A processing system for processing raw slurry material comprising a barrel member defining a feed portion, a processing chamber, and an outlet opening, at least one pre-processing member, and at least one pre-processing opening formed in the barrel member adjacent to a first portion of the pre-processing member. As the barrel member rotates, the at least one pre-processing member transports at least a portion of the raw slurry material such that at least some of the heavy particulate material in the raw slurry material is transported to the outlet opening, at least some of the liquid material in the raw slurry material is allowed to flow back towards the feed portion, and at least some of the liquid material and at least some of the light particulate material is allowed to flow through the at least one pre-processing opening.
