Poziom sprzedaży danego dobra uzależniony jest w dużej mierze od sieci dystrybucji. Przestrzenna analiza dystrybucji umożliwia racjonalizację sieci sprzedaży, co podnosi efektywność i wydajność sprzedaży przedsiębiorstwa z bezpośrednim przełożeniem na wzrost zysków. Z pomocą przychodzą tu tak zwane analizy przestrzenne. W artykule przedstawiono analizę sieci autoryzowanych sprzedawców Polskiej Grupy Górniczej dla województwa opolskiego. Analiza została wykonana z wykorzystaniem narzędzi GIS (SIP). Celem przeprowadzonej analizy było zaprezentowanie możliwych do zastosowania narzędzi weryfikacji już istniejącej sieci dystrybucji, jej racjonalizacji, bądź też tworzenia nowych punktów sprzedaży. Przedstawione narzędzia należą do operacji GIS stosowanych do przetwarzania danych przechowywanych w zasobach Systemów Informacji Przestrzennej. Są to tak zwane narzędzia geoprocessingu, czyli geoprzetwarzania. W artykule zaprezentowano kilka analiz przestrzennych, których rezultatem jest wybór najlepszej lokalizacji punktu dystrybucji pod względem określonych kryteriów. Stosowane narzędzia to między innymi zapytanie przestrzenne intersect (iloczyn), suma. Posłużono się także geokodowaniem, utworzono tak zwany kartodiagram. Przedstawiona przykładowa analiza może zostać wykonana dla sieci autoryzowanych sprzedawców zarówno w skali jednego województwa, miasta, jak też obszaru całego kraju. Użyte narzędzia dają możliwość sprecyzowania grupy docelowych odbiorców, obszarów na jakich się oni znajdują, obszarów koncentracji potencjalnych odbiorców. Pozwalają tym samym na ulokowanie punktów sprzedaży na obszarach charakteryzujących się wysokim prawdopodobieństwem znalezienia nowych klientów, umożliwiają wybór lokalizacji, np. zapewniającej dostęp do dróg, transportu kolejowego, lokalizacji o odpowiedniej powierzchni, sąsiedztwie.
The study included bituminous coal seams (30 samples coal from the Bogdanka and Chełm deposits) of the Lublin Formation, the most coal-bearing strata in the best developed and recognized in terms of mining parts of the Lublin Coal Basin in Poland. High phosphorus concentrations in coal of the Lublin Formation were found (1375 g/Mg) as well as P2O5 in coal ash (2.267 wt%). The phosphorus contents in coal and coal ash from the 385 and 391 coal seams in the area of the Lubelski Coal Bogdanka Mine and in the area of its SE neighbor is the highest (max. 2.644 wt. % in coal and 6.055 wt. % of P2O5 in coal ash). It has been shown that mineral matter effectively affects phosphorus contents in coal and coal ash. At the same time, phosphate minerals (probably apatite and crandallite) present in kaolinite aggregates of tonsteins contain the most of phosphorus and have the greatest impact on the average P content in the 382, 385, 387, and 391. The secondary source of phosphorus in these coal seams and main source of phosphorus in these coal deposits that do not contain mineral matter of pyroclastic origin (378, 389, 394) may be clay minerals, which absorbed phosphorus compounds derived from organic matter released during coalification. Phosphorus-rich ash from the combustion of the Lublin Formation coal tend to be environmentally beneficial to the environment and also useful for improving the soil quality. Due to the low degree of coalification and high content of phosphorus in coal, this coals of little use for coking.
Explosions of coal dust are a major safety concern within the coal mining industry. The explosion and subsequent fires caused by coal dust can result in significant property damage, loss of life in underground coal mines and damage to coal processing facilities. The United States Bureau of Mines conducted research on coal dust explosions until 1996 when it was dissolved. In the following years, the American Society for Testing and Materials (ASTM) developed a test standard, ASTM E1226, to provide a standard test method characterizing the “explosibility” of particulate solids of combustible materials suspended in air. The research presented herein investigates the explosive characteristic of Pulverized Pittsburgh Coal dust using the ASTM E1226-12 test standard. The explosibility characteristics include: maximum explosion pressure, (Pmax); maximum rate of pressure rise, (dP/dt)max; and explosibility index, (Kst). Nine Pulverized Pittsburgh Coal dust concentrations, ranging from 30 to 1,500 g/m3, were tested in a 20-Liter Siwek Sphere. The newly recorded dust explosibility characteristics are then compared to explosibility characteristics published by the Bureau of Mines in their 20 liter vessel and procedure predating ASTM E1126-12. The information presented in this paper will allow for structures and devices to be built to protect people from the effects of coal dust explosions.
The article presents the challenges faced by the hard coal mining sector in Poland. The biggest challenge results from a decrease in the demand for coal, which was triggered mainly by the climate policy, including the tightening of environmental standards and an increase in the efficiency of generating units. The fundamental model of the MRÓWKA domestic coal market has been described. The model allows for determining the marginal price of a given fuel for a given generating unit in the system and the optimal mix of fuels to meet the energy demand. The results of the model calculations for the baseline and alternative scenarios were presented. It has been shown that the optimal distribution of coal mining capacities promotes the import of the discussed fuel in the north-eastern part of the country and that the individual customer valuation leads to a decrease in the competitiveness of the units located in the central-western part of the country. The paper also discusses the potential impact of the domestic oversupply on the balance sheet and the price of coal. According to the obtained results and the basic laws of economics, an oversupply of coal leads to a decrease in prices. For the analyzed variants, the dependence of prices was estimated at PLN 0.0308 / GJ for every million tons of the oversupply. The fall in prices is largely due to the fuel supply to units located close to ports or railway border crossings. Based on the presented arguments it can be concluded that the maximization of financial result from the extraction of coal should be based on an analysis taking incremental changes in fuel prices into account.
Gasification technology is often seen as a synonym for the clean and efficient processing of solid fuels into combustible gas containing mainly carbon monoxide and hydrogen, the two basic components of synthesis gas. First and foremost, the facts that gas may be cleaned and that a mixture with any composition may be prepared in a relatively easy and inexpensive manner influence the possibility of using gas produced in the energy and chemical industries. In the energy industry, gas may be used directly to generate heat and electricity in the systems of a steam power plant or in combined cycle systems. It is also possible to effectively separate CO2 from the system. However, in chemistry, synthesis gas may be used to produce hydrogen, methanol, synthetic gasolines, and other chemical products. The raw material for gasification is full-quality pulverized coal, but a possibility of processing low-quality sludges, combustible fractions separated from municipal waste as well as industrial waste also exists. Despite such a wide application of technology and undoubted advantages thereof, making investment decisions is still subject to high uncertainty. The paper presents the main technological applications of gasification and analyzes the economic effectiveness thereof. In this context, significant challanges for the industrial implementation of this technology are discussed
The evaluation of threats connected with the presence of methane in coal seams is based on our knowledge of the total content of this gas in coal. The most important parameter determining the potential of coal seams to accumulate methane is the sorption capacity of coal a. It is heavily influenced by the degree of coalification of the coal substance, determined by the vitrinite reflectance R0 or the content of volatile matter V daf. The relationship between the degree of coalification and the sorption capacity in the area of the Upper Silesian Coal Basin (USCB) has not been thoroughly investigated, which is due to the zonation of methane accumulation in this area and the considerable changeability of methane content in various localities of the Basin. Understanding this relationship call for in-depth investigation, especially since it depends on the analyzed reflectance range. The present work attempts to explain the reasons for which the sorption capacity changes along with the degree of coalification in the area of Jastrzębie (the Zofiówka Monocline). The relationship between parameters R0 and V daf was investigated. The authors also analyzed changes of the maceral composition, real density and the micropore volume. Furthermore, coalification-dependent changes in the sorption capacity of the investigated coal seams were identified. The conducted analyses have indicated a significant role of petrographic factors in relation to the accumulation properties of the seams located in the investigated area of USCB.
The Bogdanka coal mine, the only currently operating mine in the Lublin Coal Basin (LCB), extracts coal from the Upper Carboniferous formations of the LCB. The average sulfur content in the No. 385/2 seam is 0.98%, while in the case of the No. 391 seam it is slightly higher and amounts to 1.15%. The iron sulfides (pyrite and marcasite) in bituminous coal seams form macroscopically visible massive, vein, and dispersed forms. A microscopic examination has confirmed their complex structure. Massive forms contain euhedral crystals and framboids. The sulfide aggregations are often associated with a halo of dispersed veins and framboids. Pyrite and marcasite often fill the fusinite cells. Framboids are highly variable when it comes to their size and the degree of compaction within the carbonaceous matter. Their large aggregations form polyframboids. The cracks are often filled with crystalline accumulations of iron sulfides (octaedric crystals). The Wavelenth Dispersive Spectrometry (WDS) microanalysis allowed the chemical composition of sulfides in coal samples from the examined depoists to be analyzed. It has been shown that they are dominated by iron sulfides FeS2 – pyrite and marcasite. The examined sulfides contain small admixtures of Pb, Hg, Zn, Cu, Ag, Sb, Co, Ni, As, and Cd. When it comes to the examined admixtures, the highest concentration of up to 0.24%, is observed for As. In addition, small amounts of galena, siderite, and barite have also been found in the examined coal samples. The amounts of the critical elements in the examined samples do not allow for their economically justified exploitation. Higher concentrations of these elements can be found in the ashes resulting from the combustion process.
The new legislative provisions, regulating the solid fuel trade in Poland, and the resolutions of provincial assemblies assume, inter alia, a ban on the household use of lignite fuels and solid fuels produced with its use; this also applies to coal sludge, coal flotation concentrates, and mixtures produced with their use. These changes will force the producers of these materials to find new ways and methods of their development, including their modification (mixing with other products or waste) in order to increase their attractiveness for the commercial power industry. The presented paper focuses on the analysis of coal sludge, classified as waste (codes 01 04 12 and 01 04 81) or as a by-product in the production of coals of different types. A preliminary analysis aimed at presenting changes in quality parameters and based on the mixtures of hard coal sludge (PG SILESIA) with coal dusts from lignite (pulverized lignite) (LEAG) has been carried out. The analysis of quality parameters of the discussed mixtures included the determination of the calorific value, ash content, volatile matter content, moisture content, heavy metal content (Cd, Tl, Hg, Sb, As, Pb, Cr, Co, Cu, Mn, Ni, and W), and sulfur content. The preliminary analysis has shown that mixing coal sludge with coal dust from lignite and their granulation allows a product with the desired quality and physical parameters to be obtained, which is attractive to the commercial power industry. Compared to coal sludge, granulates made of coal sludge and coal dust from lignite with or without ground dolomite have a higher sulfur content (in the range of 1–1.4%). However, this is still an acceptable content for solid fuels in the commercial power industry. Compared to the basic coal sludge sample, the observed increase in the content of individual toxic components in the mixture samples is small and it therefore can be concluded that the addition of coal dust from lignite or carbonates has no significant effect on the total content of the individual elements. The calorific value is a key parameter determining the usefulness in the power industry. The size of this parameter for coal sludge in an as received basis is in the range of 9.4–10.6 MJ/kg. In the case of the examined mixtures of coal sludge with coal dust from lignite, the calorific value significantly increases to the range of 14.0–14.5 MJ/kg (as received). The obtained values increase the usefulness in the commercial power industry while, at the same time, the requirements for the combustion of solid fuels are met to a greater extent. A slight decrease in the calorific value is observed in the case of granulation with the addition of CaO or carbonates. Taking the analyzed parameters into account, it can be concluded that the prepared mixtures can be used in the combustion in units with flue gas desulfurization plants and a nominal thermal power not less than 1 MW. At this stage of work no cost analysis was carried out.
The paper discusses the current situation as well as the perspectives for hard coal extraction in India, a global leader both in terms of hard coal output and import volumes. Despite this, over 300 million people lack access to electricity in this country. The main energy resource of India is hard coal and Coal India Limited (CI L) is the world’s biggest company dealing with hard coal extraction. CI L has over 450 mines, employs over 400,000 people, and extracts ca. 430 million tons of hard coal from its 471 mining facilities. India is planning the decisive development of hard coal mining to extract 1.5 billion tons in 2020. Hard coal output in India can be limited due to the occurrence of various threats, including the methane threat. The biggest methane threat occurs in the mines in the Jharia basin, located in East India (the Jharkhand province), where coal methane content is up to ca. 18 m3/Mg. Obtaining methane from coal seams is becoming a necessity. The paper provides guidelines for the classification of particular levels of the methane threat in Indian’s mines. The results of methane sorption tests, carried by the use of the microgravimetric method on coal from the Moonidih mine were presented. Sorption capacities and the diffusion coefficient of methane on coal were determined. The next step was to determine the possibility of degassing the seam, using numerical methods based on the value of coal diffusion coefficient based on Crank’s diffusion model solution. The aim of this study was the evaluation of coal seam demethanization possibilities. The low diffusivity of coal, combined with a minor network of natural cracks in the seam, seems to preclude foregoing demethanization carried out by means of coal seam drilling, without prior slotting.
Several surface measurement methods for determining the volume of deep or layered stone exist. One of the key indicators of coal extraction efficiency in open cast mining is to determine the volume of excavated rock. Procedures for determining the volume have been used for many centuries. Determining the extracted volume or layered material has been a periodically recurring role of mine -surveying practice, and mine surveyors apply different methods for its determination. The incorrect determination of the rock volume may result in large economic losses of the mining enterprise. The choice of the method for determining the volume depends on the deadline by which the determined volume has to be submitted to the superior components or the mining enterprise management, as well as on the requirements for accuracy of the volume determination, and a financial limit beyond which this volume determination has to be done. Secondary conditions for determining the volumes include the level of personnel training in the individual procedures and methods of measuring and calculating volumes, the technical standards of the enterprise, the applied instrumentation, hardware and software. The article compares the values of the accurately defined mathematical solid (a cylindrical segment) to the methods of calculating the volume normally used in mining and surveying practice and programs commonly used to calculate volumes in order to determine the threshold value of the systematic deviation in input measurements to determine the volume. The mathematical model is the basis for determining the correct volumes of the extracted material. The surface of the drawn or layered material does not form a smooth surface as a mathematical model. The process of determining volume errors on the mathematical model has been verified on the real body of coal deposition. The comparison of the determination of the errors between the digital terrain model on the mathematical body and the real homogenization coal stock is presented at the Conclusion of the article.
The aim of the article is to present the selected results of analytical investigations concerning possible directions of reducing the unit production costs in the mining company together with some results of practical calculations. The investigations emphasize the role of the rate of utilising the production capacity leading to reducing the unit production costs. The main component having an essential influence on the unit production costs are the fixed unit costs. Two basic indices of a crucial meaning for searching for possibilities leading to decreasing the unit production costs are assumed. The first index (w1) is a measure of the rate of utilising the production capacity, the second one (w2) concerns the fixed costs coincided with the unit of the production capacity. Theoretical considerations concerning the mathematical modelling of the unit production costs as the values depending on the rate of utilising the production capacity and the fixed costs coincided with the production capacity unit, are presented in the first part of the paper. The rationalisation criteria of the mine unit production costs are formulated. These criteria can constitute the elements of restructuring program for the mining company. The calculation example with the use of the practical input data shows the impact of the rate of utilising the production capacity on the mine unit production costs. In the example two variants of annual working time are taken into account. Results of appropriate calculations are presented and analysed in an aspect of reducing unit costs of production as a result of increasing rate of utilising the mine production capacity.
An analysis of the impact of mining with caving on the surface shows that a type of rock mass strata seems to be one of the critical factors affecting the process. Correlating the values of mining-induced surface deformation with the rock mass structure and the state of its disturbance is of crucial importance. Therefore, if other mining conditions are left unaffected, then those factors exert the key influence on a course and distribution of subsidence and rock mass deformation. A proper description of rock mass type and properties also seems rational for a proper determination of prediction parameters, especially in the case of a multi-seam coal mining, and/or the exploitation carried out at considerable depths. A general outcome of the study discussed in this paper is the development of the methodology and model practices for determining the rock mass type and, as a result, for selecting the optimal values of parameters for predicting the values of surface subsidence in relation to particular geological and mining conditions. The study proves that the type of rock mass may be described by such factors as the influence of overburden strata, the influence of Carboniferous layers, the disturbance of rock mass and the depth of exploitation.
A significant part of hard coal production (15–19% in the years 2010–2017, i.e. 1.0–1.3 billion tons per year) is traded on the international market. The majority of coal trade takes place by sea, accounting for 91–94% of the total coal trade. The article discusses the share of coal in international seaborne trade and the largest coal ports. Coal is one the five major bulk commodities (in addition to iron ore, grain, bauxite, alumina, and phosphate rock). In the years 2010–2016, the share of coal in international seaborne trade and major bulk commodities was 36–41% and 11–12%, respectively. Based on the analysis of coal throughput in different ports worldwide, the ports with the largest throughput include the ports of Qinhuangdao (China), Newcastle (Australia), and Richards Bay (South Africa). For 2013–2017, their throughput amounted to a total of 411–476 million tons of coal. The largest coal exporting countries were: Australia, Indonesia, Russia, Colombia, South Africa, and the US (a total of 85% share in global coal exports), while the largest importers are Asian countries: China, India, Japan, South Korea and Taiwan (a 64% share in global imports). In Europe, Germany is the largest importer of coal (54 million tons imported in 2016). The article also discusses the freight costs and the bulk carrier fleet. Taking the price of coal at the recipient’s (i.e. at the importer’s port) into account, the share of freight costs in the CIF price of steam coal (the price of a good delivered at the frontier of the importing country) was at the level of 10–14%. In the years 2010–2016, the share of bulk carriers in the world fleet was in the range of 11–15%. In terms of tonnage, bulk carriers accounted for 31–35% of the total tonnage of all types of ships in the world. The share of new (1–4 years) bulk carriers in the total number of ships on a global scale in the years 2010–2016 was 29–46%.
Households are the most significant group of consumers in the municipal and household sector in Poland. In 2010-2016, households consumed annually from 8.9 to 10.8 million Mg of coal (77-81% share in this sector). As of the beginning of 2018, seven voivodships in Poland have already introduced anti-smog resolutions, one has its draft, three are considering introduction of such resolutions. In the face of introducing anti-smog resolutions, the analysis of coal consumption by households was conducted for a situation where anti-smog resolutions will be introduced in all voivodships in Poland. A forecast of hard coal consumption by Polish households in 2017-2030 was presented in the article. Two scenarios differentiated in terms of calorific value of coal were taken into account: (i) concerned coal with a calorific value of 24 MJ/kg (min. Q for eco-pea coal: grain size 5.0-31.5 mm), (ii) – coals with a calorific value of 26 MJ/kg (Q recommended for use by producers of class 5 boilers). In the perspective of 2030, the largest decrease in hard coal consumption can be expected (jointly) in the voivodships of Śląskie, Dolnośląskie, Opolskie and Lubuskie. Under the assumptions made, in relation to 2016, it may be reduced by half and fall from 2.8 to the level of 1.4-1.5 million Mg. The smallest decreases in consumption may occur (jointly) in the Małopolskie, Lubelskie, Podkarpackie and Świętokrzyskie voivodships – decrease by 16-22% and fall from 2.6 to approximately 1.9-2.0 million Mg. On a national scale, coal consumption may decrease from the current 10.4 (2016) to around 6.3-6.8 million Mg (a decrease of 30-35%). Despite the decrease in hard coal consumption in the 2030 perspective, one should expect an increase in demand for high quality coal dedicated to modern boilers (usually pea assortments) as well as qualified coal fuels (mainly eco-pea coal).
This article presents the use of a multi-criterion Analytic Hierarchy Process (AHP) method to assess geological and mining condition nuisance in longwall mining operations in selected coal mines in Poland. For this purpose, a methodology has been developed which was used to calculate the operational nuisance indicator (WUe) in relation to the cost of mining coal in individual longwalls. Components of the aggregate operational nuisance indicator include four sub-indicators: the natural hazards indicator (UZN), an indicator describing the seam parameters (UPZ), an indicator describing the technical parameters (UT) and an environmental impact indicator (UŚ). In total, the impact of 28 different criteria, which formed particular components of the nuisance indicators were analysed. In total 471 longwalls in 11 coal mines were analysed, including 277 longwalls that were mined in the period of 2011 to 2016 and 194 longwalls scheduled for exploitation in the years 2017 to 2021. Correlation analysis was used to evaluate the relationships between nuisance and the operating costs of longwalls. The analysis revealed a strong correlation between the level of nuisance and the operating costs of the longwalls under study. The design of the longwall schedule should therefore also take into account the nuisance arising from the geological and mining conditions of the operations. Selective operations management allows for the optimization of costs for mining in underground mines using the longwall system. This knowledge can also be used to reduce the total operating costs of mines as a result of abandoning the mining operations in entire longwalls or portions of longwalls that may be permanently unprofitable. Currently, underground mines do not employ this optimization method, which even more emphasizes the need for popularizing this approach.
Geodesic measurements of mining area deformations indicate that their description fails to be regular, as opposed to what the predictions based on the relationships of the geometric-integral theory suggest. The Knothe theory, most commonly applied in that case, considers such parameters as the exploitation coefficient a and the angle of the main influences range tgβ, describing the geomechanical properties of the medium, as well as the mining conditions. The study shows that the values of the parameters a = 0.8 and tgβ = 2.0, most commonly adopted for the prediction of surface deformation, are not entirely adequate in describing each and every mining situation in the analysed rock mass. Therefore, the paper aims to propose methodology for determining the value of exploitation coefficient a, which allows to predict the values of surface subsidence caused by underground coal mining with roof caving, depending on geological and mining conditions. The characteristics of the analysed areas show that the following factors affect surface subsidence: thickness of overburden, type of overburden strata, type of Carboniferous strata, rock mass disturbance and depth of exploitation. These factors may allow to determine the exploitation coefficient a, used in the Knothe theory for surface deformation prediction.
The technology for gob-side entry retaining in steep coal seams is still in the development stage. The analysis results of the caving structure of main roof, low influence of gateway’s stability because of long filling distance and weak dynamic effect of the gateway, and the low stress redistribution environment indicate that using this technology in steep coal seams has significant advantages. Moreover, to reinforce the waste rock and the soft floor and to better guard against the impact of the waste rock during natural filling, a rock blocking device and grouting reinforcement method were invented, and theoretical calculations result show that the blocking device has high safety factor. In addition, we also developed a set of hydraulic support devices for use in the strengthening support zone. Furthermore, because the retaining gateway was a systematic project, the selection of the size and shape of the gateway cross section and its support method during the initial driving stage is a key step. Thus, first, a section the size of bottom width and roof height of a new gateway was determined to meet any related requirements. Then, according to the cross sections of 75 statistical gateways and the support technique, it chosen a trapezoidal cross section when the dip of the coal seam is 35° < α ≤ 45°, a special and an inclined arch cross section when 45° < α ≤ 55°. Eventually, a support system of bolts and cables combined with steel mesh and steel belts was provided. The support system used optimized material and improved parameters, can enhanced the self-bearing ability of the surrounding coal and rock masses.