Szczegóły publikacji
Opis bibliograficzny
In situ spinel formation in a smart nano-structured matrix for no-cement refractory castables / Dominika MADEJ, Karina TYRAŁA // Materials [Dokument elektroniczny]. — Czasopismo elektroniczne ; ISSN 1996-1944. — 2020 — vol. 13 iss. 6 art. no. 1403, s. 1–20. — Wymagania systemowe: Adobe Reader. — Bibliogr. s. 16–20, Abstr. — Publikacja dostępna online od: 2020-03-19
Autorzy (2)
Słowa kluczowe
Dane bibliometryczne
| ID BaDAP | 128083 |
|---|---|
| Data dodania do BaDAP | 2020-04-14 |
| Tekst źródłowy | URL |
| DOI | 10.3390/ma13061403 |
| Rok publikacji | 2020 |
| Typ publikacji | artykuł w czasopiśmie |
| Otwarty dostęp |  |
| Creative Commons | |
| Czasopismo/seria | Materials |
Abstract
The hydration of an equimolar mixture of MgO and Al2O3 nano-powders has been proven to be an effective way to synthesize Mg6Al2CO3(OH)16∙4H2O as a component of a nano-structured matrix and magnesia-alumina spinel precursor for high-performance cement-free corundum-spinel refractory castables. (Mg3)–OH–brucite sites (417 °C) formed initially within the magnesia–alumina hydrating blended paste were replaced with (Mg2Al)–OH and (Mg3)–OH hydrotalcite sites, which were dehydroxylated at 420 °C and 322 °C, respectively. This reorganization was connected with the incorporation of anions and water molecules in the interlayer spacing of hydrotalcite, which was dehydrated at 234 °C. Hence, the thermal decomposition of a nano-structured matrix system containing mainly Mg6Al2CO3(OH)16∙4H2O consists of a complex sequence of dehydration, dehydroxylation and decarbonization, and this finally leads to the formation of inverse spinel MgAl2O4 and periclase MgO through many intermediate stages containing the mixed tetrahedral-octahedral Al phase and MgO-like structure. Hence, the hydraulic bond that primarily existed was replaced by a ceramic bond at a relatively low temperature, i.e., 700 °C, where a spinel was formed. Important changes in oxygen coordination polyhedra around Al3+ in the dehydrated-dehydroxylated hydrotalcite occurred between 600 and 1100 °C.
