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.
Hydrogen as a raw material finds its main use and application on the Polish market in the chemical industry. Its potential applications for the production of energy in fuel cell systems or as a fuel for automobiles are widely analyzed and commented upon ever more frequently. At present, hydrogen is produced worldwide mainly from natural gas, using the SMR technology or via the electrolysis of water. Countries with high levels of coal resources are exceptional in that respect, as there the production of hydrogen is increasingly based on gasification processes. China is such an example. There some 68% of hydrogen is generated from coal. The paper discusses the economic efficiency of hydrogen production technologies employing lignite gasification, comparing it with steam reforming of natural gas technology (SMR). In present Polish conditions, this technology seems to be the most probable alternative for natural gas substitution.
For the purpose of evaluating the economic efficiency, a model has been developed, in which a sensitivity analysis has been carried out. An example of the technological process of energy-chemical processing of lignite has been presented, based on the gasification process rooted in disperse systems, characteristics of the fuel has been discussed, as well as carbon dioxide emission issues. Subsequently, the assumed methodology of economic assessment has been described in detail, together with its key assumptions. Successively, based on the method of discounted cash flows, the unit of hydrogen generation has been determined, which was followed by a detailed sensitivity analysis, taking the main risk factors connected with lignite/coal and natural gas price relations, as well as the price of carbon credits (allowances for emission of CO2) into account.
This publication presents the research aimed at developing statistical models, on the basis of which it was possible to prepare credible forecasts of unit cost and coal net output for longwalls in 5 hard coal mines in P oland. The argument has been verified that there is a dependence between the level of nuisance and the level of costs, as well as longwall production results.
A research procedure has been developed for that purpose, which aimed at developing two statistical models connecting the nuisance due to geological and mining conditions with costs and longwall production results. The multiple linear regression technique has been used to develop statistical models. The set of data taken into account in the analyses comprised 120 longwalls mined in the years 2010–2019. Two models have been developed – one for forecasting unit costs, the other for forecasting coal net output. Subsequently, the models’ forecasting ability has been verified on a sample of historical data. A relative forecast error for 75% of observations has been in the range of (–25%; +37%). That result has been considered satisfactory. Subsequently, using those models, forecasts of unit costs and coal net output have been prepared for 220 longwalls planned for mining in the years 2020–2030. Those forecasts have been prepared in the stipulated ranges of geological and mining nuisance influencing mining process, by means of dedicated W Ue and W Ut factors. The nuisance models for forecasting purposes have been developed using the AHP (Analytic Hierarchy Process) method. The research hypothesis has been confirmed on the basis of the obtained results. An increase in the level of nuisance leads to an increase in the unit costs for longwalls and the deterioration of production results. Unit operating costs for longwalls in specific ranges of nuisance may differ by up to 30%, being in the range of 52.0–120.3 zł/Mg. Likewise, the coal daily output of longwalls may be even 22% lower, having the average level in the range of 1.89–3.61 thousand Mg/d.
The subject of the research presented in this paper were financial results of mining industry enterprises (PKD 5 – P olish C lassification of A ctivity – “Mining of coal and lignite”) in 2007–2019. The research was conducted using relative and absolute financial measures, forming an extensive and coherent set of features characterizing their financial condition. The purpose was to measure and evaluate the efficiency of examined enterprises operation, considered as an attribute of development as well as factors describing and determining it. This evaluation was made against the background of ongoing restructuring processes taking into account their potential effects.
The article presents the course of the process of adapting P olish hard coal mining to market economy conditions after 1989. The process can be conventionally divided into several periods. The scope and intensity of changes in the mining industry followed the subsequent government programs for mining industry restructuring.
The lignite mining has not implemented any specific restructuring programs. The remedy processes were mainly related to organizational and ownership changes.
In relation to operation efficiency and value creation three turning points in the development path of enterprises were highlighted – 2011, 2015 and 2017, while the period of strong deterioration of results occurred in 2011–2015. I t was proved that restructuring processes did not affect the operating return on sales. However, there was a strong relation between changes in economic conditions on the coal market (prices) and the accumulation rate.
The paper presents multi-criteria optimization method allowing for selection of the best production scenarios in underground coal mines. We discuss here the dilemma between strategies maximizing economic targets and rational resources depletion. Elaborated method combines different geological and mining parameters, structure of the deposit, mine’s infrastructure constrains with economic criteria such as the net present value (NP V), earnings before deducting interest and taxes (EBIT ) and the free cash flows to firm (FCFF). It refers to strategic production planning. Due to implementation of advanced IT software in underground coal mines (digital model, automated production scheduling) we were able to identify millions of scenarios finally reduced to a few – the best ones. The method was developed and tested using data from mine operation “X” (a real project – an example of a coking coal mine located in Poland). The reliability of the method was approved; we were able to identify multiple production scenarios better than the one chosen for implementation in the “X” mine. The final product of the method were rankings of scenarios grouped according to economic decision criteria. The best scenarios reached NP V nearly 50% higher than the Base Case, which held only 52. position out of 60. According to EBIT and FCFF criteria, 10 scenarios achieved results higher than the Base Case, but the percentage differences were very small, below 2 and 4%, respectively. The developed method is of practical importance and can be successfully applied to many other coal projects.
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