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Apr 28, 2017 - The Purpose of Overhead Magnets in the Mining Industry

Magnets play a vital role in the mining industry. They are used to protect other equipment from being damaged. Typically, electro magnets and permanent magnets are used for this purpose, with self cleaning magnets also becoming more common.

Gordon Russell provides both high quality overhead electro magnets and permanent magnets from Ding. Keep reading to learn more about the role of industrial magnets in the mining industry.  

Purpose of Magnets in the Industry

When you think of mining, it’s unlikely that the first thought that comes to your mind is magnet related; but the reality is that magnets play a vital role in the mining industry. Particularly, in this industry, magnets are used in magnetic separators, which are industrial machines used to create a powerful magnetic flux. A magnetic flux is the measurement of the total magnetic field that passes through a specified area.

The purpose of magnets in the mining industry is usually to protect other equipment from damage while it produces a separated final product. This type of equipment includes hammer mills, jaw crushers, cone crushers, and other tertiary crushers. Magnetic separators can also prevent sharp shards of metal from damaging conveyor belts.

Another common use of magnetic separators is to separate unwanted or damaged metal from nonmagnetic materials, also known as tramp iron. Tramp iron originates from landfills or from excavating machinery used to drill, extra, mine, or recover raw material.

Application in the industry

Just like many other parts, the type and style of magnets used in different industries will depend on the location and purpose of the magnet within the process. For instance, mining larger materials and at deeper depths will require larger magnets.

Magnets that are hung over the conveyor belt are designed to remove large iron material, including scrap iron, machinery tips, and hand held tools. They can also remove smaller pieces of magnetic material, such as nuts, bolts, wire, and nails from the process.

Earth magnets are used to remove fine metals like pins, bits of wire, and iron flakes. These rare earth magnets have now been improved so that now they can they even remove materials that are only slightly magnetic, such as stainless steel.

It is crucial to remove any ferrous impurities as soon as possible to prevent damage to the equipment; hence why magnetic separators are installed at the beginning of the conveyor belt. Most magnetic separators are designed to retrofit on any existing conveyor system.

Types of magnets used for protection of conveyors

In order to keep up with the ever-changing requirements of the mining industry, new and improved magnetic separators have been developed to meet this need. Again, the type of mineral being mined will determine the size of the magnet, and a number of occurring tramp irons vary. So, depending on the material being mined, the magnetic separators need to be able to produce various degrees of magnetic flux; these are separated into permanent magnets, electro magnets, and self-cleaning magnets.

Permanent Magnets

Permanent magnets are created from a material that is magnetized and creates its own constant magnetic field. Materials that can be magnetized are referred to as ferromagnetic and include; nickel, cobalt, iron, a few types of rare earth metals, and some naturally occurring minerals, for example, lodestone.

Permanent magnetic separators are typically used when only small levels of ferrous materials are predicted. The magnet attracts the ferrous material and operators monitor a number of ferrous metals being picked up. A nonmetallic stainless steel scraper is used to remove the scraps off of the magnet in order to clean it.

Electro Magnets

The second type of magnets used in mining applications is electro magnets. These powerful magnets require rectifiers and are mainly used in suspended applications. In order to keep the magnets suspended above the conveyor belt, an overhead structure is required to support it.  

Electro magnets contain two coils; when power is applied to the coils it creates a strong magnetic field that is used to remove the scrap metal from the conveyor belts. Electro magnets are able to remove larger pieces of metal. In order to remove the scraps from electro magnets, the operator would simply have to turn off the power source, and the scraps will come right off.

Self Cleaning Magnets

Self-cleaning magnets were designed based on the existing and improved technology of both permanent magnets and electro magnets. Self-cleaning magnetic separators are used to automatically remove and separate metallic and nonmetallic materials. These magnets are typically only used if large quantities of metallic materials are expected.

These magnetic separators have motors to drive belts, a nonmetallic sweeper belt, and speed reducers. These parts can be placed either in the cross belt configuration or in line with the conveyor belt.

Looking to replace your overhead magnets? For a quote on Ding overhead magnets call our BC office at (604) 940-1627.