of galleries had been created underground, situated on 9 levels and a few interlevels. In 1978, the mine was included in the UNESCO World Heritage List, which stated that parts of the mine with historical value had to be preserved for future generations. In order to preserve the most valuable chambers and galleries, activities aimed at establishing a protection pillar for excavations were conducted in the conservation area on Levels I-V. The need of large scope preserving works created the necessity to conduct a new and truly comprehensive geomechanical analysis. Such an analysis could only be done by means of advanced numerical modelling codes. Three-dimensional calculations were performed by means of FLAC 3D finite difference code. Rock mass stability assessment in the vicinity of excavations was carried out on the basis of the distribution and range of the so called failure zones. This comprehensive geomechanical analysis allows for verification and give the directions for future preservation and closure works in the “Wieliczka” mine.


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