Abstract: The invention herein describes a novel photobioreactor (PBR) system for culturing algae. The PBR system utilizes vertical transparent tubes that can be cyclically filled with an algae culture. The vertical tubes further feature pipe pigs deployed therein to disrupt formation of biofilm on the inner walls during the cyclic filling and emptying of the cultures.

Abstract: A method for selective separation of particles from a particle-containing material includes preparing a slurry of the particle-containing material and a dispersant, passing the slurry through a hydraulic classifier in a first direction, establishing a particle flow in a direction that is different from the first direction, and recovering particles having a mean particle size of about 2-7 ?m. The flow of particles defines a cross-current flow relative to the slurry feed direction. The method further includes providing the classifier with an interior divider assembly defining at least one inclined channel. The divider assembly typically includes a plurality of substantially parallel dividers separating the classifier into multiple channels having a substantially equal internal volume. A hydraulic classifier for separating particles having a mean particle size of from about 2-7 ?m in accordance with the present method is provided also.

Abstract: A method for selective separation of particles from a particle-containing material includes preparing a slurry of the particle-containing material and a dispersant, passing the slurry through a hydraulic classifier in a first direction, establishing a particle flow in a direction that is different from the first direction, and recovering particles having a mean particle size of about 2-7 ?m. The flow of particles defines a cross-current flow relative to the slurry feed direction. The method further includes providing the classifier with an interior divider assembly defining at least one inclined channel. The divider assembly typically includes a plurality of substantially parallel dividers separating the classifier into multiple channels having a substantially equal internal volume. A hydraulic classifier for separating particles having a mean particle size of from about 2-7 ?m in accordance with the present method is provided also.

Abstract: The present invention provides a method of beneficiating slag, including mixing the slag with water to form a slurry. The slurry is screened through a first screen to remove a first portion of material and then screened through a second screen to remove a second portion of material. In one embodiment, the second portion of material has a carbon content less than about 5% and, more preferably, a carbon content less than about 1%.