Mine Water as Geothermal Resource in Nowa Ruda Region (SW Poland)

The Lower Silesian Coal Basin in south-western Poland was a region of intensive coal mining until the late 1990s. After mining was stopped and the mines were closed, the underground workings were flooded. This created an underground reservoir of waters that can be economically managed to supply energy, using heat pumps, to the town of Nowa Ruda. The article analyses the energy potential of these waters. It was shown that open loop with reinjection system based on mine shafts can provide 10 GWh of geothermal energy while reducing emissions from 4.27 tCO2 to 0.22 tCO2. In addition, 2.09 GWh can be extracted from water flowing out of mine shafts via adits. As a final result, this will lead to improve air quality as well as increase the environmental value of the region. These results can act as a reference tool for local government, specialists in energy policy at the local scale. They are also the basis for future work aimed at acquiring external funds to carry out detailed studies of the condition of mine shafts, geothermal profiling of water in sunken shafts and test pumping, which will make it possible to determine the real quantities of water to be used.

Automatic Monitoring System Designed for Controlling the Stability of Underground Excavation

Ensuring the stability of mining excavations is a crucial aspect of underground mining. For thispurpose, appropriate shapes, dimensions, and support of workings are designed for the given mining andgeological conditions. However, for the proper assessment of the adequacy of the used technical solutions,and the calibration of the models used in the support design, it is necessary to monitor the behavior of theexcavation. It should apply to the rock mass and the support. The paper presents the automatic systemdesigned for underground workings monitoring, and the example of its use in the heading. Electronicdevices that measure the rock mass movements in the roof, the load on the standing support, and on bolts,the stress in the rock mass, are connected to the datalogger and can collect data for a long of time withoutany maintenance, also in hard-to-reach places. This feature enables the system to be widely used, inparticular, in excavations in the vicinity of exploitation, goafs, or in the area of a liquidated exploitationfield.

Preliminary sources identification of nitric oxide (NO) emissions in underground mine

Gas hazards in Polish underground mines are a major problem for the ventilation service. Ensuring appropriate environmental conditions is becoming increasingly difficult, especially with the introduction of new, more stringent restrictions on the concentration limits of harmful gases. According to [1], the most dangerous gases in underground mines are carbon monoxide, hydrogen sulfide, nitrogen oxides, c arbon dioxide, sulfur dioxide, and m e thane. T ogether with the introduction of new limit values for the above-mentioned gases by the European Union, it is necessary to accurately identify the sources of their emission in mine workings in order to select an appropriate reduction method. This article presents daily measurements of nitric oxide (NO) concentrations in the workings of one of the copper ore mines owned by KGHM Polska Miedź S.A. The measurement results were used for preliminary analysis of sources of gas emissions to underground workings. The analysis is carried out through a graphical interpretation of the measured values. Knowing the details of the technological processes carried out in the mine under consideration (blasting, diesel engine machines, natural oxidation of nitrogen to NO) the graphs were interpreted by assigning individual values of NO concentrations over time to a specific t echnological process.

Early Pumping Engines in the Attercliffe-Darnall-Orgreave coalfield and the role of John Curr

By the mid-1700s, Attercliffe had a developed into a major industrial centre, specialising in steelmaking, and distinct from the town of Sheffield. It also had its own coalfield, which included the Barnsley Coal, valued for its steel-melting coke. The first ‘engine-drained’ coal pit at Attercliffe opened in 1747, close to the River Don and the Sheffield road. It was succeeded by a sequence of further collieries, each following the crop of the Barnsley Coal progressively eastwards towards Orgreave. Development of underground workings by separate, competing partnerships was uncoordinated, and all the collieries faced a constant struggle with inflowing water, including leakage between properties through failed barriers. Nine Newcomen-type pumping engines were eventually erected in this small coalfield during the remainder of the eighteenth century, two of which were also fitted with flywheels for coal-winding. A further four engines, of presumed Newcomen-type, were also erected for winding only. Four of the pumping engines were designed by John Curr, including the Greenland engine, which is described in detail in his book. He also designed and manufactured one of the winding engines.

Investigation of Backfilling Step Effects on Stope Stability

Cemented rock fill (CRF) is commonly used in cut-and-fill stoping operations in underground mining. This allows for the maximum recovery of ore. Backfilling can improve stope stability in underground workings and then improve ground stability of the whole mine site. However, backfilling step scenarios vary from site to site. This paper presents the investigation of five different backfilling step scenarios and their impacts on the stability of stopes at four different mining levels. A comprehensive comparison of displacements, major principal stress, and Stress Concentration Factor (SCF) was conducted. The results show that different backfilling step scenarios have little influence on the final displacement for displacement in the stopes. Among the five backfilling scenarios, the major principal stress and stress concentration factor (SCF) have almost the same final results. The backfilling scenario SCN-1 is the optimum option among these five backfilling scenarios. It can immediately prevent the increase of the displacement and reduce the sidewall stress concentration, thereby preventing possible failures. Using the same strength of CRF can achieve the same effects among the four mining levels. Applying backfilling CRF of the same strength at different mining depths is acceptable and feasible to improve the stability of the stopes.

Investigation of Backfilling Step Effects on Stope Stability

Cemented rock fill (CRF) is commonly used in cut-and-fill stoping operation in underground mining. This allows for the maximum recovery of ore. Backfilling can improve stope stability in underground workings, and then improve ground stability of the whole mine site. Backfilling step scenarios vary from site to site. This paper presents the investigation of five different backfilling step scenarios and their impacts on the stability of stopes at four different mining levels. A comprehensive comparison of displacements, major principal stress and stress concentration factor (SCF) was conducted. The results show that different backfilling step scenarios have little influence on the final displacement for displacement in the stopes. Among the five backfilling scenarios, the major principal stress and stress concentration factor (SCF) have almost the same final results. The backfilling scenario SCN-1 is the optimum option among these five backfilling scenarios. It can immediately prevent the increase of the displacement and reduce the sidewall stress concentration, thereby preventing possible failures. Using the same strength of CRF can achieve same effects among the four mining levels. Applying backfilling CRF of the same strength at different mining depths is acceptable and feasible to improve the stability of the stopes.

Justification of the requirements for the construction of protective structures by means underground workings in an explosive manner

In the opposition of the people of Ukraine to the aggressive policy of the Russian Federation, the question of studying the experience of combat operations in the east of our state is relevant. Analysis of the losses suffered by the Armed Forces of Ukraine and the civilian population during the operation. The Joint Forces (anti-terrorist operation) in Donetsk and Luhansk region clearly point to the need to study the issue of creating safe shelters, especially for the civilian population with limited time and resources. This can be realized provided that explosive methods of underground construction are used alongside traditional earthworks. The construction of such structures must be strong and have a sufficient internal volume and ensure the safety of the people there and allow the placement of various household and sanitary equipment. Based on the above, it should be noted that the article considers the topical issue of arrangement of underground structures and shelters in one of the ways, namely explosive. The essence of the explosive method of arranging underground workings is that a well is arranged in the soil, in which the appropriate charge of the explosive is installed and detonation is carried out. Due to the explosion of the charge, a camouflet cavity is formed, which is used for the construction of an underground protective structure or its elements. The use of this method can significantly reduce and sometimes completely eliminate time-consuming and unproductive work on the development and removal of soil from the slaughter. Accordingly, the conditions of camouflage of buildings are significantly improved and the terms of their construction are reduced. The purpose of the article is to highlight the methodological approach to substantiate the requirements for the main indicators of construction of protective structures by arranging underground workings in an explosive manner. The considered methodical approach can be used both at planning of actions for the fortification equipment of shelters for the civilian population and during carrying out scientific researches for the purpose of substantiation of requirements to the basic indicators of construction of protective constructions by arrangement of underground workings by explosive way. As a direction of further research in the subject area is the improvement of scientific and methodological approach to the calculation of a multilayer underground protective structure.

Copper Mining in the Bronze Age at Mynydd Parys, Anglesey, Wales

The Bronze Age in Britain is now a term often used to include both the first use of copper c. 2400 bc and also tin-bronze from c. 2100 bc, all of which required the extensive use of copper. Prehistoric mining for this metal has been identified in surface and underground workings in Parys Mine, Mynydd Parys, Anglesey, although almost all of the surface workings are now obscured by the extensive deep spoil from more recent mining in the industrial period. These copper-bearing ores are in bedded lodes, together with some intruded vein deposits. The Bronze Age workings have been exposed underground where they have been intersected by the early 19th century industrial workings on and above the 16 fathom and 20 fathom levels in the Parys Mine. Spoil exposures contain stone hammers (‘mauls’), wood fragments, and charcoal; samples of the latter have been radiocarbon dated with chronological modelling suggesting activity took place in the first half of the 2nd millennium cal bc. Although relatively limited in extent, these important prehistoric mining sites are among the earliest found in the UK. They have survived due to their protection from surface erosion and limited accessibility.