Refractory Lining Design and Installation

MgO Refractory Doped with ZrO2 Nanoparticles: Influence of Cold Isostatic and Uniaxial Pressing and Sintering Temperature in the Physical and Chemical Properties

“…Reaction of nanoparticle by affinity (similarity) in ionic radius: Due coincidence in ionic radius, Zr 4+ (0.84 Å) and Ca 2+ (0.95 Å) a new phase was formed in solid solution (CaZrO 3 ). This phase has a density of 4.95 g/cm 3 [40] higher than that of the matrix (3.58 g/cm 3 ) [4]. Also, a substitution of Mg 2+ ions (0.89 Å, from the matrix) with ions of Zr 4+ (0.84 Å) occurred thus stabilizing chemically the ZrO 2 phase in tetragonal structure, until room temperature; the ionic compensation is made possible by oxygen vacancies.…”

“…Also, the high melting points of the MgO (2800 • C) [3,4,25], ZrO 2 (2715 • C) [3,4] and of the phase formed in situ CaZrO 3 (2340 • C) [3,4], promoted the densification of the material by sintering in solid state. The CaO/SiO 2 ratio remained high (>2.8) in the raw material of MgO; no liquid phase sintered was present which would have promoted a higher density, but it would have an impact on the formation of phases of low melting point, making the refractory susceptible to resist lower temperatures.…”

“…%) [24], MgAl 2 O 4 (up to 6 wt. %) [25], TiO 2 [26,27], Cr 2 O 3 [28], trivalent oxides [29], ZrSiO 4 [30], SiO 2 [31] and Fe 2 O 3 [32]. They have obtained optimal results in mechanical, physical, chemical, and thermomechanical properties, but also improvements in the hydration resistance and in the sintering process were observed.…”

“…to obtain bricks with different shapes, are used in the lining of both furnaces and ladles employed in the metallurgical industry (basic oxygen furnace (BOF), electric arc furnaces (EAF), argon-oxygen-decarburization (AOD), ladle metallurgical furnaces (LMF), cement kilns and furnaces for nonferrous materials [3]). The main consumer of magnesia-based refractory bricks is the metallurgical industry, and particularly the iron and steelmaking industry, where they are mainly used in the slag line of the LMF, in the EAF and in the BOF [4]. Other consumers of magnesia bricks (magnesia-chromite) are the submerged arc furnaces (SAF) used in the copper manufacturing process, because of the resistances to the chemical degradation by molten phases and to the abrasion, the thermal shock resistance and the mechanical strength [5].Presently, the industry requires research on refractories with better properties that are manufactured using new technologies of agglomeration (faster, cheaper and cleaner) to improve their processes, for instance, studies of: new clean techniques of sintering (solar synthesis, laser, microwave and conventional sintering), synthesis of ceramic composites, incorporation of additives to improve properties of the refractories and study of nanomaterials added to the refractory matrix [6][7][8][9][10][11].…”

“…The main consumer of magnesia-based refractory bricks is the metallurgical industry, and particularly the iron and steelmaking industry, where they are mainly used in the slag line of the LMF, in the EAF and in the BOF [4]. Other consumers of magnesia bricks (magnesia-chromite) are the submerged arc furnaces (SAF) used in the copper manufacturing process, because of the resistances to the chemical degradation by molten phases and to the abrasion, the thermal shock resistance and the mechanical strength [5].…”