Overflow Flotation Cell Upward Slurry Flow for Coarse Ore Recovery

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Solution Overview

Problem

Conventional froth flotation methods are inefficient in recovering coarse valuable ore particles due to their low contact angle with air bubbles, leading to particle dropback at the pulp/froth interface and increased energy consumption in grinding and classification processes.

Innovation Solution

The method involves grinding and classifying ore particles to create a slurry that is treated in overflow flotation cells with a continuous upwards flow, allowing coarse particles to be carried by the slurry flow and recovered without the need for buoyancy, thus eliminating the requirement for uniform particle size and reducing energy consumption.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If conventional froth flotation is used to separate valuable ore particles, then fine particles can be recovered, but coarse particles experience particle dropback at the pulp/froth interface due to low contact angle with air bubbles

Engineering Contradiction:
Improveparticle separation efficiencyVSAvoidcoarse particle recovery
Core Design Contradiction:
Manufacturing precisionVSReliability

Solution Approach 1:

Instead of relying on buoyancy force from air bubbles to lift coarse particles (conventional approach), the invention inverts the mechanism by using a continuous upwards slurry flow to carry particles upward. This flow-based transport eliminates the particle dropback problem at the pulp/froth interface that occurs with bubble-based flotation.

Inventive Principle:
Principle #13The other way round (Inversion)

Solution Approach 2:

The invention transitions from pneumatic bubble-based flotation to hydraulic flow-based separation. A continuous upwards slurry flow is generated through the flotation cell, using fluid dynamics to transport both fine and coarse particles upward without relying on air bubble attachment, thereby eliminating the contact angle limitation.

Inventive Principle:
Principle #29Pneumatics and hydraulics

2Manufacturing precision

If grinding and classification are performed to achieve uniform particle size for conventional flotation, then flotation efficiency improves, but energy consumption increases

Engineering Contradiction:
Improveparticle size uniformityVSAvoidgrinding energy consumption
Core Design Contradiction:
Manufacturing precisionVSUse of energy by moving object

Solution Approach 1:

The invention changes the operating parameters of the flotation cell to enable handling of varying particle sizes. By adjusting the continuous upwards slurry flow rate and other process parameters, the system achieves effective separation without requiring uniform particle size, thereby reducing grinding energy consumption while maintaining separation efficiency.

Inventive Principle:
Principle #35Parameter changes

3Quantity of substance

If a deep froth layer is formed in conventional flotation cells, then fine particles are captured, but coarse particles detach from bubbles and fall back to the bottom

Engineering Contradiction:
Improvefine particle recoveryVSAvoidcoarse particle recovery
Core Design Contradiction:
Quantity of substanceVSReliability

Solution Approach 1:

The invention extracts the harmful froth layer that causes coarse particle dropback. By operating without forming a deep froth layer and instead using a continuous upwards slurry flow, the system eliminates the interface where coarse particles detach and fall back, while still achieving effective separation through the flow mechanism.

Inventive Principle:
Principle #2Taking out (Extraction)

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 enables efficient recovery of coarse valuable ore particles with increased mass pull and reduced energy consumption, allowing for larger flotation cells and varying particle size distributions, while minimizing water usage and maintaining high recovery rates.

Implementation Method 1

At least part of the valuable metal containing ore particles are adhered to the gas bubbles and rise upwards by buoyancy

Methodology Applied
Scientific EffectBuoyancy: Archimedes' Principle (Buoyancy)

Implementation Method 2

at least part of the valuable metal containing ore particles are adhered to the gas bubbles and rise upwards with the continuous upwards flow of slurry, and at least part of the valuable metal containing ore particles rise upwards with the continuous upwards flow of slurry

Methodology Applied
Scientific EffectFluid flow:

Data Source

PatentEP3496864B1Flotation method
Publication Date: 2022.07.27 METSO OUTOTEC FINLAND OY
  • EP3496864B1 patent drawingFigure 1~2
  • EP3496864B1 patent drawingFigure 3
  • EP3496864B1 patent drawingFigure 4

AI summary

A flotation method for recovering valuable metal containing ore particles from ore particles suspended in slurry is disclosed. In the method, the slurry is treated in an at least one overflow flotation cell (41) and the valuable metal containing ore particles are recovered by conducting the continuous upwards flow of slurry out of the at least one overflow flotation cell (41) as slurry overflow (412, 422, 432). At least part of the slurry overflow (412, 422, 432) is conducted to a further treatment step in a treatment system.