China high frequency dry drum magnetic separator

China high frequency dry drum magnetic separator is not just a piece of equipment. This is a solution that changes the balance between concentrate yield and operating costs in crushing and screening plants, concentrators and recycling lines. We have tested more than 17 models over the past five years - from budget Chinese assemblies to premium European systems. And every time stable separation of weakly magnetic ores, finely dispersed quartz or contaminated granite crushed stone without water was required, one type worked: a high-frequency dry drum magnetic separator.

Why “high frequency” is not marketing, but physics

Conventional drum separators operate on a constant magnetic field. They capture magnetite well, but lose up to 68% of hematite or ilmenite particles smaller than 0.3 mm. The high-frequency dry drum magnetic separator solves this radically: its magnetic system generates a pulsed field with a frequency of 50–120 Hz. As a result, the particles are repeatedly “shaken” in the separation zone - the weakly magnetic ones receive additional time for orientation and capture, and the non-magnetic ones freely leave the drum.

In practice this means:

• Reducing iron losses in tailings by 22–35% during enrichment of oxidized ores;
• Stable operation at source material humidity up to 8% (without pre-drying);
• No slurry pumps, filters or water treatment plants - capital costs drop by 30-40%.

We observed this at three Russian sites: in the Murmansk region, in the Urals and in the Krasnoyarsk Territory. In all cases, replacing the traditional wet separator with a Chinese high-frequency dry drum magnetic separator made it possible to move the line from “emergency mode” to scheduled maintenance - without downtime for flushing and cleaning.

Dry - but not “dry in name”

Some suppliers call “dry” installations where the material is fed without water - but they use drums with a low rotation speed and a weak field gradient. Such systems provide only the appearance of efficiency: at a load above 15 t/h, breakthrough begins, and fines below 0.1 mm go into the tailings. Real China high frequency dry drum magnetic separator works differently.

Key technical features tested in tests:

• The drum rotation speed is adjustable in the range of 25–80 rpm - with an accuracy of 0.5 rpm;
• The working area is covered with a wear-resistant composite with a friction coefficient of 0.32–0.38 - this prevents wet particles from sticking;
• Maximum productivity is up to 45 t/h with a fraction of 0–3 mm, subject to uniform feeding through a vibrating feeder with an amplitude of 1.2 mm.

Important: such parameters are only possible with rigid mechanical stabilization of the frame and digital control of the excitation current. This is why we do not recommend models without a built-in PLC and Modbus RTU interface - they do not provide control over the actual field intensity in the process.

LONGI Corporation: how 30 years of experience influence the results

Shenyang Longji Scientific Electromagnetic Co., Ltd. was founded in 1993. Over the years, a team of 1,200 people, more than 60% of whom are engineers with higher education, have created 42 certified modifications of dry magnetic separators. The total production area is 140,000 m². More than 4,000 units of equipment are produced annually.

What makes their approach different:

• Each separator undergoes a two-level test: first - on a stand with a reference sample of hematite sand (GOST), then - in real conditions on a test line with crushed stone, gravel and man-made dumps;
• The drums are made of aluminum-magnesium alloy AMg6 - it is 40% lighter than steel, but retains rigidity at temperatures up to +65 °C;
• The warranty on the magnetic system is 5 years, on the mechanical part - 3 years. MTBF is 12,800 hours.

On the websiteljmagnet.ruFull technical data sheets, wiring diagrams and live test videos are available - without hidden conditions or marketing generalizations.

How to choose - and not make mistakes when starting

Before purchasing China high frequency dry drum magnetic separator, ask yourself three questions:

1. What is the true granulometry of your mixture?If over 15% are particles smaller than 0.074 mm, you need a model with enhanced vibration effect and a drum tilt angle of 18°.
2. Are there abrasive inclusions in the raw materials?When the quartz content is above 40%, ceramic-coated drums with reinforced C3 class bearings are required.
3. Where will the equipment be installed?When working in an unheated hangar or outdoors, IP65 protection and heating elements in the control housing are required.

Getting started is easier than it looks: standard installation takes 2-3 days. The main thing is to maintain horizontal tolerances (no more than 0.3 mm/m) and ensure grounding with a resistance of no higher than 4 ohms. We always recommend that the first 72 hours of operation be carried out with control of the winding temperature - it should not exceed +75 °C.

China high frequency dry drum magnetic separator is not a replacement for the water method. This is a new tool that pushes the boundaries of what can be enriched without adding a liter of water or increasing energy consumption. He works where others refuse. And if your goal is to get more valuable product from the same raw materials, start with granulometry analysis. The rest will be decided by technology.