Manless coal extraction

MANLESS COAL EXTRACTION (EN: manless coal winning; DE: unbemannter Kohlenabbau; FR: abattage sans hommes; ES: mineria sin mineros; RU: безлюдная выемка) is the conventional name of the methods for the extraction of coal without the human presence within the retreat stope. The manless extraction is the technology with the high level of technique and organization, in case of which there is excluded the laborious manual work within the stope, are ensured the high productivity and safety of the works.

They distinguish two groups of the methods for the manless extraction: with roof support and without roof support of the stope working space. In the first case, the presence of the people within the stope is allowed only during the time of the maintenance and repair works, installation and removal of equipment, that is during the interruption of the works on the extraction; in the second case, the human person may not be within the stope because of the conditions for the technology of the works and safety (for example, during the auger extraction), or should not be within the stope (for example, during the hydraulic extraction).

The manless extraction with the roof support within the stope working space includes the working of the layers by the mechanized complexes or aggregates (see the "Frontal aggregate" article). The manless extraction by the mechanized complexes is performed within the layers with the thin and medium thickness, including those which are dangerous because of the sudden outbursts of coal and gas.

During the process of the extraction, people are located outside of the retreat stope, and control remotely the extracting machine and the movement of the roof support. The manless extraction by aggregates is purposed for the thin and medium thickness of the layers. The aggregare can work with the software and remote control. The manless extraction without the roof support of the stope working space is performed by the drilling and auger installations, combined cutter-loader machines, vibrating devices, drilling with blasting method. There belong to this group also the plow extraction, mine hydromechanization, dissolution, hydrogenation, and gasification of coal. They use the drilling method for the manless extraction at the stopes within the steep layers with thin and medium thickness, with stable and weak lateral rocks; they use the auger method within the flat layers with the same thickness. The extraction is performed by the drilling of boreholes with the diameter, which is similar to the thickness of the layer, within the layer of the useful minerals.

In order to decrease the losses, and increase the workload onto the stope, they use the technology with the widened drilling of boreholes during the the return motion. The manless extraction by the combined cutter-loader machines with remote control is performed within the slightly inclined layers with thin and medium thickness, with stable lateral rocks, during the extraction by the narrow short stopes. They use the drilling-blasting manless extraction within the steep layers with thin and medium thickness, with stable lateral rocks; it is performed by the blasting of the long boreholes, which have been drilled parallel to the retreat stope.

They use the explosive substances, or the methods for the flameless blasting. They use the manless extraction with the help of the vibrating devices during the development of the layers with thin and medium thickness, mostly those of them, which are prone to the sudden outbursts of coal and gas. The extraction by this method prescribes the drilling of boreholes along the layer, and the installation of the special vibrating devices, which initiate the pouring of the coal from the massif, which is under the impact of the rock pressure. The promising direction for the development of the manless extraction is the creation of the cybernetic automated systems for the extraction, which permit to conduct the extraction during the automatic regime, with taking into account of the data from the systems for observation and analysis of the information on the status of the works within the retreat stope.