Steel plant rock drill principle video

What are the principles of rock drilling for excavation by blasting?

This document discusses principles of rock drilling for excavation by blasting. It describes two main drilling methods - rotary drilling and percussive drilling. Rotary drilling can be further divided into rotary cutting and rotary crushing using different drill bits.

What types of rocks are subjected to rotary drilling?

Rocks of low to medium hardness and toughness, such as mineral salts, ores, coal, and so on, are usually subjected to rotary drilling by use of cutters or bits. Typical drilling bits and cutters for rotary drilling and overburden drilling are shown in Figure 1 (a).

How do you drill a hole in a rock?

Drilling produces a circular hole in the rock, whose strength must be overcome by the drilling tool. Depending on rock properties, there are several ways to accomplish this. Rotary drilling can be subdivided into rotary cutting and rotary crushing. Rotary cutting creates the hole by shear forces, breaking the rock's tensile strength.

What type of drill is used for hard rock drilling?

The majority of hard rock drilling is still done by pneumatic drills. Figure 3 shows three drills suitable for this kind of work. In this type of drill the rotation is obtained by a separate rotation motor, which is usually of the meshing gear type.

Are rotary drill rigs good for blast hole drilling?

As blasting theories and practice have approximately 18 degrees off vertical. 30 degrees out of the vertical. However, the inclined hole drilling capabilities in rotary backwards. This causes rig stability problems, reduced penetration, and shorter life of drilling consumables. Consequently, most blast hole drilling using rotary drillrigs is in