Improvised Drilling and Blasting Techniques at Underground Metal Mine for Faster Advance to Enhance Linear Excavation and Production – A Techno-Economic Case Study

Abstract

The paper deals with innovative drilling and blasting techniques that are used for mineral extraction at the deposit located at Kadapa district, whose mineralization belongs to Vempalle formations of Papaghni group of Cuddapah Super Group and occurs in Vempalle carbonate rock, which forms the host rock to the mineralization, is essentially stratabound type. The host rock is characterized by impure, siliceous, phosphatic, dolomitic limestone with stromatolites, ripple marks and mud cracks thus also named as dolostone. This dolostone is sandwiched between lower massive limestone and upper shale. In relation to drilling and blasting works are described the main technological parameters of existing mining method; room and pillar mining with backfilling. For purpose of higher effectiveness of drilling and blasting, the works are executed by the emulsion explosives and the jack hammer 1.8m -2.4m drilling length), low profile (4.2m drilling length) and extra low profile (3.2m drilling length) electro-hydraulic drill jumbo by modern drilling pattern (modified burn cut) with single deck charging, double deck charging and without deck charging). The mentioned changes are analyzed through techno-economic analysis. The repeated calculation of drilling and blasting parameters for each individual type of faces (declines, advance strike drive, stope drive, ramp) made it possible for the blast design engineers, to provide various corrections in a new blasting plan for faster advance, resulting in higher productivity, reduced production drilling cost and reduced overall blasting cost per blast.