Description

The Rare Earth Roll Separator (RE Roll)

The Rare Earth Roll Magnetic Separator (RE Roll) is a two-pulley conveyor system with the head pulley constructed out of alternating rings of permanent Neodymium Iron Boron (NdFeB) Rare Earth Magnets and steel pole pieces. High separation efficiencies are generated by the design of the magnetic roll assembly utilising high-grade neodymium magnets and the optimum pole spacing to generate high magnetic field strengths and magnetic field gradients to maximise the magnetic force exerted on a particle as it passes over the roll.

The ultra-strong magnetic head roll of the RE Roll enables the separation of ferromagnetic, paramagnetic and weakly magnetic minerals such as muscovite mica.

The RE Roll is often preferred to other high-intensity magnetic separators (such as the Induced Magnetic Roll Separator) as the magnetic field is produced with permanent magnets and not electromagnets. This significantly reduces both operating and capital investment costs.

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Operation

In operation, a dry non-metallic mineral mix, sized between 75 microns and 15mm, is fed evenly and thinly via a Vibratory Feeder onto a short-centred and thin conveyor belt. As the material moves into the separation zone of the magnetic head pulley, magnetically-susceptible minerals are attracted towards the high-intensity steel poles. Non-magnetic material continues to flow in a normal trajectory, whilst the trajectory of minerals affected by the high-strength magnetic field is altered. With a carefully positioned splitter, the two fractions – magnetically susceptible minerals and non-magnetics – are separated from each other. In some applications, it is possible to create a third ‘middlings’ fraction constituting weakly magnetic minerals (e.g. muscovite mica).

The trajectories of all fractions are controlled and adjusted by changing the speed of the conveyor belt via an inverter in the main control panel.

Models

The Rare Earth Roll Magnetic Separator (RE Roll) has a 200mm diameter head roll, with a maximum width of 1000mm. Multiple configurations of rolls are offered to give the non-magnetic fraction a further pass for improved product purity.

Applications

The Rare Earth Roll Magnetic Separator (RE Roll) was originally developed to purify dry non-metallic minerals. However, the ultra-strong magnetic properties have more recently been utilised in recycling applications such as purifying plastic waste and in the recycling of batteries.

The optimum particle size for the RE Roll is between 75 microns and 15mm, although it is important to maintain a tight particle size distribution to maximise separation performance. Specific applications include:

Mineral Processing
- Feldspar
- Silica Sand
- High-purity quartz
- Garnet
- Talc
- Abrasive and refractory minerals including Corundum
- Beach Sands (ilmenite, etc)
- Fine iron ores
Ceramics
- Removing free fine iron from Spray Dried Ceramics;
Recycling
- Cullet (crushed glass)
- Granulated steel slag
- Granulated plastic waste
Plastics
- Removing plastic beads containing fine iron spots