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Drum separators are used for large flows of material and are generally positioned below the feed end of a conveyor.
Magma can produce to demand given sizes and axle configurations to allow customers to engineer the magnetic element into the production line or alternatively, can produce a self-contained unit with motor.
Large electromagnetic drums (usually from 1000mm diameter and above) are used in the mineral and mining industry.
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Grid separators can be produced in rectangular or round form to allow their incorporation into chutes of all shapes and sizes. Separate mangetic rods can also be supplied. Magma's rods have a very high magnetic force and grids are designed to give full coverage in the spaces between the rods. These separators are used for powders, especially where the material gravitates down a chute or spout and also in liquids passing through suitable pipelines.
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Magnetic Plates are cost-effective and esy to install at a variety of angles. The can be used in tandem to create a slalom against the flow of material in a closed chute. This option changes the somewhat weaker field created when suspended over a material flow to a strong separation technique involving direct contact with the material in process.
Commonly used to extract medium sized ferrous objects from granular or large particle flows. The photograph depicts a unit installed in a stone block factory using stone chip aggregate.
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Magnetic Overbands or Crossbands (so-called when supplied with a traverse conveyor under the magnetic band) are a mainstay of the magnetic separation sector. They are self-cleaning by virtue of the conveyor belt which is built around the magnetic plate.
The overband is positioned (often by suspension) above the flow of material and ensures that even quite large objects are lifted from the flow. The are often used in conjunction with other separators where material is deep or dense on the conveyor.
Common industrial applications include:
Recycling , Quarrying, Wood and Paper
Electromagnetic overbands are used where the distance from the flow is greater than 300mm.
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Alnico permanent magnets
Alnico materials, composed primarily of alloys of Aluminum, Nickel, and Cobalt are characterized by excellent temperature stabilities, high residual inductions, and relatively high energies.
Alnico alloys have some of the highest Curie points of any magnetic material, around 800 °C. This material is used extensively in application required high temperature up to 450°C.
Alnico magnets are manufactured through either a casting or sintering process. Cast magnets may be manufactured in complex shapes. Alnico magnets are cast close to final size and then finish machined to closer tolerances. Sintered Alnico offer slightly lower magnetic properties but better mechanical characteristics. Alnico has a low coercive force, and is easily demagnetized if not handled with care.
Some types of Alnico are isotropic and can be efficiently magnetized in any direction. Other types, such as Alnico 5, 8 and Alnico 12, are anisotropic, with each having a preferred direction of magnetization, or orientation.
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The raw material Magma uses to produce hard-ferrite magnets, is Strontium Ferrite .
This is a readily available raw material and therefore hard ferrite magnets offer the best value for money.
Anisotropic sintered ferrite permanent magnets are made by using ceramics technology, similar to that used for making porcelain The powder is pressed under the influence of an external magnetic field which determines the magnetic orientation of the powder grains.
Magma specializes in the production of anisotropic wet-pressed magnets. "Hard" magnets are characterized by high coercivity (Hcb, Hci), related to the remanence (Br).
Their magnetization is permanent, and their stability is excellent. Being oxides, hard ferrites can operate in a very tough environment, without the need of coating (the surface can however be coated, if high levels of cleanliness are needed by the customer).
Hard ferrite's mechanical properties are similar to other ceramics. They are sensitive to mechanical impact. Machining is performed with electroplated diamond grinding wheels.
Wet pressed anisotropic hard ferrites are now used extensively in the automotive industry, as rotors or stators in D.C. motors, in home appliances, as rotors for synchronous motors and in the audio industry in loudspeakers, earphones and micromotors.
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Magma can work alongside a customer at the developmental stage to ensure the most rational design for the magnet and the sub-assembly. Magma can also undertake the assembly work for a variety of material and situations, for large and small batches.
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This is the rising star of the magnet world allowing having a much greater ratio of power to weight. Smaller motors and other assemblies can therefore be designed.
NdFeB (Neodymium) magnets are fragile, susceptible to corrosion (normally supplied coated) and have working temperatures from 80-200 degrees Celsius. For higher working temperatures the more expensive Samarium Cobalt (SmCo) is used.
Both NdFeB and SmCo are available in sintered as well as bonded forms. The bonded form of the material can be produced with close tolerances requiring little or no finishing. The sintered form usually requires some finishing operations in order to adhere to close mechanical tolerances.
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... see all the products in the category
Magnets
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Magma produces a range of standard round and rectangular electromagnets which can be seen in the catalogue attached to our Direct Industry site.
Most electromagnets are 'normally off' which means that without a current running through them, they do not act as magnets. However, 'normally on' magnets are available in most standard round sizes.
Magma specializes in custom made products even in small quantities which are not readily available from large producers. We offer a personal approach and invite you to send your drawings or enquiries to us.
Some technical background:
In general, an electromagnet is a type of magnet in which the magnetic field is produced by the flow of an electric current through the coil. The magnetic field disappears when the current ceases ('normally off').
The main advantage of an electromagnet over a permanent magnet is that the magnetic field can be rapidly manipulated over a wide range by controlling the amount of electric current. However, a continuous supply of electrical energy is required to maintain the field.
In applications where a variable magnetic field is not required, permanent magnets are generally superior. Additionally, permanent magnets can be manufactured to produce stronger fields than electromagnets of similar size.
Electromagnets are used in many situations where a rapidly or easily variable magnetic field is desired.
Popular uses include: linear motor, electric motor, circuit-breakers, electromagnet brakes, electromagnet clutches, metal lifter, magnetic separators, and more.
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Magma designs and produces solenoids according to customer drawings including technical specifications which include size, position, working environment, the stroke length needed and the frequency of strokes per hour.
The smallest solenoids we can offer are 18mm x 12mm x 5mm with a stroke length of 1,0mm and an accuracy of 0,1mm in terms of the length of stroke produced.
Basic models are designed to give their full rating at 24v but they can be designed for use with other voltages. Solenoids with a force rate of between 15N and 80N will be produced for AC voltage.
Single units and mall batches are possible.
Please look at our on-line catalogue Electromagnets and Solenoids which can be viewed at the Direct Industry site.
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Magnetic Overbands or Crossbands (so-called when supplied with a traverse conveyor under the magnetic band) are a mainstay of the magnetic separation sector. They are self-cleaning by virtue of the conveyor belt which is built around the magnetic plate.
The overband is positioned (often by suspension) above the flow of material and ensures that even quite large objects are lifted from the flow. The are often used in conjunction with other separators where material is deep or dense on the conveyor.
Common industrial applications include:
Recycling , Quarrying, Wood and Paper
Electromagnetic overbands are used where the distance from the flow is greater than 300mm.
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