Phase and Microstructural Studies of Two Types Commercial
· Magnesia grain size effect on in situ spinel refractory castables. J. Eur. Ceramic Soc. 28 . Erdoğan N Yıldız R. 1995. Magnesite and Basic Refractory Material Technology Lale Publication Kütahya 43-44 s. Hamzaçebi C. 1991. The Effectes of Process Parameters on the Properties of Spinel Refractories Master of Science Thesis
Get Price
In-situ formation of spinel fibers in MgO-C refractory
· In-situ magnesia-rich spinel fiber was formed resulting from the addition of ferrocene into MgO-C refractory matrixes. The formation of in-situ spinel fiber was detected to start at 1300 °C. The amount diameter and length of the fibers increased with rising temperature. Ferrocene may have catalytic effects on the growth of the fibers in two aspects.
Get Price
Spinel s springIndustrial Minerals
· As well as production of pre-formed spinel by fusion or sintering some spinels are designed to be formed in-situ in refractory matrices from the reaction of free magnesia and alumina during use. The resulting properties in using in-situ and pre-formed spinel in castables used in steelmaking are significantly different but both types of
Get Price
Microsilica or MgO grain size Which one mostly affects the
EFFECT OF ANTI-HYDRATION AGENSTS FOR THE MgO Abstract High refractoriness basic slag corrosion resistance and competitive costs of magnesium oxide (MgO) are attractive for use in refractory castables. However the magnesia easily reacts with water (steam or liquid) resulting a Mg (OH) 2 coating layer on its particle surface.
Get Price
Effect of titanium oxide addition on magnesia refractories
· This work contains the results of investigations into the influence of titanium oxide (TiO2) addition on the properties of refractory magnesia ceramics. The presented research involved adding titanium oxide in a classic way i.e. directly to the ceramic mix. The conducted laboratory tests revealed a significant impact of this oxide on the properties of refractory materials.
Get Price
Alumina-rich refractory concretes with added spinel
· composition of alumina-rich refractory concretes has clearly improved slag attack behaviour reduced wear rates1–4 and as a consequence provided a longer lifespan for steel plant ladles than other traditional refractory products. Now magnesia (dead burned magnesite) is used as an additive as a means of generating "in situ spinel" by re-
Get Price
Evolution of in Situ Refractories in the 20th Century
Feng Wang Pingan Chen Xiangcheng Li and Boquan Zhu Effect of micro-spinel powders addition on the microstructure and properties of alumina refractory castables Ceramics International 10.1016/j.ceramint.2018.10.049 (2018).
Get Price
Effect of titanium oxide addition on magnesia refractories
· This work contains the results of investigations into the influence of titanium oxide (TiO2) addition on the properties of refractory magnesia ceramics. The presented research involved adding titanium oxide in a classic way i.e. directly to the ceramic mix. The conducted laboratory tests revealed a significant impact of this oxide on the properties of refractory materials.
Get Price
Porogenesis in the Alumina-Brucite-Magnesia-Spinel System
· Abstract Magnesium monoaluminate spinel (MgAl2O4) is an important raw material for the refractory industry and its in-situ formation from Al2O3 and MgO sources is an expansive process due to its low density. Such an expansion can be a serious drawback for the production of dense structural bricks and castables since it frequently causes deformations and cracks and hinders particles from
Get Price
Spinel-containing alumina-based refractory castables
· Considering this aspect the use of coarse MgO grains would be a suitable way to inhibit the MgO hydration as it is a surface-controlled effect. However the increase in the magnesia grain size affects the spinel formation reducing its content and leading to a higher overall expansion.
Get Price
Improvement of Resistance of MgO-Based Refractory to Slag
· MgO-in situ spinel substrate was prepared at 1773 K (1500 °C) using colloidal alumina suspension and coarse MgO as raw materials. While the addition of 10 mass pct colloidal alumina had limited effect addition of 20 mass pct colloidal alumina into the MgO matrix improved greatly the resistance of the substrate against the slag penetration at 1873 K (1600 °C).
Get Price
In situ Spinel Expansion Design by Colloidal Alumina
· Considering the alumina grain size effect on the in situ spinel formation and the associated overall volumetric expansion alumina–magnesia refractory castables containing different alumina sources were evaluated by the assisted sintering technique. Reducing the size of fine tabular alumina (<200 μm) led to lower expansion levels indicating
Get Price
Evolution of an alumina-magnesia/self-forming spinel
MgO content in the castable seems to affect the hibonite development. The development of a self-forming spinel castable without any synthetic spinel grains appears to be promissory for optimum refractory linings. Keywords Refractories magnesium aluminate spinel castable alumina-magnesia refractory lining MgAl 2 O 4 MgO-Al 2 O 3.
Get Price
In-situ formation of spinel fibers in MgO-C refractory
· In-situ magnesia-rich spinel fiber was formed resulting from the addition of ferrocene into MgO-C refractory matrixes. The formation of in-situ spinel fiber was detected to start at 1300 °C. The amount diameter and length of the fibers increased with rising temperature. Ferrocene may have catalytic effects on the growth of the fibers in two aspects.
Get PriceThe Impact of In Situ-Formed Spinel on the Porosity of No
The paper focuses on the determination of how in-situ formed magnesia-alumina spinel (MA spinel) content in corundum refractory castables influences the final properties and pore size distribution of no-cement refractory castables. The motivation for this research was the continued pressure on increasing the utility properties of refractory castables namely their corrosion resistance to blast
Get Price
In-situ formation of spinel fibers in MgO-C refractory
· In-situ magnesia-rich spinel fiber was formed resulting from the addition of ferrocene into MgO-C refractory matrixes. The formation of in-situ spinel fiber was detected to start at 1300 °C. The amount diameter and length of the fibers increased with rising temperature. Ferrocene may have catalytic effects on the growth of the fibers in two aspects.
Get Price
From Macro to Nanomagnesia Designing the in situ Spinel
Magnesia grain size affects the in situ spinel formation kinetics and expansion of alumina–magnesia refractory castables. The use of coarse grains results in a large expansion and delays the reaction s starting temperature. In this work the addition of an MgO source with different grain sizes (from macro Dmax≤0.1 mm to nano D50≤20 nm) led to a broad linear expansion range (6 –2
Get Price
Improvement of Resistance of MgO-Based Refractory to
· cles in MgO-based refractory is one of the effective approaches. More recently Braulio studied the effect of alumina particle size on controlling the expansion of alumina-magnesia refractories. 19 20 It was found that colloidal alumina suspension with nanoscale size pre-sented the best performance. In the present work in situ spinel is
Get Price
Roghayeh NikbakhtPostdoc Fellow University Lecturer
In situ spinel formation and the reaction is affected by the magnesia source and its grain size • Castables were prepared with different magnesia grain sizes and different formula the samples were evaluated by an assisted sintering technique mechanical strength and microstructural evaluation.
Get PriceEffect of titanium oxide addition on magnesia refractories
· This work contains the results of investigations into the influence of titanium oxide (TiO2) addition on the properties of refractory magnesia ceramics. The presented research involved adding titanium oxide in a classic way i.e. directly to the ceramic mix. The conducted laboratory tests revealed a significant impact of this oxide on the properties of refractory materials.
Get Price
Slag attack evaluation of in situ spinel-containing
· Some parameters (such as the MgO and alumina grain sizes the binder system the silica fume content and the refractory aggregate sources ) influence the volumetric stability of the alumina–magnesia castables. The binder system can affect the in situ spinel formation and its expansive behavior due to its reactions and sinterability at high temperatures.
Get Price
Spinel In situ versus PreformedClearing the Myth
· effect of spinel-types spinel grain size and amount of spinel on the chemical and me-chanical resistance of alumina-spinel cast-ables 1–5 . In the past ten years the cast-ables used for the ladle side wall have pro-gressively changed from alumina-spinel castables to alumina-magnesia types. One driver for this change was the consideration
Get Price
Spinel In situ versus PreformedClearing the Myth
· effect of spinel-types spinel grain size and amount of spinel on the chemical and me-chanical resistance of alumina-spinel cast-ables 1–5 . In the past ten years the cast-ables used for the ladle side wall have pro-gressively changed from alumina-spinel castables to alumina-magnesia types. One driver for this change was the consideration
Get Price
Improvement of Resistance of MgO-Based Refractory to Slag
· MgO-in situ spinel substrate was prepared at 1773 K (1500 °C) using colloidal alumina suspension and coarse MgO as raw materials. While the addition of 10 mass pct colloidal alumina had limited effect addition of 20 mass pct colloidal alumina into the MgO matrix improved greatly the resistance of the substrate against the slag penetration at 1873 K (1600 °C).
Get Price
Porogenesis in the Alumina-Brucite-Magnesia-Spinel System
· Abstract Magnesium monoaluminate spinel (MgAl2O4) is an important raw material for the refractory industry and its in-situ formation from Al2O3 and MgO sources is an expansive process due to its low density. Such an expansion can be a serious drawback for the production of dense structural bricks and castables since it frequently causes deformations and cracks and hinders particles from
Get Price
In situ Spinel Expansion Design by Colloidal Alumina
· Considering the alumina grain size effect on the in situ spinel formation and the associated overall volumetric expansion alumina–magnesia refractory castables containing different alumina sources were evaluated by the assisted sintering technique. Reducing the size of fine tabular alumina (<200 μm) led to lower expansion levels indicating
Get Price
In situ Spinel Expansion Design by Colloidal Alumina
· Considering the alumina grain size effect on the in situ spinel formation and the associated overall volumetric expansion alumina–magnesia refractory castables containing different alumina sources were evaluated by the assisted sintering technique. Reducing the size of fine tabular alumina (<200 μm) led to lower expansion levels indicating
Get PriceEffect of MgO Grain Size on Thermal Expansion Behavior of
· The effect of MgO grain size on the permanent linear change behavior of resin bonded alumina–magnesia–carbon refractory has been studied in relation to the formation of spinel phase in these refractories as a function of firing time and temperature.
Get Price
Fundamentals and applications on in situ spinel formation
· A suitable example is the effect of magnesia grain size on the overall expansion of in situ spinel-forming castables. Braulio et al. investigated this aspect and concluded that the addition of coarser magnesia grains led to higher values of residual expansion. However considering that the same magnesia volume was used regardless of the magnesia grain size different values of overall expansion
Get Price
