Mining Engineering

Surface mining or Opencast mining Surface mining is also known as opencast mining or open-pit mining. Here, the rock or ore are extracted by creating an open-air pit. The main aim of mining is to extract valuable rock, ore, mineral, coal from the earth.  There are basically two principles for rock extraction. One is blasting ( use of chemical energy), other is the mechanical cutting techniques. Among those easiest and economical ways of rock extraction is the blasting technique. Because this blasting technique is cheap as compared to other cutting technique and applicable in every type of geo-mechanical terrain.  In both opencast and underground mine, the blasting technique plays a very crucial role in the rock extraction process. Here, surface mining rock extraction through blasting is discussed.  ***************************** Notes -  Blasting is one of the rock extraction technique. In blasting, chemical energy is used for rock extraction. Blasting is the most sui...

Surface blasting   Chapter 1 -  Video      -  Blast design parameters .                        Notes      -  Blast design parameters .  Chapter 2 -   Video      -  Volume of rock blasted due to blasting .                        Notes     -  Volume of rock blasted due to blasting. Chapter 3 -   Video      -  Powder factor, Linear charge concentration . Chapter 4 -   Video      - Problems on powder factor and linear charge concentration. Chapter 5 - Video     -  Introduction to explosives Chapter 6 -  Video     -  Explosives II

The controllable parameters of blasting are divided into three group s -  (A) Blast design parameters (B) Physicochemical parameters of explosives (C) Initiation and delay timings (A) The basic blast design parameters are : H – Height of bench D – Blasthole diameter L – Drilled length of blasthole J – Sub drilling B – Burden S – Spacing I – Charge length T – Stemming length H – Height of the bench The vertical distance between the crest and toe of the bench is called the height of the bench.  Figure 1  Opencast bench view D – Blasthole diameter The drill holes or the blasholes are drilled with the help of a drill machine. The blastholes are normally drilled in a circular shape. The diameter of the blasthole is the blashole diameter. Figure 2  Opencast bench view with blasthole showing the diameter of the hole. L – drilled length of blasthole The length of the drill hole from top to bottom is the drilled length of the blasthole or drill hole.  Figure 3  Open...