Fluidized Bed Flotation Cell for Coarse Particle Recovery
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Solution Overview
Problem
Current froth flotation technologies face limitations in recovering coarse particles due to high turbulence in flotation cells, which causes detachment of particles from bubbles, and existing solutions either rely on mechanical agitation or require clean water, which is scarce and costly.
Innovation Solution
A method and apparatus utilizing a fluidized bed with controlled bubble introduction and recycle fluid to minimize turbulence, allowing hydrophobic particles to attach to bubbles and rise gently into a settling chamber, where they form a froth layer for separation, while reducing water consumption by using recycled fluid for fluidization.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If mechanical agitation or conventional flotation cells are used to keep particles in suspension and disperse air flow, then particles can be suspended and bubbles can be dispersed, but high turbulence is generated that causes coarse particles to detach from bubbles
Solution Approach 1:
The harmful turbulent motion is extracted and removed from the flotation cell by eliminating the impeller. The patent uses a static column design where particles are suspended by upward fluid flow and bubbles are dispersed by spargers, completely removing the source of turbulence that causes coarse particle detachment
Solution Approach 2:
The mechanical impeller system is replaced with a fluid-driven system. Instead of using mechanical agitation to suspend particles and disperse bubbles, the patent uses upward fluid flow to suspend particles and spargers to disperse bubbles, eliminating mechanical turbulence
2Object-affected harmful factors
If flotation columns are used to avoid mechanical agitation, then turbulence is reduced, but turbulent motions still arise from convection currents that can rupture bubble-particle aggregates
Solution Approach 1:
The harmful convection currents are extracted and eliminated by designing a system where upward fluid flow is controlled and uniform. The patent uses a distributor at the base to create smooth upward flow and spargers to generate bubbles that rise without creating turbulent convection, removing the source of bubble-rupturing currents
3Manufacturing precision
If clean water is used for fluidization to improve particle separation, then separation efficiency increases, but water consumption increases which is costly and unsustainable
Solution Approach 1:
Water is recovered and recycled within the system. The patent designs the flotation cell with an overflow outlet that collects water, which is then returned to the system for continued use in fluidization and bubble generation, eliminating the need for continuous fresh water input while maintaining separation efficiency
Solution Approach 2:
The water in the system serves multiple functions: it suspends particles, disperses bubbles through spargers, forms the continuous phase for flotation, and is recycled for continued use. This multi-functional use of water reduces overall consumption while maintaining process efficiency
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach significantly improves the recovery of coarse particles by eliminating turbulence and reducing water usage, enabling the capture of larger particle sizes with high efficiency and maintaining high capture rates across various particle sizes, while minimizing water requirements.
Implementation Method 1
making the surfaces of the values non-wetting or hydrophobic... The values adhere to the bubbles, which carry them to the surface and into the stable froth layer
Implementation Method 2
Air bubbles are then introduced into the suspension... the bubbles rise and disengage from the liquid... the values adhere to the bubbles, which carry them to the surface
Implementation Method 3
While moving towards the overflow lip, the froth drains and entrained particles are able to flow back into the pulp, enhancing the purity or grade of the flotation product
Data Source
AI summary
Separation of hydrophobic particles from a mixture of particles in a fluid is performed by providing a fluidized bed as a relatively non-turbulent contacting mechanism in a flotation cell incorporating a settling chamber located immediately above the fluidized bed. Hydrophobic particles attach to bubbles in the fluidized bed and rise to the interface with the settling chamber where non-hydrophobic particles flow over the lip of an internal launder and are removed as tailings at. The hydrophobic particles attached to bubbles float upwardly in the relatively placid settling chamber where unwanted gangue can fall back to interface. The bubbles form a froth layer at the upper surface of the settling chamber, and flow over the launder lip carrying the hydrophobic particles. An operation of the apparatus is kept stable by recirculating fluid from the settling chamber via pip and pump to mix with new feed entering at duct.