Leading permanent magnetic separator

The leading permanent magnetic separator is not just a ferromagnetic impurity removal equipment. It is a precision instrument that determines the purity of the final product, the service life of crushers and conveyors, and compliance with GOST 32510–2013 and ISO 8502-3 requirements for iron content in bulk materials. We saw how at one cement plant in the Belgorod region the replacement of an outdated electromagnet with a modernleading permanent magnetic separatorreduced crushing line downtime by 47% in the quarter. Cause? Reliability, no power consumption and stable induction - even with dust, moisture and temperature changes from -25 °C to +60 °C.

Why “leading” is not marketing, but technical status

The term “leading” in Russian practice is applied to separators that are installed directly at the inlet of the production line - before crushers, mills, screws or feeders. They “lead” the flow: they are the first to accept material, set the cleaning regime and prevent emergency situations. Such devices must withstand shock loads, high abrasiveness and continuous operation 24/7. For most competitors, this means a compromise: either high induction (up to 12,000 Gauss), but weak mechanical protection of the housing, or a durable steel casing - but with induction below 7,000 Gauss. The leading permanent magnetic separator from LONGI Corporation solves both problems simultaneously: the body is made of 304 steel with a reinforced frame, and inside there is a combination of N52 neodymium magnets and samarium-cobalt elements, providing a working induction of 11200-11800 Gauss at the surface of the pole. We tested this at the stand in Fushun: when loading 120 t/h of granite crushed stone with the inclusion of M12x80 steel bolts, there was 100% capture without slippage.

Where does it work - and where should you not install it?

This type of separator is only effective under certain conditions. It requires free fall of the material - a minimum of 300 mm in height between the exit from the bunker and the entrance to the magnetic field zone. It should not be installed downstream of dense-bed vibratory feeders or in pressure piping. But where there is a tape, gutter or free discharge, it becomes indispensable. We recorded the best results in three scenarios:

• At the entrance to cone crushers - catching pieces of rivets, lining fragments and reinforcement scraps;
• Before vertical mills in cement production - protection of rollers from chipping and premature wear;
• On recycling lines, removal of nails, staples and wire fragments from wood and plastic waste.

However, if the flow is dominated by weakly magnetic impurities (for example, iron oxides in quartz sand), a single leading permanent magnetic separator is not enough. A two-stage design is required: first a high-power permanent magnet, then a variable-force electromagnet or high-intensity roller separator.

How to choose a specific model - 4 parameters that cannot be ignored

The choice depends not on marketing names, but on four measurable characteristics:

1. Working area width: must exceed the width of the tape by 100–150 mm - otherwise there will be “closing” of the edges of the flow;
2. Field penetration depth: for large fractions (>50 mm) ≥250 mm is required, otherwise impurities at the bottom of the flow are not captured;
3. Magnetic system inclination angle: optimally 45–60° relative to the direction of flow - ensures retention and subsequent removal of impurities without “clogging”;
4. Self-cleaning system: manual removal - only for rare cases; automatic (with a pneumatic cylinder or electric drive) - required when the reset frequency is >1 time per hour.

LONGI Corporation produces seven basic versions of leading permanent magnetic separators - from the compact PMS-600 (for 600 mm belts) to the heavy PMS-2200 (for belts up to 2200 mm, weight up to 3.8 tons). All models undergo 72-hour testing on a vibration stand and have a 5-year warranty on the magnetic system.

What remains behind the scenes - and why it is important

Some people think: “a magnet is all.” But we know: real reliability begins where the catalog ends. For example, when installing a leading permanent magnetic separator, the rigidity of the fastening is critical. Even 0.5 mm of play in the anchor bolts causes resonance at 1200 rpm of the crusher - and within 3 months a microcrack occurs in the weld. We recommend using fastener kits with torque control and mandatory checking of the horizontal installation with a laser level. Also, do not skimp on damping pads under the base: they reduce the transmission of vibration to the magnetic system by 68%. This information is rarely indicated in the passport, but it decides whether the equipment will work for 5 years or fail after 8 months.

The leading permanent magnetic separator is not a consumable, but an investment in production stability. It requires no electricity, has no moving parts and requires no daily maintenance. Its effectiveness is measured not in percent recovery, but in hours of downtime saved, no emergency repairs, and the quality of the finished product. Selection, installation and operation is a process where every detail is important. Information on technical solutions, drawings and delivery conditions can be found on the websiteljmagnet.ru.