#TITLE_ALTERNATIVE#
Development is an activity that must be done before production. Development work includes making horizontal opening such as drift footwall, crosscut and making vertical opening such as raise. Conventional method of drilling and blasting is often used to make development opening. <br /> <b...
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| Format: | Final Project |
| Language: | Indonesia |
| Online Access: | https://digilib.itb.ac.id/gdl/view/18053 |
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| Institution: | Institut Teknologi Bandung |
| Language: | Indonesia |
| Summary: | Development is an activity that must be done before production. Development work includes making horizontal opening such as drift footwall, crosscut and making vertical opening such as raise. Conventional method of drilling and blasting is often used to make development opening. <br />
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The research is conducted in development front Ramp Down Central (RCD) Ciurug Level 500 PT Antam Tbk UBPE Pongkor. The drilling equipment in RCD is Hand Held Rock Drill or often called Jack Leg. The drill rod length is 1,6 m. The average drill hole depth is 1,4 m with a diameter of 38 mm. Explosive that is used is 25 mm diameter dayagel magnum. There are 2 blasting pattern that is often used, which is 40 and 44 blast hole pattern. Both only use one 38 mm diameter empty hole. The average advance using 40 blast hole is 67% from the hole depth. As for 44 blast hole the average advance is 71,3%. The average advance from those two blasting pattern still not fulfill the expected advance which is 80% from the hole depth. Powder Factor (PF) obtained from those patterns is 2,74 kg/m3 . <br />
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Using Persson et al. charge calculations for tunneling, a new blast pattern is created. This new pattern consist of 45 blast hole with 4 empty hole, with a diameter of 38 mm. From blasting trial using the pattern, with dayagel magnum as the explosives, an average 81,4 % advance is obtained. And the PF is 2,4 kg/m3. <br />
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The research finds that inaccuracy of drilling, lack of empty hole and vast burden between blast hole and empty hole are the factors that make poor advance. Number of blast hole and PF are still in literature and calculation window. From the literature, it is find out that for rock mass condition in the site, it needed 40- 47 blast hole. And for the PF, regarding to the face area of the opening and rock mass condition, it is between 2 – 2,83 kg/m3. The new blast pattern, if ANFO is used as the explosive, can saved Rp 826.254 per round for explosive and accessories cost compared to if dayagel magnum is used. |
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