• Explosives and Blasting
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• v.22 no.1
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• pp.1-4
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• 2004

The gelatine dynamite, which has been traditionally used in Korea as the 2nd generation explosive, is now being rapidly replaced by an emulsion explosive because of the change in life environment economic schemes, and safety reasons. However, there has been lack of study in the surfactant which is an important factor in manufacturing technology of emulsion explosives, and especially GMB technology has not been used in Korea. In this study, effective usage of surfactant with optimum dosage and optimum mixing temperature of GMB was investigated to increase safety and effectiveness.

• Explosives and Blasting
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• v.24 no.1
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• pp.29-37
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• 2006

The demand of the bulk emulsion explosives is being increased more and more by using the mechanization loading system in a domestic tunnel sites. Thus, a rational design criteria that is suitable for rock and circumstance condition has been required. In this study, authors investigated a optimum specific charging weight and resonable charging weight based on domestic blasting construction cases, which were performed by using a mechanization bulk emulsion explosives loading system up to now. Authors also analyzed the blasting results and got the following formula $({\Upsilon}= 0.669 + (0.0154{\times}RMR),\;r=0.81)$ from the relationship between a optimum specific charging weight of bulk exp. and rock mass rating. A range of resonable charging weight with a drilling depth is calculated considering a rock conditions.

• Proceedings of the Korean Institute of Industrial Safety Conference
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• 2001.11a
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• pp.274-280
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• 2001

우리나라에서 전통적으로 건설$\cdot$토목 현장에서 암절취 목적으로 주로 사용되고 있는 젤라틴다이나마이트 폭약의 경우 폭속이 비교적 높고 강력한 폭발위력으로 인해 암반의 강도가 높은 현장에 주로 사용해 왔다. 그러나 최근에는 폭약의 안전도 감소와 원가절감을 위해서 현재 사용중인 폭약 중 가격이 가장 저렴한 안포폭약을 개선하고 에멀젼폭약의 특징을 살린 벌크 에멀젼폭약의 공급을 눈앞에 두고 있다.(중략)

• Explosives and Blasting
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• v.26 no.2
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• pp.64-76
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• 2008

Bulk Emulsion blasts using mechanized charging system, which is generally used in foreign countries, have recently introduced and gradually increased in Korea. The Bulk Emulsion are safe and able to increase the charging density for improvement of fragmentation and advancement especially in tunneling, and minimizing environmental problem. Because of less toxic gas generation, the explosives are called, namely ech-friendly products. There are two kinds of Bulk Emulsion; one is for open cut and the other is for tunneling. According to features of blast sites and its purpose, the compositions are different, but the principle is the same. In this study, trial blasts using Bulk Emulsion for tunneling had executed at 10 sites in Korea. The major result of the major job-sites is the following. First of all, compared with cartridge explosive, Bulk Emulsion was able to increase its charging density up to $35{\sim}60%$, to decrease the blast holes to approximately $10{\sim}30%$ down, and the advancement was improved up to $8{\sim}20%$ and also 30% up in its fragmentation. Toxic gas production after cartridge blasting showed 34.44ppm of its CO. Bulk Emulsion, however, showed 20.13ppm, which was 58.45% production of the cartridge explosive, and NOx was below 2ppm. The mechanized charging system of Bulk Emulsion should be applied to large sized tunnel blasting, long advanced tunnel which can secure the advancement of over $4{\sim}5m$, and the sites required finishing rapidly.

• Proceedings of the KSEE Conference
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• 2008.10a
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• pp.3-16
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• 2008

• Explosives and Blasting
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• v.18 no.3
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• pp.15-28
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• 2000

국내에서는 Heavy ANFO로 더 잘 알려져 있는 Emulsion Blends는 왁스 대신 오일을 사용 하여 상온에서 펌핑이 가능하도록 한 에멀젼과 ANFO(또는 초안)의 혼합물을 일컫는다. ANFO는 저렴하고 안전하며 장약이 쉽고 밀장전되는 장점이 있지만, 내수성이 거의 없고 폭발 속도가 느리며 장약 비중이 0.75∼0.90g/cc 정도로 낮아 폭약으로서 그 위력이 작은 단점을 갖고 있다. Blends는 수용성 ANFO 입자 사이의 빈 공간을 내수성 에멀젼이 태우고 있는 형태로서 에멀젼 함량 25%부터 내수성이 나타나기 시작하여 에멀젼 함량 40% 이상에서는 완전한 내수성을 갖게 되며, 에멀젼의 함량이 증가할수록 폭발속도는 카트리지 에멀젼 폭약에 근접하게 된다. 장약 비중은 에멀젼의 함량이 증가하여 45% 근처에서 1.25∼ 1.30g/cc의 최대 값을 갖지만, 그 이상의 에멀젼 함량에서는 기폭 감도 저하로 예감제를 사용하여 비중을 감소시키는 것이 바람직하다. Blends는 자체에 물을 함유하고 있으므로 열역학적으로 계산된 단위 중량당 반응열은 ANFO에 비해 매우 적지만, 폭발속도, detonation pressure(폭굉압), borehole pressure(폭발압력) 등이 ANFO에 비해 크므로 폭발압력에서부터 암석의 파괴가 가능한 압력가지의 단위 중량당 유효한 에너지의 양은 암석의 강도가 커질수록 ANFO에 비해 매우 적지만, 폭발속도, ANFO와 비슷해진다. 따라서 장약 비중이 ANFO의 130∼145%로 높은 Blends는 동일한 천공에 더 많이 장약할 수 있어 단위 천공당 암석 파괴에 이용되는 유효 에너지의 총 양이 커지게 되므로, 공간격과 저항선을 늘릴 수 있어 총 천공수를 감소시킬 수 있다. 결론적으로, Blends의 장점은 내수성과 함께 비장약량은 비슷하거나 약간 증가하는데 비해, 천공수는 크게 감소하여 전체적으로는 발파 현장의 경제성이 향상된다는데 있다.

• Explosives and Blasting
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• v.25 no.2
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• pp.61-70
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• 2007

Korean large limestone mines started to employ bulk emulsion explosives to improve the productivity in early 2000s. As the application of the bulk emulsion explosives became common in the mid 2000s, the bulk emulsion application increases overall performance but it tends to decrease the moving and heaving because it lacks in gas volume and heat energy. Therefore, the chemical gassing technique was introduced to improve the blasting efficiency of the existing bulk emulsion explosives. The chemical gassing is a technique to replacing GMB(Glass Micro Balloon), which is used for a sensitizer, with gassing agent to chemically sensitize it. This paper introduces the case of successful application of chemical gassing in a Korean large limestone mine. We also compared and evaluated the blast and work efficiency between bulk emulsion GMB & gassing agent (chemical gassing). The results indicate that the replacement of GMB with gassing agent improved fragmentation in the upper part and toe of a bench as well as moving efficiency of the material.

• Proceedings of the KSEE Conference
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• 2004.08a
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• pp.77-95
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• 2004

• Explosives and Blasting
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• v.22 no.3
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• pp.79-84
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• 2004

It is well accepted that modem emulsion explosives are intrinsically much less sensitive than traditional products such as dynamites or black powder. However, they have still been involved in a significant number of accidental explosions. In October 1975, Canadian Research, Limited's, Energetic Research Laboratory in Quebec exploded. Although explanations for the incident varied, one logical explanation was that the pump used in transporting the emulsion dead headed, thereby turning mechanical work in to frictional heating under a zero flow rate. There is a minimum pressure required for combustion(MBP) to propagate in emulsion explosives. A stable deflagration may lead to a deflagration-to-detonation transition(DDT) in emulsion explosives. Tests were also performed on sensitized sampled consisting of 6 to 21% waters as well as 1 to 11% aluminium powder. It was founded the emulsion explosives consisting of 6% waters had the lowest minimum homing pressure(MBP) of 3 bar, and the 21% waters were unable to achieve sustained homing at pressures as high as 100 bar. The aluminium contained explosives tested here displayed a MBP higher than that of without emulsion. It appears that this test may offer a firm ground for the classification of emulsion explosives in view of the regulating the hazards associated with the various process used for their manufacturing and transport.

• Explosives and Blasting
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• v.38 no.4
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• pp.37-45
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• 2020

Todo was an uninhabited island located in the sea of Pusan Newport. It was a small island with the height of 32 m above sea level, and its area including the submerged part was approximately 24,400 ㎡. Unfortunately, the island was located exactly in the middle of the narrow entrance way to the North and South Container Wharfs of Pusan Newport so that a number of ships had to turn quickly to avoid collision with the island, which frequently caused collisions with other ships or cranes. To avoid such a danger and make the water way wider and deeper, the Ministry of Oceans and Fisheries decided to remove the island. This was believed to make even super-large vessels operate safely in the sea of Pusan Newport so that the competitiveness of the port could be highly enhanced. This paper describes in detail the whole process of the removing work, which was the first case of successful underwater blasting operation using bulk emulsion explosives and non-electric detonators to remove a whole island in South Korea.