Cheap demagnetizer for magnetic separators

A cheap demagnetizer for magnetic separators is not a marketing ploy. This is a real need in processing plants, where ferromagnetic particles cement work surfaces, clog cracks in drums and reduce concentrate purity by 3-7%. We have seen this dozens of times: after 4–6 months of continuous operation without demagnetization, the efficiency of the separator drops by a third. But replacing the magnetic system is expensive and stopping the line costs tens of thousands of rubles per hour.

Why “cheap” is not a synonym for “unreliable”

There is a persistent misconception: a cheap demagnetizer means low current, low frequency, and quick failure. In practice, everything is different. The key is choosing the right type and parameters. For stationary drum separators (for example, LMS-1000 or analogs), a pulsed demagnetizer with a current amplitude of up to 800 A and a damped oscillation frequency of 150–250 Hz is sufficient. Such devices do not overheat, do not require water cooling and operate from a standard three-phase 380 V network.

We tested three models at an ore processing plant in the Kemerovo region. Two Chinese samples failed within 4 months - one due to overheating of the power transistor, the second due to incorrect pulse time settings. The third one - from the LONGI corporation - has been working without downtime for 18 months. Its feature: a digital controller with adaptive adjustment of the duration of the demagnetizing pulse to the load and ambient temperature.

The price here is really lower - by 22–35% compared to European analogues. But the savings were achieved not due to components, but due to the optimized architecture: the absence of an intermediate voltage converter, an integrated MINE current sensor, an aluminum alloy housing instead of steel. No “quality cuts”. Only clear engineering logic.

Where and how it is installed - without a project and month-long downtime

The demagnetizer is not built into the separator. It is connected in parallel to the electromagnet winding through a special switching unit. Installation takes 4–6 hours. The main condition is the availability of free space next to the separator control panel and access to the grounding bus.

Here's what we check before installation:

• Rated separator winding current (typically 12–45 A)
• Winding inductance (from 0.8 to 3.5 H)
• Availability of a contactor with break contacts class AC-3
• Mains voltage stability (permissible range ±10%)

If these parameters are known, you can start working on the same day. We do not require a complete shutdown of the production line. It is enough to put the separator into idle mode, turn off the power and connect the demagnetizer. The connection diagram is available on the websitehttps://www.ljmagnet.ru— there is also a table of compatibility with the main models of domestic and Chinese separators.

When “cheap” becomes unprofitable

Not all cases are suitable for a budget solution. If your separator works with material containing fine magnetite (less than 10 microns), you need a demagnetizer with an adjustable frequency from 50 to 400 Hz and the ability to set up to 5 attenuation stages. Such devices are more expensive, but the payback period is less than 4 months due to an increase in concentrate yield by 1.2–1.8%.

Also, don’t skimp on installation. Connecting “according to a scheme from the Internet” often leads to breakdown of power switches. The cause is incorrect polarity or missing snubber diode. We have certified engineers in 7 regions of the Russian Federation. They will come, check the parameters, select a model and launch the system with a guarantee of results.

Experience shows: every savings on diagnostics or setup increases the risk of downtime by 3.2 times. It is better to spend 12,000 rubles on a specialist visit than 350,000 on restoring a line after an accident.

A cheap demagnetizer for magnetic separators is a matter of accuracy, not price

LONGI Corporation has been producing such devices since 1993. In 31 years, they have evolved from simple RC circuits to digital systems with current and temperature feedback. Today, their equipment is installed at 127 enterprises in Russia, Belarus and Kazakhstan - from small processing plants to large mining and processing plants.

“Cheap” here means no markups for the brand, minimal logistics costs and direct deliveries without intermediaries. But technical reliability remains at the level of the IEC industry standard. Each device undergoes 72-hour stress testing at -25°C and +55°C.

If your separator loses concentrate purity, if energy consumption per unit of material processed increases, if operators complain about particles “sticking” - this is not a sign of wear. This is a signal: it’s time to turn on demagnetization. And do it right - quickly, inexpensively and without risks.