Main Trends in Research and Development in Belgium Collieries

Summary

The very high strata pressures underground make mining conditions in the Belgian Campine collieries among the most difficult in the world.

These severe conditions are particularly noticeable in the behaviour of roadways and headings.

Through much research, it has been possible gradually to improve roof support in the stone drifts, which are nowadays all driven in circular section with prefar-bricated reinforced—concrete liner components however, research aimed at improving roof support in these roadways is still continuing, since a fairly high proportion of them need floor and/or roof re-profiling. On-site trials are always preceded by intensive laboratory testing. Efforts are concentrated on improving the shape and density of frames, concrete (cement or resin) quality, arch elasticity and the most effective packing methods and materials for the space between the supports and surrounding ground.

Another difficult problem is maintenance of the headings. In the Campine, few inseam headings can be driven ahead of the face in advancing working; the proportion of retreating faces is very low. The form of support which has given complete satisfaction is that of metal frames supported on wood piling and placed a few metres from the face in the goaf. Unfortunately, this form of support calls for rather highly skilled manpower and requires great care in setting the props. Trials are in progress with a view to substituting various kinds of packing for the timber.

Much other research is being carried out by the colliery services in fields such as hydraulic transport of coal and stone, methane drainage, radio communication, remote control, etc.