DRILLING VERTICAL ACCURACY ANALYSIS AND THE USED OF EXPLOSIVE TO POST BLASTING FRAGMENTATION AT PUSHBACK 7 SOUTH GRASBERG SURFACE MINE

• Main Author: BINDU HUTAHAEAN (NIM 12103026), MICHAEL
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/8592
• Institution: Institut Teknologi Bandung

Drilling and blasting activity in Grasberg surface mine takes an important role within the whole mining process. Planning and detail technique is required, that is include technical planning of drill and blast, drilling accuracy, loading and type of explosive that used at Pushback 7 South known as hard zone area. Purpose of doing this research is to evaluate the accuracy of Aquila drilling system (specially the depth accuracy), evaluates the choose of explosive type that used (Energen/ Powergel), evaluates and notes usage of explosive at Pushback 7 South, to analyze post blasting fragmentation using Split Desktop 2.0 TM and data obtained form crusher. The Percentage of drilling vertical accuracy in sequence, Blast #2 in amount of 72.5%, Blast #3: 64.42%, Blast #4 :77.46%, Blast #5 : 53.01%, Blast #6 is 77.78%, and Blast #7 is 76.97%. Drilling vertical accuracy is used to decide the explosive used for each hole. Split Desktop fragment size P80 for each blast activity are 39.26 cm for Blast #2, 88.51 cm for Blast #3, Blast #4 : 35.01 cm, Blast #5: 46.62 cm, Blast #6 : 23.76 cm, and 56.66 cm for Blast #7. While data fragment size P80 that obtained from crusher are 60.1 cm for Blast #2, Blast #3: 66.44 cm, Blast #4:54.74 cm, 45.21 cm for Blast#6, and 55.4 cm for Blast #7. With the use of drilling accuracy level that influence explosive used, recommendation table of explosive based on whole depth is needed. <br /> <br />