Dry Processing with the Induced Magnetic Roll
For testing dry, free-flowing materials, a High Intensity Bench Top Induced Magnetic Roll (IMR) was supplied. The design of the laboratory-scale IMR allows adjustability in the magnetic intensity in the separation area including:
- A control panel that provides variable flux control to the magnetic coils increasing or decreasing the magnetic intensity;
- A roll speed can be adjusted varying the centrifugal forces on the particles;
- A gap between the roll and the magnetic pole can be adjusted, and the greater the gap the more the magnetic field is reduced;
Magnetic intensities in the separation zone can exceed 2 Tesla. Samples are fed through the machine and two products are collected a ‘magnetic’ and a ‘non magnetic’ fraction which can be weighed, before chemical analysis to evaluate the minerals present in each fraction.
Wet Processing with the Wet High Intensity Magnetic Separator (WHIMS)
For very fine materials (particle size < 65µm), the optimum separation can be achieved when the material is in a wet slurry form. For wet processing, Vito were supplied with a Wet Test Chute with two interchangeable magnet systems:
- A low magnetic intensity Strontium Ferrite magnet system;
- A high intensity Neodymium Iron Boron (Rare Earth) magnet system;
This design is ideal for quick and easy sample testing prior to more complex and in depth analysis.
For testing weakly para-magnetic minerals with fine particle size, a magnetic separator wit a high intensity is required. The Laboratory WHIMS (Wet High Intensity Magnetic Separator) Jaw Type Separator was supplied and enables the treatment of slurry samples to separate weak para magnetic particles.
The Laboratory WHIMS in Operation
A stainless steel canister is placed between two high intensity electromagnetic poles. Inside the canister various matrices can be placed depending on the material being processed. Three wedge wire matrices, made from magnetic stainless steel, are supplied with the equipment with different aperture sizes (4 x 2mm, 3 x 1·5mm & 2 x 1mm), which are selected depending on the particle size of the sample being tested. When placed in a strong electromagnetic field, the sharp edges on the matrices become extremely magnetic, reaching in excess of 2 Tesla. Paramagnetic minerals are then captured on the sharp edges of this matrix.
When conducting a test, a slurry sample is poured through the matrix inside the canister. With the electro magnet turned, any magnetic particles in the flow are retained on the sharp edges within the matrix and the clean slurry is simply collected in a bucket. To ensure that product loss is minimised, at the end of the process the matrix is flushed through with water when the electromagnet is still on.
The bucket is then replaced and the electromagnet turned off so. Water is again flushed through the matrix, removing captured magnetic particles from the sharp edges. Each fraction is then dried, weighed and analysed. A control panel is supplied with the laboratory WHIMS to enable variation of the magnetic field.
Master Magnets have an extensive range of laboratory equipment for mineral processing. Tests can also be conducted at our laboratory in Redditch.
For further information on Master Magnets laboratory or production scale Magnetic Separators for mineral processing please contact us on:
Telephone: +44 (0) 1527 65858