What is potassium feldspar What is potassium feldspar used for?

Potassium feldspar Feldspar is an aluminosilicate mineral of alkali metals such as potassium, sodium, and calcium or alkaline earth metals, also called feldspar group minerals. Potassium feldspar[1] (kalsi3o8), also commonly known as orthoclase, is a monoclinic crystal system that is usually flesh-red, white or gray in color. Density 2 54-2 57g cm, specific gravity, hardness 6, its theoretical composition is SiO2, K2O.

It has the characteristics of low melting point (1150 20), long melting interval time and high melting viscosity, and is widely used in ceramic blanks, ceramic glazes, glass, electric porcelain, abrasive materials and other industrial sectors and potash fertilizers. In addition to orthoclase, there are two homogeneous polymorphic variants: feldspar and potassium microcline.

The former also belongs to the monoclinic crystal system, also commonly known as orthoclase; The latter belongs to the triclinic system. In addition to being used as raw materials for the glass industry (accounting for about 50-60% of the total amount), feldspar minerals account for 30% in the ceramic industry, and the rest are used in chemical industry and glass melting.

Agents, ceramic body ingredients, ceramic glazes, enamel raw materials, abrasives, glass fiber, welding rods and other industries. It is mainly used for glass, ceramics, and can also be used to prepare potash fertilizer, and better quality potassium feldspar is used to make TV imaging glass shells. Potassium feldspar: , of which K2O, Al2O3 16% or more, SiO2 70%, density 3, Mohs hardness of 6, monoclinic crystal system, color white, red, milky white, melting point 1290 c 。

Aluminosilicate minerals of sodium and potassium. It is the most common mineral in the earth's crust and can be found in igneous rocks, metamorphic rocks, and sedimentary rocks. Feldspar is the main mineral component of almost all igneous rocks and is of great significance for the classification of rocks.

Feldspar isomorphic substitution is well developed, and their chemical composition is often expressed by orxaby anz (x y z 100). OR, AB and AN represent kals3O8, naalsi3O8 and caal2Si2O83 components, respectively. Mainly with a certain two components, it can be divided into two quasi-homogeneous series:

alkaline feldspar series (i.e. OR-AB series); plagioclase series (i.e. ab-an series). The OR and AN components are only very limited miscible and do not form a series. The basic structural unit of feldspar is the tetrahedron, which consists of 4 oxygen atoms surrounding a silicon or aluminum atom.

Each of these tetrahedra shares an oxygen atom with the other tetrahedron, forming a kind of three-dimensional skeleton. Alkaline or alkaline earth metal cations with large radii are located in large voids within the skeleton with a coordination number of 8 (in monoclinic feldspar) or 9 (in triclinic feldspar). Feldspar crystals are mostly plate-like or plate-shaped columns that extend along a crystalline axis.

The phenomenon of double crystal is very common, and there are more than 20 kinds of double crystal laws. The common ones are albite law, Maniba, Bawinno's law, casbarr, and Xiao albite law bicrystal. They are found in triclinic crystals or monoclinic and triclinic crystals, respectively.

Feldspar is commonly milky white, but it is often dyed yellow, brown, light red, dark gray and other colors because it contains impurities, and some can also have beautiful color change or halo. There are two groups of complete cleavage, which are angled at 90° (monoclinic system) or nearly 90° (triclinic system). The specific gravity increases with the increase of the AN content in the component, and decreases with the increase of OR.

The Mohs hardness is 6. Feldspar rich in potassium or sodium is mainly used in the ceramic industry, glass industry and enamel industry; Feldspar containing rare elements such as rubidium and cesium can be used as mineral raw materials for extracting these elements; Beautifully colored feldspar can be used as a decorative stone and as a secondary gemstone.

1. Characteristics and chemical composition:

The hardness of feldspar fluctuates, the specific gravity fluctuates, it is brittle, has high compressive strength, and has strong chemical stability to acids. The color of potassium feldspar is mostly flesh red, but there are also gray and white-brown. Albite is white, gray and light yellow, and afeldspar is white or light gray.

Chemical Composition: SiO2, Al2O3, Fe2O3, K2O, Na2O, Others, Trace.

2. Uses: Manufacture of potash fertilizer, ceramics and enamel, glass raw materials, abrasive abrasives, etc.

Specification chemical composition of the product name.

Feldspar powder 40-80 80-120 120 mesh or more SiO2: 67% Al2O3: 16% P+S>

K2O+Na2O> 13% (up to 18%)

K2O, Na2O are inactive, and are Na, K metal elemental liveliness.

1. Preparation of potash fertilizer. Potassium is an important element for the growth of crops, and there are many potassium-containing resources in the world, but most of them are insoluble or insoluble in water. China is rich in potassium resources, and soluble potassium resources are very poor.

The soluble potassium resources in foreign countries are sufficient to meet the needs of agriculture, so there are few studies on the use of water-insoluble potassium resources to produce potassium fertilizers.

2. Potassium feldspar fireproof calcium silicate board.

The principle of using potassium feldspar to make calcium silicate board is to make a good slurry of raw materials, mix evenly in proportion (potassium feldspar powder: lime: fiber = 229:91:80), prepare the slurry, and use the flow slurry plate making process to make slabs, and the slabs are stacked and sent to the autoclave.

High-temperature and high-pressure steam curing makes the calcium oxide in the silicon aluminum and lime in the material form hydrated calcium silicate under the action of high-temperature hydrothermal reaction, and the hydrated calcium silicate crystalline mineral is cemented with the fiber to form a whole.

3. Use potassium feldspar to produce potassium fertilizer and silica at the same time.

The potassium content in potassium feldspar is, according to the characteristics of the remaining mineral stone after potassium extraction, the comprehensive utilization of research: the principle of preparing silica is based on the potassium feldspar structure has been destroyed after potassium extraction, and then, at a certain temperature reaction with NaOH to prepare water glass, dilute with water while adding an appropriate amount of electrolyte, neutralize with acid and age at a constant temperature, and then filter and wash to obtain silica.

The current state of demand

Potassium feldspar is used as a ceramic body ingredient and ceramic glaze in the ceramic industry, accounting for 30%, and the rest is used in other industries such as chemical industry, glass flux, enamel raw materials, abrasives, glass fiber, welding electrodes and so on. With the development of the economy, the amount of glass products, architectural ceramics and other materials is increasing, the demand for potassium feldspar is increasing, and the market prospect is broad.

With the vigorous development of the ceramic industry, the large consumption of potassium feldspar resources has made the reserves of potassium feldspar continue to decrease, and the cost of mining is increasing, so potassium feldspar has become inevitable. The domestic supply of high-quality potassium feldspar exceeds the demand, and the high-quality potassium feldspar resources used in the ceramic industry are imported from North Korea, India and other countries in large quantities.

From the perspective of the nature of potassium feldspar enterprises in China, the mining operators of potassium feldspar are mainly private enterprises, and the distribution of potassium feldspar mines in China is scattered, the mining conditions are poor, the starting point is low, and the relative risk is small. The concentration of the potassium feldspar industry is low, the number of enterprises is large, the scale is small, and the waste of resources is serious.

The above content reference: Encyclopedia - Potassium Feldspar.

1. Preparation of potassium fertilizer: potassium is an important element for the growth of crops, and there are many potassium-containing resources in the world, but most of them are insoluble or insoluble in water. China is rich in potassium resources, and soluble potassium resources are very poor.

Since the early 60s of the twentieth century, China has begun to use potassium feldspar to produce potash fertilizer, and has carried out dozens of process researches, which can be divided into: sintering method, high-temperature melting method, hydrothermal method, blast furnace smelting method and low-temperature decomposition method.

2. Potassium feldspar fireproof calcium silicate board: The use of potassium feldspar to manufacture calcium silicate board, the principle is to make the raw materials into a pulp, according to the proportion (potassium feldspar powder: lime:

Fiber = 229:91:80) is mixed evenly, the prepared slurry is made into a slab by the flow slurry plate making process, and the slabs are stacked and sent to the autoclave, and the slabs are stacked and sent to the autoclave, and the high temperature and high pressure steam curing makes the calcium oxide in the silicon aluminum and lime in the material generate hydrated calcium silicate under the action of high temperature hydrothermal reaction, and the hydrated calcium silicate crystalline mineral is cemented with the fiber to form a whole.

3. The use of potassium feldspar to produce potassium fertilizer at the same time to produce silica: the potassium content in potassium feldspar is, according to the characteristics of the remaining mineral stone after potassium extraction, the study of comprehensive utilization: the principle of silica preparation is based on the potassium feldspar structure has been destroyed after potassium extraction, and then, at a certain temperature with NaOH reaction to prepare water glass, diluted with water while adding an appropriate amount of electrolyte, neutralized with acid and aged at a constant temperature, and then filtered and washed to obtain silica.

4. Ceramic body ingredients: before firing, feldspar can play the role of barren raw materials, reduce the drying shrinkage and deformation of the body, improve the drying performance, and shorten the drying time. During firing, it can be used as a flux to reduce the firing temperature, promote the melting of quartz and kaolin, and accelerate the formation of mullite by diffusion and penetration in the liquid phase.

The feldspar glass formed during the melting is filled between the mullite grains of the green body, which makes the green body dense and reduces the voids, thereby improving its mechanical strength and dielectric properties. In addition, the generation of feldspar glass can also improve the light transmission of the green body.

5. Glass flux: feldspar is one of the main components of glass mixture. Feldspar has high Al2O3 content, low iron content, and is more fusible than alumina, not only low melting temperature but also wide melting range, mainly used to improve the alumina content in glass ingredients, reduce the melting temperature in glass production and increase the alkali content, so as to reduce the amount of alkali.

In addition, the process of feldspar melting into glass is relatively slow, and the crystallization ability is small, which can prevent the precipitation of crystals and damage to the product during the glass formation process. Feldspar can also be used to adjust the stickiness of glass.

Uses of potassium feldspar

1. Use potassium feldspar to produce potassium fertilizer and silica at the same time.

2. Preparation of potassium fertilizer, potassium is an important element for crop growth, and there are many potassium-containing resources in the world, but most of them are insoluble or insoluble in water.

3. Potassium feldspar fireproof calcium silicate board is made into slabs by flow-slurry plate making process, and the slabs are stacked and sent to an autoclave for high temperature and high pressure steam curing.

Potassium feldspar is an aluminosilicate mineral of alkali metals such as potassium, sodium, calcium, or alkaline earth metals, also known as feldspar group minerals. Potassium feldspar, also commonly known as orthoclase, is a monoclinic crystal system that is usually flesh-red, white, or gray in color. The potassium feldspar series are mainly orthoclase, microcline feldspar, permear, etc.

Potassium feldspar ore is a non-water-soluble potassium resource with higher potassium content, the most widely distributed and the largest storage of cherry blossoms. There are 60 sources of potassium feldspar, and its average potassium oxide content is about, and its reserves are about 100 million tons, which are converted into potassium oxide reserves of about 100 million tons according to the average content. Anhui, Inner Mongolia, Xinjiang, Sichuan, Shanxi and other provinces have concentrated potassium feldspar distribution and abundant reserves, which have become the dominant non-metallic mineral resources in the local area.