Study of the Effect of Drilling Bite Depth and Bit Wear Condition on Drilling Specific Energy and Dust Generation During Bolt-Hole Drilling

Abstract

The respirable dust generated during bolt-hole drilling can present serious health problems to the miners involved in roof drilling operations. The amount of respirable dust generated mainly depends on the rock strength and the way of drilling is conducted. Previous research indicate that a higher drilling bite depth is preferable for the reduction of respirable dust. In this research, the effects of drilling bite depth and bit wear on drilling specific energy and respirable dust generation have been investigated through laboratory experiments. The relationships among drilling specific energy, respirable dust and drilling bite depth were established. The influence of bit wear on drilling specific energy and respirable dust were also accounted. The results have shown a significant reduction in respirable dust amount, as well as a reduction in specific energy when drilling under larger bite depths properly determined for the type of rock. It was found that the use of worn bit can decrease the energy efficiency and generating more respirable dusts than drilling with new bit. The findings from this research has demonstrated the feasibility of using drilling control technique as a proactive approach for dust control and productivity improvement.