Basalt Continuous Fiber (BCF) production techniques

Basalt Continuous Fiber (BCF) production techniques

Manufacturers of fiber and composite materials have already shown an interest in basalt continuous fiber (BCF). More importantly, consumers do have a great interest in this material. This interest is due to the following factors:

• BCF possesses some advantages over glass fiber, including its strength, chemical stability and temperature of application;
• Wide availability and low cost of basalt, which is an initial raw material for BCF production;
• Production is carried out with application of one- phase technology;
• Development of technology and equipment for BCF production during recent years allowed achieving the cost of production as low as the cost of production of E-fiber glass.

At the present time in the world there are two main variants of technologies and equipment for basalt continuous fiber production. There are big melting furnaces with long feeder (feeding installation), and technological lines consisting from modular units.
BFMTD Company possesses both types of techniques, has patents for its technologies and know-how, as well as for the most part of special equipment. Last years BCF production based on modular units is more perspectives.

In brief, BCF production technology can be introduced as the following sequence of operations:

• Melting of basalt breads into basalt melt;
• Homogenization of basalt melt and its preparation for production;
• Forming of basalt melt through a platinum alloy bushing assembly;
• Extraction of initial fiber, lubrication and winding on bobbins.

All those operations are quite simple, especially if you consider that primary fusion, homogenization and enrichment of basalt initial raw material was made by ancient volcanoes, i. e. by nature. Aimtechnologies: to ensure a good quality of BCF, production stability and the required level of production cost.

The basalt continuous fiber production process is similar to the glass fiber production process only visually and differs from the glass fiber production process by the following characteristic features:

1. Basalt is ready natural raw material that was initially melted to the state of super fluent magma.
2. The physical properties, crystalline structure, and chemical composition of basalt differ from these of glass.
3. The thermo-physical properties of basalt melts essentially differ from these of aluminosilicate glass melts.
4. The process of basalt melting does no contain the operations that are specific for glass melting and clearing and cooling glass melts, so the design of basalt melting furnaces significantly differs from the design of glass melting furnaces.
5. The basalts from different basalt deposits differ by their properties that have an effect on the parameters of the basalt continuous fiber production process.

The properties of basalt raw materials essentially specify the parameters of BCF production process and modification of BCF technological equipment.

All those technological features determine the particular qualities of equipment and bushing assemblies, which are used for BCF production. The experts emphasize that, while BCF production technologies seem to be simple, in practice they are quite complex and require a great deal of know-how.

The basic features of technologies are as follows:

• Selection of basalts breads according to their fiber-forming (long basalts) characteristics, as well as in accordance with application of BCF materials;
• Technological processes of basalt melting melt homogenization and its preparation for formation in accordance with degree of its amorphism, viscosity and temperature interval;
• Processes of fibers forming through bushing assembly.

To secure achieving the goal of industrial production of high-quality BCF, the whole range of technological features in their complexity are ought to be considered, and special equipment needs to be designed to match the goal.

BCF Production techniques

The diagram of the production process of basalt continuous fiberDescription of the production process

The basalt raw material is reduced to fractures 5 ~ 20 mm in dimension→ the basalt fractions are fed by the charging conveyer (1) to the melting furnace (2)→ the charged basalt is melting at a temperature of 1400 ~1600 °C → the melted basalt passes through the die holes of the bushing (3) → from the bushing, the basalt continuous fibers 9 ~ 15 mm in diameter (4) are fed to the unit (5) for applying lubricant → the winding unit (6) performs the operation of winding the continuous basalt fibers on the spools (7) → the basalt continuous fibers from the spools are rewound into the bundles (9) of basalt fiber roving.

A technological process of BCF manufacturing

Smelted basalt is loaded to the stove feeder and goes through the holes of bushing assembly Basalt is smelted in the stone smelting furnace under 1450~1600oC

Winding machine is winding continuous fiber on drumsDrum of BCF filament

Handling trolley with drums of BCF filament (primary fiber)Coils of BCF roving

ADVANTAGES OF BCF TECHNOLOGIES

1. Only one component – basalt, which is an environmentally safe natural material – is used for BCF production;
2. Cost of basalt raw material is very low; the share of raw materials cost in the cost value of production is less than 5-7%;
3. BCF production technology consists of only one phase – melting. There is no need for primary enrichment, fusion and homogenization, as all of those were made for free by nature;
4. To make BCF basalt should be heated up only one time;
5. Further processing of BCF into materials does not require energy; it’s made with application of “cold technologies".
6. BCF techniques are energy-saving technologies, BCF Production is ecologically clean manufacture with use of high NANO-Technologies, making it possible to produce fibers of 6-21 microns in diameter and length of 40-60 kilometers.

Development of technologies and equipment for BCF production from the past to the present. Patents for inventions and “know how”.

BCF industrial production has a short history of only 25 years. The initial BCF industrial equipment was very expensive, and energy-hungry. To be able to realize the perspectives of development of BCF production, one should clearly understand that BCF technologies are still on the initial stage of their development and that their real perspectives are enormous.
At last years BFMTD completed the earlier started researches of fusion processes of various basalts types, thermo-chemical reactions during active basalts melting and homogenization of basalt melts, workability and characteristics of melts during continuous fibers production, developing of bushing assemblies. All these scientific researches were implemented in practice in the new series of technological equipment.

At the present time the new generation of BCF equipment provides the possibility to reduce consumption of energy, includes: natural gas at 3 times and electricity at 7 times (against the feeder melting furnaces, it was equipment of more earliest design ), increase productivity at 2 times, and, accordingly, the production cost of high quality basalt fiber was reduced significantly.

The production processes and processing equipment for basalt fiber production are protected by the following patents

The history of development of technologies and equipment for BCF production.

The first samples of BCF were received in Ukraine of the Soviet Union in 1959- 61. The first basalt continuous fibers of satisfactory quality were produced with laboratory equipment in 1963. A great deal of work followed to develop BCG production techniques and equipment for, to study fiber characteristics; to develop of samples of BCF materials and to study their potential fields for application.

In the middle of 1980-ies the first industrial installation for BCF production was designed and launched in a factory near Kiev. Within several years some other plants with annual output of 350 and 500 tons were launched. Those installations were equipped with furnace for basalt melting with two feeding installations, which had platinum alloy bushings. The bushing assemblies consisted of stream feeders (heating tubes) and special bushing plates. Feeding installations were a significant step forward in development of basalt technologies.

But this kind of equipment had some shortcomings, such as high energy consumption on unit of production, great weight of bushings and rather low productivity. In Soviet time the main consumer of basalt materials was the defense industry (the armaments industry), so there was no attention paid to the high cost of BCF production.

In the end 1990-es a new generation of BCF production technologies and equipment based on a modular approach were designed, it was made in order to decrease energy consumption, lower equipment costs and minimization of the bushing weight. On the basis of new modular techniques in 2000-2002 the Ukraine-Japanese joint venture for BCF production was built, new BCF Plant produced heat-resistant fibres used in Toyota's car mufflers. In Ukraine, in 2003 year, the new BCF plant was established using new techniques.

A new modular laboratory and industrials installation with low energy consumption was developed and commissioned for two BCF plants in PR China. Experience of BFMTD technical experts in China gave a new impetus to the developments of basalt technologies. New types of basalt were tested for BCF production, new energy saving equipment were developed and launched. Dr.Osnos S.P., the leading specialist of the company, carried out all the basic scientific and engineering development works according to the state program No. 863 of Chinese Peoples Republic, "Continuous Basalt Fiber and Composite Materials on its Basis". Two BCF factories in China were established use new modular techniques designed by Dr. Osnos. One in Chengdu city, «Chengdu Aerospace Tuoxin Science & Technology Co., LTD» later renamed in «Sichuan Aerospace Tuoxin Basalt Industrial Co., LTD»; and another in Shanghai «Shanghai Russia Gold Basalt Fiber» and Zhejiang province «Hengdian Group Shanghai Russia Gold Basalt Fiber» - «GBF»(Gold Basalt Fiber).
In 2008-2009 BFMTD’s experts established a new BCF plant “NPO” “Vulkan”” in Russia Federation.

Beginning from 2000 year, experts of our company have extensive experience of organization of production on the basis of basalt fiber to use of new technologies on a modular approach. Their portfolio includes seven plants for BCF and STBF projects in Ukraine, Russia and China.

More information see «Development of BCF technologies and equipment from the past to the present» and «Performed projects»