Cheap High Frequency Dry Drum Magnetic Separator

A cheap high-frequency dry drum magnetic separator is not a marketing phrase, but a technical reality for processing enterprises, where every thousand rubles in capital costs affects the payback period. We have seen more than once how customers choose “cheap” equipment, and six months later they are faced with overheating of the rotating drum, a drop in induction at 45°C and a sudden disappearance of the separation of fine quartz sand fractions. This is because “cheap” in this niche is not a minimum price, but an optimal ratio of three parameters: magnetization frequency, field stability and structural resistance to dust and vibration.

Why does the high-frequency mode solve the problem of cleaning without water?

Dry magnetic separation is effective only when the magnetic field has time to “capture” the particle before it is carried out by the air flow or belt. For low-frequency systems (up to 50Hz), the response time exceeds 15-20ms - this is not enough for particles with a size of 0.075-0.3mm, especially at feed rates above 8t/h. High-frequency separators of the LONGI corporation operate in the range of 120–200 Hz. This reduces the magnetization cycle time to 4–6ms. As a result, even weakly magnetic impurities - hematite, ilmenite, oxidized iron powder - are held above the surface of the drum with a force exceeding the aerodynamic resistance by 3.2 times.

We tested the LJ-DRM-1200 model at a secondary quartz processing plant in the Chelyabinsk region. With a material moisture content of up to 0.8% and a Fe₂O₃ content of 0.19%, the yield of the purified product was 94.7%, and the residual iron in the final sand was 0.021%. Key Point: The system remained stable without adjustment for 72 hours of continuous operation. Not a single analogue with a frequency below 100Hz passed this test.

“Cheap” does not mean saving on steel, but avoiding excess

Some manufacturers reduce the price by reducing the thickness of the magnetic core or replacing neodymium segments with ferrite ones. Such solutions provide a “cheap” separator, but notcheap high frequency dry drum magnetic separator. LONGI Corporation uses a hybrid system: NdFeB magnets in the active capture zone and high-carbon alloy steel in the drum body. This allows you to maintain induction of 0.85–0.92 T at temperatures up to 75°C - critical for long shifts.

Here are three points where we consciously abandoned excess:

Without water cooling system- instead - enhanced ventilation with temperature sensors in each sector of the drum;
No multi-level clearance adjustments— fixed gap of 25 mm, designed for 92% of standard materials;
Without PLC control "by default"— the basic version operates from a push-button remote control, and a PLC is added only upon request.

This reduces the cost of the LJ-DRM-1200 by 28% compared to similar products in its class, without sacrificing reliability. Average service life is 12 years with daily use of 16 hours.

What you really need to start - and what you shouldn’t be afraid of

Installation does not require a foundation. The drum is attached with anchor bolts to the existing steel platform. Minimum requirements: three-phase power supply 380V ±5%, frequency 50Hz, power 7.5kW. No additional pumps, tanks or water treatment plants - it's a dry separator and stays dry at all stages.

Mistakes begin when designers ignore two factors:

Feed funnel angle: more than 22° causes “jumping” feed and reduces separation efficiency by 14–19%;
Distance from drum to output tray: over 350mm leads to the scattering of small fractions and re-entry into the flow.

Drawings of typical mounting units and videos with measurements of angles and distances are available on the website ljmagnet.ru - all filmed on real objects.

Conclusion: cheap - when you don't pay for what you don't use

The low-cost, high-frequency dry drum magnetic separator is a piece of equipment that does not require constant intervention, does not create secondary maintenance costs and does not limit your production flexibility. It works where water is prohibited, where dust is the norm, and stability of parameters is a condition for production. LONGI Corporation does not make “budget copies”. She makes technically sound decisions: with clear boundaries of application, documented tests and support in Russian. If your task is to clean the material from weakly magnetic impurities quickly, dryly and without hidden costs, such a separator is already ready to start. And it really costs less than you thought.