Current issue

 

 

 

Pavlo PRYSYAZHNYUK

Ivano-Frankivsk National Technical University of Oil and Gas, Ukraine

Krzysztof KRAUZE

AGH University of Science and Technology, Poland

Liubomyr ROMANYSHYN, Yurii MOSORA 

Ivano-Frankivsk National Technical University of Oil and Gas, Ukraine

 
Increasing the wear resistance of mining machines equipment tools by
FCAW with Fe-Mo-Mn-B-C hardfacing alloys

p. 64-70

In this study hardfacing by flux-cored arc welding with Fe-Mo-Mn-B-C-based alloy as an alternative technique for improving wear resistance of mining machines conical picks was investigated. The microstructure of hardfaced layer consists of the uniformly distributed faceted grains of binary (Fe,Mn)Mo2B2 boride phase with average size of 25 μm and austenite-based eutectic. The hardness measured by microindentation and microscratching techniques across the interfaces between deposited layer and base steel was within 2.2 – 18 GPa. No welding defects such as cracks, pores or non-metal inclusions in the hardfaced layer and heat affected zones were detected. Comparative studies of the developed hardfacing alloy with commercially available Capilla HR MAG hardfacing and heat treated 35HGS steel were carried out using testing machine developed at the department of machinery engineering and transport of AGH university of science and technology for semi-industrial wear tests of mining machines conical picks. Wear measurement results show that using hardfacing with proposed alloy of Fe-Mo-Mn-B-C system leads to decreasing of impact-abrasion wear rate in approximately 3 times than that for tested commercial materials. This allows to recommend hardfacing by FCAW with proposed material in form of flux-cored wire for conical picks insert holders’ surfaces during mining of hard rocks.

Keywords: hardfacing, iron-molybdenum boride, impact-wear resistance, manganese austenite, mining tools

 

Stefan CZERWIŃSKI

retiree

Agnieszka CZERWIŃSKA-LUBSZCZYK

University of Bielsko-Biala Faculty of Management and Transport, Poland

Michalene GREBSKI 

Northampton Community College, Monroe Campus, USA

 

Increase in the production capacity of a hard coal mining plant

p. 71-80

During the current war in Europe and the restriction of hydrocarbon imports to the EU, there was a need to temporarily increase the production capacity of hard coal mining plants in order to ensure continuity of supply. This requires an increase in the number of longwall excavations (which is time-consuming and requires additional financial resources) or an increase in the efficiency of already operated longwall excavations. The article presents how the organization of the longwall ancestor's work would be shaped with ad hoc production work 24 hours a day, assuming a five-day working week, i.e. from Monday to Friday.

Keywords: hard coal mining plant, production, effectiveness, economic effects

 

Marian LASEK, Zbigniew CZERNECKI, Antoni JAKUBÓW

AZIS” Mining Sp. z o. o., Poland

 

Innovative technology for inertization of goaf in operating longwall
panel – presentation of gained experience

p. 81-87

The article presents an innovative technology of fire prevention in goaves, based on injection of nitrogen and carbon dioxide inert gases mixture from treatment of exhaust gases from a methane combusting gas engine. The developed innovative technology and the constructed prototype of the installation producing inert gases are the final result of the research project entitled "Innovative and effective technology of inerting the goaf active or dammed longwall in an underground mining plant, extracting hard coal, using mixtures of inert gases obtained from the purification of exhaust gases from a gas engine and preventing the formation of endogenous fires", co-financed by the National Center for Research and Development (NCBR). The prototype installation was demonstrated in real conditions at the “Borynia” part of "Borynia-Zofiówka" mine, where, at the end of the research project, the prototype and the developed fire prevention technology with the use of gas engine exhaust gases were optimized and validated. Until now, under normal conditions in a hard coal mine, the fumes generated as a result of methane combustion in gas engines were emitted directly to the atmosphere. Innovative inerting technology, processing and reusing the exhaust gases produced by methane-fueled gas engines, in ecological context will contribute to the reduction of pollutant emissions in the mining sector, and, with mixing at the same time the carbon dioxide and nitrogen in the proper ratio in the mixture, it will fully utilize the advantages of each of these gases, as known when used in separate form. As a result, considering the possibility of generating a much higher amount of inert gases per time unit compared to the available technologies, and combining the physicochemical properties of nitrogen and carbon dioxide in one mixture, the innovative technological solution significantly increases the effectiveness of fire prevention, thus reducing the possibility of an endogenous fire.

Keywords: endogenous fires, fire hazard prevention, intertization, diesel engine, catalyst, purification of exhaust gases

 

Maxim KONONENKO, Oleh KHOMENKO,
Inna MYRONOVA

Dnipro University of Technology, Ukraine

Ihor KOVALENKO

Ukrainian State University of Chemical Technology, Ukraine

 

Economic and environmental aspects
of using mining equipment and emulsion explosives for ore mining

p. 88-97

The calculation of economic efficiency during the preparatory mine operations using various mining equipment and types of explosives was performed. The general exponential regularity of determining the cost of carrying out 1 m3 of working depending on the strength of rocks to compression when using different types of explosives and tunneling equipment was established. An environmental assessment of the use of emulsion explosives in an iron ore mine showed a decrease in concentrations of environmentally hazardous substances and a decrease in environmental hazard coefficients, which resulted in a decrease in the pollution of the atmospheric air.

Keywords: iron ore, mining equipment, emulsion explosive, economic efficiency, environmental assessment

 

Piotr MOCEK

Silesian University of Technology, Faculty of Mining,
Safety Engineering and Industrial Automation, Poland

Kinga MOCEK

Pomeranian Medical University in Szczecin, Faculty of Medicine and Dentistry, Poland

 

Mine dust - as a cause of respiratory diseases of miners

p. 98-109

The risk of industrial dust in the work process is one of the greatest challenges not only in Europe but also in the modern world, where over a million people die each year from pneumoconiosis and other respiratory diseases. In Poland, one of the most numerous groups of employees constantly exposed to polluted air at the workplace are miners employed in hard coal mines, who in 2021 they accounted for 89.8% of all exposed persons in Poland (34,876 employees). In order to assess the impact of industrial dust hazards on the health of miners, employees of the Department of Safety Engineering of the Silesian University of Technology, in cooperation with students of the Pomeranian Medical University in Szczecin and a pulmonology specialist, conducted a pilot assessment of the effects of long-term exposure of employees of the preparatory departments of mine X to mine dust. The scope of diagnostic tests included: interview with the patient, physical and spirometric tests. Among the surveyed miners, 18.4% had various disorders and changes in the respiratory system, including the diagnosed pneumoconiosis. The article describes the health effects of long-term exposure of miners to mine dust and the partial results of the diagnostic tests.

Keywords: mine, hazard, mine dust, preparatory departments, pneumoconiosis, respiratory diseases, preventive measures, diagnostic tests, spirometry

 

Kamil SZEWERDA

KOMAG Institute of Mining Technology, Poland

Tibor KRENICKY

Faculty of Manufacturing Technologies of the Technical University
of Kosice with a seat in Prešov, Slovak Republic

 

Use of the MBS method in mining industry R&D projects

p. 110-120

Virtual prototyping methods are an important aspect both in the designing process and in research processes aimed at the modification and optimization of machines and devices. It allows one to analyse the way of operation, the flow of forces, the cooperation between components, as well as finding the weakest points of the structure. This article presents the possibilities of using the MBS method, which is one of the tools used in virtual prototyping, on the basis of the results of R&D projects realized at the KOMAG Institute of Mining Technology.
The main objective of the MBS method is to simulate the kinematics and dynamics of multi-body systems, the results of which will enable a series of analyses related to the operation of machines and devices.

Keywords: : numerical simulations, kinematics and dynamics, MBS (MultiBody System), mining industry