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Underground hard rock (metal/non-metal) mining
Published in A.J.S. (Sam) Spearing, Liqiang Ma, Cong-An Ma, Mine Design, Planning and Sustainable Exploitation in the Digital Age, 2023
A.J.S. (Sam) Spearing, Liqiang Ma, Cong-An Ma
The main explosive used in mining today is ANFO (Figure 3.95). This powerful and inexpensive explosive has replaced dynamite due to its stability and economic viability. ANFO consists of ammonium nitrate and fuel oil. The ammonium nitrate provides the oxygen and the fuel oil consumes and burns the borrowed oxygen, creating gas and pressure. ANFO has a low sensitivity, a wanted characteristic in multiple blast designs that require staged detonation. ANFO prill is manufactured inside towers that spray a concentrated ammonium nitrate solution at the top. The solution condenses as it falls through a mixture of natural gas and air.
Rock excavation techniques
Published in Ömer Aydan, Rock Mechanics and Rock Engineering, 2019
ANFO (ammonium nitrate/fuel oil) is a widely used bulk industrial explosive mixture. It consists of 94% porous prilled ammonium nitrate (NH4NO3) (AN) that acts as the oxidizing agent and absorbent for the fuel and 6% fuel oil (FO). ANFO is widely used in open-cast coal mining, quarrying, metal mining and civil construction as it is a low-cost and ease-of-use matter among other conventional industrial explosives. The initiation of blasting is achieved using primer cartridges.
Blasting
Published in Ömer Aydan, Rock Dynamics, 2017
ANFO (Ammonium Nitrate/Fuel Oil) is a widely used bulk industrial explosive mixture. It consists of 94% porous prilled ammonium nitrate (NH4NO3) (AN) that acts as the oxidizing agent and absorbent for the fuel and 6% fuel oil (FO). ANFO is widely used in open-cast coal mining, quarrying, metal mining, and civil construction as it is low cost and easy to use matter among other conventional industrial explosives. The initiation of blasting is achieved using primer cartridges.
Comparative study of analytical and numerical evaluation of the dynamic response of buried pipelines to road-cut excavation blasting
Published in Geomechanics and Geoengineering, 2020
Amir Sajjad Abedi, Nader Hataf, Sina Shivaei, Arsalan Ghahramani
Improvements to transport infrastructure have always been emphasised as a means of making economically deprived areas more appealing to the tourism industry. This would necessitate the implementation of road or railway construction projects, some of which requires rock blasting. With the advent of chemical explosive mixtures, particularly Ammonium Nitrate Fuel Oil (ANFO), blasting operations have received wider currency in roadworks. ANFO has long been utilised as an effective explosive in the civil engineering industry. ANFO explosives are not only safe but also cheap, widely available, and above all, highly efficient at creating a controlled explosion. In most cases, the volume of rock, types of ground and cut and fill geometries render excavation impractical. Under such circumstances, controlled explosion, an efficient excavation method, may be employed in the vicinity of pipeline routes that must remain intact. Hence, the underground gas or oil pipelines running through large-scale construction projects are often at risk of blast-induced strong motion. Pipeline safety regulations tend to greatly overestimate the allowable explosive weight and the safe distance for explosions near pipelines, leading to a substantial increase in the cost of the project. Accordingly, calculation of explosion-related parameters in civil engineering projects is of great interest to many researchers.
Estimating the effect of blast and ventilation parameters on blast fume dilution time in underground development blasting using computational fluid dynamics
Published in CIM Journal, 2023
A. Adhikari, P. Tukkaraja, S. Jayaraman Sridharan
Every blast will produce toxic fumes such as CO, NO, NO2, and NH3. The type of explosive has a significant effect on the amount of fumes produced. Commercial explosives produce 10–20 times more CO than NOx. NO readily oxidizes into NO2 in presence of air. NO2 is soluble in water and water sprays are effective means to control it. However, in some mines the faces might not be sprayed. Other gases such as NH3 are also produced but at lower concentration. The CO dilution time was analyzed for four commonly used explosives. ANFO is a mixture of porous ammonium nitrate prills and fuel oil normally mixed in a weight ratio of 94:6. It is the most commonly used explosive of choice in the mining industry because of its low price and convenience. It provides more energy per pound than other commercial explosives (Stiehr, 2011). The drawbacks of using ANFO are that it has low water-resistance and bulk density.Dynamite is a cartridge explosive mixture wrapped in paper shells, plastic films, or tubes. Alfred Nobel invented dynamite, which allowed safer and easier means to use and transport nitroglycerin (Stiehr, 2011). It is used only in non-bulking loading applications. Its important properties include its high density and low water resistance.Emulsion is a blend of two immiscible liquids/phases (water and oil) and ammonium nitrate. In addition, an emulsifier is also added to uniformly distribute one liquid throughout the other liquid/phase. Emulsions are water-resistant and highly preferred in wet conditions.Watergel consists of a mixture of water, oxidizer, and fuel components. It is manufactured in both packaged and bulk forms. It has exceptionally good water resistance and is less hazardous, sensitive, and expensive than conventional explosives.