The effect of temperature time basaltic rock melting regimes on physicochemical properties of the resultant glasses is studied. The high frequency melting of rocks at elevated temperatures is shown to reduce the glassmaking time, ensure a more complete degassing and homogenization of melts to provide them with a high chemical homogeneity, and result in expanded temperature range of fiber drawing due to the optimized physicochemical parameters. The basalt fibers thus fabricated have a practically flaw free sur face and, consequently, high strength properties.

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The possibility of using rocks form the Khatsavitskoe, Solokhaul'skoe, and Tugupskoe deposits in Krasnodar Krai in the production of basaltic fibers has been investigated. Using laboratory single-spinneret setup it is shown that continuous, thickened, and rough fibers are formed from melts of these rocks in a wide temperature interval. Using a setup with an induction method of melting the raw materials and acoustic blowing of the melt with compressed air, commercial prototype batches of superthin staple fibers, whose main technical characteristics fall into the range regulated by GOST 4640-93, were obtained.

An approximate relation for calculating the viscosity of fused basaltic glass according to the chemical composition of the initial mineral raw material is proposed. This relation was obtained as a result of a multifactor regression analysis of a set including 27 rocks. The experimental values of the viscosity of melts and x-ray fluorescence data on the content of oxides in the raw material were used in the modeling. The relation makes it possible to predict to a high degree of accuracy the viscosity of melts at a prescribed temperature.One of the most important physical-chemical properties of aluminosilicate glass that determine the suitability of the glass for manufacturing different types of fibers is the viscosity h, which is usually compared with the values of the acid-base indicators, first and foremost, the acidity modulus M a calculated as the ratio of the mass content (%) of four melt-forming oxides:The larger the value of M a of the initial raw material, the higher the viscosity of its melt is.However, the magmatic rocks which are widely used in fiber manufacture are more complicated multicomponent systems which include at least nine oxides, each of which can affect the viscosity to some extent. In addition, as numerous experimental studies of raw materials from different deposits have shown, the effect of any particular oxide on the melt viscosity is determined not only by its nature but also by its content. Silica SiO 2 , alumina Al 2 O 3 , magnesium oxide MgO, and trivalent iron Fe 2 O 3 are viscosity-increasing oxides. Alkali metal oxides K 2 O and Na 2 O and divalent iron FeO lower the viscosity; the effect of others, including CaO, is quite complex and not unique: up to certain content they decrease the viscosity and above this value the viscosity of the melt increases or vice versa.Repeated attempts to predict the viscosity of melts from the chemical composition of the rocks have been made. Using of mathematical modeling the authors of [1] obtained for two sets of raw materials with different chemical composition regression equations relating the values of the logarithm of the viscosity at temperature 1400°C with the content of the main oxides in the rock: log h where SiO 2 , TiO 2 , and others denote the oxide content, molar fraction´10 3 .The equation (1) was derived for rock melts for which log h varies from 0.5 to 3.6, while in the second equation this quantity is in the range 1.4 -2.5. The coefficients of the factors in the equations are different; correspondingly, the viscosity values obtained from Eq. (1) and (2) are also different. In addition, for the chosen composition the individual oxides MgO and K 2 O increase the viscosity according to the first equation and decrease it according to the second equation.

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