Research and development of new drilling bit for roof bolt driller
3.
Galvanized mild steel roofing bolt and nut
4.
Technique of combined supporting of roof bolting with bar and wire mesh in coal roadway
5.
Expansion type roof bolt
6.
Application of the technology of roof bolting with bar and wire mesh in the zhangji coal mine
7.
Based on the rock pressure ' s characteristics of the pre - driven roadway , the rational support plan and parameters about roof bolting with bar and wire mesh are determined , and the manner of driven waste in place of coal was adopted
मोबाइल