Like other industries, mining markets are demanding low-cost products and processes that result in optimal performance and minimal environmental impact. “Because it is more economical to move rock with explosives, the mining industry prefers to move as much through blasting and as little through loading and trucking as possible,” said Dale Preece of the Global Technology Group at Orica USA. “Orica is about industry solutions, about developing integrated approaches to blasting that, less than a decade ago, would have been inconceivable. Our overarching goal is to harvest more materials from fewer well-planned blasts. What we’re currently simulating with explicit dynamics software from ANSYS is precise-delay timing and how resulting forces due to the effects of shock waves, stress waves and the effect of velocity gradients can be leveraged to produce optimal fragmentation.” These capabilities are a critical component of Orica’s Blast Based Services, which is changing the market approach to explosives by allowing the industry to purchase mine-specific solutions tailored for the client’s unique operational and commercial challenges.
Whether applied to mining coal, gold, copper, uranium, nickel or bauxite, precision-delay timing involves multiple blasts that are specifically sited and sequenced. The wrong placement/timing combination can result in muck piles that are difficult for a front loader to efficiently excavate, excessive machine wear, environmentally adverse effects, or an unsafe explosion creating excessive air-blast levels and flyrock.
A blasthole produces stress waves. Multiple blastholes cause these to collide and interact — thereby magnifying, diminishing or canceling out their effects. The physics involved are complex and dependent on the time between detonations. For example, colliding stress waves can become reinforced and reflected, producing significant damage, or stress waves can become depleted in strength due to other more powerful waves. The Orica simulation study used explicit dynamics software from ANSYS to show that blast-induced fracturing and damage lag significantly behind the initial blast’s stress wave, with the most effective delay time occurring when crack propagation and damage are maximized before a subsequent detonation occurs, a span of tens of milliseconds, depending on the rock and blast pattern. “Precise-delay timing enables detonation of adjacent blast holes with the ‘right’ delay time, not simply a guesstimate,” Preece added.
Orica has pioneered the development and implementation of new mining technology for more than a century. The company’s recent engineering simulation efforts are especially timely since rising energy prices have driven up the cost of natural gas, which when converted into ammonia is used to produce a key ingredient in explosives. Orica’s Blast Based Services seek to maximize the performance and efficiency of the blasting process.
“Mining activities remain a time- and cost-intensive business, so accurate planning is critical. Such pioneering work from Orica has the opportunity to advance the entire mining industry — helping engineers to understand the physics that go on in an explosion, which is not visible to the human eye,” said Dipankar Choudhury, vice president, product strategy and planning at ANSYS, Inc. “Technology from ANSYS enables engineers to go beyond physical constraints and perform simulated tests that would otherwise not be possible. This is so important to exploring and expanding operational boundaries in developing leading-edge products and processes.”
For downloadable images, visit http://www.ansys.com/newsimages.
About Orica USA
Orica is the world’s largest supplier of commercial explosives. Committed to innovation, Orica is continually working with customers to provide a tailored service to meet the changing needs for the global mining industry. Orica offers commercial explosives, Electronic Blasting Systems and Blast Based Services™ to many industries including open cut coal, open cut metal, underground mining, quarrying and construction industries.
Operating globally, Orica has regional offices in Australia, Asia, Europe, the Middle East, Africa, Latin America and North America. Orica USA, together with Orica Canada, provides service from more than 50 locations throughout North America.
About ANSYS, Inc.
ANSYS, Inc., founded in 1970, develops and globally markets engineering
simulation software and technologies widely used by engineers and
designers across a broad spectrum of industries. The Company focuses on
the development of open and flexible solutions that enable users to
analyze designs directly on the desktop, providing a common platform for
fast, efficient and cost-conscious product development, from design
concept to final-stage testing and validation. The Company and its
global network of channel partners provide sales, support and training
for customers. Headquartered in Canonsburg, Pennsylvania, U.S.A., with
more than 60 strategic sales locations throughout the world, ANSYS, Inc.
and its subsidiaries employ approximately 1,700 people and distribute
ANSYS products through a network of channel partners in over 40
countries. Visit
www.ansys.com
for more information.
