Ep 1-1: 馃馃獤馃ゾ馃ソDrill & Blast in mining A blast in mining, more formally known as blasting or drilling and blasting, is the primary method used to break solid rock mass into manageable fragments so it can be excavated and transported for processing. It is a highly controlled and engineered process, fundamentally different from the uncontrolled explosion the word "blast" might imply. --- The Core Purpose of Blasting in Mining The main goal is to fragment the rock efficiently and safely to expose the valuable ore or mineral. Good blasting aims to: 1. Fragment the Rock: Break it into pieces of a size suitable for loading and hauling equipment (e.g., shovels and trucks). 2. Move the Rock (Muckpile Displacement): Throw the broken rock (the "muckpile") into a convenient position for excavation. 3. Control Ground Vibration: Minimize the seismic shockwaves that can damage nearby structures, pit walls, or underground workings. 4. Control Airblast and Flyrock: Prevent the shockwave in the air (airblast) and the projection of rock fragments (flyrock) beyond the blast area for safety. 5. Achieve Final Wall Control: In open pits, blasting must leave behind stable, competent pit walls. This is often achieved through specialized presplit blasting. Types of Blasts in Mining A路 Production Blast: The standard blast used to break the main volume of rock for ore production. B路 Presplit Blast: Done before production blasting. A single row of closely spaced, lightly charged holes is fired along the final designed wall of the pit. This creates a clean, pre-fractured plane that isolates the wall from the vibrations of future production blasts, resulting in a much more stable slope. C路 Trim Blast / Cushion Blast: Similar to presplit, but used when the rock is less competent. It involves a buffer row of holes between the production blast and the final wall. D路 Underground Blasts: Methods like "cut and fill" or "longhole stoping" involve drilling blastholes upwards or sideways into the ore body from development tunnels. Next Ep= 1-2 馃馃獤馃ゾ馃ソ Drill & Blast /end