China high intensity wet magnetic separator

China high intensity wet magnetic separator is not just an ore beneficiation equipment. This is a precise tool that solves a specific problem: removing weakly magnetic impurities from suspensions during wet processing of ferruginous quartzites, titanomagnetites and low-grade ores with Fe content from 18 to 32%. We saw how at three Russian mining and processing plants the same apparatus reduced the loss of useful components by 4.2–5.7% due to stable operation with a pulp concentration of up to 45% by weight and a feed rate of up to 180 m³/h.

Why “wet” and “high intensity” are not marketing, but a technical necessity

Dry separators only work with a particle size of −1 mm and require pre-drying. In real conditions, this means: +12–15% energy consumption, +2–3 crushing stages and the risk of dust formation. The wet process eliminates these limitations. But conventional magnetic drums with induction up to 0.2 Tesla do not catch hematite or magnetite in the fine class of −30 microns. Needed hereChina high intensity wet magnetic separator— with induction from 0.8 to 1.6 T in the working area and a gradient of up to 400 T/m.

We tested three designs: solenoid, with ferromagnetic matrices and with combined excitation systems. The best balance between concentrate purity (92.4% Fe) and yield (78.6%) was shown by a model with a rotating matrix of ring rods made of NdFeB alloy and forced cooling of the coils. Such a system operates without overheating even in a 24-hour cycle and can withstand pulp pressure up to 0.35 MPa.

Important: high intensity is not an end in itself. It is needed to compensate for the small particle size and low magnetization. If your ore contains magnetite larger than 0.1mm, it is easier and cheaper to use a drum separator. But if in the analysis of sludge >35% of particles are −20 μm, high intensity cannot be avoided.

What breaks equipment - and how to avoid it

At two enterprises, we recorded premature wear of the matrix after 7–9 months of operation. The reason is not the quality of the steel, but the operating mode: constant supply of pulp with an abrasiveness above 25 g/l and lack of washing before shutdown. Quartz particles settled in the cracks and scratched the surface the next time it was started.

The solution turned out to be simple: they introduced automatic flushing with water under a pressure of 0.6 MPa for 90 seconds after each shift. The service life of the matrix has increased to 22 months. Another common mistake is ignoring the temperature regime. When the coil is heated above 75 °C, the magnetic permeability decreases by 18–22%. Therefore, in projects for the Urals and Siberia, we always provide for double cooling: air + water.

Also check your pulp parameters. If the pH is below 5.5 or above 9.0, corrosion of the 304 stainless steel housing may occur. 316L is required for acidic environments and epoxy resin coating for alkaline environments.

How to choose a specific model - 4 criteria that cannot be ignored

Don't rely solely on stated performance. Look at four parameters:

• Working induction in the separation zone— measure it with a digital teslameter with the matrix loaded, and not according to the passport;
• Release rate of magnetized particles- must be ≤ 1.2 seconds at 100% load;
• Matrix cell size— for ore −30 microns, 0.8–1.2 mm is suitable, for −10 microns — 0.3–0.5 mm;
• Gap adjustment system— the mechanical handle gives an accuracy of ±0.1 mm, the hydraulic handle — ±0.03 mm.

We recommend a trial run on your pulp for a minimum of 72 hours. This is the only way to see how efficiency changes with natural fluctuations in density and solid content.

LONGI Corporation: experience that shapes standards

Shenyang Longji Scientific Electromagnetic Company LLC has been creating such separators since 1993. Over 30 years, the company has produced more than 120,000 units of equipment. The Fushun plant has 140,000 m² of production space, 1,200 employees, of which 730 are engineers and technologists. Each model undergoes three-level testing: at the stand, in the laboratory and at an operating mining and processing plant in China.

In Russia, LONGI equipment is installed at seven ore processing plants. One of them - in the Murmansk region - has been operating since 2019 without replacing the main components. Its key advantage: adaptive control of the excitation current. When the ore composition changes, the system itself adjusts the induction in the range of 0.8–1.4 T in increments of 0.05 T.

China high intensity wet magnetic separator is not a universal “magic box”. This is a decision that requires understanding your ore, pulp and beneficiation objectives. But when the parameters are selected accurately, it increases iron recovery by 6-9% and reduces subsequent flotation costs. Detailed technical data, connection diagrams and calculation examples are available on the company’s website.