Scrubbers - Pilot Plant Testing
Pilot Work Critical for Sizing
Scrubbers are used as intensive washers to liberate valuable particles or granules and find use for the following areas:
- Processing of wet tropical laterites prior to recovery of Nickel, Cobalt etc. by leaching process.
- Washing of laterites to liberate fine precious metals for gravity recovery.
- Removal of clay from hard rock ores prior to crushing.
- Washing of crushed aggregate, gravel and sand to remove clay contamination.
- Removal of Gold "robbing" natural surface active graphite and other contaminates from Gold Ores.
- Processing of bauxite ores for aluminum production.
- Cleaning of contaminated soil and rubble.
Experience has shown proper test work is critical to the final sizing of rotary scrubbers.
Met-Solve is equipped with a pilot-scale rotary scrubber unit which is optimized for accurate small scale testing. The purpose of a scrubber system is to economically break up agglomerates or lumps in clay or mud like deposits to liberate the target mineral.
The tests are run with pulp densities of 45-60% to allow accurate calculation of water requirement in plant operation. Intermediate results are estimated via examining the slurry after operating at various time intervals, but final completion is accurately assessed by screening, sorting and classifying the material. At the end of each test the scrubber discharge is screened with the screen oversize inspected for any remaining agglomerates.
The unit is equipped with a variable speed drive allowing tests to be performed at speeds ranging from 50-75% critical speed. Speed is often critical as too low a speed can actually promote agglomeration and too high a speed may degrade more friable feed materials
A standard test program will requires 200-300 kg of feed material, preferably sub 100 mm.
The pilot scrubber is a 0.75M x 1.25M. Batch Unit-experience has shown that this is the smallest diameter that can be used to provide accurate scale up. Testing on smaller units has typically led to overly conservative sizing.
