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This guide describes the importance of mine ventilation and provides information on how it is applied. The information in this guide is primarily applicable to mining coal ... When coal is mined, coal dust can build up in the mine's atmosphere, due to the large amount of coal dust particles created during mining. This problem can be mitigated by installing ventilation shafts throughout the mine which will allow air circulation and reduce levels of atmospheric dust. Mine Ventilation encompasses the processes of mine ventilation by applying one or more of the methods. The list below shows some examples, but they are not the only methods used. The purpose of mine ventilation is to ensure that there is adequate oxygen in the atmosphere within the mine, to protect miners health and safety. Furthermore, it reduces coal dust build-up and increases comfort for miners working underground. As an example, longwall mining (extracting coal using a machine) releases approximately 2-5 tonnes of coal dust each hour per longwall panel. This can leave an atmosphere within a pit with dangerously low levels of oxygen if not treated via ventilation methods. There are 4 factors which affect the health of miners working underground, they are: The method used to ventilate a mine depends on several aspects including the depth of the mine, how much excess air is supplied, and whether or not roof supports are required. A number of ventilation methods have been used including: There are various types of mine ventilation systems which can be installed in mines. Different methods vary with respect to costs, energy consumption and different criteria such as noise level. Methods for ventilating underground mines include ventilating the working parts with forced air (natural draft) or with negative pressure (mechanical draft), or by using an inert gas like nitrogen (inert gas draft). The ventilation methods may be used together in the same mine. When ventilating an underground mine by using natural draft, air is supplied to the working parts of the mine at a higher rate than air is extracted from these parts. The pressure difference between intake and extraction causes air to flow through the mine, or to circulate through itself (natural circulation). A sufficient amount of intake air must be supplied for this method to work. This is provided by using enough entry points for fresh air into the workings, and/or installing fans in strategic places. Ventilation with natural draft usually works best in mines with one single entry. For ventilation systems with multiple entry points, the mine ventilation unit has to be designed with the help of a ventilation engineer. Guides must be installed for both intake and extraction so that rock dust is not stirred up by motors or fans. Friction motors are usually used for this purpose, but an electric motor can also be used. When using negative pressure ventilation, the working parts of the mine are supplied with air at a higher rate than air is extracted from these parts. The pressure difference between intake and extraction causes air to flow into the mines, or through itself (negative pressure circulation). cfa1e77820
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