136 / 2021-10-04 17:42:31

Experiences from research on the use of hydroslotting equipment for stress relief

hydroslotting, stress relief

The presentation will focus mainly on the experiences and results obtained on the technique of coal seam disintegration employing the so-called hydroslotting developed at Central Mining Institute.

The research work was carried out as part of the MapROC project : Monitoring, Assessment, Prevention and Mitigation of Rock Burst and Gas Outburst Hazards in Coal Mines. The project concentrated on issues involving hazards in hard coal mines in Europe, related to mining at increasingly greater depths and, consequently, at increasing stresses, pressures and gas content in the rock mass. Finding a way of decreasing gas-geodynamic phenomenon occurrence risks when carrying out mining activities in coal beds with high methane content was the main aim of the research.

During the presentation performance of the cuttings or ‘slots’ will be discussed. It was carried out using high-pressure water jet introduced into the boreholes drilled from the workings into the coal seam.

The scope of work within the project was divided into the following stages:

-           experiments conducted on the surface at EM ‘Barbara’, Poland

-           experiments conducted on the underground testing site at EM ‘Barbara’, Poland

-           experiments conducted in real-scale conditions at the hard coal mine ‘Zofiówka’, Poland

-           experiments conducted in real-scale conditions at a lignite mine Velenje, Slovenia.

Conducted measures led to a coal seam disintegration and, as a result, to partial stress relief of the rock mass decreasing at the same time hazard of the rock burst.