How is Fluorite Extracted?
Summary of Fluorite Ore Flotation Process
Taking deep research on the features, extraction methods, and fluorite mining machines have a significant positive effect on running the fluorite processing plant successfully. In the following paragraphs, I have made a detailed introduction from fluorite mineral attribute to extraction methods and machines and listed 2 cases for your reference.
1 Description of fluorite
Fluorite (also called fluorspar) is a mineral that common in nature, consists mainly of calcium fluoride( CaF2), can be symbiotic with many other minerals. More in wiki
- Mohs hardness scale: 4
- Tenacity: Brittle
- Solubility: slightly water-soluble and in hot hydrochloric acid
- Occurrence: it often occurs in the hydrothermal veins deposit, has been known as a common mineral in the igneous rocks like granites, can be found in carbonate rocks, alkaline intrusive rocks, and near the jet holes around the volcano.
- The minerals that are symbiotic with fluorite: scheelite, apatite, topaz, cassiterite, wolframite, pyrite, calcite, sphalerite, lapis lazuli, muscovite, quartz, Galena, dolomite, chalcopyrite, albite, spinel, rhodochrosite, barite.
- Types of Fluorite: Fluorite can be divided into single type fluorite and associated type fluorite, and the associated type fluorite includes quartz type fluorite, calcite type fluorite, barite type fluorite, and sulfide ore type fluorite. The single type fluorite ore has a high grade (contains only a small amount of quartz and calcite), but the reserves are low. The associated type fluorite ore reserves are large, but the grade is low, thus the beneficiation process is more difficult.
- Multi Gangue Fluorite deposit: According to the difference of deposit formation, divides into the calcite-fluorite-type stratiform deposit that in the sedimentary formation, quartz-fluorite-type vein deposits that in the metamorphic rock and magmatic rock, fluorite-barite vein deposit, and the polymetallic-fluorite-type sulfide deposit.
2 Flotation Processes of 4 types of associated fluorite
Just as is the case with almost ore processing and non-metal beneficiation, the concentrate fluorite is extracted by crushing, sieving, grinding, grading, flotation, filtration, drying, etc.
How to realize the high-efficiency sorting of associated fluorite ore is a real problem in the fluorite beneficiation process. Therefore, based on the characteristics of the associated fluorite ore, summarized the beneficiation method and floating agent of the types of associated fluorite ore. We, the JXSC mining machine factory, would be delightful provide you with the flotation machines.
2.1 Quartz type fluorite ore
The separation of quartz and fluorite achieved by grinding, it is an important factor affecting the flotation of quartz-type fluorite. The ground ore of a coarse size indicates that may have many associated fluorite ore lumps, these lumps may increase the silica content, decrease the flotation effect. If the grinding particle size is too fine, although quartz and fluorite have been dissociated from the monomer, it will cause the fluorite losing easily, thus reduce the recovery rate of fluorite.
In order to dissociate the fluorite from the quartz and not to pulverize the fluorite, the stage grinding process is generally used, which can reduce the silicon content in the fluorite concentrate after flotation and increase the fluorite recovery rate.
The results show that under the same conditions of grinding fineness, the fluorite concentrate by rod mill obtains a lower Si O2 content. Compared with ball milling, the particle size of rod grinding is more uniform, rod mill control the grinding fineness better.
In order to solve the difficulties in the separation of high calcium quartz fluorite ore, researchers did a great time of experiment. Studies have shown, the fluorite beneficiation effect of 97.21% concentrate grade and 69.04% recovery rate can be obtained when the condition of -0.074 mm grain taking 83.62% percentage, flotation 6 times, the PH value of slurry is 9-10，YN-12 as the capture agent, sodium silicate, tannic and the Calgon as the inhibitors.
When the PH value is 6, the sodium oleate has a significant effect on the recovery of pure fluorite minerals during the flotation process. However, when the slurry contains fine-grained quartz ore, the performance of sodium oleate to capture fluorite decreases. The capture ability of the oleic acid gradually improved by adding the sodium hexametaphosphate to disperse the quartz and fluorite.
In a word, fine-grained quartz type fluorite ore is better to adopt the stage grinding process method to get the best size. Besides, it is best to use Na2CO3 to adjust PH value, choose oleic acid, oxidized paraffin, sodium silicate as a combination of collector and inhibitor.
2.2 Calcite type fluorite ore
Calcite type fluorite ore mainly consists of fluorite, and calcite( more than 30%). Since both calcite and fluorite are calcium-containing minerals, they have similar surface physicochemical properties. When coexisting in solution, they are prone to the mutual transformation between minerals, making separation of the two difficult to achieve.
Fatty acid collectors can float both of calcite and fluorite, therefore, it is needed to adjust the PH value of slurry. Practice shows that the PH value has a great impact on the flotation. When the PH value in the range of 8-9.5，the fatty acid collectors can display function both of the fluorite and calcite. But in the weak acidic medium, the calcite has a lower floatability.
Although it is difficult to separate calcite and fluorite by flotation, we still have chance to realize it by adjusting the PH value, choosing suited inhibitor(sodium silicate, salinization sodium silicate, acidification sodium silicate, Calgon, lignin sulfonate, dextrin,tannin, etc.), and using oleic acid as the trapping agent.
2.3 Barite type fluoride ore
The barite type fluoride ore mainly consists of barite(10%-40%) and fluoride, also associated with iron pyrite, gelenite, sphalerite, and other sulfide minerals. It is not easy to separate the barite and fluoride because of the similar floatability.
In general, the flotation process of the barite type fluoride ore is divided into two steps, one is combination flotation that obtains the combination of concentrate both of barite and fluorite, another is flotation that separation the barite and the fluorite from the combination concentrate.
Flotation of the first step: Na2CO3 as the conditioner of PH value, oleic acid as the capture agent, and sodium silicate as the inhibitor.
Flotation of the second step has two ways:
1 Inhibiting barite and floating fluorite: inhibitors have lignin sulfonate, sodium silicate, NAF, dextrin, aluminum salt, ferric salts; captor has oleic acid.
2 Inhibiting fluorite and floating barite: adjusting the PH value the slurry to strong alkalinity by the sodium hydrate, using the citric acid, barium chloride, ammonium salt, sodium silicate as the inhibitors, and using the oleic acid or sodium alkyl sulfate as the collector.
2.4 Sulfide type fluorite
The mineral composition of sulfide-type fluorite is similar to that of quartz type fluorite, but the content of the metal mineral is higher than that of the quartz type, and sometimes, the content of lead and zinc can reach the industrial grade. Therefore, it is necessary to take the recovery of the other metal mineral into considered.
Usually, adopt the captor for sulfide minerals to select the metal sulfide minerals preferentially, then use the captor of fatty acid to recover the fluorite from the flotation tailings. In addition, roasting, leaching, and other processes can also help to extract valuable metals and to decompose fluorite.
3 Words in the End
A great deal of research and production practice shows that flotation is a useful method for recovering fluorite ores, suit for large scale fluorite ore processing, the beneficiation method( flotation process and chemical agent) varies from the ore characteristics. if you need a fluorite ore flotation machine, pls contact us.