Full-scale plant trials conducted by Eriez verifies that low-profile StackCell flotation technology provides coal recoveries and product qualities comparable to column flotation systems.
Two full-scale approaches were implemented: a single unit rougher application and a three-stage, in-series arrangement.
In the rougher application, the StackCell was able to successfully offload an existing overloaded flotation circuit, which resulted in an increase in combustible recovery in excess of 90 percent.
The metallurgical results in the three-stage circuit demonstrate that StackCells, when arranged in-series, effectively meet design requirements at a satisfactory combustible recovery, product carrying capacity and product ash content.
Developed in the early 2000s, StackCell offers a cost-saving alternative to both conventional and column flotation machines. These unique units feature a small footprint and operate with a gravity-driven feed system which allows cells to be easily stacked in-series or placed ahead of existing conventional or column ﬂotation cells.
The StackCell design takes advantage of a patented independent contacting chamber. Feed slurry and air enter this chamber and are subjected to intense shear mixing to generate bubbles and provide contacting with the hydrophobic species. Particle collection is achieved in this section and the slurry is subsequently discharged into a quiescent phase separation chamber.
StackCell provides numerous economic benefits. Since the design focuses energy specifically on creating bubbles within the aeration chamber, the total energy input to the system is approximately half that required by conventional machines.
Additionally, when plant space and/or capital is limited, the small size and low weight of this new technology makes it amenable to low-cost plant upgrades where a single unit can be placed into a currently overloaded flotation circuit with minimal retrofit costs.