Selection of tungsten coarse concentrate

Nature of tungsten minerals have been found about 20 species, which have industrial value of wolframite and scheelite two kinds. Tungsten ore is also generally classified into black tungsten ore and scheelite. China is the world's most abundant tungsten mine. Quartz vein type tungsten ore accounts for more than 90% of China's current mining volume. Tungsten minerals are mainly black tungsten ore, often containing scheelite, and also with cassiterite and molybdenite . bismuthinite gold, brass ore, pyrite, galena, sphalerite and other minerals metal, non-metallic mineral quartz, feldspar, mica-based.
The main beneficiation method of the black tungsten ore is re-election, the coarse and medium-sized jigs are used, and the fine-grained shakers are used. During the re-election process, some of the higher density minerals, such as cassiterite, scheelite and most of the sulphide ore, are accompanied by the wolframite into the coarse concentrate. Therefore, a selection is needed to improve the grade of the tungsten concentrate while recovering various by-products.
Black tungsten ore is a weak magnetic mineral, while cassiterite and scheelite are non-magnetic minerals, so they can be separated by magnetic separation. The following picture shows the magnetic separation selection process of tungsten coarse concentrate in a tungsten ore refinery in China: before sorting, the material is crushed to -3mm by a roller machine, and the sieve is divided into 0.83~3mm, 0.2~0.83mm and 0~0.2mm. , hierarchical magnetic separation to obtain black tungsten concentrate.

Magnetic separation selection process of tungsten coarse concentrate in a tungsten ore refinery

Among them, the magnetic separation tailings of 0.83~3mm are broken down to 1.17mm by the roller machine to dissociate the tungsten body, and then the magnetic separation is performed. The number of magnetic separation operations of each grain level depends on the nature of the material. Sorted using a ø900mm single-disc magnetic separator, the magnetic field strength is 955 ~ 1194kA / m. In addition to adjusting the current, voltage, pole pitch and feed size, the degree of moisture and iron contamination of the material will also affect the sorting index. The magnetic separation tailings contain scheelite, cassiterite and sulfide ore, which can be recovered by other methods.
The magnetic separation sorting results are shown in the following table: