이 논문은 필리핀 석회석 광산에 적용한 연구 결과로서 이 광산에서는 파쇄석 입도분포가 좋지 않고 벽면의 유지나 파쇄석 더미의 분산이 불량하였다. 기폭패턴을 대각선 방식에서 V 타입으로 바꾸고 전색장을 조정하여 저항과 가스압의 유지기간을 향상시켰다. 이를 통하여 발파결과가 향상되었다. 특히 공당발파영역이 넓어진 것으로써 그 성과를 확인할 수 있다. 공당발파영역은 기존의 $8.96m^2$에서 $12m^2$로 넓어졌다. 화약계수는 증가하였고 대괴의 수는 감소하였으며, 전방적재기의 행정시간이 감소하였다. 또 공전 시간이 줄었으며 적재높이가 향상되었다.
이 논문은 필리핀 석회석 광산에 적용한 연구 결과로서 이 광산에서는 파쇄석 입도분포가 좋지 않고 벽면의 유지나 파쇄석 더미의 분산이 불량하였다. 기폭패턴을 대각선 방식에서 V 타입으로 바꾸고 전색장을 조정하여 저항과 가스압의 유지기간을 향상시켰다. 이를 통하여 발파결과가 향상되었다. 특히 공당발파영역이 넓어진 것으로써 그 성과를 확인할 수 있다. 공당발파영역은 기존의 $8.96m^2$에서 $12m^2$로 넓어졌다. 화약계수는 증가하였고 대괴의 수는 감소하였으며, 전방적재기의 행정시간이 감소하였다. 또 공전 시간이 줄었으며 적재높이가 향상되었다.
The paper presents a case study of a limestone quarry of the Philippines, where major problems in terms of improper fragmentation, poor wall control, and poor heave of the muck pile were witnessed. The paper highlights the significant role of switching over from diagonal firing pattern to V-type fir...
The paper presents a case study of a limestone quarry of the Philippines, where major problems in terms of improper fragmentation, poor wall control, and poor heave of the muck pile were witnessed. The paper highlights the significant role of switching over from diagonal firing pattern to V-type firing pattern, and also of making suitable adjustments in the stemming column length for improved confinement and gas retention. The study revealed that by making aforesaid design modifications in the blast round, marked improvement in blasting results was registered. Looking at the results, it was further contemplated to expand the mesh area in the subsequent blast rounds. The mesh area was incremented from the existing $8.96m^2$ to $12m^2$. The results were meticulously registered in the field, and clearly depicted definite improvements in the blast results in terms of increased P.F., reduced boulder count, reduced FEL cycle time, reduced dozing hours and improved heave.
The paper presents a case study of a limestone quarry of the Philippines, where major problems in terms of improper fragmentation, poor wall control, and poor heave of the muck pile were witnessed. The paper highlights the significant role of switching over from diagonal firing pattern to V-type firing pattern, and also of making suitable adjustments in the stemming column length for improved confinement and gas retention. The study revealed that by making aforesaid design modifications in the blast round, marked improvement in blasting results was registered. Looking at the results, it was further contemplated to expand the mesh area in the subsequent blast rounds. The mesh area was incremented from the existing $8.96m^2$ to $12m^2$. The results were meticulously registered in the field, and clearly depicted definite improvements in the blast results in terms of increased P.F., reduced boulder count, reduced FEL cycle time, reduced dozing hours and improved heave.
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문제 정의
The author expresses sincere gratitude towards the excellent support and co-operation rendered by the management and staff of Republic Aggregates Company Inc., the Philippines for the successful conduct of the study. Especial acknowledgement is due to Mr.
가설 설정
1. Diagonal firing pattern was not able to provide the requisite fragmentation, and, even the desired throw.
1. The indirect evaluation methods are of great consequence in small-scale quarry blasts and pave the pathway for improvement.
3. FEL was over assisted by dozer because of coarse fragments inside the tight muck piles, which, resulted into unwanted escalation in the dozing costs.
제안 방법
In the light of this problem, the author of this paper was requested upon to improve the productivity of the FELs by attempting suitable changes in the blast design parameters in order to increase the production as well as productivity from the quarry. Hence, keeping the importance of the problem the author visited the field to diagnose the problem areas and harp upon the ways to resolve them.
The plugging was done at the top of the explosive column without making any changes in the stemming column length. On critically evaluating the success of incorporating the aforesaid changes on 3.2mx 2.8m mesh area (SxB), similar changes were attempted on incrementally expanded mesh areas (up to 4.0mx3.0m) in order to authenticate the validity of said changes.
Imperial, President of the company, who stood as a great facilitator in providing requisite field facilities and ready support for the conduct of the blasts. The author is also indebted towards Dr. R.T.Domingo, Professor Asian Institute of Management, Manila, the Philippines, for not only providing the much needed motivation to the operational crew, but also, for critically appraising the blast performance through six sigma approach.
The main objective of research programme was to achieve suitable fragmentation with good throw and drop (heave characteristics) so that the blasted muck could be easily loaded by Front-End-Loaders (FELs). It may be worth mentioning here that the poor diggability feature of the FELs call for good fragmentation within the muck pile along with its proper heave, in order to facilitate the loading operations.
The annual production of the quarry was over 3 million tonne of limestone. The quarry was worked in three sections, namely, West, Central and East. The present study pertains to the East section workings where the limestone beds, separated at 2-3m interval, were dipping at an inclination of 30 to 40 degree.
To overcome the problem of collar over sizes, the stemming region confinement was contemplated and implemented in the blasts B6 and B7 with stemming plugs in last row and last two rows respectively without changing the length of stemming column, and, also without changing the mesh area (SxB). A post blast result distinctly indicates the combined success of V-type firing along with the adjustments made in the stemming by incorporating the stemming plugs.
성능/효과
2. Shift in firing pattern from diagonal to V-type has been effective in improving the fragmentation, reducing the boulder count and also improving the throw, drop and spreading characteristics of the muckpile. V-type firing in combination with stemming plug has been able to retain the blasthole pressure for longer duration, which, in turn, seems to further increase the heaving characteristics of the blasted muck.
3. Due to better fragmentation and heave of the muckpile, the extensive use of dozer ( to assist the FELs), was reduced significantly. The performance of loader in terms of reduction in cycle time was markedly enhanced and explosive consumption was significantly reduced.
참고문헌 (16)
Ash, R.L., 1973, The influence of geological discontinuities on rock blasting, Ph.D. thesis, Univ. of Missouri, Missouri, USA.
Brinkmann, J.R., 1990, An experimental study of the effects of shock and gas penetration in blasting, Proc. 3rd Int. Symp. on Rock Fragmentation by Blasting, Brisbane, Australia, pp. 55-66.
Chiapetta, R.F. and J.L. Wyciskalla, 2004, Bottom-hole and multiple power decks, Quarry Management Journal, pp. 21-30.
Floyd, J.L., 1999, Explosive energy relief -The key to controlling over break, Proc. Int. Conf. Explo '99, AusIMM, Kalgoorlie, WA, pp. 147-153.
Hagan, T.N., 1983, The influence of controllable blast parameters on fragmentation and mining costs, Proc. 1st Int. Symp. on Rock Fragmentation by Blasting, Lulea, Sweden, pp. 31-51.
Kanchibotla, SS., 2001, Optimum blasting? Is it minimum cost per broken rock or maximum value per broken rock?, Proc. Explo-2001, AusIMM, Hunter valley NSW, pp. 35-40.
Konya, C.J., 1996, Problems with deck loaded blast holes, E&MJ, pp. 73-74.
Marton, A. and R. Crookes, 2000, A case study in optimizing fragmentation, The Aus. IMM Proc. No.1, pp. 35-43.
Mclonghlin, M., 2004, Softly softly, World Mining Equipment, Vol. 28, No. 1, pp. 33-34.
Rai, P., 2002, Evaluation of effect of some blast design parameters on fragmentation in opencast mine, Ph.D. thesis, Banaras Hindu University, Varanasi, India.
Rzhevsky, V.V., 1985, Opencast mining unit operations, Mir Publishers, Moscow, 1985.
Singh, S.P. and T. Yalcin, 2002, Effect of muck size distribution on scooping operations, J. Int. Soc. Explosive Engineers., V.1, pp. 315-325.
Smith, N.S., 1976, Burden rock stiffness and its effects on fragmentation in bench blasting, Ph.D. thesis, Univ. of Missouri, USA.
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