Comment: Fly Rock, Blasting, environmental impact, the future of blowing up Virginia hillsides for uranium!Orica USA Simulates Blasting Precise-Delay Timing for Process Improvement Benefits.
SOUTHPOINTE - ANSYS, Inc. (NASDAQ: ANSS), a global innovator of simulation software and technologies designed to optimize product development processes, today announced that its software is being used in the mining industry to develop precise-delay timing for blasting. Orica USA, a division of the world's leading supplier of commercial explosives — Orica Limited — is studying the effects of multiple blastholes on rock fracturing and fragmentation to further its ability to provide advanced Blast-Based Services™ to industry. The effort is shedding light on the complex physics set in motion in the rock blasting process, and the results will be used to improve overall processes — including blast control along with time and cost savings.
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.
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