The Basic Principle of Magnetic Separation

Because of the different magnetism among the minerals, the magnetic force they bear is also different when they enter the magnetic field of the magnetic separation equipment (magnetic separator) , and thus the trajectories is different. And finally the minerals will be divided into magnetic product and the non-magnetic product (or ferromagnetic products and products with weak magnetism), achieving magnetic separation.
Mineral magnetic differences are the basis of magnetic separation. The magnetism of minerals can be measured and the minerals can be divided into three categories according to the degree of magnetic strength of the mineral : (1) strong magnetism minerals, such as magnetite, pyrrhotite, the number of such minerals is small; (2) weak magnetism minerals, such as hematite, limonite, ilmenite, psilomelane pyrolusite, garnet, the number of these minerals is larger; (3) non-magnetic minerals, most of the non-metallic minerals and non-ferrous minerals belong to this category. In the magnetic field of the magnetic separator, the ferromagnetic minerals suffer the maximum magnetic force, the weak magnetism minerals suffer smaller magnetic force and the non-magnetic minerals bear no magnetic force or weak magnetic force.
The magnetic field of the magnetic separator is a necessary condition of the magnetic separation. The magnetic field can be classified into the uniform magnetic field and nonuniform magnetic field. And the degree of nonuniformity of the magnetic field can be measured with the magnetic field gradient, which is the changing rate of the magnetic field strength along the space, i.e. the unit length variation amount of the magnetic field strength. The greater the magnetic field gradient is, the greater the degree of nonuniformity of the magnetic field will be, that is, rate of change of magnetic field strength along the space is large. The magnetic force that the magnetic ore particles bear is proportional to the product of the magnetic field strength and the magnetic field gradient. If the magnetic field gradient is equal to zero (in the uniform magnetic field, no matter how high the magnetic field strength is, the magnetic field gradients are equal to zero) and then the magnetic force that the magnetic mineral grains stand is zero and the magnetic separation can not be carried out.

Sand washing equipment : http://www.best-crushers.com/sandwasher.htm
China cement mill : http://www.ore-machine.com/cement-mill.html