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By Zahra Hosseini, S. Hassan Khoshroo, Mohsen Amirrahmat

The Sarcheshmeh Copper mine will be developing its open-pit in order to reach to the remaining ore in the deposit. One of the problems regarding the development plan is the ore handling system from the pit. After its development, the pit depth and its daily production will be increased. Therefore, the present transportation system (shovel and trucks) can no longer be used efficiently. It is necessary to use a new system that can reduce transportation costs and handle the new amount of blasted material at the same time. Studies show that an in-pit crusher and conveyor belt is the most suitable system that could be used in this situation. One of disadvantages of the conveyor belt, however, is its limitation in the particle sizes that it could carry. Consequently, size distribution resulting from the fragmentation process is an important parameter in choosing an efficient conveyor belt system. The size distribution of the fragmentation process also affects the operations following blasting. The determination of this parameter allows the optimization of blast design and explosives. Hence, during this project, the size distribution of blast fragmentation in the different types of ore at the Sarcheshmeh mine was determined by the image analysis technique. Numerous digital pictures were captured of the different blasted faces to prepare a representative sample of each kind of rock. They were then analyzed using the GoldSize image analysis software. Results show that fragmentation in the blasted rock is relatively high. It is therefore expected that an appropriate conveyor belt could be selected for further developing the open-pit mine at Sarcheshmeh.

Jan 1, 2004

By Inc. The HDH Group

The Alternative Risk Market is defined as the segment of the insurance market that is made up of self insurance, risk purchasing groups, risk retention groups and captives. It is commonly referred to as the alternative to the traditional market, even though more the majority of companies today are insured through the alternative risk market than the traditional market.

Jan 1, 2007

By Wang Zhong Qian, Liu Hui

The paper proposed a fractal and damage model for rock-breaking by blasting, which assumed that the process of rock-breaking results from intrincent fractal development and the accumulation of damage. Remarkably, the process is of fracture character. Based on the model, a computer program is compiled to calculate the 3-dimension damage distribution in blasting crater. Trial results agree well with the predicted results, showing the model set up in the paper is sound.

Jan 1, 1997

By R. K. Wharton

A European Directive requires that an explosive which is sold or transported within Europe must meet certain essential safety requirements from 1 January 2003. The assessment and certification of such an explosive is undertaken by an Explosives Notified Body and if the explosive meets the requirements a certificate is issued that allows the affixation of a CE mark. The presence of a CE mark ensures the product free access to European markets. The paper examines the requirements of the Directive, identifies those explosives that come within its scope, considers the role of an Explosives Notified Body, and explains the process of applying for certification.

Jan 1, 2002

By B. A. Cheeseman, R. Skaggs, C. F. Yen, S. Wolf

Shallow buried explosives pose a significant threat to lightweight vehicles and their onboard personnel. To date, designers of lightweight vehicles are limited in their knowledge of what occurs during the blast. The high intensity, short term loading imparted by the explosion is enormously complex and can be significantly affected by a number of parameters including the size, shape, type, detonation point and depth of burial (DOB) of the explosive and the type, density and water content of the soil. Recent advancements in numerical simulations have enabled the complex blast event to be accurately modeled by coupling Eulerian and Lagrangian analyses: the former is well suited to modeling the blast and while the latter, the structural response. Further validation of the modeling technique is considered in the current paper, which details simulations performed utilizing the coupled Eulerian-Lagrangian analysis to the study the blast output of explosives buried in saturated sand. These experiments varied explosive charge size, its depth of burial, the target stand-off (SO) distance and target plate dimension. The investigation concludes with a discussion of the accuracy of the numerical simulations when compared with the experimental observations.

Jan 1, 2005

By Alan R. Cameron, William Forsyth, Tom H. Kleinel

Because good and bad blasting must be defined in terms of overall mining costs, blast optimization requires combined blasting and costing models. Furthermore, the models must be both accurate and comprehensive. A combined fragmentation and preliminary costing model was developed to investigate alternative blasting strategies.

Jan 1, 1995

By T. Bajpayee, G. Mowrey, D. Ingram, T. Rehak

Blasting operations are an essential element in the recovery of our Nation’s mineral resources. The mining industry uses billions of pounds of explosives annually. The majority of blasting occurs in surface mining .operations. Blasting results in the fragmentation and often the projection of rocks. Frequently, the rocks are thrown beyond the expected limits. Flyrock and failure to secure the blasting area dominate blasting-related accidents in mining, especially in surface mining.

Jan 1, 2001

By Raymond V. Adolphson

The introduction of a new explosive component in 1955-56, called ANFO, featured much safer, effective blasting characteristics when compared to dynamite, accompanied by a notable reduction in cost. These savings mounted as borehole diameter or depth was increased with ANFO volume subsequently enlarged.

Jan 1, 1983

By Virgil J. Stachura, Larry R. Fletcher, Matthew N. Plis

Falls of ground remain a leading cause of fatalities and injuries in underground mines. In response to this situation, the Bureau of Mines conducted a series of experiments in the White Pine room-and-pillar copper mine which resulted in smoother, safer ribs due to a reduction in the amount of overbreak caused by blasting. The tests evaluated the effects of changes in the loading of the rib holes of the mine's 20- by 28-ft drift round driven in shale and sandstone. The relative integrity of the ribs remaining after the blasts was measured using both photographic and seismic refraction techniques.

Jan 1, 1989

By Travis Watts, Chris Prater, G. T. Lineberry

Moving overburden at minimal cost is becoming increasingly important to coal mining companies throughout the U.S. The coal market is currently doing well, with an average spot coal price for Central Appalachia product (12,500 Btu, 1.2 SO2) standing at $62.00 for the week ending November 11, 2005, so it is at this time that companies stand to achieve healthy rates of return on their investments. Cast blasting is one method of blasting used effectively by some surface mining operations. This method allows most of the overburden to be removed and placed (cast) directly in the spoil pile by the use of explosive energy. With the proper design of a cast blast, a high percentage of overburden material can be directed into piles without the use of earthmoving equipment, hence increasing production and lowering the cost associated with overburden removal.

Jan 1, 2006

By Paul Downing

A major component of an effective blasting company safety program is the self-audit. A self-audit can help reveal hazardous conditions that should be corrected and training needs that should be addressed before accidents occur, insurance claims are filed, and/or fines are levied. Such audits, when they lead to appropriate corrective action, can provide significant economic benefits for employers by reducing the costs associated with insurance claims, accidents, and injuries.

Jan 1, 2001

By Don Houston

Vertical crater retreat mining (VCR) requires initiation methods that minimize debris in the borehole. The use of detonating cord and shock tube detonators eliminates debris that could interfere with subsequent loading operations and avoids the cost of using drilling equipment to clear the debris. The explosive must not be sensitive to the strength of detonating cord used, otherwise timing will be affected. “Slicing and Dicing” of product before “Air mailing” down boreholes may facilitate loading, especially in wet holes, and can result in product surrounding the detonating cord. Cord sensitivity testing confirmed that having the detonating cord surrounded by product significantly increases the likelihood of an energetic reaction. Careful formulation and testing, based on a thorough knowledge of the application and the role of ingredients in affecting performance, ensures reliable initiation and avoids cord sensitivity. The use of certain metallic nitrate salts, even in relatively small amounts, was found to significantly increase the cord sensitivity of watergel formulations. Evidence of increasing cord sensitivity includes increasing amounts of damage to product and packaging, to ejection of product from the test pipe, then cracking of the pipe, followed by deflagration then detonation of the product. Predictably, the likelihood of an energetic reaction increases with product temperature, cord strength, and borehole diameter, while it is inversely related to product density.

Jan 1, 2002

By Lauren Shields

This paper discusses the application of current fragmentation models for underground blasting, establishes a conceptual fragmentation model for underground operations, and discusses the applicability of the mine-to-mill approach for underground blasting. Additionally, this paper also discusses selected case studies where the mine-to-mill approach is applied to underground mining operations.

Feb 1, 2020

By Robert Hopler

In part one we discussed a Chinese seismoscope allegedly invented and used in the year 136 (or 132, depending on the source). Interestingly, historical references to the measurement of earth movements then seem to be nonexistent until up into the 1700’s. There could be two explanations for this hiatus: first, that there were no earthquakes in the world for 1600 years, or, second, the “Dark Ages” really did exist, where intellectual inquiry and all sorts of learning came to a halt. Of course there were earthquakes, so the explanation for the lack of a record of invention is the reality of the Dark Ages. explained is the fact that the Dark Ages ended in about A.D. 1000, but that is beyond the scope of this story.

Jan 1, 2006

By Kaby K. Kabongo

The paper is drawn from a project intended to explore a technique of prediction, control and optimization of fracture in coal induced by blasting. It evaluates the fines generated in coal submitted to dynamic loading stresses in an impact stamp mortar. The aim is to analyze a complex phenomenon of coal response to blast-generated stresses from a series of discrete simulations of shock and gas actions in controllable processes.

Jan 1, 1995

By Jiang Han, J. F. Shao

Based on the rock blasting engineering, The Self-Organizing Map (SOM) network has been implemented for the concept and method of rock blastability classification. The Self-Organizing Map (SOM) is a neural network algorithm which is especially suitable for the analysis and visualization of high-dimensional data. It maps nonlinear statistical relationships between high-dimensional input data into simple geometric relationships, usually on a two-dimensional grid. The mapping roughly preserves the most important topological and metric relationships of the original data elements and, thus, inherently clusters the data. SOM allows easy data fusion enabling visualization and analysis of large databases of rock blasting engineering. As a case study, the classification technique based on SOM has been used to classify the rock mass blastability rank. It can be founded from this paper that the SOM networks can be developed well based on a comprehensive data set of rock blasting engineering.

Jan 1, 2002

By Rob Grant, Manuel Lopez Cano, Mike Briggs, Ken Fletcher

The scorched desert sands and life giving waters of the River Nile in Egypt have been the back drop to awe inspiring engineering feats for over 4,700 years. The latest engineering marvel to grace the land of the Pharaohs is the Mubarak Pumping Station Project at Toshka. This ambitious project aims to open up an area of 607,000 hectares (1.5 million acres) of barren desert to irrigation based farming with the supply of 29 million tonnes (32 million tons) of water per day, drawn from Lake Nasser on the river Nile. It is anticipated that this currently unpopulated area of southern Egypt will soon flourish and become home to several million Egyptians who will conduct their lives around the water supplied by the 230 kilometers (144 miles) of concrete canals. An integral part of the pumping station is the intake canal. The canal was excavated in two sections – the dry excavation, and the wet excavation. The wet excavation comprised of some 5.5 million cubic meters (7.2 million cubic yards) of rock to be drilled, blasted, and excavated, from the surface of the lake. The challenge at hand was how to achieve this safely, quickly, and cost effectively, with water depths of up to 45 meters (148 feet), excavation depths of up to 47 meters (154 feet), blast production rate peaks of up to 30,000 bank cubic meters (39,200 bank cubic yards) per day, blistering summer air temperatures up to 60°C (140°F), and security concerns about the storage of large quantities of explosives in the Middle East region. The solutions to these challenges were engineered by UEE Explosives and centered around the use of a microgel bulk explosive called Rioflex™ and an international team of engineers and operators from three continents. The microgel and accompanying pumping system allowed pumping rates of up to 17,400 kg (38,400 lb) per day, and more importantly, enabled the bulk product to remain as an oxidizing matrix whilst in transport and storage, transforming into an explosive only moments before being pumped into the blastholes. This case study outlines the underwater drill and blast process employed at the Mubarak Pumping Station Project at Toshka, and the novel solutions to the unique challenges encountered.

Jan 1, 2004

By T. N. Singh, Vasudev Singh

To explore and exploit the natural resources like oil, gas, economic mineral water drilling is still considered to be the reliable and economical method. When a drill bit penetrates the rock mass either by percussion or by rotary and may be some times a combination generates stress and thrust on the rock mass as well as on the drill bit. The strength and hardness of the rock govern the life of the drill bit and its runnage. Physico- Mechanical properties of rocks have great influence on drillability. It is observed that higher the strength of rock, reduce the life of the drill bit while drilling, ultimately decreases the drillability. An attempt has been made in the present paper to establish relation among various physicomechanical properties i.e. uniaxial compression strength, tensile strength, shear strength, Schmidt hardness and abrasivity with drillability of different rock types. The specific energy of each rock type has been calculated using micro-bit drilling. The rocks from different lithological succession were collected. The rock specimens were prepared according to the norms of International society of Rock Mechanics (ISRM).

Jan 1, 2008

By A Gene Riggs

The Cerrejon Coal Project in Colombia, South America is one of the largest coal mines in the world. The mine is located in northeastern Colombia on the La Guajira penninsula. The area is in a remote valley 132 miles east of the city of Barranquilla.

Jan 1, 1984

By S A. Steyn, I P. Douglas

Duvha Opencast is a large South African dragline operation supplying coal to the Duvha Power Station which is operated by Eskom, the state power utility. For Duvha to remain competitive with other collieries, it has proved necessary to continuously examine and investigate methods of reducing costs. With explosives representing a major portion of the total working costs, blasting is an obvious area of investigation.

Jan 1, 1991