Sorting line for separation of ferromagnetic adulterants coming from magnezite (garnet) sand
Compound of the line
Case study
Principal types of challenges
- unique properties of the magnezite (thus garnet) sand make it to be raw material with an extraordinerily wide spectrum of applications (in food processing industry, pharmaceutical industry, agriculture, but also e. g. in nuclear energetics). The processor has appealed to SOLLAU s.r.o. with a requirement of removing the undesirable adulterants (being of fraction of 2 mm maximum), but whereas it was essential to separate not only the fine ferromagnetic particles (especially the scraps and abrasion of the devices used at crushing garnet sand) but also non-magnetic adulterants (earth, wood etc.)
- high processing capacity (up to 5 tons/hour)
- continuous (uninterupted) production process required the application of separators with automatic cleaning
Solution provided by SOLLAU s.r.o. company: a compact assorting line that has solved the problem in two stages has been delivered. As first the material is dosed uniformly by a vibrating feeder on MBZ neodym covered drum separating all undesirable strongly magnetic adulterants (bits and scrapping of machinery). In stage two the cleaning process is based on the fact that garnat sand itself is very weakly magnetic (or even paramagnetic). Consequently during this stage the material free from ferromagnetic particles goes through extremely strong magnetic field (up to 11,000 G) of VMSV roller poled radially catching the weakly magnetic particles of garnat sand and carrying them away even behind the axis of the roller to be processed further. Non-magnetic material (scraps of wood, earth etc.) falls off spontaneously by the effect of gravitation at the end of the belt into a discharging manifold. The client was satisfied both with the high effectiveness of the delivered solution and with the relative simplicity of the delivered technology removing magnetic and non-magnetic contaminants out of the final material on a relatively small area.
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SOLLAU certifications:
Authorization to perform welding on pressure equipment according to PED 2014 / 68 / EU
Pressure welder certificate according to EN-ISO 3834 - 2, EN 1090 - 2, EN 13480 - 1 to 5, EN 13445 - 1 to 5
The line is designed for processors of magnesite (garnet) sand with a fraction of up to 2 mm, who need to remove unwanted impurities from this material and obtain a final product of the required purity. Magnesite sand is used in the food industry, pharmaceuticals, agriculture and nuclear energy — the extraordinary breadth of application places high demands on the purity of the output raw material. The line processes up to 5,000 kg of material per hour.
The line simultaneously addresses two different types of impurities: strongly magnetic ferromagnetic particles (fragments and wear from metal equipment used in sand crushing) and non-magnetic contaminants (clay, wood and other organic residues). The result is three output streams — ferromagnetic fraction, non-magnetic waste, and clean magnesite sand as the final product.
Both types of contaminants require physically different capture methods. Strongly magnetic Fe impurities are removed by the enclosed neodymium drum MBZ in the first stage. Non-magnetic impurities (clay, wood) cannot be removed magnetically — they are separated gravitationally at the end of the conveyor, while the weakly magnetic garnet sand is captured by the extremely strong field of the multi-stage magnetic roller VMSV and directed for further processing. Each stage fulfils a different function; without both, it would be impossible to achieve the required purity of the final product.
The vibratory feeder uniformly feeds material onto the enclosed neodymium drum MBZ. Strongly magnetic ferromagnetic fragments (metal fragments and wear from machining equipment used in the sand crushing process) are captured by the drum's magnetic field and directed into a separate chute, while the remaining material continues to the second separation stage. The enclosed design of the MBZ drum ensures safe and clean separation of captured metal impurities from the stream of processed material.
The multi-stage magnetic roller VMSV creates an extremely strong magnetic field (up to 11,000 G) with radial polarisation. Garnet sand is weakly magnetic (paramagnetic) — this property is sufficient for the extremely high field gradient of the VMSV to capture it and carry it over the roller axis for further processing. Non-magnetic impurities (clay, wood) are not affected by the magnetic field and naturally fall by gravity into the chute at the end of the belt. The result is clean garnet sand separated from the non-magnetic waste.
Garnet sand is only paramagnetic — its magnetic susceptibility is significantly lower than that of metals. Standard magnets designed to capture ferromagnetic or mildly magnetic materials would not exert sufficient force on garnet sand. The multi-stage magnetic roller VMSV with an induction of up to 11,000 G creates a sufficiently strong field gradient to reliably capture such weakly magnetic particles in continuous industrial operation at high capacity.
Yes. Both separators — the MBZ drum and the VMSV roller — are equipped with an automatic cleaning system that continuously removes captured fractions without interrupting the material flow. The line is therefore suitable for continuous industrial operation without the need for regular shutdowns for manual cleaning. The capacity of up to 5,000 kg/h allows deployment even in demanding industrial operations with high throughput requirements.
The delivery covers the entire process — from site inspection, design and custom manufacturing through assembly, commissioning and operator training, including authorised service throughout the lifetime of the equipment. We provide a 5-year warranty on the magnetic core of the MBZ separation drum. Before ordering, we offer free testing of your material with a guaranteed completion time of three days.