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2021-11-09 14:43:31 Micro Powder Technology
Feldspar Grinding Mill Machine
During work, the main motor drives the main shaft and turntable to rotate the reducer, and the roller pins at the end of the turntable drive dozens of grinding rollers to rotate the grinding ring track.
Large material is shredded with a hammer crusher, sent to the silo by elevator, and evenly delivered to the bulk tray on top of the turntable through a vibrating feeder and inclined feed tube.
The material is dispersed around the circle by the action of centrifugal force, falls into the path of the grinding ring, is impacted by the ring roller, is rolled and ground. After the 3-layer / 4-layer circuit is processed into powder, a high-pressure fan sucks the outside air into the machine by suction and conveys the shredded material to the powder concentrator.
The rotating classifier impeller backs up and regrinds the coarse-grained material. The fine dust that meets the requirements enters the cyclone dust collector with the air flow and is discharged as a final product from the discharge valve at the bottom of the cyclone tube. The air stream containing a small amount of fine dust is purified by a pulse dust collector and discharged from the fan and muffler.
Extended reading:
Feldspar is an aluminosilicate mineral of alkali metals or alkaline earth metals such as potassium, sodium, calcium, and barium, and is one of the important rock-forming minerals. Pure feldspar rarely exists in nature. According to the type of deposit, feldspar can be divided into pegmatite-type feldspar, baigang-type feldspar, granite-type feldspar, and feldspar placer. Common feldspar beneficiation processes mainly include manual separation, desliming, magnetic separation, gravity separation, flotation, and a combination of multiple beneficiation methods to remove quartz, iron, mica and other associated minerals.
Generally, the feldspar of pegmatite-type feldspar deposits is of good quality and simple in mineral composition, so the beneficiation process is relatively simple. The beneficiation principle process includes sorting, crushing, grinding, and strong magnetic separation operations.
◆ Sorting operation: manual or color sorting to separate large gangue minerals;
◆ Crushing operation: coarse crushing and crushing;
◆ Grinding operation: use a gravel mill or rod mill lined with ceramic liner and quartzite for continuous grinding operation;
◆ Strong magnetic separation operation: strong magnetic separation is used to remove magnetic minerals such as iron, and the magnetic field strength is generally above 1200kA/m.
Baigang-type feldspar minerals are formed uniformly and have stable quality. Potash feldspar and albite account for about 50-60%. Gangue minerals mainly include quartz, mica and iron-containing minerals. Generally, this type of ore deposit needs to be processed by flotation to obtain feldspar concentrate. The main processes of beneficiation principles are as follows:
a. Crushing operation: the raw ore is crushed to about 20mm by coarse crushing (jaw crusher) and medium crushing (cone crusher);
b. Grinding and grading operation: After the crushed product is mixed, it is wet ground to -20 mesh in a closed loop operation consisting of a rod mill and a trommel, and then the -200 mesh level is removed by a cyclone and a spiral classifier. Granular clay impurities, -20 mesh-+200 mesh grade materials are sent to the flotation operation.
c. Flotation operation: remove impurities such as mica, iron minerals and quartz.
In the first stage, mica is obtained by flotation with cationic collectors (mainly amine collectors) in a weakly acidic medium. The mica is purified by flotation and wet sieved with an 80-mesh vibrating screen. Wet mica with more than 80-mesh is sold to the mica processing plant;
In the second stage, an anionic collector (mainly sulfonated oil) is used to remove iron-containing minerals in a weakly acidic medium;
In the third stage, a combined collector is used to separate feldspar and quartz in a weakly acidic medium.
Of course, the flotation operation is appropriately adjusted according to the mineral composition.
If the content of mica in the grinding product is very small, it can skip the first stage of flotation and go directly to the second stage of iron removal flotation;
If after the first and second stages of flotation operations, the content of iron and quartz can meet the requirements of some glass factories, the third stage of flotation and separation of feldspar and quartz can be omitted, and the product can be made of feldspar silica sand. The form of the mixture is directly used as the glass batching.
Granite-type feldspar is a kind of coarse-grained acidic plutonic igneous rock. Its distributing grain is finer than pegmatite. The quartz content accounts for about 25-30%, and the mica and iron-containing minerals account for about 10%. Feldspar is its main component (alkaline), that is, a kind of crystalline feldspar composed of potassium feldspar and albite in a certain ratio.
Granite inlaid cloth has a fine grain size, so the cost of grinding and beneficiation is relatively high.
The granite-type feldspar beneficiation process is roughly the same as the baigangite beneficiation process. The beneficiation principle includes crushing, grinding, classification, flotation (removal of iron and mica), and flotation (separation of quartz and feldspar).
The flotation operation of grinding products should be determined according to the mineral composition.
If the content of mica and iron is low, it usually goes directly to the flotation separation operation of quartz and feldspar after grading desliming.
If the content of impurities such as mica and iron is high, it is necessary to remove the impurities such as iron and mica by flotation first, and then perform the separation and flotation operation of feldspar and quartz.
The main components of feldspar placer are quartz and feldspar, which are mainly formed by the accumulation of some granite and feldspar-bearing metamorphic rocks during long-term weathering. The quality of feldspar placer is not as good as that of pegmatite feldspar deposits, but because the crushing and grinding operations are omitted in the mining process, the cost of beneficiation is relatively low, and it is also one of the important sources of feldspar concentrates.
The beneficiation process of feldspar placer is relatively simple. The beneficiation principle process mainly includes ore washing, scrubbing, grading, magnetic separation, flotation, etc.; grading products need to be determined according to the mineral composition for subsequent separation operations.
The above is the common four types of feldspar ore beneficiation process. Before feldspar beneficiation, each mine owner must determine the chemical composition of the raw ore, mineral composition, ore structure, particle size composition, raw ore density, and relative grindability of the raw ore, and scientifically select the single or combined ore recommended in the beneficiation test report. The process is to remove the associated minerals such as quartz, iron, mica, etc., and effectively recover the feldspar concentrate rich in potassium and sodium.
The characteristics and applications of potash feldspar
Potash feldspar is also called orthoclase, which belongs to the monoclinic crystal system, and is usually flesh-red, white or gray. Density 2.54-2.57g/cm. Hardness 6. Pure feldspar rarely exists in nature. Even in the mineral called "potassium feldspar", there may be symbiosis or mixing with some albite.
Potash feldspar
The feldspar mineral composed of potash feldspar and albite is generally called alkali feldspar;
The feldspar mineral composed of albite and anorthite is called plagioclase;
The feldspar mineral composed of anorthite and barium feldspar is called alkaline earth feldspar.
Potassium plagioclase is a kind of potassium feldspar whose crystal system is triclinic crystal system,
When albite is mixed in potash feldspar in a regular arrangement, it is called fringe feldspar.
Potassium feldspar powder has the characteristics of low melting point, long melting interval and high melt viscosity. The development and utilization of potash feldspar can be traced back to the Neolithic Age. People used potash feldspar and other raw materials to produce a large number of exquisite colored pottery.
1. In modern industry, it is widely used in industrial sectors such as ceramic blanks, ceramic glazes, glass, electric porcelain, abrasive materials, and potash fertilizer.
2. The amount of potassium feldspar in the glass industry and ceramic industry accounts for 80-90% of the total. The rest is used in chemicals, glass fluxes, ceramic body ingredients, ceramic glazes, enamel raw materials, abrasives, glass fibers, Welding electrodes, fertilizers and other industries.
3. There are also some innovations in the research work of potash feldspar in material preparation. The main achievements are the preparation of 13X molecular sieves, zeolite molecular sieves, and the synthesis of white carbon black.
Application of potassium feldspar in the glass industry
The consumption of potash feldspar in the glass industry accounts for about 50% of the total output of potash feldspar. As one of the glass raw materials, potash feldspar has the following main functions:
1. Potash feldspar is rich in Al2O3 and has a low iron content. It can provide the Al2O3 needed in the glass batching. It is more meltable than Al2O3, has a lower melting temperature and a wide melting range. Therefore, it can lower the melting temperature of the glass and reduce the amount of soda ash. The aluminum in potash feldspar replaces part of the silicon, which can improve the glass's toughness, strength and resistance to acid and alkali corrosion.
2. The process of melting potash feldspar into glass is relatively slow, and its crystallization ability is small, which can prevent crystals from being precipitated during the glass forming process and affect normal production or glass defects.
3. The viscosity of glass liquid can be adjusted.
Application of potash feldspar in the ceramic industry
The consumption of potash feldspar in the ceramic industry accounts for about 30% of the total output of potash feldspar. Potash feldspar in the ceramic three-component (ie clay, quartz, feldspar) blank system, in addition to supplying Al2O3 and SiO2, it can also provide alkali metal oxides. It is both a barren raw material and a solvent raw material.
As a barren raw material, it has the effects of reducing the plasticity and cohesiveness of the clay or the green body, reducing the shrinkage deformation of the green body during drying and firing, improving the drying performance and shortening the drying time. In the glaze, potash feldspar is the main component that forms the glass phase.
Potash feldspar, as a solvent component in ceramic blanks, has the following main functions:
1. Potash feldspar begins to melt at 1130°C, forming a viscous melt phase, which can reduce the melting temperature of the green body, which is beneficial to porcelain formation and lowering the firing temperature.
2. Potassium feldspar melt can dissolve part of the decomposition products of kaolin and quartz particles. The interaction of Al2O3 and SiO2 in the liquid phase promotes the nucleation and growth of mullite crystals, giving the body mechanical strength and chemical stability.
3. Potash feldspar melt is filled between the crystal grains, which helps compact the green body and reduce porosity. After the potassium feldspar melt is cooled, it forms the glass matrix of the porcelain, which can improve the transparency and help improve the mechanical strength and electrical properties of the green body.
4. The composition of potash feldspar contains the main oxides SiO2, Al2O3, CaO, MgO, Fe2O3, TiO2, K2O and Na2O in the porcelain blank, so it is used as the main raw material to replace industrial raw materials such as soda ash, pyrophyllite, and industrial alumina. Reduce production costs.
The ceramic industry is developing rapidly. With the development of special ceramics, the technological changes in the ceramic industry have put forward higher requirements for potash feldspar. Therefore, it is imperative to accelerate the application and research of potash feldspar.
Natural potash feldspar contains various oxides such as K2O, Na2O, SiO2, Al2O3, Fe2O3, and the chemical composition is unstable. Special ceramics have strict requirements on the chemical composition of raw materials, and the chemical stability of potash feldspar has become the main obstacle hindering the development of potash feldspar in the field of technical ceramics.
The potassium feldspar powder required for special ceramics has a particle size in the range of 0.05 to 40 μm, and the particle size is required to be uniform. The focus of the development of potash feldspar crushing and separation technology will be superfine crushing and fine classification technology.
Application of potash feldspar in Fertilizer Industry
The chemical properties of potash feldspar are extremely stable. Except for hydrofluoric acid, it is hardly decomposed by acid or alkali at normal pressure and temperature. The potassium oxide contained cannot be directly absorbed by plants as potassium-containing fertilizers. In order to make potash feldspar a useful potassium resource, the potassium oxide in it has been changed to water-soluble or citric-soluble. Various processes have been studied on the use of potash feldspar to make potash fertilizer, which can be divided into: blast furnace Smelting method, autoclave method, open leaching and closed constant temperature method, thermal decomposition water leaching method, thermal method to make citrate-soluble potassium, acid decomposition method, sintering method, low temperature decomposition method, microbial method, etc.
Albite is a kind of feldspar, a common feldspar mineral, sodium aluminosilicate (NaAlSi308). Albite is generally a glassy crystal, which can be colorless or white, yellow, red, green or colored. It is the raw material for manufacturing glass and ceramics.
Many rocks have albite, and people call such minerals as rock-forming minerals. Albite is mainly used to make ceramic soap tiles, floor tiles, glass, abrasives, etc. It is mainly used for glazes on ceramics.
Albite is a common feldspar mineral, sodium aluminosilicate (NaAISi3O8). Pegmatite and felsic igneous rocks such as granite are the most common. They are seen in low-grade metamorphic rocks and are found in some sedimentary rocks as authigenic albite. Albite usually forms brittle glassy crystals of various colors. It can be used to make glass and ceramics, but its main significance is that it is a rock-forming mineral.
Albite is a sodium end member mineral of plagioclase solid solution series and alkaline feldspar series. With a tri-cline structure, silicon and aluminum are coordinated in tetrahedrons to form larger vacancies (i.e. lattice positions), which are mainly occupied by the cation sodium. Although all silicon atoms and aluminum atoms occupy tetrahedral positions in this structure, their positions are different. At low temperatures, the distribution of silicon and aluminum atoms is highly ordered. At high temperatures of about 1100°C, the distribution of atoms is much more disordered.
Physical and chemical properties
The chemical formula of albite is: Na2O-AI203-6SiO2. Its theoretical chemical composition is Na20: 11.8%; AI2O3: 19.4%; SiO2: 68.8%. The appearance of albite is generally white and gray, with a hardness of 6-6.5, and density. It is 2.61 ~ 2.64g/cm3, and the melting point is about 1100°C. It is difficult for natural albite minerals to reach its theoretical value. The closer the feldspar chemical composition is to its theoretical value, the purer the feldspar and the better the quality. During the heating process of albite, its theoretical melting point is 1100°C. The melting point of natural albite ore varies with the chemical composition.
1. The melting of quartz, clay and mullite is fast and the solubility is high at high temperature.
2. Low melting temperature and good transparency.
3. The melting temperature range is narrower than that of potassium feldspar, the high temperature viscosity of the melt is smaller, and the change with temperature is faster.
In addition to being used as industrial raw materials, albite minerals account for more than 30% of the ceramic I industry and are also widely used in other industries such as chemical industry.
1. Glass solvent:
Feldspar is one of the main components of the glass mixture. Feldspar contains high alumina and low iron content, which can reduce the amount of alkali. In addition, the process of melting feldspar into glass is relatively slow, and the crystallization ability is small, which can prevent crystals from separating out during the glass formation process and destroying the product. Feldspar can also be used to adjust the viscosity of the glass. Generally, potassium feldspar is used for various glass mixtures. Or albite.
2. Ceramic body ingredients:
Feldspar can act as a barren raw material before firing, reduce the drying shrinkage and deformation of the body, improve drying performance, shorten the drying time, and can be used as a flux to fill the body during firing. Make the green body compact and reduce the voids, and can also improve the light transmittance of the green body.
3. Ceramic glaze:
Make the glaze soft and reduce the melting temperature of the glaze.
4. Raw materials for enamel:
Mainly use feldspar and other mineral raw materials to blend into enamel, and the blending amount is usually more than 20-30%.
5. Others:
Potassium and albite can also be used as high-quality raw materials for the production of fertilizers.
