Methodology for Managing Coal Dust for Underground Mining in Colombia

摘要

The aim of this study is to propose a methodology for a proper handling of coal dust. An underground coal mine in North-East ofrnColombia was chosen. The procedure consists in detecting places where it, produces, transports and deposits, the coal dust ; these placesrnusually are: the working faces, transferences of coal and return of the ventilation. Having identified these spots, the next is to collectrnsamples of the coal dust, which are collected with manual shovel and brush, leaving a proper mark on the spot. Getting new samplesrnwithin followings 30 days.rnThe new sample of coal dust is collected to determine the rate of accumulation of coal dust. These samples were subject of granulometricrnanalysis, inertization with rock dust, petrographic and proximate analysis.rnAmong the results obtained, it is high volatile A bituminous coal, with high content of free hydrocarbons (Exsudatinite); high calorificrnvalue (> 8200 Cal / g); high amount of dust production during mining activities (> 50 kg / day); high percentage of size particles smallerrnthan 150μm (> 50%); this means that most of those dusts require a high content of rock dust for inertization (generally greater than 85%).rnHowever, it can be seen that in all parts of the mine is not recommended carry out activities of inerting with rock dust, because the ratesrnof deposition of coal dust are very high (> 50 kg / day), therefore it is most convenient carry out alternative activities such as thernimplementation of water sprays, and establish cleaning seasons in places where the amount of dust is very high. It is also noted that therncoal dust often retains many of its properties, although this had been transported by the ventilation system for miles of galleries. Finally,rnthe places inside the mine where there is a high risk of coal dust explosion were identified, and they should be prepared for that situation.