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Józef Dubiński and Marian Turek

Abstract

An analysis of conditions which enable attaining possibly highest productivity of industrial scale underground coal gasification technology is presented. The analysis was prepared basing on results obtained during an experimental gasification process conducted in workings of an active hard coal mine. Basic aspects determining application and productivity of the technology concern both general conditions, referring to the hard coal seam being gasified, and practical issues, which need to be considered in coal mine conditions. To present them, the technology of underground coal gasification and still commonly used classical longwall method of mining coal seams are compared.

Open access

Józef Dubiński, Stanisław Prusek and Marian Turek

Abstract

The article presents an array of specific issues regarding the employed technology and operational efficiency of mining activities, which could and should become the subject of conducted scientific research. Given the circumstances of strong market competition and increasing requirements concerning environmental conditions, both in terms of conducted mining activities and produced coal quality parameters, it is imperative to develop and implement innovative solutions regarding the employed production technology, the safety of work conducted under the conditions of increasing natural hazards, as well as the mining enterprise management systems that enable its effective functioning. The article content pertains to the last group of issues in the most detailed way, particularly in terms of the possibility for rational conducted operation cost reduction.

Open access

Józef Dubiński and Marian Turek

Abstract

The actual situation of hard coal mining in Poland has been presented. In particular, these factors, which have impact on the competiveness of mining sector were highlighted and need of its improving has been stressed. Outlining present situation of hard coal mining an attention was paid to its specific threats. The primary analytical material is based on the results of questionnaire conducted among 92 specialists and experts from the mining sector. The questions were related to chances and threats for development of hard coal mining in Poland. The factors determining them were grouped in such domains as economy, technology, geology, social and law aspects. Moreover, the special attention was paid to the problem of increasing and high costs of coal production which constitute significant threat for the financial and economic situation of the mining enterprises. Also the adverse influence of these high cost on the competitiveness of Polish hard coal with other world producers and with other energy carriers was emphasized. The conclusions summarize the achieved results of analysis.

Open access

Grzegorz Mutke, Józef Dubiński and Adam Lurka

Abstract

The paper presents new criteria of seismic and rock burst hazard assessment in Polish hard coal mines where longwall mining system is common practice. The presented criteria are based on the results of continuous recording of seismic events and analysis of selected seismological parameters: spatial location of seismic event in relation to mining workings, seismic energy, seismic energy release per unit coal face advance, b-value of Gutenberg-Richter law, seismic energy index EI, seismic moment M0, weighted value of peak particle velocity PPVW. These parameters are determined in a moving daily time windows or time windows with fixed number of seismic tremors. Time changes of these parameters are then compared with mean value estimated in the analyzed area. This is the basis to indicate the zones of high seismic and rock burst hazard in specific moment in time during mining process. Additionally, the zones of high seismic and rock burst hazard are determined by utilization of passive seismic tomography method. All the calculated seismic parameters in moving time windows are used to quantify seismic and rock burst hazard by four level scales. In practice, assessment of seismic and rock burst hazard is used to make daily decision about using rock burst prevention activities and correction of further exploitation of monitored coal panel.