Liberty Star Uranium and Metals Corp (LBSR)

[PoorRich]

Vermeer Excavator Provides Precision Mining
Vermeer Corp. has developed equipment that it claims allows mine operators to selectively extract mineral seams in surface mining applications. The technique, which Vermeer refers to as precision surface mining, uses the company’s T1255 Terrain Leveler surface excavation machine (SEM).

The Terrain Leveler SEM was created when Vermeer engineers swapped out a trencher attachment and added a patented tilt-head milling attachment to the company’s T1255 model tractor. The Terrain Leveler SEM utilizes top-down cutting, a process that allows the cutter teeth to gain penetration without using the machine’s tractive effort to drive the teeth into the minerals.

The process allows operators to control material size by adjusting tooth penetration depths. Increased tooth penetration decreases the material size; while decreasing the depth of penetration makes for a larger material size. This is all done automatically by adjusting the control from within the operator cab. A patented drum tilt system also allows the operator to control grade in both the lateral and longitudinal directions. The unit can dig up to 27 in. deep (68.6 cm) and 12 ft (3.66 m) wide in a single pass.

The machine, according to Vermeer, can handle a wide variety of materials. In Western Australian iron ore operations, production rates have ranged from 150 to 450 bank cubic meters per hour, averaging about 250 bm3/h. In South African coal, the machines can produce 600–900 m3/h, and in tests at a U.S. copper operation, an SEM achieved a rate of 1,100 t/h, producing a 16-in. product. The company reported that three of the units will soon be operating at a copper mine in the Democratic Republic of Congo.

Precision surface mining will also incorporate high-technology communication in the future by using Global Positioning System (GPS) technology and two-way data communication. An engineer could create a mine plan in the office and send the data to the on-board computer of the Terrain Leveler SEM. The operator can then pull up the plan on the screen and tackle the various layers of material based on the new plan. The SEM can also be set up for laser guidance. For mining applications, Vermeer conducts what it calls a “Rock Lab” test, analyzing core samples to assess the compressive strength, abrasive properties and other characteristics of the material, allowing them to select the right style of cutting tooth to be mounted on the drum.

http://www.womp-int.com/story/2008vol9/story025a.htm