What are the main differences between large cells and small to mid-size cells? Are there any defining specifications for them?
The Delkor Specialised equipment division furnish commercial and pilot plant flotation machines (BQR) now spanning a volume range commonly to 200m3 and in two cases up to 300m3. A useful ratio between volumes of adjacent members of a family of machines is from 1.5:1 to 2:1. The BQR flotation cells should be capable of similar performances characteristics for grade and recovery, with throughput, air, and power requirement predictably proportioned to machine size.
There are not many differences in terms of design between BQR flotation cells. However, from the BQR1000 upwards, the flotation cells have internal launders to maintain the design objectives and benefits highlighted in previous question.
Operating variables, such as impeller speed, air rate, pulp and froth depths have to be adjustable over a sufficient range to provide optimum results with a given ore, grind and chemical treatment, but adjustment should not extend beyond the hydrodynamic regime in which good flotation is possible.
Do large cells operate and perform differently to smaller cells? What applications are the larger cells more appropriate for?
With larger volume machines, and in some cases with a new impeller/Stator mechanism design, however, the rational analysis of design and performance parameters and of scale-up relationship becomes more complicated. The BQR design data show that for one design the volume/size and speed/size relationship are given by VαL3.2 and SαD0.3 respectively for volume below 10m3 while for larger machines with volume up to 100m3 the relationship between V, L, S and D changes while maintaining the similar performances characteristics for grade and recovery, with throughput, air, and power requirement predictably proportioned to machine size.
Where :
- V: effective volume
- S: Impeller peripheral speed
- L: Cell length
- D: Cell Diameter
The performance of larger cells compare to smaller cells is based on the dimensionless number. And the applications for larger cells are more appropriate where there is a need of high tonnage production and mostly in the rougher and scavenging circuit.
Hydrodynamic analysis also known as dimensional analysis was developed by a variety of flotation machines practitioners to allow the design of full-scale machines on the basis of tests using prototypes of a much smaller size. The Dimensionless numbers derived in the dimensional analysis of the BQR flotation machines include:
- The Reynolds number, S
- specific Air Flow number
- Circulation Intensity
- Liquid Rise Velocity
- Power Intensity and Power Number
- Air Flow Number and
- Air Capacity Number
These dimensionless numbers define and differentiate the operation and performance of the large cells to small cells with the same design objectives define above
What are the current dimensions of the largest cells, and will they be increasing in size in future?
The variability in ore, size of grind for liberation, pulp density, reagent pretreatment, machine design and size, operational settings and metallurgical performances requirements for maximum profits warns that the relationship for capacity and performance estimate in terms of other operational parameters can only be approximations. The BQR flotation cell current dimension of the largest cell is shown in the table below. In the near future the BQR2000 and BQR3000 will be available to the market. The complete design of these cells is available and cost associated of a given installation
| Designations |
BQR
1500 |
| Nameplate Volume (m^3)aaaaaaaaa |
150 |
| Diameter (m) |
6.1 |
| Height (m) |
5.98 |
| Total Surface Area (m^2) |
29.22 |
| Effective Surface Area (m^2) |
15.28 |
| Total Volume (m^3) |
174.7 |
| Volume in Internal Launders |
4.08 |
| Volume Lost in Stator Tube |
1.06 |
| Crowder diameter at Surface |
2.5 |
| Volume Lost in Crowder |
2.05 |
| Effective Volume - no air |
167.5 |
| Effective Volume - aerated |
150.8 |
How does the circular design of some flotation cells improve product yield, energy consumption and circulation within the cells? Is automation possible?
Circular cells reduce the amount of dead volume when compared to square cells. This enables a much higher effective pulp volume, hence increasing the effective energy input into the flotation cell. In addition the ‘Tank Type’ flotation cells offer enhanced froth removal due to the uniform shape of the circular launders.
Fully automated flotation cells are becoming more and more common with the aid of smart control and advances in software in the marketplace.
Are there any new releases planned for the near future in the range of Delkor flotation products?
Yes, the new BQR2000 and BQR3000 will be released soon to the market.
If you have any questions regarding our BQR Flotation Cells or any other products please contact us
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