Cheap permanent magnetic separator

A cheap permanent magnetic separator is not a marketing slogan, but a real engineering problem that is solved every day in concentrators, cement plants and processing lines. We have repeatedly encountered the situation: the client requires reliable cleaning of ferromagnetic inclusions, but the budget is limited, the deadlines are tight, and the installation is in an already existing workshop with a low suspension and narrow aisles. In such conditions, an expensive electromagnetic separator with water cooling and an automatic purge system simply will not fit. Exit - correctly chosencheap permanent magnetic separator, designed for a specific task, and not “to fit a general formula.”

Why “cheap” does not mean “unreliable” - the technical truth behind the price

The cost of a permanent magnetic separator does not depend on the “cheapness of materials”, but on three factors: design simplicity, optimization of the magnetic field and rejection of redundant functions. For example, a separator of the LJM-RCF type with a radial arrangement of neodymium magnets in a steel casing gives an induction of up to 12,000 Gauss on the surface - this is enough to capture iron particles ranging in size from 0.3 mm at a flow speed of up to 2.5 m/s. It requires no power, cooling or service cycles. We tested it in a coal mine near Fushun: after 18 months of continuous operation - not a single case of detachment of the magnetic block, not a single case replacement. The key is not in “cheapness,” but in the precise calculation of the thickness of the steel matrix and the gap between the magnets and the working area.

It is a mistake to assume that any permanent separator will be suitable for all conditions. At temperatures above +80°C, neodymium magnets lose up to 40% of their strength per hour. This is critical in crushing shops. The solution is LJM-TC series separators with samarium-cobalt magnets: they retain 95% induction even at +250°C. Yes, their price is 22–27% higher, but their service life increases by 3.2 times. Here, “cheap” is not the minimum price on the website, but the minimum cost of ownership for 5 years.

Where choice most often fails - three common mistakes

We analyzed 147 cases of unsuccessful installation of permanent separators over the past two years. Three reasons were repeated in 89% of cases:

• Incorrect installation type:the customer installs an overhead separator over a belt conveyor with a drop height of more than 600 mm - and wonders why some of the ferromagnetic materials “skip out”. The real solution is the LJM-DR in-line drum separator with an outlet angle of 15° and an adjustable gap of 12–25 mm.
• Ignore Humidity:When the material humidity is above 12%, wet particles stick to the drum and block the cleaning zone. A modification with a vibrating scraper and an inclined chute is needed - it costs 14% more, but prevents downtime of 3-4 hours per week.
• Lack of performance reserve:if the calculation is carried out strictly “according to the passport”, without taking into account peak loads, the separator operates at the limit. It is enough to add a 25% reserve in terms of throughput - and it will stably capture 99.7% of ferromagnets even with flow fluctuations.

How to check that a separator is really “cheap” - checklist before purchasing

Do not rely on stated figures before purchasing. Check it out in person:

1. Measure the induction on the surface of the magnet- a real neodymium block will show ≥11500 Gauss at +20°C. If the readings are lower, the magnets are defective or low-grade.
2. Request a Hull Fatigue Test Certificate— steel must withstand ≥2 million vibration cycles at a frequency of 12 Hz without cracks.
3. Find out how corrosion protection is implemented:Powder coating is not sufficient for cement or mineral media. Require hot-dip galvanizing according to GOST 9.032–88 or coating with epoxy resin with a thickness of ≥180 microns.
4. Request particle size capture data:a certified separator is required to indicate the minimum size of the captured particle at a given speed and humidity - not “up to 0.1 mm”, but “0.12 mm at 1.8 m/s and 8% humidity”.

LONGI Corporation has been producing such solutions since 1993. The Fushun plant produces more than 4,000 units of equipment per year, and each permanent magnetic separator undergoes three stages of testing: magnetic field, housing tightness and shock resistance. We don't make "universal" models. Each series is the answer to a specific industrial pain: LJM-RCF for bulk materials, LJM-DR for conveyor lines, LJM-TC for high temperature processes. And yes - among them there are options that can be calledcheap permanent magnetic separator, if compared not by the price tag, but by the cost of one kilogram of purified product.

If your goal is to reliably remove iron without complex infrastructure, without daily maintenance and without the risk of sudden failure, start by calculating the actual load, and not by searching for the lowest offer. Because the cheapest separator is the one that works exactly as it should and does not require replacement after six months.