Eriez' CrossFlow Separator is a highly efficient hydraulic classifier for the separation of material based on particle size, shape and/or density. This technology can also be used for desliming, counter-current washing and acid neutralization of minerals. The CrossFlow separates particles based on hindered-settling principles providing an economical and efficient means of classifying material such as silica and frac sands, mineral sands and industrial minerals. Ores containing a mixture of high- and low-density components can also be upgraded based on their difference in specific gravity. Examples include iron ore, and heavy mineral with silica contamination and run-of-mine coal containing various ash-forming components such as rock and pyrite. The hindered-settling environment creates the optimum conditions for efficient counter-current washing to rinse, clean, and neutralize ore prior to secondary unit operations.