OPTIMATION STUDY OF BLASTING PATTERN TO INCREASE THE ADVANCE OF BLASTING AT RAMP DOWN CENTRAL, CIURUG LEVEL 500, PT ANTAM UBPE PONGKOR

• Main Author: ISMI (NIM : 12105003); Pembimbing : Dr. Ir. Suseno Kramadibrata, M.Sc; Dr. Ganda Marihot Siman, FARIZ
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/18456
• Institution: Institut Teknologi Bandung

Cut and fill method in underground mining that was conducted by PT. Antam demand a new hole opening as an access to get the ore. This activity known as developement. Developement activity usually done by drilling and blasting process. Blasting result expected to achieve advance at minimum 80% of the borehole depth. <br /> <br /> <br /> The research is done at one of the developement "front," which is Ramp Down Central. In this location, the blasting pattern consist of 40 or 44 blastholes and 1 <br /> <br /> <br /> empty hole with a diameter of 38 mm. From the observation, it is find out that the average advance is 69,9% from the hole depth. Therefore the research is carried out to find the cause of the bad advance and also to make a new blasting pattern to increase the advance. In this research, scanline was done to observe rock mass characteristic and also there was an observation of the geometry of the blasting pattern and drilling technique. RMR value at the research location is 65. Powder factor (PF) based on RMR is 2,34 kg/m3. The blasting pattern from the calculation needed 45 blastholes and 4 empty holes. From the blasting trial, the average of the advance is 81,7% and the PF is 2,42 <br /> <br /> <br /> kg/m3. Based on the blasting and observation data analysis, bad advance is caused by lack of empty hole, drilling deviation, and the burden and spacing between blastholes is too vast.