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Underground hard coal exploitation is accompanied by a series of natural hazards. Their number and intensity increase along with the growing depth of exploitation. Amongst the most dangerous hazards in the mining industry, one can distinguish the following: methane hazards, seismic hazards (including the rock-burst hazard) and coal dust explosion hazards. They are a common issue in Polish coal mines, thereby making it necessary for coal mines to identify the level of these hazards. It can also be assumed that ther...

Underground hard coal exploitation leads to the formation of granular porous media. These media occur both in the underground parts of mines and on the surface. In the underground areas, these are the caving goaves of longwalls and the caved-in roof rocks in active mine headings. On the surface, these are most commonly the post-mining waste dumps. In both of these cases, a crucial role is played by the knowledge on the resistance of air and gases flowing through these media. In the case of underground exploitation...

The methane hazard is one of the main natural hazards occurring in underground hard coal mining. This hazard is related to the potential ignition and/or explosion of methane when mixed with air. The underlying cause of this problem is methane release from the body of coal, the goaves with caving and the excavated coal area. The region most vulnerable to this hazard in coal exploitation during longwall ventilation using the U-type system from the exploitation field borders is the intersection of the longwall and th...

Conditions of the microclimate prevailing in mine workings are one of the most important factors influencing on the comfort and safety of the working mine crews. This climate depends on parameters of the ventilated air stream and conditions prevailing in these workings. Parameters having the most important influence on the conditions of microclimate are temperature of the air and rock mass, humidity, velocity of air stream and average temperature of radiation of wall surface of the working. Nowadays, due to the la...

The article describes the chosen Japanese production and maintenance management philosophies, such as Lean Management, kazien and TPM. Japanese approaches to the process of work organizing and work planning, workplace preparing, tasks, duties and responsibilities turn out to be the most effective and the most efficient in the world. The practical application of these philosophies entails achieving the measurable benefits by the companies that use them. The basis of these philosophies is the elimination of all kind...

One of the commonly present gas hazard in hard coal mines methane hazard. The most endangered region by this hazard, during ventilation of longwall in пїЅU from boundariesпїЅ system is the crossing with ventilation roadway (so called пїЅupper corner of longwallпїЅ). Accumulation of methane in this place results from its release from goaf. Therefore, in order to decrease methane concentration in this region, auxiliary ventilation devices are used. They are aimed to supply to this place such an amount of fresh air, ...