What is Basalt Fiber?
Basalt fiber is a type of high-performance fiber produced from basalt rock. Basalt is a natural mineral from volcanic magma and flood volcanoes; it is a very hot fluid or semifluid material under the earth’s crust, solidified in the open air. When basalt rock is heated at around 1400–1600°C and then extruded into fine fibers, it becomes basalt fiber. Basalt fibers can be considered as bio-based fibers because they are produced from natural resources, which is very critical for new-generation materials. Basalt can be used to produce high temperature-resistant and chemically inactive products. When extracted from volcanic rocks, basalt fibers are practically amorphous, and at high temperatures, the fiber crystallizes partially depending on the quenching temperature. Among many other reinforcing fibers, basalt fiber has been the least studied fiber, especially in the area of polymer composites.
The history of basalt fiber dates back to 1923 and it was further improved during World War The United States and the Soviet Union investigated basalt fiber, especially for aerospace and military purposes, during the cold war. Investigations were conducted on the insulating and raw material properties of basalt fibers for the textile industry. Unfortunately, basalt fibers could not be widely used for civilian applications due to the political issues in the world during that period. However, after 1995, basalt fibers were produced and used on a commercial scale due to declassification. After 2000, basalt fiber applications and scientific research have been gradually increased. Today, the basalt fiber industry is improving day by day, developing technology in composite research and applications.
Basalt largely consists of plagiocene and pyroxene, which are SiO2 and Al2O3 compounds, respectively, and is chemically highly stable in strong alkalis. In strong acids, basalt has a relatively low stability. The individual components of basalt dominate SiO2 (optimum range 43.3% – 47%), followed by Al2O3 (optimal range 11% – 13%), CaO (optimal range 10% – 12%), and MgO (optimum range 8% – 11%).
Basalt is a non-polymeric fiber; hence, it has a low elongation to fracture property of 3.15%. Other properties include a tensile strength of 2.8 GPa and a density of 2.8 g/cm3.
Basalts are the most common minerals on the surface of the Earth, and are found in several geotectonic environments. Safe and abundant, basalt rock has long been known for its thermal properties, strength, and durability. The basaltic rocks are used for the extrusion of fibers during industrial production. Basalt fiber can be classified as a sustainable material because it is made of natural material and during its production no chemical additives or any solvents, pigments, or other hazardous materials are added.
Basalt has excellent properties such as corrosion resistance, minimal moisture absorption, the ability to withstand high temperatures, it provides thermal insulation, and absorbs sound. It is also a cost-effective and high-strength material that has been widely used in road construction, buildings, and other applications that require reinforcement.
Basalt products can be used from very low temperatures (about -200°C) up to the comparative high temperatures 700 – 800°C. Figure 1 shows the pictures of basalt continuous filament and short fiber.
Basalt fiber will be a potential replacement for glass fibers and other synthetic fibers in some applications. It is a cost-effective and eco-friendly material. Basalt has wide range of applications due to its high mechanical properties and thermal stability. Basalt fiber is becoming a popular choice for the material scientist for the replacement of steel and carbon fiber due to its rigidity and low elongation, or extension, at break.
It can be considered environmentally friendly and a nonhazardous material. Basalt, being an ecologically pure substance, has a wide spectrum of applications. It is not a new material, but its applications are surely innovative in many industrial and economic fields, from building and construction to energy efficiency, from automotive to aeronautic, thanks to its good mechanical, chemical, and thermal performances. Its applications are numerous. Basalt-based geocomposites are extensively used in making radiation-proof protective caps for nuclear waste disposal sites. Another example is basalt geomesh. Basalt casting can be a good solution for equipment facing high wear and tear in casted pipes. It has already replaced asbestos as a heat insulator due to its low thermal conductivity. Apart from these examples, basaltic tapes/fabrics have also been in use for insulating high tension wires during power transmission and for protection against fire hazards. In the automobile industry BFs are employed in the fabrication of car brakes.
Hence, basalt fiber has gained increasing attention as a reinforcing material especially when compared to traditional glass fibers. The production process, even if it is very similar to glass fibers, does not require additives, and a lower amount of energy is needed with benefits in terms of environmental impact, economics, and plant maintenance. The base cost of basalt fibers depends on the quality and the chemical composition of the raw material, and this leads to the production of several kinds of fibers with different thermal, chemical, and mechanical properties. Basalt fibers within polymer (i.e., thermoplastic, thermoset, and biodegradable), metallic, and concrete matrices exhibit promising properties. Due to this, these fibers have the potential to be the next-generation materials for structural application for infrastructure, automotive industry, and consumer applications.
Similarities with Glass Fiber:
Basalt fiber is produced with a melt spinning process similar to glass fiber spinning with basalt rock as the raw material. Basalt fiber’s modulus and tenacity are at the same level of glass fiber. Similar to glass fiber, basalt fiber also possesses electrical insulating properties, corrosion resistance, and high temperature resistance. It is also fragile and easily breaks like glass fiber; therefore processing basalt fiber such as twisting and weaving requires great care. Basalt fiber is also irritating to skin like glass fiber.
Basalt fiber is considered as a viable alternative to traditional glass fiber by the composite industry. Therefore, many manufacturers and suppliers around the world are interested in basalt fiber, but with unlimited basalt reserves, Russia plays a key role in basalt technology.
Properties of Basalt Fiber:
Basalt fiber is valued for its combination of strength, durability, and environmental benefits. Basalt fiber has excellent mechanical properties, including high tensile strength and a high elastic modulus, making it three times stronger than steel by specific strength.
Following are the typical properties of basalt fiber:
- Specific gravity: ∼ 2.70 g/cc
- Tensile strength: 2.7 – 3.2 GPa
- Tensile modulus: 85 ∼ 95 GPa
- Elongation at break: 2% – 3%
- Density: 2.67 g/cm³
- Color: Naturally brownish to golden
- Thermal Resistance: -260 °C to ~700 °C (up to 1095 °C in advanced products)
- Chemical Resistance: High resistance to acids, bases, and UV
- Moisture Resistance: Does not absorb water like some synthetic fibers.
- Mechanical: Superior impact resistance, tensile strength better than fiberglass
- Eco-friendly: Made from natural rock, recyclable, non-toxic, inert, rot-proof, and environmentally friendly
Chemical Composition of Basalt Fiber:
Basalt rocks are obtained from volcanic lava that is solidified in the open air after flowing as a hot fluid. Basalt fibers, which consist of plagioclase, pyroxene, and olivine minerals, are obtained by spinning basalt rocks under certain conditions.
The general composition of basalt rocks is given in Figure 2. As seen in this figure, the dominant chemical compounds are SiO2 at 52.8%, Al2O3 at 17.5%, Fe2O3 at 10.3%, and CaO at 8.59%.
Manufacturing of Basalt Fiber:
The manufacturing of basalt fiber is relatively simple compared to other synthetic fibres, as it requires no additives. The basic method for production of basalt fiber is a melt-blowing technique such as the Junkers method. In this technique, basalt rocks are melted and poured into a rotating cylinder mechanism, and air jets are used to blow fiber off. In this way, fibers are shaped by means of blowing air and then being rapidly solidified. Basalt fibers produced by the Junkers method are low cost and have poor mechanical properties. Short basalt fibers can be easily manufactured at a low cost using this method. The production of continuous basalt fibers shows some similarities to glass fibers. Such fibers are produced by spinning melted basalt stones from a spinneret from 1350°C to 1420°C. Spun filament bundles of between 1.0 and 1.2 m are taken downward below the spinneret at between 2000 and 5000 m/min and then spooled. The general procedure for continuous basalt fiber production is shown in Figure 3.
Basalt fiber manufacturing procedure illustrates in Figure 3 the following steps, (1) crushed stone silo, (2) loading station, (3) transport system, (4) batch charging station, (5) initial melt zone, (6) secondary heat zone with precise temperature control, (7) filament-forming bushings, (8) sizing applicator, (9) strand formation station, (10) fiber tensioning station, and (11) automated winding station.
After spinning, the fibers are generally woven to form composite structures. The woven fabrics of basalt (a) and carbon (b) fibers and also strands of carbon (c) and basalt (d) fibers are all shown in Figure 4. Basalt fibers are quite novel in the area of composite application. Due to its resistance to high temperature, basalt fiber is generally used for high-temperature applications such as flame-retardant materials, disk brakes, and heat-insulation applications.
Applications of Basalt Fiber:
Basalt fiber is a unique and natural material based on its high mechanical strength, high resistance to wear, impact and corrosion performance, good thermal endurance, light weight, relatively low cost, and eco-friendly nature. Therefore, basalt fibers and their derivatives have a wide range of engineering applications because of a proved high-performance level and desirable characteristics. Several researchers have mentioned the applications of composite materials based on basalt fibers so far.
Due to its excellent properties, basalt fiber is used in a wide range of industries such as in the aerospace and automotive industry, civil engineering, the chemical and petrochemical industry, manufacturing engineering, and the power engineering and electric industry.
1. Aerospace and automotive industry
In the aerospace and automotive industries, the competitive advantage of basalt fibers comes from properties like noise damping, acoustic absorption, high specific strength, and good ductility. The use of basalt fiber in aircrafts and automobiles helps to reduce the undesired noise generated externally and by engines, and basalt fibers may be used as acoustic proofing in the aerospace industry. In addition, they are used in the manufacturing of aeronautical machines thanks to their frictional, chemical, and heat resistance. Moreover, basalt fibers are increasingly used in the automotive industry for production of car headliners, compressed natural gas (CNG) cylinders, brake pads, and clutch facings. Basalt fibers also offer several benefits for use as fillers for car mufflers— having good sound-insulating properties and good resistance to thermal cycling. Hence, basalt products are extensively preferred in the aerospace and automotive industry.
2. Civil engineering
Composite materials such as fiber-reinforced polymer (FRP), glass FRP (GFRP), and carbon FRP (CFRP) have been used in the construction industry for three decades. Many construction codes and standards focus on the use of composite structures developed in the construction industry. By comparison with FRP, GFRP, and CFRP, the use of basalt fibers in construction applications is relatively new. However, the use of basalt fibers has greatly increased in civil engineering, and it has recently gained wide acceptance in the construction industry. Currently, many different construction materials based on basalt fibers—which might be an alternative to traditional construction materials—have been developed, and these innovative materials such as rebars, laminates, panels, grids, chopped fibers, veils, and plates have delivered beneficial solutions in civil engineering applications.
The experimental results from previous literature show that basalt rebars have the potential to replace steel in reinforced concrete structures wherever a corrosion problem exists because of the noncorrosive behavior of basalt rebars. In addition, chopped basalt fibers might be used as a strengthening material for existing conventional building materials, such as concrete and mortar. Chopped fibers in concrete or mortar are effective additives that enhance the structural and mechanical performance of these materials. Chopped basalt fibers are incorporated into concrete or mortar to improve certain material properties. By comparison with plain concrete, the mechanical properties of the chopped basalt fiber reinforcement increased with the addition of basalt fibers. Furthermore, SEM images show a good bond is obtained between chopped basalt fibers and concrete.
In addition to the rebars and chopped fibers, as an internal- and external-strengthening building material, basalt fiber-based laminates, panels, and plates have been widely used in existing structures to increase their load capacity and construction life. In the most common uses, masonry and concrete structures are fully or partially wrapped with continuous basalt laminates. Furthermore, basalt fiber-based panels and laminates have been used as thermal and acoustic insulation in buildings, and they are successfully used in structures where corrosion has damaged the steel reinforcement and concrete due to environmental impacts.
3. Chemical and petrochemical industry
Basalt fibers have high chemical and thermal stability and have effective thermal-, electric-, and sound-insulating properties. Thanks to their proved properties, basalt fibers are widely used in the chemical and petrochemical industry. Basalt fiber-based equipment such as tanks or pipes are among the most convenient materials for on-site transportation, collection, and storage of corrosive liquids and gases like hydrogen sulfide, acids, and alkali chemicals because of their resistance to corrosion and aggressive chemical compounds. Basalt-based pipes may be used to transfer petroleum, oil, gas products, hot and cold water, aggressive liquids and loose materials from the reservoir to the end user. Moreover, basalt-based pipes are effective in the conveyance and storage of radioactive nuclear materials because of their radiation-resistant properties. Since basalt fibers produce no chemical reactions in contact with other chemicals, they are widely used in many different applications such as hosing and crop watering, gas tubes, hydrocarbon pipelines, land drainage, and construction. The low thermal conductivity of basalt fibers helps to minimize unwanted deposition inside the pipes.
4. Manufacturing engineering
Basalt fibers have many advantages such as light weight, design flexibility, and relatively low cost. Moreover, basalt fibers are extremely strong and durable, which makes them ideal materials for manufacturing engineering. Due to their superior properties, basalt fibers have major applications in manufacturing engineering as well. Potential applications of basalt fibers in manufacturing engineering are widespread, ranging from small to large consumer products. During the past decades, basalt fibers have become commercially productive manufacturing materials with an increasing market potential. The use of basalt has the potential to reduce costs in industrial applications, and basalt fibers will undoubtedly constitute a greater portion of the total material market. In particular, they are industrially used for many different products, such as lightweight car and bicycle frames, motorcycle parts, golf clubs, skis, furniture, snowboards, containers, fishing rods, and sporting goods.
5. Power engineering and electrical industry
In power engineering, basalt fibers are used to produce wind turbine blades and lampposts due to their corrosion-resistant properties. Moreover, basalt fibers are widely preferred in specialty power products because of their electric- and heat-insulating properties. Basalt, which has a good thermal conductivity and significant resistance to fire, allows woven tapes to be used for manufacturing fireproof power cables. Basalt fibers might be included on printed circuit boards (PCBs) providing special properties in comparison with ordinary components made of fiberglass. Basalt fibers are additionally used as a part of other electrospecialized applications, for example, in additional fireproof protection for electric links and underground conduits. There are other benefits in using basalt-based materials, including the disposal phases and its maintenance during the consequent portion of the postclosure phase.
Conclusion
Basalt fiber is a modern engineering material that has gained attention as a strong, eco-friendly, and cost-effective alternative to traditional fibers like glass and carbon. With its excellent mechanical, thermal, and chemical properties, it is becoming a preferred choice in construction, aerospace, automotive, and other industries. As industries continue to focus on sustainable and high-performance materials, basalt fiber is expected to play an even bigger role in the future.
References
[1] Seydibeyoglu, M. O., Mohanty, A. K., & Misra, M. (2017). Fiber technology for Fiber-Reinforced composites. Woodhead Publishing.
[2] Patnaik, A., & Patnaik, S. (2019). Fibers to smart textiles: Advances in Manufacturing, Technologies, and Applications. CRC Press.
[3] Bunsell, A. R. (2018). Handbook of Properties of Textile and Technical Fibers. 2nd Edition Woodhead Publishing Limited.
[4] Li, D. (2020). Cut protective textiles. Woodhead Publishing.
Founder & Editor of Textile Learner. He is a Textile Consultant, Blogger & Entrepreneur. Mr. Kiron is working as a textile consultant in several local and international companies. He is also a contributor of Wikipedia.
