Wetting, Spreading, and Structural–Rheological Behavior of Basalt Melt during Continuous Fiber Formation

Abstract

Abstract This paper examines the wetting, spreading, and structural-rheological behavior of basalt melts during continuous basalt fiber formation, with particular attention to the interaction between the melt and the bushing material. The study is based on experimental observations accumulated during the development and operation of continuous basalt fiber production processes. Basalt melt is considered not as a chemically and structurally uniform glass-forming liquid, but as a complex multicomponent system whose behavior may depend on its initial mineral structure, thermal history, redox state, and interaction with the materials of the melting and fiber-forming equipment. Experimental observations indicate that melts having similar conventional acidity modulus values may exhibit substantially different rheological behavior. The limitations of using the acidity modulus as a universal criterion for evaluating basalt raw materials for continuous fiber production are therefore discussed. Particular attention is given to wetting and spreading of basalt melt on bushing materials, formation of the melt meniscus (“bulb”) at bushing outlets, temperature gradients, heat transfer, and changes occurring at the melt–bushing interface. The possible role of Fe²⁺/Fe³⁺ transformations and the author's hypothesis of “mineral memory” in determining melt behavior are considered. Experimental observations concerning the influence of electrical operating conditions of the bushing, including changes in heating frequency, current type and polarity, are also discussed. A pronounced reduction in melt throughput and increased crystallization tendency observed under certain experimental conditions suggest that electromagnetic effects may influence melt flow and structural transformations. The magnitude and mechanism of these effects require further systematic investigation and may depend strongly on basalt composition and equipment materials. The results demonstrate that continuous basalt fiber formation should be considered as a coupled system involving melt composition and structure, thermal and electrical conditions, interfacial phenomena, bushing material and geometry, rather than as a process governed by melt viscosity and temperature alone. Citation and attribution: When using or referring to the experimental observations, figures, hypotheses, technical interpretations, or other original material presented in this work, please cite the original publication and its author: Aleksandr Novytskyi. DOI: 10.5281/zenodo.22554572. ORCID: 0000-0002-2572-5361.