Dust removal

When they talk aboutdust removal, many immediately imagine a rag and a fan. In the mining industry, this is generally considered a low-level task, they say, the duty officer blew it away - and that’s it. And then they wonder why the bearing on the LONGI separator failed after six months, and not after three years. Dust is not just dirt, it is an abrasive, a conductor of static, and sometimes a chemically active agent. And the approach to it should be systematic, almost philosophical: first understand its nature, then choose a method of struggle, and only then act. Otherwise, this is not cleaning, but an imitation of activity.

Where feet grow from: sources of dust in production

At our site with magnetic separators from the LONGI Corporation, the main dust is ferromagnetic. Small things that bounce off during separation, plus ordinary man-made dust from the air. But if you dig deeper... Here, for example, is the SMB dry drum separator. There is always a cloud when feeding raw materials. They used to think it was a necessary evil. We have not yet begun to analyze the fractional composition. It turned out that a significant part is not magnetic, but simply a light fraction of ore, which is carried away by the air flow from the conveyor. That is, the problem is not in the separator itself, but in the supply system.Dust removalIn this case, it begins not with the casing over the drum, but with a revision of the design of the loading tray and the belt speed.

There were also funny cases. At one of the old workshops they complained about constant dust on the electrical cabinets. We installed additional filters - it didn’t help. It turned out that the dust was... organic. She was driven by a draft from a nearby warehouse with bags. Dust from old burlap and grain. No magnetic traps work here; a banal sealing of the doorway is needed. This is about diagnostics.

Another subtle point is wear dust. The same LONGI separator, if abrasive gets into the bearing assembly, begins to generate metal dust from friction. It turns out to be a vicious circle: dust provokes wear, wear creates new dust. Here alreadycleaning- This is not only cleaning, but also preventive replacement of seals, monitoring the condition of the lubricant. Sometimes it is easier to install a more reliable labyrinth seal than to deal with the consequences for ten years.

Methods: from broom to fine filtration

The most primitive method is mechanical. Brushes, scrapers, compressed air. They are still used on small repair sites. But on equipment like what LONGI makes, this method is dangerous. A blast of air can drive dust even deeper into the nodes. Using a brush can damage the coating or displace the adjustment marks. I personally saw how a “handyman” tried to clean the drum position sensor with a brush and knocked it off. After this, the drum went into emergency position.

Wet cleaning is also a double-edged sword. For non-electronic parts, for the floor - yes. But try wiping the separator control cabinet with a damp cloth. Remaining moisture plus fine dust, which is still in the air, creates a conductive film on the boards. The risk of short circuits and contact corrosion increases significantly. Therefore, for electronics, we switched to special moisture-displacing aerosols and alcohol-containing wipes. More expensive, but more reliable.

The best thing that has been introduced in recent years is an aspiration system with a cyclone and a bag filter right in the transfer zone on the line before separation. Not a universal solution, of course. Requires calculation of air ducts and selection of fan power. But when you see how 90% of the dust cloud immediately goes down the chimney and does not settle on the equipment, you understand that this pays off in the saved resource of the mechanisms. This is especially important for precision magnetic systems, where the gap between the poles is a matter of tenths of a millimeter. Any dust there is like a cobblestone in a watch.

Special case: electrostatics and magnetic dust

With magnetic dust that is generated during the operation of LONGI equipment, conventional methods may not work. It sticks to surfaces not only due to humidity, but also due to residual magnetization of some parts of the case or frame. I just blew it away - an hour later she was right there again. It is necessary to use two-stage cleaning: first neutralize static (with an ionizing air curtain or antistatic agents), and then remove dust. Sometimes it helps to simply ground the entire casing of the device, which is forgotten during installation.

We had experience with cleaning the insides of a high-gradient separator. There is a matrix of steel mesh, which creates local areas of strong field. Over time, fine magnetic dust gets stuck in these meshes, which reduces efficiency. Washing with water is undesirable - rust. We tried to blow it with steam at low pressure. The result was average, some of the dust was baked together. As a result, after consultations with technologists from the manufacturing plant (and this is precisely the LONJI corporation, their website, by the way, is https://www.ljmagnet.ru, there are technical memorandums there), they came to the method of washing in an ultrasonic bath with a special corrosion inhibitor. Long, but clean and without damage. This is the case when the general rule does not work, and you need to delve into the specifics of a particular node.

By the way, about the site. When looking for maintenance information, you often come across common phrases. LONGI sometimes has real technical notes from engineers in the support section. It is clear that they were written by people who themselves faced the problem. For example, about the fact that whencleaning from dustIn the magnetic system of a dry separator, ferromagnetic tools cannot be used - they can become magnetized and then themselves become dust collectors. It’s a trifle, but without knowledge you can make a lot of mistakes.

Organization of the process: not heroism, but a system

The biggest mistake is to schedule cleaning 'as needed'. This always turns into a rush before checking or after a breakdown. We now have regulations. Each type of equipment: separator, crusher, conveyor has its own schedule. Not just “wipe once a week,” but clearly: what to clean (surface, ventilation grilles, sensors), what to clean with (a brush made of a certain lint, a lint-free cloth, a special solution), in what order (from the highest points to the lowest, from clean areas to dirty ones). It’s boring, there’s a lot of paperwork, but when a new mechanic carries out cleaning according to regulations and doesn’t break anything, you understand that it’s worth it.

Another important point is the disposal of collected dust. Especially magnetic. It cannot simply be thrown into a common tank - it is a raw material, albeit of low quality. We collect it separately, then pass it through a low-power separator and extract the remaining magnetic fraction. The savings are meager, but fundamental. It turns out to be a closed cycle: LONGI equipment extracts the metal, we capture and return to the process what it accidentally lost in the form of dust. Ecology and economics in one bottle.

Staff motivation is a different matter. If cleaning is considered low-skilled work, it will be treated as such. We try to explain why it is important to clean this particular unit. We show examples of breakdowns due to dust. When a person sees a connection between his rag and the smooth operation of an expensive separator, the responsibility is different. Sometimes we even hold mini-competitions or reviews on the condition of the equipment. Works better than an order from above.

Conclusions that do not smell like theory

So, back to the beginning.Dust removal- this is not about a rag. It's about understanding technology. If your production has equipment, for example, from the LONGI Corporation - and this is a serious manufacturer with a history since 1993, which produces thousands of pieces of mining equipment a year - then the approach to its maintenance should be at the same level. You can't treat a machine that has tons of metal and engineering put into it like a home vacuum cleaner.

The main advice I would give, based on my not always smooth experience: start with a dust map. Just observe for a day or two: where the dust comes from, where it settles, what it is like. Then select methods. And don’t hesitate to look into the documentation or write to the manufacturer. The same ones in LONGI, they have a staff of more than 1200 people, and most of them have specialized education, they often give practical advice on service. Their experience, multiplied by your specific workshop, can provide the optimal solution.

Ultimately, proper cleaning prolongs the life of equipment, reduces downtime and, paradoxically, frees up time. Time that can be spent not on emergency wiping, but on something more useful. This is the same preventive measure that pays off in silence in the workshop and an even schedule on the repair board. And this is perhaps the best indicator of the quality of work.