The mineral processing technology of wolframite and scheelite is introduced
Tungsten is a kind of rare metal, widely distributed, almost exists in all kinds of rocks. Because of its low content, it can only be enriched through relevant geological processes to form the deposit and be mined. At present, there are more than 20 types of tungsten ore found in nature, among which scheelite and wolframite are of higher mining value, and they are also the main sources of tungsten resources.
In the beneficiation method, because scheelite and wolframite both mineral properties and deposit types are different, the process is also very different, we respectively introduce scheelite and wolframite ore properties and beneficiation method.
First, scheelite mineral processing method
Scheframite is generally sandstone type and compound (vein-disseminated type - dolomite skarn compound), which is often associated with or symbiosis with a variety of non-ferrous metals such as molybdenum and bismuth. Useful minerals have fine disseminated grain size and are mostly disseminated in the ore.
According to the degree of mineral distribution, scheelite beneficiation can be divided into two kinds: gravity separation method and flotation method. For scheelite with coarse distribution size, general gravity separation method can obtain alloy scheelite very well. For scheelite with fine disseminated grain size, flotation method is more suitable.
1. Scheelite gravity separation method
The relative mineral density is 5.8 ~ 6.2, which is much different from gangue mineral density. Therefore, qualified scheelite can be obtained directly by gravity separation method.
2. Scheelite flotation method
Scheelite has good natural floatability, its flotation process can be roughly divided into roughing and cleaning two parts: roughing is mainly to maximize scheelite recovery, and cleaning is to get qualified tungsten concentrate, in order to get qualified tungsten concentrate, often need several cleaning to achieve the desired effect.
Scheelite coarse separation: Commonly used methods for lime method, using the Ca2 + in the gangue mineral surface adsorption, change the potential on the surface of the gangue mineral, then adding sodium carbonate precipitation gangue minerals on the surface of Ca, scheelite surface adsorption also Ca, but its still negatively charged surface charge remains the same, do not produce CaCOs precipitation, so adding sodium silicate only suppress the gangue minerals such as inhibitor, Scheelite has no effect on the separation of tungsten and gangue minerals.
Scheelite concentration: the key is to separate gangue minerals containing calcium from scheelite. The commonly used process is normal temperature method and heating method, normal temperature method is not strong adaptability to ore, separation index volatility is large, flotation scheelite concentrate grade is generally 55%~60%, high impurities, usually by adding hydrochloric acid leaching method to recover more than 65% of tungsten concentrate.
The essence of heating method is mainly refers to the coarse concentration of concentrate, concentrated pulp concentration between 60% and 70%, then add a lot of sodium silicate to them, stirring at high temperature, and finally dilution of pulp, and then normal temperature flotation.
Two, wolframite beneficiation process
Wolframite is generally quartz large-vein type or vein-type deposit. Wolframite usually presents coarse plate-like or vein-like crystals enriched in quartz, with coarse disseminated grain size and easy to separate. For gangue minerals associated with wolscheite, the density of wolscheite is large, and the combined beneficiation method based on gravity separation is generally adopted. The process is divided into coarse separation, gravity separation, cleaning and fine mud treatment.
1, wolframite coarse separation process
Due to the uneven distribution of wolframite in quartz gangue, it is often thick plate or vein-like, the vein is narrow, and the thickness is not uniform, so it is necessary to carry out the waste disposal operation by hand before gravity separation.
2. Wolframite gravity separation process
Generally, the process of multi-stage jigging, multi-stage shaking table and medium ore regrinding is adopted. Finely after qualified ore after vibrating screen classification of multi-stage jig, output jigging re-election MAO sand, coarse grained jig tailings again into the rod mill grinding, fine grained jig tailings after hydraulic classifier classification into multistage bed one thick one sweep to produce wave re-election MAO sand bed, table tailings in the tailings, and secondary return of middlings was shaking table, jig and shaking table re-election MAO sand into the selected operation.
3. Wolframite cleaning process
In general, floating-recombination or floating-gravity-magnetic combination are used for various separation processes, and the associated elements are recovered in the cleaning section. Through the thick grain of floating and machine floating removing sulfide ore, floating and machine flotation sulphide ore merge into the sulphide ore flotation separation, floating and machine float wolframite further black tungsten concentration, produced by the re-election if black tungsten concentrate containing scheelite or cassiterite, by gravity separation - flotation and gravity separation - flotation - magnetic separation (electricity), and other joint process to select the black tungsten concentration, white tungsten concentration and tin ore concentrate.
4. Wolframite fine mud treatment process
Normally, wolframite treats the fine slime separately. Firstly, desulfurization is carried out, and then tungsten minerals are recovered by gravity separation, flotation, magnetic separation, electric separation and other separation processes or a combination of several processes according to the properties of fine mud materials, while associated metal minerals are comprehensively recovered and utilized.
The above is the common process flow of tungsten ore dressing. In addition, magnetic separation and electric separation are sometimes used in the selection of tungsten ore, mainly for the separation of wolframite and scheelite, wolframite and cassiterite, scheelite and cassiterite and ferromagnetic material.
For the separation of tungsten ore, it is necessary to determine the ore composition of tungsten minerals and the degree of difficulty in separation. It is recommended to find manufacturers with beneficiation qualifications for beneficiation test, according to the report to customize the process according to the actual situation, in order to effectively select useful minerals, remember not to apply randomly.
