Cavitation Tube spargers are the heart of the patented bubble generation technique used in EFD column flotation cells. The specially designed “CavTubes” are an integral part of the hydrodynamic aeration system used to maximize fine bubble generation and improve bubble-particle collision rates. CavTubes can also be used as part of a pre-aeration system that can be applied independently in a flotation feed line or part of a separate equipment package to increase the recovery of overloaded circuits or improve the flotation response of “hard-to-float” material.
• Aeration of Column Flotation Cells
• Pre-Aeration Systems
CAVITATION TUBE SPARGING
The CavTube design is based on hydrodynamic cavitation. This occurs when the pressure in a moving liquid is momentarily reduced below its vapor pressure, creating ultra-fine air or vapor-filled bubbles. These fine bubbles are carried by the flow to a region of higher pressure resulting in a bubble dispersion that resembles fine smoke. Cavitation and the shearing of additional gas ensure the generation of fine bubbles suitable for the recovery of both ultra-fine and coarser particles.
CavTubes are offered in a variety of materials-of-construction to provide a long wear life. Material selection is based on application specifics and includes polyurethane, ceramic, tungsten carbide and hardened steel.
• Ensure a higher attachment probability... higher recovery of hydrophobic particles
• Produce higher recoveries for ultra-fine material... greater concentrate production
• Improve bubble/particle collision rates... lower reagent costs
• Have no direct impediments to flow... longer wear life with better materials of construction
PICOBUBBLE ENHANCED FLOTATION
Ultra fine bubbles naturally exist in liquids and can be created through dynamic cavitation. These picobubbles readily attach to hydrophobic particles due to their lower ascending and rebound velocities and the improved free-energy conditions. Combining cavitation-induced bubble generation with mechanically generated bubbles produces higher flotation recoveries than by either method alone. This synergistic effect is caused by the nucleation of picobubbles on the particle surface.
Picobubbles improve the flotation response by acting as a secondary “collector,” enhancing the bubble-particle attachment probability and reducing detachment. Cavitation-Tube sparging systems have been demonstrated on an industrial scale in base metals, sulfides and non-metallic applications. These installations have yielded improvements in recovery, reagent consumption and wear.