Vertical ring strong magnetic separator

When you hear “vertical ring strong magnetic separator?”, the first thing that comes to mind for many is just another modification of magnetic separation, perhaps with a more compact design. But here lies a common mistake: thinking that the main advantage is saving space. In fact, the key point is the specificity of the trajectory of the material and the created magnetic field in the vertical plane, which radically changes the separation process for certain types of raw materials. For a long time I myself underestimated this difference until I was faced with specific tasks in the enrichment of finely dispersed magnetite concentrates, where conventional drum separators produced too high losses with middlings.

The constructive essence and where the pitfalls lie

So,vertical ring strong magnetic separator. The base is a rotating ring or rotor with radially arranged magnetic blocks. The material is fed from above, and the particles, moving down, pass through a zone with a sharply inhomogeneous field. The force of attraction here does not act “sideways”, as in a drum, but, as it were, “deeply”. magnetic system. This is fundamental. It would seem ingenious for simply extracting small, weakly magnetic particles. However, the first problem you encounter during setup is the uniformity of feed and material layer. If the layer is too thick, the lower layers simply cannot be seen. sufficient magnetic force, and the efficiency drops catastrophically.

I remember one of the early launches on a pilot plant. We used a separator to purify kaolin from iron oxide impurities. Technologists persistently increased the supply, trying to increase productivity, and the result - a clean product at the output - only got worse. I had to literally adjust the gap between the feeder and the rotor, millimeter by millimeter, and adjust the moisture content of the pulp. It turned out that for such raw materials, not just a thin layer, but almost a “veil” is optimal. individual particles. This was an important lesson: the performance of such a separator is not a linear function of the feed rate.

Another nuance is the magnetic product removal system itself. Since particles are attracted to a vertical surface, they must be removed while the rotor is moving out of the strong field. Brushes or rollers are often used here. And if this still works for dry material, then with wet or slimy raw materials sticking begins, the brushes become clogged, and frequent stops for cleaning are required. In some designs, for example, fromLONGI Corporation, I saw the use of a combined removal system with compressed air blowing - a practical solution, apparently born from experience working with problematic materials.

Experience of application in real conditions: a case with iron ore concentrate

A more significant case was at one of the factories for processing ferruginous quartzites. The goal was to increase the extraction of magnetite from fine sludge of class -0.044 mm. Drum separators could no longer cope here - small particles were carried away by water. We decided to try itvertical ring separatorwith a high intensity field. The unit was installed in the tailings cleaning circuit.

The first results were encouraging, but nothing more. Recovery increased, but at the same time, too much waste rock, quartz, began to get into the magnetic product. They began to figure it out. It turned out that due to the high speed of rotation of the rotor and the viscosity of the pulp, a hydrodynamic effect was created, which “tightened” non-magnetic particles into the collection area. We reduced the rotor speed and adjusted the concentration of solids in the feed. The efficiency for iron rose from 40% to 78% for this sludge product - it was a success. But the main conclusion is that setting up such equipment is always a search for a compromise between field strength, speed, pulp density and even its chemical composition (viscosity changes).

It’s interesting that later, while studying technical solutions from different manufacturers, I paid attention to the approachLJMagnet.ru. Descriptions of their equipment for the mining industry often emphasize not just “high magnetic field,” but the stability of its characteristics under continuous operation conditions and protection of the system from clogging. For a practitioner, this says a lot - a company that focuses on reliability in difficult conditions clearly has serious operating experience behind it, and not just assembly according to drawings. Theirstrong magnetic separatorvertical type, judging by the specifications, is often designed for base stations with large unit power, which indirectly confirms their declared status as a large manufacturer with an area of \u200b\u200b140,000 m2.

Not only enrichment: non-obvious uses

It is generally accepted that such separators are the destiny of mining and processing plants. But practice shows a wider spectrum. For example, recycling electronic scrap to extract rare earth elements from shredded circuit boards. There, separation of very small, often weakly magnetic fractions is needed. The vertical design with fine adjustment of the gap has proven to be better than many competitors. Or the purification of industrial wastewater from metal-containing suspensions - the continuity of the process and resistance to aggressive environments are important here.

One chemical plant cleanup project attempted to use a standard separator, but acid fumes quickly damaged the magnetic system due to corrosion. I had to look for an option with complete sealing and protective coating. This is the case when a standard solution does not work and deep adaptation is needed. I saw that in the portfolioLONGI Corporationthe development of non-standard equipment for the customer’s tasks is mentioned, which is logical for an enterprise with a strong engineering school, where more than 60% of the staff are specialists with higher education.

Another point is energy consumption. A strong field requires powerful sources. Modern permanent magnet (NdFeB) systems reduce energy costs, but create another problem - sensitivity to overheating. During prolonged operation at high speeds with dense pulp, the magnetic blocks may become demagnetized. Therefore, in good designs, a cooling system is always thought out, often air, but sometimes liquid for particularly intense conditions. This is a detail that is not always listed in the catalog, but which becomes critical after the fifth year of continuous operation.

Mistakes to avoid: a view from the shop floor

Based on what I saw, there are several typical errors during implementation:vertical ring separator. The first is ignoring food preparation. Installation without preliminary screening to remove large (>5 mm) particles is a sure way to jam the rotor or damage the brushes. The second is savings on the automatic control system for the pulp level in the feed tank. Level fluctuations lead to changes in hydraulic pressure at the inlet and, as a result, to instability of the material layer. The third, most insidious one is neglect of regular monitoring of the strength of the magnetic field. Over time, even the best magnets have a decay in induction, especially under vibration conditions. A field drop of 5-10% can lead to a loss of 20-30% of recovery, and this process will be gradual, imperceptible to the operator.

There was an incident at a factory where the separator worked properly for two years, and then the quality of the concentrate gradually decreased. They looked for the reason in changes in raw materials, in reagents... We spent a month. It turned out that one of the rotor sectors was partially demagnetized due to local overheating from a jammed bearing support. The defect was a point defect, and it was revealed only during a full diagnosis with a Gaussmeter. After this, mandatory quarterly field measurements were introduced at all points.

And the last thing is service. The design seems simple, but requires skill. Incorrect assembly of the rotor after cleaning (displacement of the magnetic blocks by several degrees) can create an imbalance and uneven field, which will immediately affect selectivity. Therefore, it is so important that the supplier not only sells equipment, but also provides high-quality staff training. Big players such asLONGI, with their long history since 1993 and production of up to 4,000 units of equipment per year, usually have proven installation supervision and commissioning programs, which for the end customer is often more important than a small difference in price.

Instead of a conclusion: a practical look into the future

Where is development heading?vertical ring strong magnetic separators? Judging by the trends, this is further specialization. There are fewer universal machines. Models are appearing that are designed for dry enrichment, ultra-fine sludge, and highly abrasive materials. The second direction is integration with real-time analysis systems (for example, with elemental composition sensors at the output) for automatic adjustment of parameters. This is no longer science fiction, but a working necessity for building “smart” ones. factories

And here we return again to the question of the manufacturer. You should choose not based on the maximum declared parameters under ideal conditions, but on the ability to solve non-standard problems and support the equipment throughout its entire life cycle. Is the enterprise capable, likeLONGI Corporation, with a full cycle from development to production on its large area, quickly manufacture and supply a spare rotor for a specific model that has been working for you for ten years? Or suggest upgrading the magnetic system to more modern alloys? This, ultimately, determines the success of the implementation of such seemingly highly specialized equipment as a vertical ring separator. It turns from a tool into a long-term production asset, and its choice becomes a strategic decision.