Magnetic Separation Mining
Magnetic separation is a process used to separate materials from those that are less or nonmagnetic. All materials have a response when placed in a magnetic field, although with most, the effect is too slight to be detected. The few materials that are strongly affected (magnetised) by magnetic fields are known as “Ferromagnetics”.
This type of material includes the five common iron based (Ferromagnetic) minerals; magnetite, hematite, goethite, limonite or siderite, along with irons in non-magnetic form. A list of ferromagnetic materials used in everyday life includes; stainless steel, permanent magnets and electric motors.
The most commonly used type of magnetic separator is the “dry” type. This involves passing the material over a strong magnetic roller. The magnetic field created by the rollers attract and hold any ferromagnetic particles and therefore separate them from the other material.
The dry method of magnetic separation is especially suited to process relatively large quantities of material from a wide variety of sources. It is also often used in maintenance and in other applications where it is important to know that any ferromagnetic material is removed.
The wet process of magnetic separation is more useful when dealing with smaller volumes and smaller material size fractions. In this process, a strong magnetic field is introduced to a suspension of finely divided material. The magnetic field imparts a magnetic force to any ferromagnetic particles within the suspension, which makes them move towards the magnetic field.
Once the ferromagnetic particles have been attracted to the field, they can be removed by filtration or other means. The particles which remain suspended within the suspension are then non-magnetic. This process is ideal for removing magnetic particles from solutions, and can be used in the production of iron from ore.
The use of magnetic separation in mining has increased greatly since the beginning of the 20th century. Huge developments in the field have been made over the past decades and it is now possible to separate materials with unprecedented precision. Magnetic separation is used in almost all fields of industry.
Whether it be from unwanted particles in food, collecting magnetic particles from refrigeration systems, or in mining for the separation of minerals, magnetic separators provide an efficient and economic way to filter ferromagnetic particles from liquid or solid mixtures.
