According to International Energy Agency (IEA) energy security is the continuous supply of energy at acceptable prices. National energy is based primarily on its own energy resources such as hard coal and brown coal. The 88% of electric energy production from these minerals gives us full energy independence. Additionally, the energy production costs from these raw materials are the lowest compared to other technologies. Of these two, the energy produced from brown coal is characterized by the lowest unit technical generating cost. Poland has the resources of these minerals for decades to come, the experience related to mining and processing them, scientific and design facilities and technical facilities and factories producing machines and equipment for their own needs, as well as for export. Coal is and should remain an important source of electricity and heat supply in Poland for the next 25–50 years. It is one of the most reliable and profitable energy sources. This policy may be difficult in the next decades due to the exhaustion of the available resources of hard and brown coal. The conditions for the construction of new mines, and thus for the development of coal mining in Poland, are very interdisciplinary in legal, environmental, economic and reputational terms. Germany has similar problems. Despite the fact that it is an image of a country investing in renewable energy sources, which are pioneers of energy production from RES, in reality hard and brown coal are still the primary sources utilized to produce electric energy.
The paper presents brown coal as one of the two basic domestic energy raw materials apart from hard coal. Historically, the use of brown coal in Poland is primarily fuel for the power plants. It was used for the production of lignite briquettes in small quantities and as fuel for local boiler houses and as an addition to the production of fertilizers (Konin and Sieniawa). At present, after changes in the case of the quality of fuels used in local boiler plants, brown coal remains as a fuel for the power plants in almost 100%. Currently, the brown coal industry produces about 35% of the cheapest electricity. The cost of electricity production is more than 30% lower than the second basic fuel – hard coal. The existing fuel and energy complexes using brown coal, with the Bełchatów complex at the forefront, are now an important guarantor of Poland’s energy security. In contrast to the other fuels such as: oil, natural gas or hard coal, the cost of electricity production from brown coal is predictable in the long term and almost insensitive to fluctuations in global commodity and currency markets. Its exploitation is carried out using the high technological solutions and respecting all environmental protection requirements, both in the area of coal extraction and electricity generation. Importantly, the fuel and energy complexes using brown coal showed a positive profitability so far and generated surpluses enabling the financing of maintenance and development investments, also in other energy segments. In particular, the sector did not require and has yet not benefited from public aid in the form of, for example, subsidies or tax concessions. Polish brown coal mining has all the attributes necessary for long-term development to ensure the country’s energy security. The document which is a road map for the brown coal industry is the Program for the Brown Coal Mining Sector in Poland adopted by the Council of Ministers on May 30, 2018. The Program covers the years 2018–2030 with a perspective up to 2050 and presents the development directions of the brown coal mining sector in Poland together with the objectives and actions necessary to achieve them. The Program presents a strategy for the development of brown coal mining in Poland in the first half of the 21st century. Possible scenarios have developed in active mining and energy basins as well as in new regions with significant resources of this mineral. This is to enable the most efficient use of deposits in the Złoczew and Konin regions as well as the Gubin and Legnica brown coal basins, and then deposits located in the Rawicz region (Oczkowice) as well as other prospective areas that may eventually replace the existing active mining and energy areas. This will allow power plants to continue to produce inexpensive and clean electricity, using the latest global solutions in the field of clean coal technologies.
Coal reserves in the Czech Republic are estimated to be 10 billion tons – hard coal about 37%, brown coal about 60% and lignite 3%. Hard coal is produced in Northern Moravia. In 2017 the production of hard coal was 5.5 million tons. Brown coal is mined in North-Western Bohemia − the production of brown coal in 2017 was 38.1 million tons. Significant quantities of hard 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 hard 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 Kopalnia Důlní závod 1 – (consists of three mines: ČSA Mine, Lazy Mine, Darkov Mine) and Mine Důlní závod 2 (ttwo 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 Hermanice heap.
The article characterizes geological formations occurring in the Polish lignite deposits having the characteristics of raw materials, i.e. accompanying minerals, giving their location, quality characteristics, estimated resources and potential applications. Attention has also been paid to the economic suitability, e.g. in infrastructure works and for the reclamation of many geological formations found in the overburden, classified as so-called earth or rock mass. There are also raw materials of sorption properties representing a huge potential source of minerals valuable for the economy and environmental protection. This refers to e.g.: beidellite clays from Bełchatów, Poznań clays from the region of Konin and Adamów, lacustrine chalk from Bełchatów, as well as Mesozoic limestone from the lignite bedding in Bełchatów. The reasons for the unsatisfactory use of accompanying minerals have been given. The authors described the methods used in the mining operation and processing of associated minerals, also applicable in Poland, as the legal basis for the extraction of these minerals and the economic and financial conditions. They stressed the need to protect mined not associated minerals used by the construction of anthropogenic deposits. This activity primarily requires regulating the legal status of these deposits and the development and application of an economic and financial system that stimulates the economy of these minerals. In summary, the necessary actions were taken to increase the use of the accompanying minerals and their contribution to the balance of mineral resources in the country.
One of the parameters which enables the evaluation of carbonaceous material is the thermal effect of wetting. The value of the heat of wetting provides information about the surface energy and the texture of the materials immersed in the wetting liquid. Knowledge of the heat of wetting of the carbonaceous materials is used to research their sorption properties, to characterize the structure and to determine the surface area. A method of me asuring the wetting of the carbonaceous materials as one of the methods to evaluate the carbonaceous materials was proposed. On the basis of research which was conducted, one determined the heat of wetting black coal from the Brzeszcze mine by methyl alcohol and lignites from the Turów and Bełchatów mine. One of activated carbons furnished by the Gryfskand company (WD-extra) was selected for the purpose of the comparison. The enthalpy of immersion was calculated on the basis of the results, the surface of the carbonaceous materials that were studied. It was revealed that the energetic effects of wetting depend both upon the microporous structure and the chemical nature of the adsorbent. The greatest heat of wetting calculated per 1g of the carbonaceous material, which has the most developed surface area and micropore volume, was obtained for the activated carbon. However, the heat of wetting does not increase proportionally to the surface area. The study revealed that the thermal effects of wetting for fossil coal decreases with the increasing of the surface area. The linear relationship was obtained for the three samples which were studied. The highest thermal effects (ΔT) and heat of wetting (Q) among the fossil coals was determined for the lignite from the Bełchatów mine, even though this coal had the least-developed porous structure. One may discern a clear influence of the swelling process upon the measured thermal effects on the basis of this sample.
The main energy source in Poland is still hard coal and lignite. The coal combustion process produces large quantities of by-products, e.g. fly ashes, slag furnace and harmful chemical gases (CO2, NOx, sulfur compounds) which enter the atmosphere. Fly ashes, due to their being fine grained (cement-like), chemical and phase compound and reactivity, have also been widely used in various technological solutions e.g. in the production of ordinary cement, hydro-technical cement and the new generation of cements. The adequate amount of fly ashes additive has a positive effect on fresh and hardened cement slurry properties. What is more, it allows for the pro-ecological and economic production of cement mix The exploitation of natural resources is connected with performance mining excavations at different depths. After a certain period of time, those voids break down which, in turn, leads to the slip of upper layers and the so-called landslides forming on the surface. This situation imposes the necessity of basis and sealing rock mass reinforcement. To minimize the risk connected to geotechnical problems on the mining areas, there is a need to use engineering solutions which could improve soil bearing in a universal, economical and efficient way. This leads to the development of new cement slurry recipes used during geoengineering works, especially in the mining areas. Moreover, economic requirements are forcing engineers to use less expensive technical and technological solutions simultaneously maintaining strength properties. An example of such a solution is to use suitable additives to cement slurry which could reduce the total unit cost of the treatment.
The exploitation and processing of lignite in the Bełchatów region is connected with the formation of various mineral waste materials: varied in origin, mineral and chemical composition and raw material properties of the accompanying minerals, ashes and slags from lignite combustion and reagipsum from wet flue gas desulphurisation installations. This paper presents the results of laboratory tests whose main purpose was to obtain data referring to the potential use of fly ashes generated in the Bełchatów Power Plant and selected accompanying minerals exploited in the Bełchatów Mine in the form of self-solidification mixtures. The beidellite clays were considered as the most predisposed for use from the accompanying minerals , due to pozzolanic and sorption properties and swelling capacity. Despite the expected beneficial effects of clay minerals from the smectite group on the self-settling process as well as the stability of such blends after solidification, the results of physical-mechanical tests (compressive strength and water repellence) were unsatisfactory. It was necessary to use Ca (OH)2, obtained from the lacustrine chalk as an activator of the self-settling process It was necessary to use lacustrine chalk as an activator of the self-solidification process. The presence of calcium will allow the formation of cement phases which will be able to strongly bond the skeletal grains. Also, the addition of reagipsum to the composition of the mixture would contribute to the improvement of the physico-mechanical parameters. The elevated SO4 2– ion in the mixture during the solidification allows for the crystallization of the sulphate phases in the pore space to form bridges between the ash and clay minerals. The use of mixtures in land reclamation unfavourably transformed by opencast mining in the Bełchatów region would result in measurable ecological and economic benefits and would largely solve the problem of waste disposal from the from the operation and processing of lignite energy.
Power production is the largest source of emissions of anthropogenic carbon dioxide. The main fuels in Poland are solid fuels - hard coal and lignite. Their combustion produces large quantities of waste, primarily fly ash. The ashes from lignite, due to the chemical and phase composition, and thus their properties, have - so far - limited economic use. Among their possible applications is the use of mineral sequestration of carbon dioxide - this is the result of their relatively high content of active CaO and MgO, which can react with carbon dioxide in aqueous suspensions. The paper presents maximum theoretical capacity of CO2 bonding for examined fly ashes and the results of the research on absorption of CO2 by the ash-water suspensions from fly ash resulting from the combustion of lignite from Pątnów and Turów power plants. Calculated for the examined fly ashes maximum theoretical capacity of CO2 bonding amounted to 14% for the ashes from Pątnów power plant and 14.4% for the fly ashes from Turów power plant. Studies have shown that most CO2 - 8.15 g/100 g of ash, was absorbed by suspension with ashes from Turów power plant with a mass ratio of ash to water of at 0.8:1. In the case of ash from Pątnów power plant absorption was lower and amounted to a maximum - 8.7 g CO2/100 g ash. The largest increase CO2 absorption was observed in the first 30 minutes of carbonation in the suspensions of fly ash from Pątnów power plant and the first 15 minutes in suspensions of fly ash from Turów power plant. After this time, the absorption has increased slowly. An increase in temperature in the chamber system, confirming the occurrence of the process of carbonation and its endothermic character. The highest temperature - 44.8 C recorded in the suspension with ashes from Turów power plant, which has also the greatest absorption of CO2. The results confirm the usefulness of these ashes to sequester carbon dioxide.
Fly ashes from the combustion of lignite coal are suitable materials for the creation of suspensions in which CO2 is bound by mineral carbonation. Considering their limited economic uses, mineral sequestration, as a stage of the CCS technology in lignite coal power plants, can be a way of recycling them. Mineral sequestration of CO2 was researched using fly ashes from the combustion of lignite coal in the Pątnów power plant, distinguished by a high content of CaO and free CaO. Research into phase composition confirmed the process of carbonation of the whole calcium hydroxide contained in pure suspensions. The degree of CO2 binding was determined on the basis of thermogravimetric analysis. A rise in the content of CaCO3 was found in the suspensions after subjecting them to the effects of carbon dioxide. Following carbonation the pH is lowered. A reduction in the leaching of all pollutants was discovered in the studied ashes. The results obtained were compared to earlier research of ashes from the same power plant but with a different chemical composition. Research confirmed that water suspensions of ashes from the combustion of lignite coal in the Pątnów power plant are distinguished for a high degree of carbonation.
Significant quantities of coal sludge are created during the coal enrichment processes in the mechanical processing plants of hard coal mines (waste group 01). These are the smallest grain classes with a grain size below 1 mm, in which the classes below 0.035 mm constitute up to 60% of their composition and the heat of combustion is at the level of 10 MJ/kg. The high moisture of coal sludge is characteristic, which after dewatering on filter presses reaches the value of 16–28% (Wtot r) (archival paper PG SILESIA). The fine-grained nature and high moisture of the material cause great difficulties at the stage of transport, loading and unloading of the material. The paper presents the results of pelletizing (granulating) grinding of coal sludge by itself and the piling of coal sludge with additional material, which is to improve the sludge energy properties. The piling process itself is primarily intended to improve transport possibilities. Initial tests have been undertaken to show changes in parameters by preparing coal sludge mixtures (PG SILESIA) with lignite coal dusts (LEAG). The process of piling sludge and their mixtures on an AGH laboratory vibratory grinder construction was carried out. As a result of the tests, it can be concluded that all mixtures are susceptible to granulation. This process undoubtedly broadens the transport possibilities of the material. The grain composition of the obtained material after granulation is satisfactory. Up to 2 to 20 mm granules make up 90–95% of the product weight. The strength of the fresh pellets is satisfactory and comparable for all mixtures. Fresh lumps subjected to a test for discharges from a height of 700 mm can withstand from 7 to 14 discharges. The strength of the pellets after longer seasoning, from the height of 500 mm, shows different values for the analyzed samples. The values obtained for hard coal sludge and their blends with brown coal dust are at the level from 4 to 5 discharges. The strength obtained is sufficient to determine the possibility of their transport. At this stage of the work it can be stated that the addition of coal dust from lignite does not cause the deterioration of the material’s strength with respect to clean coal sludge. Therefore, there is no negative impact on the transportability of the granulated material. As a result of mixing with coal dusts, it is possible to increase their energy value (Klojzy-Karczmarczyk at al. 2018). The cost analysis of the analyzed project was not carried out.
Bełchatów lignite deposit is located in the central partof Poland in the tectonic Kleszczów graben. It is dividedinto several parts, which are mining fields: Kamieńsk area (eastern part of the deposit), Bełchatów area (central partof the deposit) and Szczerców area (western part of the deposit). The subject of this study was the Belchatow area.The main issue of the investigations was the dependence of local, regional and global, horizontal variability of selected lignite qualitative parameters (moisture, ash content, calorific value and sulfur content in the as receivedstate) is a function of viewing direction. There was applied the geostatistical analysis of the lignite variability parameters with use of semivariograms.
The researches which were conducted at different scales of observation: in the locale scale – in small field size8 ́8 m called experimental area (local analysis), in larger homogeneous separated parts of the Belchatow area(regional analysis) and in the whole Bełchatów area scale (general analysis). The results proved the visible anisotropy of variability mine lignite parametres. Anisotropy structure observed in regional and global scale isconnected with tectonic structure of the Bełchatów Graben. The detailed studies show the variated level of anisotropy observed in different areas of Bełchatów field.
However, no dependence of the relative level of ash and total sulfur content anisotropy on the environment of sedimentation of the main coal deposit in different parts of the Belhchatów field has been observed. Both parameters characterize with strong or medium anisotropy level in examined fields. Moreover, anisotropy is alsovisible in the local scale. Conducted researches confirmed the thesis that zonal anisotropy is prevalent kind of anisotropy in the regional scale. In the range of the whole deposit the total sulfur content showed zonal anisotropy,whereas the ash content revealed geometric anisotropy
The transitional siliceous rocks from the Belchatow lignite deposit belong to the deposits with heterogeneous petrographic composition. The research allows us to identify among others, opoka-rocks and gaizes. The mineralogical-chemical analysis proves that the main ingredients of the studied rocks commonly used as building material are minerals of the SiO₂ group. Laboratory tests show that the nature of siliceous mineral phases has several effects on the geomechanical parameters of the studied transitional rocks. They are a reduction in water content and rock porosity, which leads to the transition of opal type A to opal type crystobalit and trydymit and then to quartz or microquartz. Their density and strength parameters are increased.
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