The AAC Pumpcell mechanism combines the functions of pumping, screening, and agitation in a single drive unit operating within a high capacity contactor. A typical AAC Pumpcell arrangement incorporates a series of pumpcells set at the same elevation and arranged to operate in a carousel mode. This approach has significant cost and operational benefits in comparison with a comparable conventional cascade CIP adsorption circuit.

As the AAC Pumpcell operates in a carousel mode, improved resin management is achievable when compared to a conventional counter current arrangement. By eliminating the need to pump resin upstream, the amount of resin handling required is reduced and this, in turn, positively impacts on resin consumption rates.

The carousel mode of operation is based on keeping the carbon a discreet batch within each contactor. To facilitate the carousel mode of operation, the circuit infrastructure is designed in such a way that each contactor can be the head or tail contactor. Consequently, high grade pulp is directed via the feed launder to the designated head contactor. Pulp exiting this contactor is directed to the next contactor in the sequence. This movement of the pulp continues until it exits the tail contactor in the carousel sequence. Residue pulp exits the tail contactor and is directed via the residue manifold to the residue section.

Once the loaded carbon grade in the head contactor has reached the desired gold on carbon loading, this contactor is isolated and the high grade pulp is directed to the next contactor in the carousel sequence. The contents of the original head contactor is drained and screened to recover the loaded carbon. On completion of the draining and screening cycle, the original head is brought on line as the new tail contactor in the carousel sequence.

Regenerated or virgin carbon is added to the new tail contactor, while in the process of being filled with pulp received from the original tail contactor.

The carousel mode of operation is based on operating the plant in a batch format in which the head and tail contactors are rotated in a carousel mode. This simulates the counter current movement of carbon relative to pulp without physically having to pump carbon through the circuit.

The carousel mode of operation improves carbon management and stage adsorption efficiencies.

The MPS screen relies on gravity to create a pulp height differential in order to facilitate the flow of pulp to the next stage in the adsorption circuit. The MPS(P) screen is equipped with a pumping impeller that pumps pulp to the next stage in the adsorption circuit.

Consequently, the MPS(P) screen is typically used when the adsorption tanks are all located on the same elevation, whereas the cascade arrangement is used for the MPS screen.

The benefit of the MPS(P) screen is that capital cost savings associated with the civil installation are realised on circuits that have all adsorption tanks on the same elevation.