Technologies for production of basalt fibres

Technologies for production of basalt fibresRaw Material.  Basalts, andesites, andesite-basalts, diabases, dolerites, porphyries, gabbro-diabases, gabbros, amphibolites and others basaltic rocks have magmatic nature origin. Primary fusion, enrichment and homogenization of basalt breeds were made by nature as a result of ancient volcanic activities. Basalts has being laying for many millions years on the surface of the Earth.  The main feature of basalts is that the basic energy inputs for preparation them for the production of fibres were made ​​in the bowels of the earth.  Basalt breeds are ones of the strongest natural silicate breeds.  
Whinstone fibres possess high natural initial durability and are stable against corrosions environment, they have good electro-insulating and sound-insulating properties. It is worth noting that not every basalt deposit can be used as a source of basalt for production of basalt fiber, especially basalt continuous fiber. The specialists of our companies developed the special procedure to analyze and select basalt deposits and quarries which can be used as raw materials for the fiber production. Information about basalt rocks and their choice for the production of fibres are presented in section «Basalts»

Technologies for production of basalt fiber and materials on their basis are most demanded in the world. It is determined by number of factors:

• Usage of ready natural raw material –basalt that was initially melted to the state of super-fluent magma;
  
• Basalt fibers and fiber-based materials possess high natural strength qualities, resistance towards corrosive mediums, durability, electro insulating and other properties that ensure their wide application in industry, construction and many sectors of national economy;
  
• Low power consumption at the manufacturing of basalt fiber materials;
  
• High economic profitability of technologies for basalt fiber production;
  
• The technology of production process is not hazardous for environment; it does not produce any emission, excluding of gas combustion products.

The main technological processes of basalt fiber production:

• Heating and melting of basalt,  transition of basalt  from the crystalline to the amorphous state in the melting;
• Homogenization of the melt on the chemical composition and the degree of amorphism;
• Preparation of melts to formation of fibers - achievement of homogeneity of the melts and required parameters on the viscosity and output characteristics;
• Pulling from melts of continuous, staple thin and super thin fibres.

Technologies for the production of basalt continuous fiber

Technologies for the production of basalt continuous fiberThe processes of melting, homogeneity and preparation of melts are performed at a temperature of 1400 ~1600 °C.   Further processing of BCF into materials and products does not require energy; it’s made with application of “cold technologies”.
 For all its apparent simplicity the production of basalt continuous fibers is a rather complicated process. Previously wide usage of BCF was restrained by complexity of industrial equipment and their production technology. The production cost of BCF was relatively costly and it was significantly higher than the production cost of fiberglass.

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.

The most up-to-date BCF technologies. Quality and production cost of BCF

Modern BCF production technologies are directed to solving of three main objectives:

• Improving the quality of the fiber and characteristics of fiber on strength and elasticity;
  
• Increased productivity of equipment per one bushing- assembly;
  
• Reduced energy consumption (gas and electricity) per unit of production. Natural gas, LPG, associated petroleum gas can be used as a source of energy.
  

The first direction of the development of technologies - is to reduce breakages in the production of primary filaments, and to approximate of BCF characteristics on the strength and elasticity  to the characteristics of carbon fibers. In that technological direction our company is working at the choice and selection of basalt, the most suitable for the BCF production. To analyze and select basalt deposits, our specialists developed the special procedure. The special burners, laboratory and pilot furnaces were developed for performing of these tests. The works to improve the quality of BCF are executing. Implementation of the second and third directions is aimed at reducing the production cost of BCF.

O At last years our company 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.  

Our experts developed BCF technologies and created the new generation of BCF equipment provides the possibility significantly to reduce consumption of energy: natural gas and electricity (against the feeder melting furnaces, it was equipment of more earliest design), and increase productivity at 1, 5-2 times per single bushing assembly. New generation slotted bushing-assembly was developed, their weight was decreased, and output per one bushing-assembly was increased, 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 patents for inventions.

BCF technologies and equipments are enough new and have huge prospects for developing. Currently our experts continuing to research on melting processes of whinstone and of workable characteristics of various basaltic melts in the fibers production, also they are creating new series of bushing-assembly.

The purpose of the research - improving technology of BCF production and their quality, reducing energy consumption, increasing the productivity of BCF production processes. (see articles "Study of the melting processes of basalt", "Study of workable properties of  basalt melts in the BCF production").

Technologies for production of Super-thin basalt fiber

Technologies for production of Super-thin basalt fiberSuper-thin basalt fiber (STBF) production technology is developed long ago, it was improved and more than 40 years STBF installations have wide application at many STBF plants.
In brief, conventional technology of STBF production consists of the following processes:

- Loading crushed basalt rock in the furnace;

- Basalt melting and melt homogenization in the furnace;

- Production of basalt melt from furnace feeder through a bushing assembly in the form of continuous primary fibers ( filament);

- Blowing of primary fibers with burner into staple super-thin fibers;

- STBF felt formation at the corresponding conveyor.

STBF technological process has two enough power-intensive processes, including: melting of basalt for pulling of primary basalt fibres and blowing them by a high-temperature gas flow.

Last innovative technical solutions  made it possible to improve technological process of STBF production and new types of STBF equipment  of low energy consumption  BSTF 20 and BSTF 40 were created (electricity and gas consumption were decreased in two times in comparison with conventional STBF production plants).

Basalt scale

Basalt scale made from melts of basalt rocks.

Brief technology description of Basalt scales production:

• Loading crushed loosened rock in the rock-melting furnace;
• Producing the melt in the furnace;
• Extracting the melt from the furnace feeder and bushing assembly;
• Producing the primary scale at the scale-forming unit;
• Separating the basalt scale fractions;
• Dosing and packing of basalt scales

The present technology gives the possible to manufacture of flaked materials with low power inputs.  Basalt scales production technology provides high-performance of the equipment and high quality of materials. Basalt scales is used in the production of protective, wear-resistant, anti-corrosion, and chemical-resistant coatings, reinforced composite materials and plastics.

ENERGY SAVING TECHNOLOGIES

ENERGY SAVING TECHNOLOGIESEnergy-saving technologies in industry are of most interest, because largest part (about 80%) of consumed power resources is spent in Industry. The operational experience in these fields shows that the application of energy-saving technologies during the reconstruction of operating and construction of new furnaces and thermal equipment allows to reduce of energy consumption by 20… 50%.
Last years a cost of energy resources (gas, oil, electricity) is permanently growing and energy-saving technologies got the special urgency.

Energy-saving technologies include the use of modern, high-performance materials, equipping of gas-burner path of furnaces by heat recovery systems and management, system of automation and control of technological processes and a number of other engineering solutions. It allows achieving decrease in power consumption up to 40%, and this parameter becomes still above at reconstruction of old furnaces.  To date, wide experience of fibrous materials application was accumulated at reconstruction and construction of many types of industrial furnaces in the Ukraine, Russia and Belarus.

Application of fibrous materials and efficient heating systems in the furnaces is confirmed their high efficiency and reliability in operational process. In China, Jingdezhen city, results of works on reconstruction of the chamber furnace for baking of porcelain at low total investments volume have already allowed to lower LPG consumption on 25% (the Information on reconstruction of the furnace for baking of porcelain).

High-temperature composite materials

Experts of our company developed perspective production techniques of high-temperature materials and products with application of non-fired technologies.

The essence of these technologies consists in creation of high-temperature materials with usage of "cold" technologies, without application of traditional kilning operation at the manufacture of fire-resistant materials.

Thus offered high-temperature composite materials (HTCM) possess new characteristics:

• Low specific density from 300 up to 1200 kg/m3 ;
• High heat-insulating properties;
• Sudden changes in temperature have no effect on their quality and operating life;
• Materials are easy formed and are pliable into machining at manufacturing products of a complex configuration.

Experience of application of high-temperature composite materials, including: in China, has shown their high characteristics and operational properties at fettle works and repair of furnaces, at manufacturing of burner stones for gas -and LPG burners, and, especially, as a materials for fettling of bushing-assemblies in the manufacturing of basalt and glass fibres.