Assessing and tailoring the dilatometric profile of novel chromium‐free refractory raw materials

Journal of the American Ceramic Society, Год журнала: 2024, Номер 108(3)

Опубликована: Ноя. 24, 2024

Abstract Reducing dependence on toxic electrofused magnesia‐chromium aggregates is essential to meet demands for eco‐friendly refractories. Some authors have proposed alternative compositions using lab‐scale electrofusion produce small specimens (< 0.5 g). However, this size limits the evaluation of key refractory properties, such as thermal expansion. As an alternative, study explored conventional sintering at 1600°C 5 h and both methods resulted in equivalent chemical mineralogical compositions. Despite presenting higher porosity (24 % – 30 %) than ones (4 6 %), consistent microstructural parameters supported route larger (5 × 25 mm 3 ), which were assessed dilatometric profiles up 1400°C. Combined with thermodynamic calculations, Rietveld's refining X‐ray diffraction patterns differential scanning calorimetry, analysis indicated that spinel dissolution periclase causes a high expansion during heating, whereas its re‐precipitation results shrinkage. behavior could result challenges lining design, computational thermodynamics was used find additives capable increasing transition temperature. TiO₂ identified promising candidate effectiveness attested.

Язык: Английский

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Enhanced infrared radiation properties of MgFe2O4 doping with in-situ generated Fe2+ by adjusting the sintering temperature and atmosphere

Journal of the European Ceramic Society, Год журнала: 2025, Номер 45(6), С. 117186 - 117186

Опубликована: Янв. 5, 2025

Язык: Английский

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Impact of atmospheric conditions on the high‐temperature thermal conductivity of novel Cr‐free refractory materials

Journal of the American Ceramic Society, Год журнала: 2025, Номер unknown

Опубликована: Апрель 4, 2025

Abstract In high‐temperature applications, the effective thermal conductivity ( k eff ) of refractory ceramics significantly influences energy efficiency. However, formulating refractories with low remains challenging, especially when avoiding toxic electrofused magnesia–chromium aggregates (EMCAs). This study investigated Cr‐free alternative compositions produced by sintering at 1600°C, evaluating their up to 1500°C—thermal diffusivity, heat capacity, and density assessed laser flash analysis (LFA), thermodynamic calculations immersion test corrected dilatometric data, respectively. Results showed that fewer distinct cations exhibited higher temperatures, whereas increased compositional complexity enhanced lattice distortions, lowering it. Above 1000°C, formation solid solutions in systems induced a rapid decrease this property, ultimately falling below EMCA. behavior suggests using these nontoxic processes could enhance Nevertheless, another aspect observed was reversible effect environment inside LFA equipment on microstructure samples. Detailed characterization one composition before after revealed generation slightly reducing atmosphere, increasing iron solubility periclase even inhibiting spinel precipitation during cooling. Consequently, led microstructures greater disorder reduced conductivity.

Язык: Английский

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Abrasion resistance and hardness of Cr-free zinc and iron co-doped spinel and magnesia-spinel refractory matrices for copper smelting

Journal of the European Ceramic Society, Год журнала: 2025, Номер unknown, С. 117545 - 117545

Опубликована: Май 1, 2025

Язык: Английский

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