Application of Improved Blasting Techniques in Open Pit Mining for Maximum Productivity: A Case of Oakyam Quarry Limited, Ogun State, Nigeria

摘要

Blasting is an important unit operation in mining and civil engineering projects that is aimed at effective rock fragmentation. However, it is always associated with some harmful and unwanted effects on the surrounding environment and humans, including ground vibration, air blast, flying rock, etc. Open-pit mining is the most widely used means of mineral exploitation in Nigeria, where it has been employed with considerable success, including at Oakyam Quarry. The conventional blasting technique has been applied in the quarry since its inception, with mixed results. Significant challenges associated with blasting, such as ground vibration, air blast, and fly rock occurrences, have been incurred at the quarry owing to the adoption of this conventional method. It is thus important to develop an alternative method to the conventional method to prevent further occurrences of the adverse blasting effects. This paper aims at developing an alternative blasting technique to improve the productivity and safety of lives and properties in proximity to quarry operations. The newly developed method, termed an alternative blasting technique, entails the replacement of delay-relays with electric detonators for blast sequencing, replacing laterite with 16mm granite chips for stemming, and adopting deck charging. The alternative method was tested and compared with the conventional methods adopted over the years by Oakyam Quarry. The technique recorded a higher degree of fragmentation with minimal air blast, ground vibration, and flying rocks. Likewise, a good muck-pile with a 14-16 reduction in explosive consumption was achieved, thereby increasing the profitability of the quarry operations. The newly developed blasting technique is proposed and recommended for adoption by engineers and blasters in various fields and aspects of blasting.