The main fluorite beneficiation process is 1, and fluorite ore is hand-selected.
Hand-selected method is mainly used in fluorite mine where the boundary between fluorite and gangue is very clear, waste rocks are easy to be removed, and ores of different grades are easy to be identified by naked eyes. The fluorite hand selection method mainly includes washing, screening and hand selection. The washed and screened raw ore is divided into large blocks, medium blocks and particles (the particle size is 6- 15mm), which enter the hand-selected field, and are manually classified and stacked in stages. Granular ore enters gravity separation, and tailings are processed into fluorite concentrate by flotation.
2, fluorite ore gravity separation method
The fluorite gravity separation method is mainly used to separate high-grade granular ore with particle size of 6-20 mm. The technological process of fluorite gravity separation is as follows: the raw ore is crushed to below 25-30mm, screened and classified, the fine fraction is separated by jig or shaker, the coarse fraction is separated by heavy medium, and ferrosilicon is often used as a weighting material (high-density solid particles for preparing heavy suspension). When the selected fluorite contains heavy metal minerals such as barite and galena, fluorite is recovered as the first heavy object.
3, fluorite flotation method
The mineral types of fluorite can be divided into single fluorite type, isochron-fluorite type, calcite-fluorite type, carbonate-fluorite type, sulfide-fluorite type, barite-fluorite type, siliceous rock fluorite type and so on. Flotation is a widely used method of fluorite ore at home and abroad at present, and it is the main beneficiation method to obtain high quality fluorite concentrate. Flotation can be used for single fluorite ore or associated fluorite ore, fluorite ore with simple ore structure or complex fluorite ore, and fluorite ore embedded with coarse or fine crystals.
Mineral processing methods of different types of fluorite ore 1, timely fluorite ore processing.
The timely fluorite ore is mainly composed of fluorite (about 85%) and timely, with only a small amount of calcite, barite and sulfide. The key to its separation lies in the silicon reduction of concentrate.
If we want to separate chronometer from fluorite, we must determine the appropriate grinding fineness, and chronometer and fluorite can be separated by grinding. Therefore, grinding fineness is an important factor affecting the flotation of timely fluorite.
If the grinding particle size is too coarse, there will be symbionts of timely and fluorite in the product, which will lead to too high silicon content in the rough concentrate after flotation. Grinding particle size is too fine. Although timely and fluorite have been separated, it will lead to excessive crushing of fluorite in grinding products and greatly reduce the recovery rate of fluorite. Therefore, it is suggested that the stage grinding-stage flotation process can not only reduce the silicon content in fluorite concentrate after flotation, but also improve the recovery rate of fluorite concentrate.
2. Mineral processing of carbonate fluorite
The main minerals of carbonate fluorite are fluorite and calcite (with a content of more than 30%), some contain a small amount of calcite, and sometimes form calcite-fluorite.
The difficulty in mineral processing of fluorite ore containing calcite is that calcite and fluorite are both calcium-containing minerals with similar surface physical and chemical properties, and it is easy to transform between minerals when they exist in solution. To realize the separation of calcite and fluorite, it is necessary to adjust the pH value of pulp and cooperate with collectors to achieve good separation effect. In the range of pH 8-9.5, both ores can be floated when oleic acid is used as collector, but the floatability of calcite is relatively lower than that of fluorite in weak acid medium. Sodium silicate, sodium salt silicate, acidified sodium silicate, sodium hexametaphosphate, lignosulfonate, dextrin, tannin and tannin extract are used alone or in combination to inhibit calcite, thus achieving the purpose of separation.
3. Mineral processing of barite fluorite
The main minerals of barite fluorite ore are barite and fluorite, and the barite content is generally 10%-40%. This kind of ore is often associated with pyrite, galena, sphalerite and other sulfide minerals. The difficulty in beneficiation of barite fluorite is that the floatability of barite and fluorite is similar and it is difficult to separate. In this regard, the flotation of barite fluorite generally requires mixed flotation process and Na2CO3 to adjust the pH value of pulp, and oleic acid and sodium silicate are used as collectors and inhibitors respectively to obtain mixed concentrate of fluorite and barite, and then barite is separated from fluorite by flotation.
4. Mineral processing of sulfide fluorite
The mineral composition of sulfide fluorite is similar to that of seasonal fluorite, but the content of metal sulfide is high, and sometimes the content of lead and zinc can reach industrial grade. Therefore, the recovery of metal ore should be considered when developing and utilizing fluorite. Generally, sulfide collectors can be used to preferentially select sulfide minerals, and then fatty acid collectors can be used to recover fluorite from flotation tailings.