In hard rock mining and quarrying, this is achieved through a controlled process of drilling and blasting. A blast hole drill rig is a specialised piece of equipment that creates a series of holes in a specific pattern, depth, and diameter across a section of rock known as a “bench.”
[pdf] A down-the-hole drill, usually called DTH by most professionals, is basically a screwed on the bottom of a . The fast hammer action breaks hard rock into small cuttings and dust that are evacuated by a fluid (air, water or ). The DTH hammer is one of the fastest ways to drill hard rock. The system is thought to have been invented independently by Stenuic.
[pdf] Before starting casing, the drilling supervisor should hold a pre-job safety meeting and confirm the following with the crew: 1. Remove unnecessary tools. 2. Good Housekeeping before the job 3. Rig up Casing handling equipment: Using appropriate hand. .
A circulation sub, fitting the casing thread, equipped with a WECO connection, shall be readily available on the rig floor at all times during casing running.
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