Abstract: A flexible, steerable device for conducting exploratory procedures is disclosed. The device includes at least one spine, each having stiffening means for selectively rendering the spine rigid and flexible along its length. A flexible sheath surrounds the spine and is axially slidably moveable relative to the spine so that the sheath will follow and conform to the shape of a spine in the rigid state and resist further flexure when the spine is in a relaxed state. A steerable distal tip is provided on the distal end of the device. Controls for the distal tip are mounted on the proximal end of the device. Mechanisms are provided on the distal end of the device for selectively activating and deactivating the stiffening means of the spine. An instrument conduit may be mounted on the sheath.

Abstract: A coal preparation plant separates a low specific gravity clean coal fraction from a high specific gravity refuse fraction, and separately processes those fractions. Run of mine coal having particle sizes up to about 4 inches is mixed with a slurry of water and magnetizable particles, and is introduced into a heavy media cyclone to separate the high and low specific gravity fractions. The high specific gravity refuse fraction is delivered to a first magnetic separator to extract the magnetizable particles, while the low specific gravity clean coal fraction is delivered to a second magnetic separator to remove the magnetizable particles. The system is highly efficient and has a high processing capacity.