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Research BOOMing at U. mines school

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Think of scientific research and chances are good that quiet pursuits come to mind: astronomers guiding vast telescopes, researchers in lab coats peering through microscopes.

But at the University of Utah College of Mines and Earth Sciences, research is BOOM!-ing. Firing projectiles and blowing up explosives, scientists are delving into such noisy pursuits as how detonation cord burns, how much pressure different types of rock can stand, and how stone fractures.

The studies are about to take a giant step forward with the establishment of the Utah Center for Rock Blasting Research.

The center, funded by industry with facilities provided by the U., is intended to fill a research void left when the federal government shut down the U.S. Bureau of Mines. Organized under the U.'s Department of Mining Engineering, in the College of Mines and Earth Sciences, the center will expand research already conducted on campus.

So far, three companies have committed support at $15,000 per year. More may join. The center's director is William A. Hustrulid.

Among the subjects examined are improved ways of "making little rocks out of big rocks," said Kim McCarter, dean of the College of Mines and Earth Sciences.

The crushing of mined rocks to refine ore or make cement powder is a major consumer of electricity, he said. If the center can find ways to do it more efficiently, industry can save money.

Another topic, how to protect mines and miners from the collapse of excavation walls weakened by blasting, is a question pursued by master's degree student Amanda Smith, who graduated from the U. in May.

"I'm working in blast damage, monitoring or preventing of blast damage," said Smith of Provo. If damage extends too far "into the walls, that is undesirable; you could have problems with cost or safety."

A computer program may calculate hardness of the rock walls, force of explosives, fracture frequency and how far into the rock that hairline fractures are likely to extend. "Hopefully, it would be able to return a blasting pattern with the explosive load per hole and the spacing between the holes," she said.

One of the center's most impressive pieces of equipment is a high-speed camera capable of taking detailed photographs at the rate of 2 million frames per second. The gear is mounted on a rail, with a separate lens in front.

"Of course, you don't have very many frames," McCarter said.

The camera photographs through a thick glass portal as cord burns or explosives blow up in a protective chamber.

McCarter showed photos taken at the rate of 113,740 frames a second, fast enough to stop the flash of a burning detonation cord.

"You can see the explosive gases flying out in a kind of a V shape," he said.

A piece of quartzite used in a detonation was sliced and examined for hairline cracks. The fractures show how the explosive propagated through the rock.

In her studies to improve mine safety, he said, Smith would "like to be able to predict how far this zone of damage would propagate around the blast hole."

Wenbo Lu, a visiting scholar from Wuhan, China, said he is interested in studying damage control and the mechanization of air decking.

Air decking involves the amount of air left in a blast hole between the explosive and the hole's top.

Meng Xianhong, from Northeastern China University, was working in one of the center's research labs. He is interested in blasting and and drilling because his city of Shenyang is in a province with a lot of mining. There are "several big mines, very near to my hometown."

A massive piece of equipment, the Hopkinson bar, measures the impact of forces on columns of rock.

Scientists "try to determine what strain rate will cause damage in the rock," McCarter said.

A projectile fired by pressurized gas is blasted into a sample rock column while tiny monitors on the rock sample measure the strain.

When fully engaged, the center should attract more students and expand explosively into new areas of research.

E-MAIL: bau@desnews.com