Basalt fiber

Basalt fiber is a material made from extremely fine fibers of basalt, which is composed of the minerals plagioclase, pyroxene, and olivine. It is similar to carbon fiber and fiberglass, having better physicomechanical properties than fiberglass, but being significantly cheaper than carbon fiber. It is used as a fireproof textile in the aerospace and automotive industries and can also be used as a composite to produce products such as camera tripods.

Manufacture

Basalt fiber is made from a single material, crushed basalt, from a carefully chosen quarry source and unlike other materials such as glass fiber, essentially no materials are added. The basalt is simply washed and then melted.[1]

The manufacture of basalt fiber requires the melting of the quarried basalt rock at about 1,400 °C (2,550 °F). The molten rock is then extruded through small nozzles to produce continuous filaments of basalt fiber. There are three main manufacturing techniques, which are centrifugal-blowing, centrifugal-multiroll and die-blowing. The fibers typically have a filament diameter of between 9 and 13 µm which is far enough above the respiratory limit of 5 µm to make basalt fiber a suitable replacement for asbestos. They also have a high elastic modulus, resulting in excellent specific strength—three times that of steel.

Properties

The table refers to the continuous basalt fiber specific producer. Data from all the manufacturers are different, the difference is sometimes very large values.

Property Value[2]
Tensile strength 4.84 GPa
Elastic modulus 89 GPa
Elongation at break 3.15%
Density 2.7 g/cm³

Comparison:

Material Density
(g/cm³)
Tensile strength
(GPa)
Specific
strength
Elastic modulus
(GPa)
Specific
modulus
Steel re-bar 7.85 0.5 0.0667 210 26.7
A-glass 2.46 3.31 1.35 69 28.0
C-glass 2.46 3.31 1.35 69 28.0
E-glass 2.60 3.45 1.33 76 29.2
S-2 glass 2.49 4.83 1.94 97 39.0
Silicon 2.16 0.206–0.412 0.0954–0.191
Quartz 2.2 0.3438 0.156
Carbon fiber (large) 1.74 3.62 2.08 228 131
Carbon fiber (medium) 1.80 5.10 2.83 241 134
Carbon fiber (small) 1.80 6.21 3.45 297 165
Kevlar K-29 1.44 3.62 2.51 41.4 28.8
Kevlar K-149 1.47 3.48 2.37
Polypropylene 0.91 0.27-0.65 0.297–0.714 38 41.7
Polyacrylonitrile 1.18 0.50-0.91 0.424–0.771 75 63.6
Basalt fiber 2.65 4.15–4.80 1.57–1.81 100–110 37.7–41.5

History

The first attempts to produce basalt fiber were made in the United States in 1923 by Paul Dhe who was granted U.S. Patent 1,462,446. These were further developed after World War II by researchers in the USA, Europe and the Soviet Union especially for military and aerospace applications. Since declassification in 1995 basalt fibers have been used in a wider range of civilian applications.

Uses

*Heat protection

*Windmill blades

*Car bodies *Sports equipment

[3]

References

External links

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