Portable Dredge Used to Mine Silica Sand

Dresser Minerals, a division of Dresser Industries, Inc., has been using a Mud Cat from Mud Cat International’s Mud Cat Division to recover silica sand from an open pit mine filled with water at its Dubberly, Louisiana, plant.

According to Stephen Yeich, plant manager, Dresser has been using a dredge for mining purposes since 1974. Before that, a heavy duty scraper had been used, until at 75 feet, the water table was reached and the mine was filled with water.

“When we reached the water table we had to find a new way to mine the sand, and dredging was the logical choice because the process is much cheaper,” said Yeich. “We began looking at dredges, including the Mud Cat, but at the time I thought the Mud Cat was too small for our purposes.”

Instead, Yeich purchased a larger dredge, and used that until May 24, when it developed a “fatigue crack” in one of its hulls and sank.

“After the old dredge sank we began looking for a machine that would suit our purposes, and yet be economical. We wanted one with a cutter head because we felt it would increase our production and make it a better operation overall,” said Yeich.

“We looked at larger dredges but finally decided on a Mud Cat.”

Mud Cat is equipped with a patented auger assembly mounted at the end of a hydraulically-operated boom which is attached to the front of the machine. This auger, covered by a specially designed auger-shield, is lowered into the water during operation. As the auger turns, the silica sand coming into contact with the auger is trapped in the shield and forced to the center of the auger where a powerful suction pump sucks the sand through the intake tube and pushes it out through a discharge pipe. This pipe floats on the surface by means of attached floatation tubes.

The Mud Cat pumps 50 tons an hour with an average of 20% solids, although the solids level has been as high as 36%. The sand is pumped 1000 feet with an elevation of about 100 feet.

Yeich has added an extra attachment to the Mud Cat. It is an irrigation hose used to wash the sand off the high banks into the water so the Mud Cat’s™ cutter head can mine it.

“The Mud Cat is a lot smaller than our old dredge and to avoid being caught when the bank caves in, we added the irrigation hose. That way we can control the caving,” said Yeich.

Mud Cat’s Dredge Division designs and builds larger dredges when digging depth or output requirements exceed the capabilities of the portable Mud Cat.

Mud Cat Division of Mud Cat International