Abstract: Conditioning and concentration of microalgae are accomplished by the process steps of grinding a dilute aqueous dispersion of microalgae in the presence of grinding media and then applying adsorptive bubble separation. This process is amenable to the use of dilute feed microalgal dispersions such as are encountered in the production of algal biomass for biofuel applications.

Abstract: Conditioning and concentration of microalgae are accomplished by the process steps of grinding a dilute aqueous dispersion of microalgae in the presence of grinding media and then applying adsorptive bubble separation. This process is amenable to the use of dilute feed microalgal dispersions such as are encountered in the production of algal biomass for biofuel applications.

Abstract: Process and apparatus are described for adsorptive bubble separation of hydrophobic particles from liquid dispersions. When a gas-liquid-particle dispersion is introduced into a separation vessel, a baffle directs the rising bubbles toward the perimeter of the apparatus. At the liquid surface, bubbles with attached hydrophobic materials form a floating froth layer, which is directed toward a froth collection launder. Also disclosed is an improvement for froth flotation processes comprising using a vacuum to pull froth and/or collapsed froth into and through the froth collection launder and froth drain line.

Abstract: Process and apparatus are described for adsorptive bubble separation of hydrophobic particles from liquid dispersions. The process may be used to treat the gas/liquid dispersion after it has been introduced from two or more ducts near the perimeter or from a central duct of the separation vessel. When the gas-liquid-particle dispersion is introduced from a central duct, the rising bubbles are directed by, e.g., a baffle toward the perimeter of the apparatus, where they rise. At the liquid surface, bubbles with attached hydrophobic materials form a floating froth layer, which is directed toward a central froth collection launder. Rising froth at the perimeter pushing the froth bed into the reduced area of the center encourages further coalescence of the bubbles and increases liquid drainage from the froth, thus leading to concentration of the collected materials without the need for complex equipment geometry.

Abstract: A method of concentrating particles in a liquid-particle dispersion feed by adsorptive bubble separation by intimately contacting a gas with a pressurized stream of liquid in a chamber to form an aerated dispersion that retains at least some of the kinetic energy from the pressurized stream, and removing at least some of the kinetic energy from the aerated dispersion to form a dense foam. A liquid-particle dispersion feed is then injected into the dense foam to form a gas-liquid-particle dispersion. The gas-liquid-particle dispersion is injected into a flotation chamber at a point below a surface of a liquid contained therein, where the gas-liquid-particle dispersion forms bubbles of a gas-particle agglomerate, and the bubbles are released from the feed liquid depleted in hydrophobic particles and rise to the surface to form a floating froth enriched in particles.