CHOICE OF RAW MATERIALS FOR THE PRODUCTION OF BASALT  FIBERS FOR VARIOUS USES

 

According to the research, taking into account the properties of the rocks, we have developed recommendations for the use of rock melts for the production of specific types of fibers (see Table 1). Classification of rock melts was made Makhova MF et al., but has not been made to optimize the properties of melts of specific species indicating the direction of their use. We have found that the high viscosity of melts may obtain continuous fiber. However, the process is characterized by the largest energy consumption and the maximum wear assembly fiberization by its operation at elevated temperatures. When using viscous melts continuous fiber production process is stable. The manufacturing process of superfine fibers is the bushing at elevated temperatures above 1360 ° C, which in turn has increased wear, the resulting fiber satisfactory quality. Group rocks with medium viscous melts are the most versatile raw material for the production of all types of fibers. The production process is continuous and super fine fiber runs from the lowest energy costs.

                                                                                               Table 1

Use of rock for the production of different types of fibers

class melt	raw material	Viscosity,  ¶Па×с at a temperature		Use of raw material
		1450°С	1300°С
High viscosity	Andesites	more 150	more 1000	Applications not found
Viscosity	Andesite basalts, Diabase, basalt, amphibolite.	50-150	200-1000	Production of continuous fibers
Medium viscosity	Diabase, basalt, amphibolite.	30-50	100-200	Manufacture superthin staple fibers
Low-viscosity	Basalt, amphibolite.	less 30	less 100	Manufacture of fine staple fibers

 

      Low-viscosity melts almost unsuitable for the production of continuous filament due to the narrow temperature range output. Because the bulk of the species in this group is possible to obtain super thin fibers. Fine fibers using melt of low viscosity is obtained with the lowest power consumption, the amount of non-fiber components according TU.U B. 2.7-21-356-99 with an average diameter of less than 8 microns and a maximum average fiber length of 15 mm. The basis for producing a fiber with predetermined properties take a single component raw material, rocks that have different chemical (Table. 2) and mineralogical composition, such as andesite basalt, diabase, basalt and amphibolites, which has large reserves of Ukraine. The chemical composition of glass C taken for comparison of properties: SiO2-71.9%; R2O3-2.2% (Al2O3 + Fe2O3); CaO-6.5%; MgO-4.2%; Na2O-14.9%; SO3-0.3%. Knowing the properties of each breed, we can adjusting additives of oxides in the melt to produce fibers with the required characteristics. Technology for producing a particular type of fiber is mainly dependent on the viscosity of rock melts in the range of development (Fig. 1).
The equations, depending on the temperature of the melt viscosity for different breeds:

η = 0,0504T² - 144,19T + 103216   Andesite basalts                     (3.1)

η = 0,0188T² - 53,396T + 37946  Diabase                                      (3.2)

η = 0,009T² - 25,905T + 18622  Basalt                                        (3.3)

η = 0,0036T² - 10,368T + 7484,4   Amphibolite                             (3.4)

  Depending on the operating conditions of basalt fibers production, they must possess certain physicochemical and mechanical properties. Such properties include primarily mechanical tensile strength; chemical resistance to acids, alkalis and water as well as temperature stability.
          The studies determined that fibers from different breeds are characterized by different temperature-resistant (Fig. 2).

Table. 2

The average chemical composition of various rocks

 

№	rocks	SiO2	TiО2	А12Оз	Fе2О3	FеО	MgO	CaO	Na2O	K2O
1	Andesite basalts	48,0-56,0	0,5-2,0	10,0-20,0	6,0-15,5		3,0-9,5	7,0-14,0	1,2-3,5	1,2-3,0
2	Diabase	46,0-49,0	0,5-1,5	12,0-18,0	7,0-15,0		4,0-8,5	8,0-12,0	0,6-3,5	0,6-3,0
3	Basalt	44,0-50,0	0,5-2,0	12,0-18,0	7,0-17,5		5,0-11,5	6,0-14,0	0,7-3,5	0,7-3,0
4	Amphibolite	44,0-50,0	0,5-2,0	12,0-18,0	7,0-15,5		5,0-11,5	6,0-14,0	0,7-3,5	0,7-3,0

 

Fig. 1 Dependence of melt viscosity on temperature: 1 andesite basalts; 2- diabase; 3- basalts; 4- amphibolites.

      

Temperature resistant mineral fiber depends on the presence of oxides in the rock ratios increasing temperature resistance SiO2, Al2O3 and others lowering it. When heated basalt fibers observed continuous change their content and at certain temperatures - a complete transition of divalent iron to trivalent form with the loss of thermal stability. The fastest transition Fe2 + to Fe3 + BSTF fibers made from diabase and BTV, t. E. In the fibers, wherein the content of Fe2 + is less than Fe3 +. Just when drawing continuous fiber on the surface of the bulb formed oxide film Fe3 +, due to ferrous iron capture oxygen from the air, which significantly increases breakage and lowers the strength of the fiber. To eliminate these drawbacks is necessary to create a protective atmosphere hood assembly inert gases.

Fig. Figure 2 mineral fiber strength loss versus temperature: 1 - andesite; 2 - diabase; 3 - amphibolites; 4 - basalts; 5 - C-glass.

 

One important feature of the fibers is their resistance to acids and alkalis (Fig. 3) because they are applied in various branches of the filters, as a filter element for cleaning a variety of corrosive environments.
As can be seen from the figure, the most resistant to the acid are mineral fibers obtained from andesite. Alkali resistance characterized by fiber obtained from melts and diabase amfobolitov.
In the production of plastics based minerals plays an important role mechanical tensile strength of the fiber (Fig. 4). The diameter of the test fiber 12 microns, all the fibers produced in the same conditions. As can be seen from the diagram the greatest strength characterized by fibers produced from molten andesite.

Fig. 3 Stability of fibers from rocks of acid (s), base (b): 1-diabase, 2 basaltic andesites; 3-basalts; 4 C-glass; 5- amphibolites.

 

Fig. 4 Diagram mechanical strength of mineral fibers. 1-diabase; 2- andesite; 3- basalts; 4 C-glass; 5- amphibolites. 

Qualitative characteristic properties of mineral fibers obtained from various rocks and is given in Table. 3. This creates a prerequisite for control of fiber quality characteristics obtained from molten minerals. There are several ways to control the quality of the resulting fiber. This selection of raw material, maintaining a rational parameters of melting mode and creation of optimal conditions for cooling the strands, when drawing from the melt.

                                                                                             Table. 3

Qualitative characteristic properties of mineral fibers from different rock

rock	Temperature  resistance	Chemical resistance		Strength
		acid	alkali
Andesite	high	high	low	high
Diabase	satisfactorily	satisfactorily	high	low
Basalts	low	satisfactorily	satisfactorily	satisfactorily
Amphibolites	satisfactorily	low	high	satisfactorily

         However, the main way of getting fiber with predetermined characteristics is the selection of the appropriate chemical and mineral composition of the feedstock. The properties of the resulting fiber has a greater influence chemical composition. And on the economic performance of producing the melt and the fibers generally more influenced by the mineral composition of the rock.