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Brief introduction of potash feldspar2020-08-31 16:57:09

Potash feldspar is usually also called orthoclase; potash feldspar series mainly include orthoclase, micro-plagioclase, streak feldspar and so on.
Potash feldspar is a potassium aluminosilicate mineral with a framework crystal structure composed of silicon-oxygen tetrahedrons. Its chemical formula is: K2O·Al2O3·6SiO2; its main components are SiO2, Al2O3, K2O, CaO, etc. Theoretical chemical composition: K2O16.7%, Al2O318.3%, SiO264.7%.
Potash feldspar is generally fleshy red, yellowish white, white or gray; crystals are often short column or thick plate; glass luster; specific gravity 2.56; Mohs hardness 6; melting point 1290℃.
Potash feldspar is widely used in ceramic blanks, ceramic glazes, fireproof calcium silicate boards, glass industry and enamel industry, abrasive abrasive tools, etc. The beautiful color can be used as decorative stones and inferior gems. In addition, potash feldspar can also be used to make potash fertilizer; potash feldspar with better quality is used to make television imaging glass bulbs.
Application in the glass industry
Potash feldspar is one of the main components of the glass mixture, and the amount used in the glass industry accounts for about 50-60% of the total amount of potash feldspar. The main functions are: (1) Potash feldspar is rich in Al2O3 and has low iron content. It can provide Al2O3 required in the glass batching, reduce the melting temperature of the glass, reduce the amount of soda ash, and improve the glass toughness, strength and resistance to acid and alkali corrosion. (2) The process of melting potassium feldspar into glass is relatively slow, and the crystallization ability is small, which can prevent the precipitation of crystals during the glass formation process and affect normal production or glass defects. (3) The viscosity of the glass can be adjusted to improve the processing adaptability of the glass.
Application in the ceramic industry
Ceramic blank
The amount of potash feldspar in the ceramic industry accounts for about 30% of the total amount 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, which is both a barren raw material and a flux raw material. Potash feldspar can act as a barren raw material before firing, reducing the drying shrinkage and deformation of the green body, improving drying performance, and shortening the drying time; it can be used as a flux to reduce the firing temperature during firing, and promote the melting of quartz and kaolin. And diffuse and penetrate each other in the liquid phase to accelerate the formation of mullite, and the formed feldspar glass body is filled between the mullite grains of the green body to make the green body compact and reduce voids, thereby improving its mechanical strength and Dielectric properties. In addition, the formation of feldspar glass can also improve the light transmittance and transparency of the green body, and give the green body higher mechanical strength and chemical stability.
Ceramic glaze
Ceramic glaze is mainly made of feldspar, quartz and clay raw materials. Among them, the most commonly used potassium feldspar can reach 10-35%. It is the main component of the glass phase and has a wide melting range and a large high temperature viscosity. , It can broaden the melting temperature range of the glaze, which is conducive to porcelain-forming and lowering the firing temperature, improves the gloss, transparency and smoothness of the glaze layer, improves the chemical stability of the glaze layer, and improves the grade and quality of the product.

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