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By Visitor Makiyi, Chris Batten

Poor coal recovery due to coal damage or loss caused by blasting can have a significant impact on a mining operation. Increasing coal recovery by reducing blast damage can provide a significant opportunity for coal mines to maximise their revenue and reduce their operating costs. This paper provides details on advanced drilling and blasting techniques used throughout the coal industry globally to prevent coal damage and movement during blasting. Typical coal loss and damage mechanisms are explained, along with how each of the applied techniques works to minimise the impact of each mechanism. Key requirements for a coal loss reduction program are detailed with typical design parameters used for each of the methods discussed. The positives and negatives of each method are also provided to enable comparisons and help determine suitability for a particular coal mining operation.

Jan 21, 2025

By Doug Hoy

The scope of the Cliff Avenue Reconstruction Project in Sioux Falls, South Dakota was to widen a two lane highway to five lanes, along with removing and reconstructing both above and below ground utilities located along the project limits. The objective of this paper is to present the blasting techniques used in the rock excavation phase of the Cliff Avenue Reconstruction Project.

Jan 1, 1992

By Wm. L. Giachino

"Over the last 10 years, C-1-L has played a significant role in the major advances that have taken place in blasting technology, among them the following: development and introduction of capsensitive slurries; development of bulk slurry systems both for underground and open-pit operations; development of the TOE-DET and ANODET systems of delay blasting;introduction of the NONEL system of initiation;development of the Vertical Crater Retreat (VCR) system of mining.This paper identifies areasin which we foresee further developments in blasting technology over the next 10 years and outlines how and to what extent C-1-L will become involved."

Jan 1, 1980

By E Emery Gray, Gary Ard

Each year when hundreds of Engineers and Specialists in the explosives industry meet for the SEE Annual Conference, new ideas are exchanged and new business relationships formed. Harbert Construction Corp. and EGA, Inc., a company specializing in drilling and bIasting, formed such a relationship through mutual interest in such a manner.

Jan 1, 1981

This is the story of a blast - not a large blast by todays standards as it only involved a total of approximately 50 cubic yards of rock. Nor did this blast involve any new or revolutionary blasting technique or require involved analysis or the applications of rock mechanics theories. Instead, it was a blast that involved the tried-and-true principles of good blasting: precise alignment of blastholes; selection of explosives and detonators designed for the conditions encountered; extreme care in loading and hooking up and the use of several ingenious devices and techniques to achieve the proper loading and firing of the blast

Jan 1, 1976

Explosives have been an important tool for unlocking minearl wealth from the earth's crust for several countries. In'the past, innovation in explosives technology, spurred on by industry needs has assisted the Mining Industry to improve productivity and reduce costs. A symbolic relationship exists between Explosives and Mining. Australia has vast mineral wealth. Our Mining Industry is of major importance to the Economy., The value of mineral produc- tion in 1987 was $25 million or 10% of GDP. Australian Mining is a business depending on international markets. The Mining Industry is our leading export earner, generating 44% of all export income. 60% of mineral production is exported. About half of these minerals are extracted using explosives. Explosives rank as one of the top three consumable expenditures for a mine. For example: A major open-cut iron or coal mine can spend $6 million dollar per annum on explosives.

Jan 1, 1988

By C. Harries

The mechanism of blasting and the effect that blasting has on rock properties including the generation of new cracks and the opening of existing joints is discussed and compared with changes in seismic velocities. .Knowing the extent of blast induced damage and the overall stable slope angle it is shown that it is possible to design blasting so as not to induce any damage behind the toe of the blast area. Practical methods of blasting to meet this criterion and the results of these blasts are then discussed.

Jan 1, 1983

By Terry Matts, Henry Heidrich, Cluny Randell, Carl Kottmeier

Until 1990, all production of asbestos ore at Cassiar was by open-pit methods. With the impending exhaustion of open-pit reserves, a decision was made in February 1988 to continue mining underground, using the block-caving technique.

Jan 1, 1992

By Brad Bulow

Blasting is an essentially violent process aimed to disrupt and loosen rock for productive excavation. Some dilution of any ore present is the inevitable result. This makes blasting a dirty word to most geologists, particularly in narrow vein gold mines. A 1% increase in gold recovery may be worth $1 M extra revenue to a large mine.

Jan 1, 2000

By Jerry Wallace

A highway bridge demolition project to allow shipping access to a new container port in Puget Sound ran into trouble when contract-stipulated mechanical means of demolition failed. Blasting was then employed under less than ideal conditions and was successful.

Jan 1, 1999

By D. Lansburg

Electronic detonators are increasingly being used in today’s blasting in quarries, seismic, surface and underground mines. Electronic detonators offer several distinctive features over electric and non-el (shock tube) detonators including better timing accuracy resulting in excellent fragmentation and vibration control, field programmability and digital safety means. Because of the prerequisite electrical communications between the electronic detonators and the blasting machine, the layout or hook-up of these detonators can play an important role in obtaining the communication fidelity.

Jan 1, 2011

By N K. Jain, Rajesh Jain

This article has been written indicating the present trend in Blasting all over the World, so as to help in planning production and development of Industrial Explosives for the development of industries in all the countries in general

Jan 1, 1992

By P Geddes, K Grohs, C K. McKenzie, M Morrish

Low grade surface gold mining at the Acacia Resources, Union Reefs Gold Mine in Australia's Northern Territory, involves the excavation of benches in three slices after blasting. Blast patterns span zones of high and low grade ore, as well as zones of waste, and selective excavation is required in order to maintain economical head grades for the carbon-in-leach processing plant.

Jan 1, 1998

By Braden Lusk

A typical rural house surrounded by a surface coal mine was instrumented in 2008. Information regarding ground vibration, airblast, and sounds inside the house was collected. Previous publications have included conclusions about this data with regard to blasting source (far-field or near-field) and results as to how the residents experience the blast were made. Several events were also recorded that were not related to blasting due to the nature of the trigger system. The trigger of the monitoring system was attached to one of the mid walls of the house, thus other normal daily events produced vibration levels significant enough to trigger the monitoring system.

Jan 1, 2011

By J W. Muir, N Bedford

Hong Kong is one of the most rapidly developing cities in the world. With constant population growth and limited opportunities for space, the development of a fast and effective underground public transportation network is essential. Hong Kong’s Mass Transit Railway (MTR) Corporation is currently undertaking several large underground expansions to its existing network. Much of the excavation will be carried out using the drill and blast excavation method.Drill and blast excavation is common in Hong Kong and with the continued development of underground infrastructure the use of the drill and blast excavation method will increase. Although an effective method of excavation, the blasting vibrations caused during construction can have an adverse impact on surrounding structures and impose disruption on the local community.In order to minimise the risks associated with blasting vibrations, and to demonstrate that the impact on local stakeholders will remain within acceptable limits, it is generally necessary for a contractor to submit a blasting assessment report for approval by government authorities before blasting may commence.Continued increases in population density will force more infrastructure to be constructed underground. Tunnels and caverns are increasingly excavated in closer proximity to critical sensitive receivers. This leads to greater potential impacts on the community, tightening constraints on contractors and a higher level of confidence required for approval authorities. Finding a balance between the needs of the community and rising construction costs becomes more challenging.This paper presents a case study on how the blasting assessment report process has been successfully implemented for a major MTR project situated in a densely developed area of Hong Kong. It describes several methods of assessing blasting vibration impacts, innovative uses of blasting for excavation and the mitigation measures employed to provide the best outcome for all project stakeholders.CITATION:Bedford, N and Muir, J W, 2014. Blasting vibration assessment and innovative blasting methods in high-density urban environments, in Proceedings 15th Australasian Tunnelling Conference 2014 , pp 9–20 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 17, 2014

By Jennifer P. Harrell, D. Joseph Hagerty

In many areas of the eastern United States, especially in the Midwest, past mining activities have left large and extensive underground openings. Now, renewed mining is occurring in such areas in surface pits. Also, construction blasting often occurs in rock over such old openings. Within the last fifteen years, some attention has been given to the interaction between surface blasting and underground cavities; concern has been expressed about the possible changes in vibrations transmitted through areas underlain by old mine workings (Siskind, Stachura and Nutting 1987). Previous studies also had indicated that underground openings could influence transmission of surface mine blast vibrations (see, for example, Woodward-Clyde Consultants 1977). The principal concern is that underground openings under surface blasting may intensify low-frequency vibrations. If such intensification occurs, use of available equations to predict peak particle velocities and to design blasting patterns and select blasting parameters could lead to possibly damaging ground shaking.

Jan 1, 2002

By B Mohanty, R Yang

Blasting vibration information is now commonly used to diagnose blast malfunctions. These range from limiting vibration levels to protect normal dwellings to determining scatter in detonator firing times, and even to rating of explosives in the borehole. Although blasting vibrations have the potential to yield reliable information in all these issues, there are key restrictions on their specific use, which are often ignored. These include all aspects of instrumentation, and sensor layout, as well as methods of analysis. This paper highlights these limitations. It emphasizes the distinction between near-field and far-field seismic recording in terms of borehole dimensions and blast geometry. Several case studies from both underground and open-pit blasting operations are discussed to illustrate and emphasize the essential characteristics of blasting vibrations and their optimal use in diagnosing blast malfunctions.

Jan 1, 1997

By Thierry Bernard, Pierre M. Vuillaume, Michel Kiszlo

"In the context of its studies for the trench ministry of the environment and for the French national coal board, INERIS (the French institute for the industrial environment and hazards, formerly CERCHAR) has made a complete critical survey of the methods generally used to reduce the levels of blastingvibrations."

Jan 1, 1996

By Thierry Bernard, Pierre M. Vuillaume, Michel Kiszlo

In the context of its studies for the french ministry of the environment and for the French national coal board, INERIS (the French institute for the industrial environment and hazards, formerly CERCHAR) has made a complete critical survey of the methods generally used to reduce the levels of blasting vibrations.

Jan 1, 1996

By Doug Wathen, Philip M. E Thomas

The City of Fort Myers needed to replace a 40-year old 42-inch storm sewer line in downtown Fort Myers with a new 54-inch line to accommodate population growth. The old line had to be kept operational while a new line was installed. The contractor spent two months using a drop ball, a hoe ram, and large rippers trying to break the three to four feet of rock that needed to be removed to accmmodate the new pipe. Mechanical trenching was considered but was proven to be overly expensive. On very short notice, Ireco of Florida was asked to design and execute a blasting procedure that would allow this project to proceed. Nearby buildings were over 80 years old, three of them containing antique shops specializing in glass antiquities with attorney offices above them. High water table compounded problem with a 20-year old steel water main and clay drainage pipe 15 feet frcan the new sewer line. Holes had to be drilled within six inches of the edge of the existing pipe to four feet below the pipe on either side of the pipe and blasted. No interruption in the sewer line flow was to be tolerated.

Jan 1, 1996