What is gas dispersion?
What is gas dispersion?
Gas dispersion refers to the distribution of air within a flotation cell, i.e. bubble size, air rate, froth stability. These factors play an important role in flotation performance.
Collection zone
Minerals are collected through what can be thought of as a reaction with the surface of air bubbles.
Feed
Bubbles
Response
Increasing the total surface area of bubbles pushes this reaction to the right, increasing reaction kinetics of particle collection. Faster kinetics tends to a more recovery response from the flotation machine.
The control of the total bubble surface area allows for control of the collection zone kinetics.
Froth zone
The froth zone acts to clean collected concentrate of non selective entrained gangue mineral. This cleaning action comes at a cost of recovery. As water drains from the froth, it carries with it entrained mineral, increasing concentrate grade. However, the decreased water content causes bubbles in the froth to become less stable, decreasing concentrate recovery.
Froth structure
Concentrate
Increasing froth stability thus pushes the flotation process to a recovery response, at the expense of concentrate grade.
The control of froth stability allows for control of the tradeoff between concentrate grade and recovery.
Tuning flotation response with gas dispersion.
Control of gas dispersion can tune the flotation machine towards a grade or recovery response.
Collection zone
Froth zone
Flotation Response
For example, if a recovery response is desired, increased reaction kinetics (recovery bias) and a stable froth (recovery bias) should be targeted. If a grade response is desired, decreased reaction kinetics (grade bias) and a less stable froth (grade bias) should be achieved.
This can be achieved through simple operational changes, for example, air rate, froth depth and frother dosage.
Circuit optimization through gas dispersion control.
The tuning of flotation response becomes a powerful optimization tool when implemented over a bank of cells. Gas dispersion parameters can be controlled in both the collection and froth zone to achieve the optimum flotation performance, based on the desired circuit response.
Grade bias
Recovery bias
Flotation bank
While a strict recovery or grade response is straightforward to achieve, gas dispersion control allows for effective control schemes to improve flotation efficiency.
Discover how gas dispersion can improve your flotation process.
Flotation Metrics specializes in measurement, analysis, optimization and control of gas dispersion in flotation processes.
increase flotation efficiency through gas dispersion optimization
Contact us today to explore how Flotation Metrics can increase the efficiency of your flotation operation.