Overview: Fluorite, also called calcium fluoride, is a common halide mineral. It is a compound, and its component is calcium fluoride, which is an important mineral for extracting fluorine. Fluorite has many colors and can also be transparent and colorless. Transparent and colorless fluorite can be used to make special optical lenses. Fluorite also has many uses, such as being used as a flux for steelmaking and aluminum production, as a catalyst for making ivory glass, enamel products and high-octane fuel production. Fluorite is generally granular or massive, with glassy luster, mostly green or purple. Fluorite often emits blue-green fluorescence under the irradiation of ultraviolet rays or cathode rays, and its name comes from this characteristic.
Chemical composition: CaF2
Crystal structure: the unit cell is face-centered cubic structure, and each unit cell contains 4 calcium ions and 8 fluorine ions.
Crystalline state: crystal
Crystal system: equiaxed crystal system
Crystal habit: usually cubic, octahedral, rhombic dodecahedron, polygonal, or strip-shaped dense block aggregate.
Common colors: green, blue, brown, yellow, pink, purple and colorless.
Gloss: glass luster to sub-glass luster.
Cleavage: Four groups of perfect cleavage.
Mohs hardness: 4.
Density: 3. 18 (+0.07, -0. 18) g/cm3.
Optical properties: isotropic body.
Polychromaticity: None.
Refractive index: 1.434 (0.00 1).
Birefringence: None.
Ultraviolet fluorescence: it varies with different varieties, and generally has strong fluorescence and can emit phosphorescence.
Absorption spectrum: featureless, with large variation, and generally strong absorption.
Magnification inspection: banded, two-phase or three-phase inclusions show that cleavage is triangular.
Special optical effect: color change effect.
Optimization processing:
Heat treatment: Black and dark blue are often heat-treated into blue, which is relatively stable. Avoid heating to above 300℃ and it is not easy to detect.
Filling treatment: filling surface cracks with plastic or resin to ensure that they do not crack during processing.
Irradiation treatment: colorless fluorite is irradiated into purple, but it quickly fades and is unstable when exposed to light.
Fluorite fluorite, also known as fluorite, is a natural ore. Compared with optical glass, fluorite has the advantages of low refractive index and low dispersion, but it can't be used in practical application because of its difficulty and economic factors. The so-called optical glass used in optics takes silicon dioxide as the main raw material, adds additives such as barium oxide or lanthanum, dissolves in a high-temperature furnace above 1300 degrees, and then solidifies from liquid to solid through extremely slow cooling.
Ancient Indians found that there were many cobras on a small hill. They always wandered around a big stone. A natural phenomenon aroused people's interest in exploring mysteries. It turns out that whenever night falls, the big stones here will flash slightly blue light, and many phototropic insects will fly over the bright stones one after another. Frogs will jump out to hunt insects, and cobras hiding not far away will also hunt frogs. Therefore, people call this kind of stone "snake eye stone". Later, I learned that snake eye stone is fluorite.
The composition of fluorite is calcium fluoride, also known as fluorite and gangue. Because it contains a variety of rare elements, it is often purplish red, green and light blue, and colorless and transparent fluorite is even more rare and precious. The crystal form is cubic, octahedral or rhombic dodecahedron. If fluorite is placed under ultraviolet fluorescent lamp, it will emit beautiful fluorescence.
The application of fluorite and its processed products has involved more than 30 industrial sectors. Adding fluorite in steelmaking can improve the fluidity of molten steel and remove harmful impurities such as sulfur and phosphorus.
Half of the world's fluorite production is used to produce hydrofluoric acid, and then cryolite is developed for aluminum smelting industry. The refrigerant (freon) in the refrigerator should be fluorite; 1986, fluorite was also used in the first generation of artificial blood in China. In recent years, scientists are developing fluoride glass, which may be made into a new type of optical fiber communication material, which can be transmitted across the 20,000-kilometer-wide Pacific Ocean without relay stations.
It is produced all over the world.
Fluorite fluorite is also called fluorite, and its chemical composition is CaF2, and its crystal belongs to the halide mineral of equiaxed system. It emits blue or purple fluorescence under ultraviolet rays, cathode rays or heating, hence the name. Crystals are often cubes, octahedrons or cubes with twins, and the aggregate is granular or massive. Light green, light purple or colorless and transparent, sometimes with rose red and white stripes, with glass luster, transparent to opaque. Octahedral cleavage is complete. Mohs hardness 4, specific gravity 3. 18. Fluorite mainly occurs in hydrothermal veins. Colorless and transparent fluorite crystals occur in caves of granite pegmatite or fluorite veins. The total reserves of fluorite in the world are about 654.38+0 billion tons, and China is one of the countries with the largest fluorite minerals in the world, accounting for 35% of the world's reserves. According to archaeological excavations, Hemudu people in Yuyao, Zhejiang Province chose fluorite as an ornament 7000 years ago. There is indeed a fluorite mine in the south of Hemudu. Location: Zhejiang, Hunan, Fujian and other places. Other major producing areas in the world are South Africa, Mexico, Mongolia, Russia, the United States, Thailand, Spain and other places. Fluorite can be used as a flux in metallurgical industry and as a raw material for manufacturing hydrofluoric acid in chemical industry.
Special note: Fluorite is often made into various ornaments because of its large size and rich colors, but its hardness is low. Please don't wear it with rock crystal, the crystal will scratch fluorite! Fluorite collected directly from the mine has certain radiation and cannot be placed in the bedroom!
Fluorite and luminous pearl: there are two ways to emit light from fluorite: fluorescence and phosphorescence. Fluorescence means that it can emit light for a short time after the light source is removed (all fluorite can be used), while phosphorescence belongs to internal energy luminescence caused by rare earth ions, and it can continue to emit light without external light source supplement. The luminous pearl that can emit phosphorescence is rare and valuable for collection (this kind of fluorite containing phosphorus is very rare in nature). Only after careful polishing can it be made into a night pearl. It is normal for fluorite to fluoresce, but it does not mean that it is a real night pearl, which leads to a fluorite ball on the market being identified as a night pearl. The luminous mechanism of the night pearl is related to the doping of rare earth elements, that is, "trivalent rare earth elements enter the crystal lattice to form luminous centers and electron capture centers". When electrons are excited by heat or light, they return to their original positions at night to release light energy, which is called "phosphorescence" in mineralogy.
Fluorite (calcium fluoride CaF2) and concentrated sulfuric acid are used to produce hydrofluoric acid in industry.
When heated to 250 degrees Celsius, these two substances react to produce hydrogen fluoride. The reaction equation is:
Calcium fluoride+sulfuric acid → hydrofluoric acid+calcium sulfate
The steam produced by this reaction is a mixture of hydrogen fluoride, sulfuric acid and several other by-products. After that, hydrogen fluoride can be purified by distillation.
Use concentrated H2SO4!
Various mineral processing methods of fluorite;
1 fluorite decalcification process CN99 1 14389
The invention discloses a mineral processing technology for removing calcium from fluorite, which consists of one roughing and multiple cleaning operations, wherein oleic acid or its substitute is used as a collector for roughing, and the mixture of sulfuric acid and acidic water glass is used as an inhibitor of calcium-containing minerals, the ratio of sulfuric acid to acidic water glass is 1: 0.5- 1: 2, and the combined dosage is 0.5-1.5 kg. The beneficiation process for removing calcium from fluorite provided by the invention has the advantages of high calcium removal efficiency, simple process and low cost, and can select super fluorite concentrate with low calcium carbonate content from fluorite ore with high calcium.
2 natural fluorite fluorescent coating
The processing technology of natural fluorite varnish includes mineral processing, crushing, preparation, mixing and sintering. The invention has the advantages of simple process and low cost, and can meet the coating requirements of handicrafts and various articles with fluorescent effect requirements.
3. A preparation method of fluorite flotation agent
The invention discloses a preparation method for preparing a fluorite flotation collector, which takes crude fatty acid or mixed fatty acid, an intermediate product produced by oleic acid, as raw materials, adds concentrated sulfuric acid accounting for 3%-65% of the weight of the fatty acid for sulfation reaction, and then adds mineral processing foaming agent accounting for 0.4%-3% of the weight of the fatty acid to obtain the product. The invention has low production cost, and the produced fluorite flotation collector has strong collecting ability, good water solubility and dispersibility, and is suitable for fluorite flotation at normal temperature and low temperature.
4 composition of fluorite flotation regulator
The invention relates to a technological method of fluorite flotation, which is based on patent number 87 105202. In the prior art, acid and synergist are used as regulators in fluorite flotation. According to the invention, a composition formed by mixing water glass with acid and one or more soluble salts of the acid is used as a regulator to form a composition series, that is, any acid of sulfuric acid, hydrochloric acid, nitric acid, oxalic acid and acetic acid and its corresponding salts can be used, and the combination ratio range is water glass, acid and salt = 1 ~ 2: 1 ~ 5: 0.5 ~ 65. The invention has strong adaptability, good stability, high concentrate quality, high recovery rate and low cost.
5 carbonate-fluorite flotation separation method
The invention provides an economical and effective flotation separation method of carbonate-fluorite ore, which is especially suitable for flotation separation of fluorite ore with high carbonate content. The key is to select an effective carbonate mineral inhibitor-acidified sodium silicate and dosing measures, so that carbonate and fluorite can be separated with high purity under conventional technological conditions.
6 Flotation method of fluorite
The invention relates to a method for flotation of fluorite ore by using an adjusting agent. According to the invention, the mixed reagent consisting of acid, alkali and synergist is used as the regulator, oleic acid or sodium oak oil is used as the collector, the technological process is a composite process, and fluorite flotation is carried out at near neutral and normal temperature, so that the obtained fluorite concentrate has high recovery rate, good product quality, low impurity content, low reagent consumption and low cost, and is suitable for various fluorite concentrator applications.
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