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INNOVATIVE MINING TECHNOLOGIES

IMTech 2019 Scientific and Technical Conference

March 25^th – 27^th, 2019

Szczyrk, Poland

The IMTech 2019 Scientific and Technical Conference on INNOVATIVE MINING TECHNOLOGIES was held in Szczyrk, Poland. It gathered over 100 scientists and researchers as well as a big group of specialists representing mining machinery producers and producers of minerals.

The IMTech 2019 Conference was oriented mainly onto innovative and environment friendly technologies and techniques for processing of minerals in the aspect of safety, quality and efficiency.

Five conference sessions contained interdisciplinary presentations on the latest achievements and implementations in the domain of minerals' beneficiation machines and equipment, a beneficiation and an exploitation of minerals, a review of technologies for a low-quality solid fuel gasification, dust control in hard coal processing plants, a remediation and a revitalization of industrial areas, a recovery of metals from e-scrap using gravitational, electrostatic and magnetic separations as well as underground mine workings as potential places for compressed air energy storage and a utilization of methane deposits from liquidated mines in the aspect of environmentally friendly energy technologies.

The conference was an interesting forum enabling an exchange of scientific and professional experience among the participants representing academia and industry. However, the conference series contains only some selected articles, giving an overview of the IMTech 2019 subject-matter.

Editors

Dr. Marcin Lutyński, DSc. Eng.

Dr. Dariusz Prostański, DSc. Eng.

Dr. Tomasz Suponik, DSc. Eng.

All papers published in this volume of IOP Conference Series: Materials Science and Engineering have been peer reviewed through processes administered by the proceedings Editors. Reviews were conducted by expert referees to the professional and scientific standards expected of a proceedings journal published by IOP Publishing.

Coal reserved in Czech Republic are estimated to be 10 billion tones – bituminous coal about 37%, brown coal about 60% and lignite 3%. Bituminous coal is produced in Northern Moravia – in 2017 production of bituminous coal was 5.5 milion tons. Brown coal is mined in Nord-Wester Bohemia − production of brown coal in 2017 was 38.1 milion tons. Significant quantities of bituminous coal are exported to Slovakia, Austria, Germany and Hungary. In accordance with the National Energy Policy, coal will remain the main source of energy in the country in the future, despite the increased use of nuclear energy and natural gas. The government expects that in 2030 energy from coal will account for 30.5% of energy produced. There are five coal companies in the Czech Republic: OKD, a.s., the only bituminous coal producer and four brown coal mining companies: Severočeské doly a.s., owned by ČEZ, the largest producer of brown coal, Vršanská uhelná a.s., with coal resources until 2055, Severní energetická a.s. with the largest brown coal reserves in the Czech Republic and Sokolovska uhelná a.s., the smallest mining company extracting lignite. OKD operates coal in two mines Důlní závod 1 – (consists of three mines: ČSA Mine, Lazy Mine, Darkov Mine) and Mine Důlní závod 2 (two mines Sever, Jih). The article also presents a pro-ecological solution for the management of waste heaps after coal enrichment - a plant for the enrichment of coal waste from the Heřmanice heap.

Mining and industrial activity causes adverse changes in the environment. The shift from industrial to post-industrial society has shaped the appearance of degraded areas. In a post-industrial society, there is a lower demand for production capabilities and higher for services, consumption and recreation. This study discusses projects involving the remediation and revitalisation of post-industrial post-mining areas.

The raw materials processing methods play important role in excavation industry. The area is nowadays a target for novel, innovative technology application. One of them is an image processing as an instrument for determination of different material properties. The paper proposes a tool – database system – dedicated for supporting images processing and computer vision methods application in the mining industry. The idea and implementation of the system is presented. The database was supplied with a set of coal images. The images were taken at a special stand, with the calibrated camera. The usefulness of system was tested by application of a pipeline of image processing algorithms. The goal was to estimate the grain size composition of coal and rock matter presented on images. Two algorithms for edges detection were tested: Sobel filter and Statistical Dominance Algorithm. After edges detection, a set of morphological operations were applied of determination of good starting markers for the watershed algorithm. The result showed that both algorithms tend to produce over segmented images. However, SDA performed noticeably better. The experiments proved the usefulness of developed database system dedicated to image processing.

Waste from energy or mining has been widely used in civil engineering for many years, ie in road engineering, construction, land reclamation as well as in mining. The most frequently performed technologies in underground mining with fine-fraction waste are the sealing of infarcted grouting of cavings and liquidation. In these technologies, transport and migration properties play a primary role. They depend on the type of fly ash. At present, in Polish hard coal mines located in Upper Silesia, most commonly used technologies are ashes with code 10 01 02 from conventional boilers, and as second ashes from code 10 02 82 from fluidized bed boilers. The article presents the results of research on selected physical properties of ash-water mixtures such as: water-ash index (W/FA), leveling, density and volume of excess water. Furthermore, for the tested ashes, the volume of water was determined, which can be utilized in the case of the technologies described above, and it will constitute an added value.

The article presents the place and scope of testing the NEPTUN prototype spraying system intended for neutralization of total and respirable dust at workplaces in the processing plant of Bolesław Śmiały mine. The testing procedure and the results of dust concentration measurements at each workplace, covered by the operational range of the NEPTUN spraying system are presented. In the final part, the results of tests were analyzed and the reduction efficiency of total and respirable dust at the tested workplaces is given.

The article presents a construction and operational principle of a pulsating jig, a device for obtaining minerals in a pulsating water medium. A smart control system of the device is discussed. Examples of jig implementations for obtaining minerals from natural deposits and for a recovery of minerals from mine heaps are presented. Tests results of used equipment are provided, indicating a possibility of obtaining purified aggregate and steam coal concentrate of high quality parameters.

The article presents a topic related to generation of heat and power in small and medium size coal power units which are able to comply with the emission benchmark of 550 g of CO₂/kWh through utilization of biomass. The concept for coal and biomass cogasification installation is based on GazEla reactor, which has been developed by Institute for Chemical Processing of Coal. Authors also present a discussion on issues related to technological scheme of the gasification unit which has been integrated with a selected district heating system. The system has been set up for generation of hot technological water and electrical power. Focal point of the installation is a fixed bed gasification reactor. For the system to provide means enabling cogeneration of heat and power, downstream from the generator a high-temperature gas dedusting system, a unit for recovery of heat from process gas coupled with separation of tar contaminants as well as a gas engine were proposed. A sorted chart presenting historical data for annual demand for heat together with the most important assumptions used during the analyses are discussed. Finally authors present results of calculations for the integrated unit that are further broadened by sensitivity analyses for change of gasification reactor's efficiency, as well as engine's efficiency for heat and power generation.

For several decades the KOMAG Institute of Mining Technology has been involved in a construction of pulsating jigs - devices for a gravity beneficiation of hard coal. The conducted research and conceptual work enables their constant development, resulting in their high reliability and efficiency. The article presents the latest design solutions and examples of implementations of the KOMAG state-of-the-art pulsating jigs in the Polish hard coal mines. The operational principle and possibilities of an innovative control system of the KOGASTER SSWO jig node are also discussed

The article presents a proprietary visualization software for the coal beneficiation process, which enables monitoring of the jig node operation and full control of trends relating to all signals from sensors installed in the system and connected to the controller, among others a movement of the float, a position of the culvert and a position of the overflow threshold. The results of analyses regarding the selection of PID regulator settings, determined on the basis of industrial research, are also presented.

Theoretical backgrounds of airborne dust control with use of atomized stream of liquid are presented. Testing procedure, with a special attention paid to analysis of drops fraction distribution, is presented on the example of new nozzle design developed at KOMAG. The method for calculation of absorption surface is discussed. The test results are used to analyse operational parameters of the nozzle which are important for the dust control systems.

A requirement to limit the temperature of diesel engine components results from the recommendations of the drive manufacturers as well as from the mining regulations. In order to meet these requirements it is necessary to reduce the temperature of the exhaust gases below 150 °C and in order to achieve this objective, in the exhaust system of the diesel engine various types of heat exchangers are used. The article presents the procedures and results of testing the pressure free heat exchanger for cooling the exhaust systems in underground mining machinery drives applied in hard coal mines.

The article discusses World's current status of surface coal and other resources gasification technology. Examples of existing and planned gasification plants efficiencies up to the year 2022 along with the use of syngas for chemical resources production and distribution of plants are given. The SGT (SES Gasification Technology) gasification technology where produced syngas is used for energy production is described.

Open pit mines are frequently accumulating significant amounts of material in the form of dumping grounds, landfills or forming land for reclamation. Often the form of emerging dumping grounds is determined by stability analysis of their slopes at the design stage. During the operation of the mining site and the collection of material on the pile, only the geometry of the slope is a subject of control. In many cases, after making slopes of a dozen or so meters height or even up to several tens of meters, and after a certain time has elapsed since their formation, deformation of the escarpments can be observed. At this stage, the only option is to change the geometry, i.e. inclination of a slope or, in the worst case, rebuilding of the dump. In the paper the analysis of the impact of the method of forming slopes and material quality on stability of formed slopes and their safe exploitation has been presented. It also presents a proposal to normalize the methodology of design and construction of slopes in a manner ensuring stability and taking into account the variability of the material parameters from which the slope is to be formed.

The article gives a brief overview of current developments and projects of Compressed Air Energy Storage (CAES). Typical CAES configurations such as Adiabatic CAES and Diabatic CAES are described. The concept of air storage in isolated workings of closed coal mine is presented taking into account availability of such places in the Silesian Coal Basin of southern Poland. The article also discusses major challenges of such concept such as insulation of underground workings, geomechanical stability of workings and site availability. As a proof of concept examples of underground coal mines converted into natural gas storage sites are given. Types of underground workings that could serve as a part of potential compressed storage site are listed and an example of volume calculation available in coal mine for storage is given.

A possibility of diagnosing the welded joints in the components of powered roof supports used in longwall panels of hard coal mines is analysed. It was found that the magnetic-and-powder method is most useful for that purpose. Devices which facilitate assessment of technical condition of welded joints in canopies and bases are discussed. Design and principles of operation of welded joints liquid detector adapted for operation in industrial conditions are presented. Two ideas of a magnetic inductor for technical diagnosis of powered roof support components by the magnetic-and-powder method is discussed.

The purpose of the work was to recover metals from e-scrap, in particular from mainboards of desktop computers, using gravity, electrostatic and magnetic separation. The article describes the method of comminution as well as the yield of size fraction after this process. In addition, the separation of the fraction of 0.32 - 0.56 mm with the use of two systems: I) electrostatic and magnetic separation, and II); gravity and magnetic separation, was presented. The feed to the magnetic separator for both systems was metals (high density products). The yield of fraction 0.32 - 0.56 mm obtained after comminution was 40.7% while the yields of the products obtained from the first system were as follows: in the case of electrostatic separation, 24.9% metals and 75.1% plastics and glass; and for magnetic separation 0.7% of ferromagnetics, 19.0% of diamagnetics and 5.3% of paramagnetics. The yields of the products in the second system were: in the case of gravity separation, fraction with a density ρ > 2.96 g/cc = 33.0% and fraction with a density ρ<2.96 g/cc = 67.0%; and for magnetic separation 0.8% of ferromagnetics, 25.3% of diamagnetics and 6.9% of paramagnetics.

At the beginning of the article main factors occurring in polluted atmospheric air and their connection with the methods of energy production are discussed. Various energy sources in the aspect of energy production technologies, including primary energy sources are presented. Two main actions taken to improve the quality of atmospheric air in Poland are described: Clean Air Programme, assuming a subsidy for an exchange of individually-used coal boilers for ecological ones or for gas heating, and the Polish Energy Policy until 2040, which assumes a gradual reduction in the share of hard coal and lignite in energy production. Methane as a mineral accompanying coal seams as well as ways of its recognition and management are presented. An example of the conducted research project shows a significance of the resource recognition and dynamics of the deposit in planning an economically justified exploitation of the deposit from closed down mines. Finally, there is hope that due to a further process of efficient restructuring of the Polish mining industry, the importance of using methane from closed down mines as a green energy source will increase.

Self-propelled suspended railways are one of the main means of auxiliary transport in underground coal mines. Their dynamic development and increase of their widespread use in Poland took place at the turn of the 20th and 21st centuries. Due to their advantages which include among others no need to maintain tracks on the floor and transport safety. The suspended railway is used instead of other means of transport. Individual subassemblies of the suspended monorails are still under development. Improvement of safety and increase of the work comfort of the operator and conveyed persons are among the objectives of manufacturers of these machines. A possibility of increasing the speed of suspended monorails, especially when conveying people, associated with a continuous extension of the access roads to coal mining faces, is also an important aspect. Increasing the speed will enable a more efficient used employees' working time. This article presents an example of using one of virtual prototyping methods to support the modernization process of existing solutions or to support designing of new machines. Use of this method for a modification of the operator's suspended cabin in a suspended monorail is described.

The article presents problems related to the mining of compact and very hard rocks with cutting tools, mainly with tangential-rotary picks. The currently used disc tools, their parameters and the way of working are described. The disadvantages of selected solutions and related obstacles to their wider use in mining have been presented. The directions of further development of disk tools were presented, allowing their use, for example, in mining heads of longwall shearers and roadheaders.