Mining of the thick coal layers that include roof caving operation can results in residual coal quantities in the gob as a potential threat causing occurence of spontaneous oxidation process, smoldering, and endogenous mine fire that can affect the safety and regular mine operations. Endogeneous fire occurences in Zenica coal mines are directly linked to complex natural conditions reflecting in complex geological conditions, great depth of mining, high methane content in coal seams, and tendency of coal to spontaneous oxidation process. The subject of the paper is the analysis of endogenous fire supression method applyed in conditions of complete coal thickness longwall mining in Raspotočje mine, that has been rehabilitiated upon the endogeneous fire and then reactivated. The following methods were used in fire fighting: passive fire fighting methods (sealing of the area affected by the fire), active method (injection of electrofilter ash) and ventilation methods. Furthermore additional data (position of gob area and sealing objects, air flow regulators, routes of possible air migration, suggested technical solutions, etc) were added in the linear and canonic schemes for the purpose of defining efficient solutions for fire fighting. Key words: endogenous fire, longwall mining, advancing mining, fire fighting.
Due to properties as flammability, explosiveness, suffocation (decreased oxygen content), toxicity (incomplete combustion), large lengths of gas pipelines, risk of leakage, etc., natural gas is media that requires special care during transport and use. There are many examples in the world where unprofessional and negligent use of gas led to unimaginable and tragic consequences with human casualties and huge material damages. This paper analyzes management of accidental situations at the Sarajevo Canton gas system. Problematic aspects of management will be presented through two case studies instead of presenting idealized models that integrate all structures responsible for dealing with such accidental situations. The methodological approach in this paper is presented through selection of accidents on gas network that had a significant impact and required a coordinated response from the competent services. The goal is to consider possibilities of improving technical measures by installing valves with remote control, which would raise safety to a higher level. With this step forward in technical terms, it would be possible to close the valve on gas system in the shortest period of time by controlling it from the dispatch center, which would stop the uncontrolled gas release. The paper will suggest locations where it would be optimal to install valves with remote control, in order to close the necessary section, and at the same time, the least number of consumers would have a gas supply interruption. Key words: gas system, accident, technical measures
Safety risk management in Bosnian-Herzegovinian underground coal mines is not based on a systematic approach and standardized risk management methods. Mostly there is a traditional approach present, i.e. reaction to incidents/accidents that happen. This paper aims to point out the need for proactive approach introduction with an emphasis on importance of ventilation systems failure mechanism simulation analysis in planning of people and property defense and rescue in crisis situations. Based on ventilation parameters measuring results for a given research site (brown coal mine), a model was developed on which a simulation analysis was performed for three characteristic ventilation failure cases: spontaneous oxidation at the longwall exit, collapse at the entrance to the longwall and methane outburst - preparation of a new excavation field. VnetPC and CFD “Fluent” software packages were used to simulate mine ventilation. Keywords: risk management, brown coal mine, safety, ventilation system, longwall, simulation analysis, VnetPC, Fluent.
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