1. 12. 2019
Overview of magnetic separators
In the majority of modern industries a ferrous impurity can result in damage to the machine equipment and in the undesirable contamination of the final product. Products can be contaminated by metal impurities practically everywhere: in transport means, in the machine equipment (mills, crushers, etc.), due to common wear and tear or as a result of the human factor (either unintentional, or deliberate)...
The field of permanent magnetic separators has undergone considerable changes in the past 70 years. New materials have been discovered and developed and advanced technologies have been applied. Magnets based on the alloys of aluminium, nickel, cobalt and iron (usually abbreviated as ALNICO) were among the first ones used for the separation of magnetic impurities. The 1960s witnessed the start of the production of ceramic magnets also known as ferrite magnets (the mixture of iron oxide with one or more metallic elements). Magnetic force of these magnets is more or less comparable with that of the ALNICO type magnets. In the 1980s the first magnets containing so-called rare earths appeared. At the very beginning the products of this kind included samarium and cobalt. Later on, the most powerful permanent magnets, sometimes called neodymium magnets (based on the mixture of neodymium, iron and boron) capable of separating the smallest or only partially magnetic metal impurities (such as rust, iron dross or magnetic stainless steel), started to be manufactured.
In the majority of modern industries a ferrous impurity can result in damage to the machine equipment and in the undesirable contamination of the final product. Products can be contaminated by metal impurities practically everywhere: in transport means, in the machine equipment (mills, crushers, etc.), due to common wear and tear or as a result of the human factor (either unintentional, or deliberate). Magnetic separators allow the negative impacts of ferromagnetic contamination to be eliminated and are available in a number of various designs, multipurpose as well as highly specialized.
Considering the fact that a magnetic separator plays a key role in achieving the necessary purity, in particular the following factors must be taken into account when selecting the most suitable product:
Properties of the material to be cleaned
Big pieces or extremely viscous materials would quickly damage or obstruct for example the very popular grate separators. The type of magnets installed in the separator then depends on the degree and kind of contamination and on the required degree of the final product's purity. The definition of the properties of the material intended for cleaning is thus one of the most important parameters for the selection of the optimal separator.
Temperature
The efficiency of certain types of permanent magnets significantly decreases with an increase in temperature and therefore it is always necessary, when selecting a magnetic separator, to specify in detail the environment and temperatures to which the magnetic separator will be exposed during the separation process.
Flow rate
The best results of separation are achieved when the thinnest possible layer of the material being cleaned is moving as closely to the magnetic core as possible - and therefore it is necessary to find for every application the optimal separator which complies best with this general definition. Another very important detail is the type of flow rate (this means whether the material flows through the separator continually or rather in bursts). Last but not least, it is important to know whether it is possible to interrupt the flow rate of the material being cleaned or whether this is not possible because of production and technological reasons (which will subsequently be the decisive factor for the selection of either manually or automatically cleaned separator).
For this reason, magnetic grate separators are usually used for the separation of metal impurities from free-flowing materials of good bulk properties. On the other hand, in piping systems there are used special pipeline magnetic separators for the purification of liquids. For separation of small ferromagnetic particles from materials of worse bulk and pouring properties it is advisable to use external pole magnet separators or magnetic plates (which are not in direct contact with the material being cleaned and hence cannot be obstructed by such material). Magnetic drums and cylinders are widely used for practically all sorts of applications as they can also arrange for continual separation without the necessity to interrupt the technological process. Eddy current separators are used for the detection of non-ferrous metal contaminants. These separators are equipped with powerful high-speed rotors with integrated rare earths magnets.
From the above mentioned it is obvious that the selection of a permanent magnetic separator optimal for the respective application can be rather difficult. However, our highly experienced technicians are ready to elaborate solutions meeting customer's individual needs and requirements in the most effective manner.
Types of magnetic separators SOLLAU
Permanent magnetic separators
Separator shape |
Separator name |
Model |
Application |
---|---|---|---|
Plate |
DND-MC |
Separation of ferromagnetic particles from materials transported on a belt conveyor. The separator can be also chute-mounted. |
|
DND-AC |
Separation of ferromagnetic particles from materials transported on a belt conveyor |
||
ML |
Separation of small ferromagnetic particles from materials of worse bulk and pouring properties |
||
DND-SFX |
Separation of ferrous particles from dry or semi-liquid materials (above-the-flow chute or belt applications). |
||
Tube |
MTN |
It is designed to separate ferromagnetic particles from dry materials or liquids. It can be used either separately or for assembling simple grate separators. |
|
MR |
Simple separator designed to separate ferromagnetic particles from free-flowing dry materials. |
||
TM
|
It is designed to separate iron tramp from free-flowing dry materials processed by moulding machines. |
||
SM |
It is designed to separate iron tramp from free-flowing dry materials processed by moulding machines. |
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MSS-MC |
Separation of magnetic iron contamination from free-flowing substances of good bulk properties |
||
MSS-AC |
Separation of magnetic iron contamination from free-flowing substances of good bulk properties |
||
MSR-MC |
Separation of the smallest magnetic metallic impurities (size from 30 µm) from materials that tend to bridge and could clog the usual magnetic grate separators. |
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MSP-S |
It is designed to separate magnetic iron contamination from a rapid stream (up to 25 m/s) of liquids or dry substances of good bulk properties. |
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MRZ |
Designed to separate magnetic iron contamination from liquid substances (such as coolants and emulsions for various machining operations). |
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MSP-MC |
It is designed to separate magnetic iron contamination from liquids or dry substances of good bulk properties. |
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Magnetic separator for pipeline transport (with automatic cleaning) |
MSP-AC |
It separates in a quick and easy way the magnetic iron contamination from free-flowing liquid or powder substances of good bulk properties. |
|
Pulley |
MV |
Usable as a conveyor head pulley for automatic and permanent removal of magnetic iron metals from inert materials. |
|
MVS |
Device for automatic and permanent removing of ferrous contaminants from liquid substances (such as coolants and emulsions for machining operations). |
||
ECS |
Separation of non-ferrous metals from small shredded pieces. |
||
Drum |
MB |
Automatic and permanent removal of magnetic iron metals from inert materials. |