An aluminosilicate mineral containing calcium, sodium and potassium. It is the most common mineral in the earth's crust and can occur in igneous rocks, metamorphic rocks, and sedimentary rocks. Feldspar is the main mineral component of almost all igneous rocks and is important for the classification of rocks.
The feldspar-like isomorphism is very developed, and their chemical composition is usually expressed by OrxAby Anz (x+y+z=100). Or, Ab and An represent KAlS3O8, NaAlSi3O8 and CaAl2Si2O83 components, respectively. Based on a certain two components, it can be divided into two isomorphic series: alkaline feldspar series (ie Or-Ab series); plagioclase series (ie Ab-An series). The Or and An components are only very miscible and do not form a series. The basic structural unit of feldspar is a tetrahedron, which consists of four oxygen atoms surrounding a silicon atom or an aluminum atom. Each such tetrahedron shares an oxygen atom with another tetrahedron to form a three-dimensional skeleton. Large radius alkali or alkaline earth metal cations are located in large voids within the framework with coordination numbers of 8 (in monoclinic feldspar) or 9 (in triclinic feldspar).
The feldspar crystals are mostly plate-like or plate-like columns extending along a certain crystal axis. The twin crystal phenomenon is very common, and there are more than 20 twin crystal laws. Commonly, there are sodium feldspar law, Manniba, Bavenno, Kasbah, and Sodium feldspar. They are present in triclinic crystals or monoclinic and triclinic crystals, respectively. Feldspar is often milky white, but it is often dyed yellow, brown, light red, dark gray, etc. due to impurities, and some can also have beautiful color change or color. There are two groups of complete cleavage with an angle of 90° (monoclinic system) or nearly 90° (triclinic system). The specific gravity is between 2.56 and 2.76, which increases with the increase of the An content in the composition, and decreases with the increase of Or. The Mohs hardness is 6 to 6.5.
The feldspar rich in potassium or sodium is mainly used in the ceramic industry, the glass industry and the enamel industry; feldspar containing rare elements such as strontium and barium can be used as a mineral raw material for extracting these elements; the beautiful feldspar can be used as decorative stone and secondary And so on.
First, feldspar characteristics and feldspar chemical composition:
The hardness of feldspar fluctuates from 6 to 6.5, the specific gravity fluctuates from 2 to 2.5, is brittle, has high compressive strength, and has strong chemical stability to acid. The color of potassium feldspar is mostly flesh red, and it is also gray and white brown. Sodium feldspar is white, gray and light yellow, and anorthite is white or light gray.
Chemical composition SiO2 Al2O3 Fe2O3 K2O Na2O Other
Content 70.12 15.84 0.09 9.55 2.65 Trace
Second, feldspar uses: Manufacturing potash, manufacturing ceramics and enamel, glass raw materials, abrasive abrasives and so on.
|Feldspar powder||40-80, 80-120, above 120 mesh||SiO2: 67% Al2O3: 16% P+S>0.05
K2O+Na2O>13% (up to 18%)
Feldspar powder making machines: