A processing system for separating raw slurry material into particulate materials and liquid materials comprising a processing structure, a frame, and a drive motor. The processing structure defines a processing chamber, an inlet, an outlet, and at least one pre-processing opening arranged between the inlet and the outlet. The frame supports the processing structure. Operation of the drive motor rotates the processing structure such that at least some of the particulate materials in the raw slurry material are transported from the inlet to the outlet, at least some of the liquid materials in the raw slurry material are allowed to flow back towards the inlet, and at least some of the liquid materials and at least some of the particulate materials are allowed to flow through the at least one pre-processing opening.