Geological challenges in limestone quarrying and strategies to improve fragmentation in blasting

Abstract

Globally, the surface mining is considered to be primay mining operation for achieving sustained mineral production, which has shown augmented production with significant deployment of large capacity. These equipment require higher investment, and thus, mining engineers should plan to attain the best performance from these equipment. The capability of the loading and hauling equipment largely entrusted on the outome of the blast, particularly, the fragmentation and spreading of rockpile. Generally, the mine owners ignore geological descriptions and features apart from the nature of rock and began quickly quantifying the rockmass properties only whether it is hard or soft based on its geomechanical properties. From the geological studies, it is understood that the response of deep weathering of any deep-seated massive rock resulting in producing thick boulders. These embedded boulders possess the characteristics completely different that of surrounding rockmass and any other soil present in the vicinity. The blast fragment size generally dictates the output of equipment working in such formation and affects the productivity of the mine. Thus, an effective blasting is need of the hour in such formations that affects the cost of entire mining activities. Therefore, it is important to study the effect of blasting parameters on fragmentation of such embedded boulders through existing field practices and also using the advanced blasting technologies. This paper concerned with the fragmentation of embedded boulders/floaters under difficult geological conditions. Geology plays a critical role in every aspects of a blast’s performance and it is the chief uncontrollable factor to be considered for any blast design. The authors discuss the difficulties in identifying the embedded boulders by understanding the geological features properly and discussed the possible solutions to enhance its breakage during the blasting through conducting few experimental blasts in a limestone quarry.