Cheap High Intensity Wet Magnetic Separator

A low-cost, high-intensity wet magnetic separator is not a marketing phrase, but a real technical compromise that we have seen in dozens of ore processing plants over the past five years. In 2022, at one of the mining and processing plants in the Kemerovo region, the replacement of an outdated separator of the MST-1200 model with a modern onecheap high intensity wet magnetic separatorwith a field of up to 1.8 Tesla, it reduced the iron content in tailings by 37% - without increasing energy consumption and without upgrading pumping stations.

Why "cheap" does not mean "unreliable"

We often hear from customers: “If the price is below the market, where’s the catch?” The only catch is the incorrect interpretation of the word “cheap”. This is not a reduction in quality, but an optimization of the design: the elimination of excess safety margins in non-magnetic units, the use of gasified casting instead of milling steel blanks, the unification of bearing units with serial solutions from SKF and NSK. As a result, the service life of the main unit is at least 12 years, and the cost per unit is 22–28% lower than analogues with the same field strength class (1.4–1.9 T) and productivity 80–150 t/h.

In practice, this means: during a major overhaul of an enrichment plant in the Sverdlovsk region, the client saved 4.3 million rubles on three units, while maintaining a 36-month warranty and service support throughout the entire service life. The main thing is not the price itself, butcost of ownership over 5 years. Here two parameters play a decisive role: the life of the magnetic system and the ease of adjusting the gap between the drum and the brushes.

Where they lose efficiency - and how to avoid it

Most failures with wet separators are not due to a weak magnet, but due to errors in pulp preparation. We record three typical cases:

• Contamination of the working area with quartz particles larger than 0.8 mm leads to scratches on the elastomeric coating of the drum and a loss of up to 15% of magnetic force over 6 months;
• Unstable pulp density (below 28% or above 42% by weight) - causes leakage of weakly magnetic inclusions;
• The lack of preliminary disaggregation is especially critical for ores with clay impurities: the particles “envelop” magnetite, masking it from the field.

The solution is not the purchase of a more powerful separator, but a comprehensive modification of the front section: a hydrocyclone with fine adjustment of 0.15–0.25 mm, a two-stage screen with a 1.2 mm cell, mandatory control of the pH of the pulp (optimum - 7.2–7.8). At our plant in Fushun, each batch of separators is tested under real conditions: with pulp from the KMA deposit, the Urals and Kazakhstan. Only after this the equipment receives permission for shipment.

What does high intensity do - and when is it really needed?

Magnetic field strengths of 1.6 Tesla and higher are not always justified. If your ore contains magnetite with a particle size of 0.045–0.3 mm and an oxidation degree below 12%, a separator with a field of 1.2 Tesla is sufficient. But if the charge contains hematite with surface magnetization, ilmenite or pyrrhotite with low coercive force, an intensity of 1.5 Tesla is already required. We measure this not by passport, but byeffective holding force: at a flow speed of 1.8 m/s and a pulp layer thickness of 35 mm.

Important: “high intensity” is not only the field strength, but also its uniformity along the entire length of the drum. For our separators, the deviation does not exceed ±2.3% over a length of 1200 mm. This is achieved through multilayer winding of coils with automatic current correction and a thermally stabilized cooling system. The winding temperature does not go beyond 65 °C even after continuous operation for 72 hours.

How to choose - and not overpay

Before purchasing, ask yourself three questions:

1. What is the maximum size of inclusions in your pulp? (if >0.5 mm, reinforced drum protection is needed)
2. What is the proportion of weakly magnetic minerals in the ore? (if >8%, calculation fields ≥1.6 T are required)
3. Is there a pre-dehydration stage in the technological scheme? (if not, choose a model with an adjustable hopper angle)

LONGI Corporation has been producing such separators since 1993. The Fushun plant produces 4,000 units of equipment per year. More than 60% of engineers have higher education in the field of mining engineering and electromagnetic systems. All technical solutions are tested on our own test site simulating operating conditions in Russia, Kazakhstan and Uzbekistan. Detailed characteristics, connection diagrams and installation recommendations are available on the website ljmagnet.ru.

The low-cost, high-intensity wet magnetic separator works where other solutions require a double upgrade. Its strength lies not in loud numbers, but in the predictability of the result: +2.1–3.4% iron extraction, −1.8–2.6% losses in tailings, stability of performance for 18 months without adjustment. This is not saving on quality. This is taking into account real conditions - without idealization and without compromises.