除鐵機是除去原料中鐵雜質或含磁性物質的設備，而這里所說除鐵(也稱磁先，即磁場分選)是基于被分離物料中不同組分的磁性差異，采用不同類型的除鐵機將物料中不同磁性組分分離的選礦方法。磁鐵的磁力所作用的周圍空間稱為磁場。表示磁場強弱的物理量稱為磁場強度，常用符號H 表示，單位是A/m 。而礦物磁性差異是磁選的依據。礦物的磁性可以測出，根據其磁性強弱程度可把礦物分為三類：非磁性礦物、弱磁性礦物、強磁性礦物。在除鐵機的磁場中，非磁性礦物不受磁力或受微弱的磁力 ;弱磁性礦物所受磁力較小;強磁性礦物所受磁力最大。

Iron removing machine is to remove iron impurities or raw materials containing magnetic material of the equipment, which in addition to iron (also known as the first magnetic field, separation) were separated by different components of magnetic materials based on differences, different types of iron removal machine dressing method in materials with different magnetic separation. The magnetic field around a magnet is called a magnetic field. The physical strength of the magnetic field strength is called the magnetic field strength. The common symbol H indicates that the unit is A/m. The difference of mineral magnetism is the basis of magnetic separation. The magnetic properties of minerals can be measured. According to the degree of magnetic strength, minerals can be divided into three categories: non-magnetic minerals, weak magnetic minerals and strong magnetic minerals. In the magnetic field of the iron removal machine, non-magnetic minerals are not affected by the magnetic force or weak magnetic force, the magnetic force of the weak magnetic minerals is small, and the magnetic force of the strong magnetic minerals is the largest.

在磁選過程中，礦粒受到多種力的作用，除磁力外，還有重力、離心力、水流作用力及摩擦力等。當磁性礦粒所受磁力大于其余各力之和時，就會從物料流中被吸出或偏離出來，成為磁性產品，余下的則為非磁性產品，達到不同磁性礦物的分離目的，因此除鐵機在礦業中應用十分廣泛，是礦業中使用的最主要磁選設備。

In the process of magnetic separation, the mineral particles are subjected to a variety of forces, in addition to magnetic force, there are gravity, centrifugal force, flow force and friction, etc.. When the magnetic particles are larger than the rest of the magnetic force and time, will be sucked out or away from from the material stream, become magnetic products, the remaining are non magnetic products, to achieve the separation of different magnetic minerals, so in addition to the application of iron in mining industry is very extensive, is the main use of mineral separation equipment in the industry.