Historical outline of iron mining and production in the area of present-day Poland

Funding Information: Funding: Funding from the European Institute of Innovation and Technology (EIT), a body of the European Union, under the Horizon 2020, the EU Framework Programme for Research and Innovation, through the MineHeritage Project (Grant Agreement 18111).The article presents the history of iron ore mining and production in present-day Poland and takes into account mining and production techniques and the influence of mining on the development of the surrounding areas. Examples of development are presented for the most important iron ore mining centers established since the period of the so-called Roman influences—Lower Silesia in the region of Tarchalice and the Świętokrzyskie region in the area of Góry Świętokrzyskie (Świętokrzyskie Mountains). The oldest traces of underground iron ore mining in Poland date back to the 7th–5th century B.C., and iron production dates back from the 1st century B.C. in the Częstochowa region where economically significant iron ore exploitation started in the 14th century and lasted until the 20th century. Studies showed that the development of iron ore mining in today’s Poland was associated with significant events in the country’s history, for example, with the expansion of a network of fortified castles in Silesia or with the industrial revolution. In each case, the increase in iron production resulted in the development and growth of the surrounding areas.publishersversionpublishe

Reversal ventilation as a method of fire hazard mitigation in the mines

Reversal ventilation is one of prevention methods against fire hazard in underground mines, but it is not recommended for the mines where methane is present. The authors introduce the new method of reversal and by conducting numerical simulations they prove that it allows to keep methane at the acceptable level during miners escape. However, it requires connection between the subnetworks of the main ventilation fans. It was also shown, that by using the method some escape routes will be shortened. It is possible to apply this method in the mines where the fans and stoppings are fully controlled across the full range of their operating parameters. The findings are important for underground mines, as well as for surface facilities where air control or smoke control is managed by two or more fans.Web of Science137art. no. 175

Influence of the auxiliary air-duct outlet and the brattice location on the methane hazard-numerical simulations

The article presents the results of research into the influence of the location of auxiliary ventilation devices on the distribution of methane concentrations at the outlet of the longwall in an underground mine. Since this area is crucial from the point of view of explosion risk, the existence of an optimal arrangement of these devices could lead to improved safety of the crew working in the area. The aim of conducted study was to examine if the impact of this devices placement is significant. The research was carried out with the use of computational fluid dynamics (CFD) modeling-Ansys Fluent. The analyses took into account the location of the two most commonly used devices: a brattice and an auxiliary air-duct. The numerical model has been prepared and validated based on in situ measurements. Thirty-two cases of device configurations were analysed. The length and position of the brattice, as well as the height and position air-duct outlet along tailgate, were modified. It has been shown that although the presented solutions are an effective risk mitigation method, contrary to the common opinion of many practitioners, the impact of their exact placement, provided it is compliant with the regulations, is not significant for the registered methane concentration distribution at a longwall outlet.Web of Science1510art. no. 367

Mechanical thrombectomy in acute stroke – Five years of experience in Poland

Objectives Mechanical thrombectomy (MT) is not reimbursed by the Polish public health system. We present a description of 5 years of experience with MT in acute stroke in Comprehensive Stroke Centers (CSCs) in Poland. Methods and results We retrospectively analyzed the results of a structured questionnaire from 23 out of 25 identified CSCs and 22 data sets that include 61 clinical, radiological and outcome measures. Results Most of the CSCs (74%) were founded at University Hospitals and most (65.2%) work round the clock. In 78.3% of them, the working teams are composed of neurologists and neuro-radiologists. All CSCs perform CT and angio-CT before MT. In total 586 patients were subjected to MT and data from 531 of them were analyzed. Mean time laps from stroke onset to groin puncture was 250±99min. 90.3% of the studied patients had MT within 6h from stroke onset; 59.3% of them were treated with IV rt-PA prior to MT; 15.1% had IA rt-PA during MT and 4.7% – emergent stenting of a large vessel. M1 of MCA was occluded in 47.8% of cases. The Solitaire device was used in 53% of cases. Successful recanalization (TICI2b–TICI3) was achieved in 64.6% of cases and 53.4% of patients did not experience hemorrhagic transformation. Clinical improvement on discharge was noticed in 53.7% of cases, futile recanalization – in 30.7%, mRS of 0–2 – in 31.4% and mRS of 6 in 22% of cases. Conclusion Our results can help harmonize standards for MT in Poland according to international guidelines

Zagospodarowanie odpadów górniczych i terenów ich składowania – aspekty środowiskowe

There are approx. 250 coal waste dumping grounds in Poland, yet there are countries in which this number is even higher. One of the largest sites for depositing mining and power plant waste in the Upper Silesian Coal Basin is the Przezchlebie dumping ground. In the article, it is considered as a secondary deposit of raw materials. An assessment of mining waste collected on the Przezchlebie dumping ground was carried out in terms of its impact on the environment and the possibility of its use. Mining waste samples were tested to determine their chemical composition. Physicochemical properties and chemical compositions of water extracts obtained from the investigated waste and groundwater in the vicinity of the dumping ground were analyzed. Due to the fire hazard resulting from the natural oxidation process of chiefly carbonaceous matter and pyrite, the thermal condition of the dumping ground was assessed. The results of the obtained tests confirmed the slight impact of mining waste deposited on the Przezchlebie dumping ground on the environment. The chemical composition, low radioactive activity of waste itself and the results of water extract tests referred to the permissible values according to the Polish Journal of Laws allow for multi-directional waste management. Due to the significant carbon content, the risk of self-ignition poses a significant threat on the dumping ground. Re-mining of the dumping ground and the recovery of raw materials, including coal contained in waste, will eliminate the risk of fire, allowing for a wider use of waste and, at the same time, will allow for other benefits, e.g. in the form of financial resources and the possibility of managing the dumping ground area.Kopalniom w zagłębiach węglowych i na świecie towarzyszy duża liczba zwałowisk odpadów powęglowych. W Polsce znajduje się około 250 tego typu obiektów, ale są kraje, w których ta liczba jest jeszcze większa. W artykule jedno z największych miejsc zdeponowania odpadów wydobywczych i energetycznych w GZW, jakim jest zwałowisko Przezchlebie, rozpatruje się jako wtórne złoże surowców. Dokonano oceny odpadów wydobywczych zgromadzonych na zwałowisku Przezchlebie pod kątem oddziaływania na środowisko i możliwości ich wykorzystania. Próbki odpadów górniczych poddano badaniom w celu określenia ich składu chemicznego. Wykonano badania własności fizykochemicznych i składu chemicznego wyciągów wodnych uzyskanych z badanych odpadów oraz wód podziemnych znajdujących się w sąsiedztwie zwałowiska. Ze względu na zagrożenie pożarowe wynikające z naturalnego procesu utleniania głównie substancji węglowej i pirytu dokonano oceny stanu termicznego zwałowiska. Wyniki uzyskanych badań potwierdziły nieznaczny wpływ odpadów górniczych zdeponowanych na zwałowisku Przezchlebie na środowisko. Skład chemiczny, niska aktywność promieniotwórcza samych odpadów oraz wyniki badań wyciągów wodnych pozwalają na wielokierunkowe zagospodarowanie odpadów. Ze względu na znaczącą zawartość substancji węglowej (do 13%) istotnym zagrożeniem występującym na zwałowisku jest ryzyko samozapłonu. Reeksploatacja zwałowiska i odzysk surowców, w tym węgla zawartego w odpadach, zredukuje zagrożenie pożarowe, pozwoli na szersze wykorzystanie odpadów, a jednocześnie pozwoli na uzyskanie innych korzyści np. w postaci środków finansowych i możliwości zagospodarowania terenu zwałowiska

Odzysk surowców jako element zagospodarowania odpadów powęglowych i ponownego wykorzystania terenów ich składowania

There are a huge number of objects constituting a storage place of coal mining waste in the coal basins in Poland and around the world. The article is a continuation of the study on the possibilities of using raw materials deposited on the coal mining waste dumping grounds on the example of the Przezchlebie dumping ground. The possibility of coal recovery from mining waste located on the dumping ground was analyzed. Tests on the quality parameters of waste were carried out, i.e. moisture and ash content, as well as the calorific value of raw waste. The relatively high calorific value and low ash content in the waste served as the basis for further tests related to the separation of coal. Tests on the mining waste enrichment using the complex based on the K-102 Komag pulse separator were carried out. As a result of coal separation, 7.66% of concentrate was obtained (in relation to feed) with the calorific value of 26.16 MJ/kg and ash content of 19.96%. Apart from mining waste, power plant waste (fly ash) can also be found on the dumping ground. They were subjected to tests for the possibility of using them in the production of construction materials, especially concrete and cement. Fly ash from the Przezchlebie dumping ground was classified as silica ash and it was found that it meets the requirements of Polish standard, except for the fineness of 42%. The separation of coal will eliminate the fire hazard on the dumping ground. A possible scenario of managing waste material on a dumping ground, which can be implemented in similar facilities, has been presented.Artykuł stanowi kontynuację badań nad możliwościami wykorzystania surowców zgromadzonych na zwałowiskach odpadów powęglowych na przykładzie zwałowiska Przezchlebie. W artykule poddano analizie możliwość odzysku węgla z odpadów wydobywczych ulokowanych na zwałowisku. Wykonano badania parametrów jakościowych odpadów tj. zawartość wilgoci i popiołu, wartość opałowa surowych odpadów. Stosunkowo wysoka wartość opałowa i niska zawartość popiołu w odpadach były podstawą do dalszych badań związanych z separacją węgla. Przeprowadzono testy wzbogacania odpadów powęglowych z wykorzystaniem kompleksu opartego na separatorze pulsacyjnym K-102 Komag. W wyniku separacji węgla uzyskano 7,66% koncentratu (w odniesieniu do nadawy) o wartości opałowej 26,16 MJ/kg i zawartości popiołu 19,96%. Oprócz odpadów wydobywczych na zwałowisku zalegają również odpady energetyczne (popioły lotne). Poddano je badaniom pod kątem możliwości wykorzystania ich w produkcji materiałów budowlanych, zawłaszcza betonu i cementu. Popiół lotny ze zwałowiska w Przezchlebiu zakwalifikowano jako krzemionkowy i stwierdzono, że poza miałkością wynoszącą 42%, spełnia on wymagania normy PN-EN 450-1. Separacja węgla wyeliminuje zagrożenie pożarowe na zwałowisku. Reeksploatacja z równoległą odbudową obiektu ukierunkowaną na docelowe zagospodarowanie terenu zwałowiska korzystnie wpłynie na środowisko, przy jednoczesnych korzyściach ekonomicznych wynikających z wykorzystania surowców znajdujących się w odpadach. Przedstawiono możliwy scenariusz zagospodarowania materiału odpadowego na zwałowisku, który może zostać zaimplementowany na innych tego typu obiektach

Heavy metals and sulfate removal from water by means of Al powder-cement-based filtration

Al powder-cement-based filters used to treat contaminated water from a coal mining area were designed and tested. Several of these multicomponent filters, containing quartz sand, Portland cement and water, as well as additional components (Al powder, CaO and CaSO4) in various mass proportions have been prepared. In this respect, an exhaustive analysis of the impact of the individual components on the properties of the filters was conducted to evaluate their efficiency in the removal of heavy metals and SO4 2–. Moreover, additional filter properties such as water permeability, uniaxial compressive strength and resistance to frost were also considered. The information gathered revealed that the designed filters pose high efficiency in respect of heavy metal removal (Cu, Cr, Ni, Co, Zn) and also exhibit proper water permeability and high mechanical strength. Based on this analysis, an optimal filter composition is provided. The results reported herein suggest that Al powder-cement-based filters are environmentally sustainable and cost effective for the treatment of water from industrial sites even in cold weather conditions

THE APPLICATION OF A JET FAN FOR THE CONTROL OF AIR AND METHANE STREAMS MIXING AT THE EXCAVATIONS CROSS – THE RESULTS OF NUMERICAL SIMULATION

The paper presents the results of numerical simulations into the distribution of methane concentration at the intersec-tion of two excavations with a fan (turned on) giving the air stream to the area of the crossing. Assumed case represents emergency situation related to the unexpected flow of methane from an excavation and its mixing with fresh air. It is possible when sudden gas outburst takes place, methane leaks from methane drainage system or gas leaks out the pipelines of underground coal gasification devices. Three options were considered – corresponding to three different speeds of the jet fan. They represent three stages of fan work. First – low air speed is forced by a pneumatic fan, when electricity is cut off after high methane concentration detection. Medium speed can be forced by pneumatic-electric device when methane concentration allows to turn on the electricity. Third, the highest speed is for electric fans. Simula-tions were carried out in the Fire Dynamics Simulator (FDS) belongs to the group of programs Computational Fluid Dy-namics (CFD). The governing equations are being solved in a numerical way. It was shown that proposed solution allows partial dilution of methane in every variant of speed what should allow escape of the miners from hazardous area

The influence of pressure drop on gas emissions from a mining shaft – an overview

Climate change can make an impact on the mining sector and post-mining sites. Among others, extreme weather events are connected with sudden and deep pressure drops which lead to gas emissions from an underground space to the surface through closed shafts. The tests undertaken in the frameworks of TEXMIN project lead to get measuring data of this phenomenon and will allow validating numerical models for further forecasts and mitigation means. Three examples of the results were presented. They showed that the intensity of pressure drop influences strongly on gas emissions from a closed shaft. Although the pressure drop process should be investigated in detail considering hourly or even more frequent variations of pressure. Considering the variation of emitted gases in the vicinity of the closed shaft they remained increased even 20-30 m from the point of emissions

The influence of pressure drop on gas emissions from a mining shaft - an overview

Climate change can make an impact on the mining sector and post-mining sites. Among others, extreme weather events are connected with sudden and deep pressure drops which lead to gas emissions from an underground space to the surface through closed shafts. The tests undertaken in the frameworks of TEXMIN project lead to get measuring data of this phenomenon and will allow validating numerical models for further forecasts and mitigation means. Three examples of the results were presented. They showed that the intensity of pressure drop influences strongly on gas emissions from a closed shaft. Although the pressure drop process should be investigated in detail considering hourly or even more frequent variations of pressure. Considering the variation of emitted gases in the vicinity of the closed shaft they remained increased even 20-30 m from the point of emissions