عنوان مقاله English
نویسندگان English
The Hodar silica deposit, located within the Khoy quadrangle ophiolitic sequences (northwestern Iran), was investigated to evaluate its potential applicability in metallurgical processes, particularly for the production of silicon metal and ferrosilicon. Comprehensive chemical analyses were carried out using X-ray fluorescence (XRF) and inductively coupled plasma–optical emission spectrometry (ICP-OES). Mineralogical and structural characterizations were performed by X-ray diffraction (XRD), optical microscopy, and Raman spectroscopy at different temperatures ranging from room temperature to 1200 °C, in addition to simultaneous thermal analysis STA (TG–DTA). XRF chemical analyses revealed that the Hodar silica samples exhibit exceptionally high SiO₂ contents (exceeding 98 wt.% in two out of three samples), accompanied by only minor amounts of impurities, including Al₂O₃, Fe₂O₃, CaO, MgO, and P₂O₅. These results indicate that the silica meets the stringent compositional requirements for metallurgical-grade quartz. XRD results confirmed the dominance of the α-quartz phase, with no detectable polymorphic phase transitions observed up to 1200 °C. Raman spectroscopic analysis indicated structural stability up to 600 °C, the onset of progressive structural disorder at 900 °C, and significant structural transformation at 1200 °C. The findings of the present study demonstrate that the quality of Hodar silica surpasses that of most Iranian silica deposits and is comparable to high-grade silica deposits worldwide. The observed thermal and structural stability of the samples highlights their high reliability and suitability for industrial applications, particularly in the silicon metal and ferrosilicon industries.
کلیدواژهها English