The Derrick® Stack Sizer® wet screening machine has revolutionised fine wet screening in the processing of minerals and metal ores. Thousands of Stack Sizers are currently in use worldwide.

Its popularity is due to the increased efficiency achieved, as well as the improvement of product quality, reduction in variability and improved downstream processes.

With up to five decks positioned one above the other and operating in parallel, the Stack Sizer screen offers mineral and metal ore processors both high-capacity and high-efficiency separation in a small footprint. Derrick designed the Stack Sizer machine-based on the screening principle that screen width is more important than screen area for efficient screening. To achieve efficient fine sizing, the feed slurry should be approximately 20% solids by volume. The liquid passes through the screen rather quickly allowing the fine screening process to be completed in a rather short screen length.

When most the fluid carrying undersized particles has passed through the screen openings the process is complete. To maximise the correct placement of particles, a repulping system is available. The system, located between the two panels on each deck, reslurries the particles from the first panel so they are further screened on the second.

When used with Derrick Polyweb urethane screens, the Stack Sizer screen’s performance is unrivaled. The non-blinding, abrasion-resistant urethane screens can last between ten and 15 times longer than conventional woven wire panels.