Rock properties and machine parameters evaluation at Rössing Uranium Mine for optimum drill performance

Abstract

This work was carried out to determine the influence of rock properties and drilling machine parameters on the penetration rate at the SJ pit of Rössing Uranium Mine, Namibia. Rock properties (uniaxial compressive strength, tensile strength, and modulus of elasticity) of samples collected were determined in the laboratory. Drilling experiments were conducted in which feed pressure, air pressure, rotary speed, weight on the bit, and torque were varied to measure their effect on the penetration rate. The uniaxial compressive strength varied from 90-180 MPa for layered marble-quartzite and banded gneiss. Increases in feed pressure, weight on the bit, and rotary speed beyond the optimum level led to a decrease in penetration rate and caused the drill bit to 'stall'. Results of the study revealed that penetration rate increases with an increase in the feed pressure and air pressure. After reaching a maximum value, the penetration rate begins to decrease despite increasing feed pressure. A very high torque causes the drill bit to stall, since the feed pressure is too high and the air pressure is not sufficient to remove the cuttings from blast-hole at maxium bailing velocities. The average penetration rate varied from 19 to 45 m/h for phase 2 of the pit, and from 17 to 68 m/h for phase 3. The optimum drilling machine parameters obtained in phase 2 and phase 3 were slightly lower than those currently being used at the mine. The trials of the optimum machine parameters will assist in reducing the cost of drilling, which varied from N$29.48 to N$36.31 per metre for the tricone bit.

Sustainability of Extraction of Raw Material by a Combination of Mobile and Stationary Mining Machines and Optimization of Machine Life Cycle

“…Drilling experiments were conducted in which feed pressure, air pressure, rotary speed, weight on the bit, and torque were varied to measure their effect on the penetration rate. The results of the study revealed that penetration rate increases with an increase in the feed pressure [10].…”

“…They demonstrated that there are recommended illumination levels that can improve the mining process and reduce accidents [9]. Adebayo et al (2019) showed that technical parameters of mining machines are very important for mining processes. They investigated the influence of drilling machine parameters on the penetration rate in mines.…”

Optimizing Driving Parameters of the Jumbo Drill Efficiently with XGBoost-DRWIACO Framework: Applied to Increase the Feed Speed

“…The unit is m/min. Under specific working conditions, increasing the feed speed to reduce the construction cost is one of the key decision-making issues for tunnel construction [ 3 ].…”

“…The unit is m/min. Under specific working conditions, increasing the feed speed to reduce the construction cost is one of the key decision-making issues for tunnel construction [3]. Previous research showed that the feed speed of the jumbo drill is mainly affected by geological conditions and driving parameters.…”