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More than 20 kinds of tungsten minerals and tungsten-containing minerals are known in the world, among which wolframite and scheelite are economically valuable minerals. At present, the beneficiation methods of wolframite are mainly gravity separation and flotation. The beneficiation method of scheelite is mainly flotation. Because the physical and chemical properties of ores are different, the beneficiation methods used are also different. The following will introduce you to the process for extraction of tungsten from wolframite and scheelite.
Use the table of contents below to navigate through the guide:
As mentioned above, wolframite beneficiation methods mainly include gravity separation and flotation separation, in which coarse-grained ore is recovered by gravity separation, and fine-grained ore is separated by combined processes such as gravity + magnetic separation, magnetic + flotation separation, gravity + flotation separation, etc.
Gravity separation is one of the main processes for extraction tungsten from wolfram ore. Its process includes multi-stage gravity separation (the equipment mainly adopts jig and shaker), medium ore returns to regrind process, and fine sludge is treated separately. The traditional wolframite gravity separation process is mainly based on early harvesting by jigging and tailing by shaking table. Nowadays, centrifugal concentrators are also widely used. Based on the different mineral processing equipment, it can be divided into jigging mineral processing method and spiral chute mineral processing method.
The jigging beneficiation method mainly uses the dynamic jigging machine's jumping room bed screen to vibrate up and down and the movement of the water medium combined with power for beneficiation. It has a larger stroke than the ordinary diaphragm jig, and has the advantages of large processing capacity and high beneficiation efficiency. Advantages, it can be used to process coarse and medium-grained ore.
The main principle of spiral chute beneficiation is that the ore pulp rotates downward along the vertical central axis and the horizontal circulation moves, so that the ore is stratified and divided according to the density and particle size. In this way, the separation of concentrate and gangue minerals can be achieved. This gravity separation process has the advantages of large processing capacity, no transmission parts, no power, no need to add water, and good separation effect.
Wolframite is brittle and easy to be crushed. The recovery rate of fine sludge wolframite by gravity separation is low, and flotation process can generally be used for recovery. During flotation, it is necessary to use combined inhibitors (mainly water glass) and mixed collectors (mainly BD single inhibitor and benzyl hydroxamic acid) to adjust the pulp.
Because wolframite has weak magnetic characteristics, strong magnetic separation process can be used to separate wolframite, scheelite and other non-magnetic minerals. High-gradient strong magnetic separator is an important equipment for magnetic separation of wolframite. Using this equipment to conduct a rough separation, a concentration, and a second sweep can obtain a higher recovery rate of concentrate.
Scheelite has a finer crystal grain size and good buoyancy, so flotation is generally selected for the separation of scheelite. The flotation of scheelite is mainly divided into roughing stage and beneficiation stage. The roughing stage is mainly to exclude gangue minerals, and the beneficiation stage is the key to flotation of scheelite. The main methods used in the beneficiation stage of scheelite concentrate are: heating method and 731 normal temperature method.
Selection and heating method: After the coarsely selected scheelite is concentrated, a large amount of water glass is added to the slurry, and it is stirred vigorously for a long time under high temperature conditions. The surface of different minerals has different resolution speeds for the collector film. In turn, the selectivity of the inhibitor is improved, and then it can be diluted and selected under normal temperature conditions. This process has strong adaptability and stable separation index, and is widely used in the mineral processing process of scheelite-calcite and fluorite-type scheelite.
731 Normal temperature method: This method is different from the heating method. It is mainly based on roughing operations. There is a synergistic effect between sodium carbonate and water glass. This method mainly uses this feature, and maintains the HSiO3- in the pulp by controlling the pH of the pulp. In an appropriate concentration range, it is mainly for oxidation inhibition. Because 731 oxidized paraffin soap has strong selectivity, it can be used as a collector for scheelite. After the above operations, a higher roughing ratio can be obtained.
After a large amount of water glass is added to the rough concentrate, it can be diluted and concentrated after a long period of strong stirring. This method is low in cost and mainly deals with skarn-type scheelite mainly composed of quartz.
The above content is the processes used for extraction tungsten from wolframite and scheelite. Tungsten ore is seldom treated with a single process, and a combined beneficiation process is often used, but how to choose a suitable beneficiation process depends on factors such as the grade of black and white tungsten ore, embedded particle size, and gangue mineral composition. Therefore, Xinhai Mining recommends to conduct ore test analysis on tungsten ore before determining the beneficiation process. Xinhai Mining has been committed to ore beneficiation general contracting services for more than 20 years. We can customize tungsten ore beneficiation process for you, produce efficient tungsten ore beneficiation equipment and follow-up complete mineral management and operation services. If necessary, welcome to consult.