7 types of fluorite beneficiation methods

Fluorite is an important non-metallic mineral raw material, widely used in chemical, steel, aluminum smelting, ceramics and other industries. It is the main raw material for preparing fluorine. With the development of science and technology, the use of fluorite in high-tech industries has gradually increased, and it has become an important strategic mineral resource. Fluorite beneficiation and separation technology is an important means to improve the grade of fluorite and the basis of fluorine chemical technology.

According to the different components of its paragenetic minerals, fluorite can be roughly divided into seven types: single-type fluorite, quartz-type fluorite, sulfide-type fluorite, calcite-type fluorite, barite-type fluorite, siliceous rock-type fluorite, and carbonate-type fluorite. Depending on the type of fluorite, its beneficiation method is also different.

Single-type fluorite

Single-type fluorite is almost composed of a single fluorite mineral, with very little quartz and calcite content, and most of it is produced in veins. This type of fluorite has a small reserve and most of it has been developed. Due to its simple composition, a single fluorite ore generally only needs simple flotation to obtain high-grade concentrate

Quartz-type fluorite

Quartz-type fluorite is mainly composed of fluorite and quartz, with a fluorite content of 80%~90%, and contains a small amount of calcite, barite, and sulfide.

Fine-grained quartz-type fluorite generally adopts a stage grinding and stage separation process to ensure that the quartz and fluorite monomers are dissociated without causing over-grinding. Sodium carbonate is used as a pH adjuster during flotation, oleic acid and oxidized paraffin soap can be used as collectors, and water glass is used as an inhibitor. Multiple selections can select high-grade fluorite concentrate.

Sulfide-type fluorite

Sulfide-type fluorite has a similar mineral composition to quartz-type fluorite, but sulfide-type fluorite contains more heavy metal sulfides. When developing, not only the recovery effect of fluorite should be considered, but also the comprehensive recovery of other metal minerals should be considered.

Calcite-type fluorite

The main minerals of calcite-type fluorite are calcite and fluorite, of which the calcite content is more than 30%, and it also contains metal sulfide minerals such as galena, sphalerite, and pyrite. Calcite and fluorite are both calcium-containing minerals with similar physical and chemical properties. It is difficult to separate them. Under different pulp pH conditions, water glass, salted water glass, acidified water glass, sodium hexametaphosphate, lignin sulfonate, dextrin, tannin, tannin extract and other inhibitors can be used to inhibit calcite, and fatty acid collectors can be used as fluorite collectors to achieve the separation of calcite and fluorite.

Barite-type fluorite

The main minerals of barite-type fluorite are barite and fluorite. The content of barite is between 10% and 40%. Barite and fluorite are vertically zoned in the ore body, and are associated with pyrite, galena, sphalerite, and a small amount of calcite.

Barite and fluorite have similar floatability. Generally, mixed flotation is adopted, sodium carbonate is used to adjust the pH value, and water glass is used as an inhibitor to obtain a mixed concentrate of barite and fluorite, and then flotation is used to separate barite and fluorite.

Siliceous rock type fluorite

Siliceous rock type fluorite is formed by sedimentation, in which fluorite is generally distributed in shale, mica quartz schist, quartzite and other siliceous rocks in the form of fine-grained impregnation, cement, band-microlayer, agglomerate, and flat lens.

This ore has more primary ore mud and uneven embedded particle size. The concentrate obtained by conventional flotation method has a high silica content. It can be improved by adding reagent pretreatment in the grinding stage, and then flotation can effectively inhibit silicate gangue minerals in this type of mineral.

Carbonate fluorite

Carbonate fluorite is also formed by sedimentation. Fluorite is fine-grained and distributed in limestone and marble. It forms a granular mosaic structure or metamorphic structure with calcite or dolomite. Some of them form stripes, bands, microlayers or thin layers. The main minerals are fluorite and calcite, and the calcium carbonate content is about 30%.

Due to the similar flotation properties of fluorite and calcium carbonate, this type of fluorite is more difficult to select. When fatty acids are used as collectors, high-temperature slurry treatment at 50~60℃ is required, and calcium inhibitors are added. However, this method has high investment costs, large land area, and high production costs.

In addition to the above-mentioned main types of fluorite, there are other types of fluorite. When fluorite is associated with multiple minerals, it is more difficult to select. The selection of flotation reagents and the flotation order are key factors affecting the selection effect.