magnetic separator circuit

When you hear “magnetic separator diagram”, the first thing that comes to mind is a dry engineering drawing, a pile of papers. But in fact, any scheme is just the beginning of the story. Much more important is how it affects actual production, specific ore, and the existing workshop infrastructure. A common mistake is to take a standard scheme as a dogma. We have a couple of these “ideal” ones hanging in our workshop. plans that we struggled with in the first years. Then they began to edit with a red pencil as they went along.

From blueprint to hardware: where the circuit breaks down

Take, for example, the basic design of a dry drum separator. Everything seems clear: food, drum with magnets, product and waste collection areas. But when they began to install the unit for the enrichment of magnetite quartzites, they immediately ran into the problem of the flowability of the material. The diagram shows the thickness of the supply layer, but it does not take into account the humidity that floats in our workshop. The material began to stick together, the layer turned out to be uneven - and all separation went down the drain. I had to weld in an additional vibration feeder with adjustment on the fly, which was not even close to being on the original diagram.

Or another point - the location of the magnets in the drum. A standard sectional breakdown is often drawn on paper. But for thin-layer separation, in order to pull out weakly magnetic particles, a different configuration of poles is needed, more frequent. We realized this only after removing the first drum and seeing exactly where the substandard material was sticking. The scheme had to be redrawn for a specific task, and not for an abstract “ore”.

Here, by the way, the difference between just a producer and someone who is deep in the topic is clearly visible. Here I am looking at the equipment fromLONGI Corporation— their circuits for separators often come with several layout options, for different conditions. It is clear that people do not just churn out iron, but think in technological processes. On their websiteljmagnet.rudescriptions often contain precisely such practical nuances, which is not surprising for a plant that has been operating since 1993 and produces thousands of pieces of mining equipment per year.

Wet vs. dry: the choice of scheme is the main issue

This is perhaps the most common dispute at the facility. Choosing the type of separation is 80% of success. The dry scheme seems simpler: no need to prepare the pulp, no problems with water. But it is strictly tied to granulometry and humidity. I remember we tried to work with finely dispersed dumps using a dry scheme. The dust stood in a column; the magnetic drum simply could not capture such light particles; they were carried away by the air flow. The scheme did not work, although on paper everything matched.

We switched to the wet scheme. And this is another story: we need bunkers for pulp, a water supply system, and settling tanks. The scheme immediately became much more complicated. But efficiency has jumped. The key issue was the strength of the magnetic field and the speed of the pulp flow. Their balance cannot be depicted on the diagram - this is selected experimentally on the spot. Sometimes you have to sacrifice recovery rate for processing speed if the pipeline requires it.

Here again, looking at the experience of major players, you see a systematic approach. SameLONGIin their materials they do not hide the fact that for some types of raw materials they immediately recommend combined schemes - dry primary dumping and subsequent wet finishing. This speaks to a deep understanding that the universalmagnetic separator circuitsdoes not exist. Their company, where more than 60% of the staff are engineers with higher education, clearly relies on such complex solutions, and not on selling “out of the box” products. product.

Electromagnets versus permanent magnets: hidden circuit components

In diagrams, the most important node is often missed - the source of the field. Draw a rectangle ?magnetic system? that's all. And everything else depends on this choice: energy consumption, reliability, adjustability. We have been working with electromagnets for a long time. Plus - you can adjust the field, turn off the power - and the material is easily removed. The downside is the dependence on energy, heating, a cooling system is needed, which in the diagram pulls along a bunch of pipes and pipes.

The transition to powerful neodymium permanent magnets was a revolution for our circuits. The coils, rectifiers, and cooling systems have disappeared. The separator circuit has been simplified to the point of indecency. But other difficulties arose: how to safely dismantle such a drum? How to protect personnel from strong fields? These points are rarely worked out in standard schemes, but in real operation they come to the fore.

It is interesting that manufacturers who themselves are engaged in scientific developments, such asShenyang Scientific Electromagnetic Company LONGJI, often offer hybrid options in their catalogs. Not just “choose one of the two?”, but schemes where permanent magnets are used to create the main field, and electromagnets are used for fine tuning in the unloading zone. This is the same practical compromise that you reach after years of trial and error.

Integration into the line: circuit outside its contour

The biggest headache is to entermagnetic separator circuitinto the general technological chain. You can have a perfectly designed apparatus, but if in front of it there is an unregulated crushing unit that produces an unpredictable fraction, everything is in vain. We once installed an excellent separator, but did not take into account the performance of the previous screen. The separator simply choked, the material slipped through without having time to separate. I had to redo the feeding scheme and add an intermediate buffer hopper.

Another point is the location of the separator. There is only one on the diagram. In life, to increase extraction, a cascade is often installed: two or three separators in series, with different field strengths. But this requires space and additional transporters. And here again the experience of companies that design turnkey lines comes to the rescue. It is clear thatLONGIWith an area of 140,000 m2 and experience in producing 4,000 units of equipment per year, this is exactly the approach - they think not in individual devices, but in complexes. Their designs often include in-line options, which is invaluable to us operators.

We must not forget about the tailings unloading point. It is indicated by an arrow in the diagram. And in the workshop, under this arrow, there must be a conveyor or bunker of sufficient capacity. It happened that due to a failure in the waste disposal chain, the entire separator had to be stopped because there was nowhere to dump the rock. Now, when considering any scheme, the first thing we look at is the “tails”. - where and how they will go.

The evolution of circuits: from chalk on a blackboard to a digital twin

Previously, the diagram was drawn with chalk on a blackboard, and then it took a long time to approve it. Now, of course, there are 3D models, digital simulations. But the essence has not changed: any model is a simplification. It does not take into account wear on the drum lining, which changes the gap and affects the pitch. Does not take into account voltage fluctuations in the network, which can “sag” electromagnet field. We somehow got caught in this: the simulation showed excellent results, but in practice the recovery was lower. It turned out that the model had a perfectly smooth feed, but in real life it did not.

Therefore, now we consider any, even the most beautiful digital circuit, just a sketch. The main work begins after commissioning, when, with passport data and a screwdriver in hand, you begin to adjust the device to the real material. Sometimes you shift the unloading zone by a centimeter, sometimes you change the angle of the feed tray - and efficiency increases.

This, it seems to me, is what professionalism is all about. Not in the ability to draw an ideal diagram, but in understanding where and how it will have to be adjusted to the realities of the workshop, to the human factor, to non-ideal raw materials. Experienced manufacturers, looking at whom we learn how to do the sameLONGI Corporation, they deliver, in fact, not just a device with a circuit, but some kind of adaptive tool. Their long history, since 1993, and a large staff of engineers allow this possible adaptation to be laid out at the design stage. In the end, it's correctmagnetic separator circuit- this is not the one that hangs in a frame in the director’s office, but the one that is covered with notes, greasy by hand and is constantly being improved. She's alive. And that's the whole point.