Electric pulse rock sample disaggregator

Summary form only given. Maxwell Physics International has developed and delivered to Woods Hole Oceanographic Institution a pulsed power-based system for disaggregating rocks. This important, new mineral-separation research tool, the Rock Sample Disaggregator 140L (RSD-140L), provides the following benefits: preferentially fractures rock along natural grain boundaries; preserves 3-D mineral grain morphology; separates complete crystals and gems from host rock; reduces the production of fines/slimes; preserves natural grain size distribution; forms fewer multi-mineral grains; and liberates accessory minerals. Conventional laboratory scale processing generally involves crushing >2 inch particles to produce <0.25 inch particles, using small, mechanical jaw-crushers. The small particles are then sieved and ground to as small as 100 mesh for separation using gravitational, magnetic, electrostatic or other methods. Compressive processing requires considerable over-grinding to achieve high degrees of mineral separation. As a result, grain morphology is degraded, microfossils are destroyed, and electron microscope analysis of micronsized particles in soft minerals is complicated by the presence of slimes. Pulse power offers an attractive alternative. When a sufficiently powerful, short-duration, pulsed electric field is applied to rock particles between electrodes submerged in water, extensive ionization occurs along mineral grain boundaries. Electrical breakdown of the rock occurs along the ionized paths, creating high peak current flow and high internal tensile stress between the mineral grains. The result is selective fracture, breaking up the rock along internal grain boundaries (disaggregation).