Upgrading Castable Performance through Matrix
· A refractory castable is composed of two parts coarse aggregates and fines. In a recipe the proportion of aggregates (>45μm) usually constitutes 65-75 of the total. Coarse raw materials for high alumina castables are for example Tabular Alumina (T-60/T-64) Magnesium Aluminate Spinel
Get Price
Microstructure and phase evolution of alumina–spinel self
· For the study of nano-alumina addition on the microstructure phase composition and other properties of these refractory castables reactive alumina is substituted by nano-alumina powder in 0–4 wt . range.The particle size distribution was calculated from the Andreasen s equation as (1) CPFT = 100 d D q where CPFT d D and q indicate the cumulative percentage finer than particle size
Get Price
Rheology of High Performance Alumina and Spinel
· ple this might be a matrix of a high alumina castable designed with high microsilica content to achieve mullite formation or a spinel containing castable for steel ladles where the use of reactive alumina is the only way to achieve high performance cast-ables. refractories WORLDFORUM 4 (2012) 2 95 η = 1- ϕ- η ϕm ηmedium ϕm
Get Price
Optimization of Properties for Alumina-Spinel Refractory
Aiming at optimizing properties of alumina-spinel refractory castables coarse corundum particles were replaced partially with the particles of a novel porous multi-component CMA (CaO-MgO-Al2O3) aggregate in the same size. Properties including the bulk density apparent porosity strength slag corrosion resistance thermal shock resistance and thermal fatigue resistance of alumina-spinel
Get Price
Effect of spinel content on slag attack resistance of high
· High alumina refractory castables based on the Al 2 O 3-MgO-CaO diagram ternary system were prepared using tabular alumina white electrofused corundum calcined alumina synthetic spinel dead-burned magnesia dolomite and calcium aluminate cement as starting raw materials.Two kinds of slags with 9.02 and 4.14 CaO/SiO 2 ratios were studied for slag resistance by means of crucible tests.
Get Price
Corrosion of high alumina spinel castables by steel ladle
· In the present study two different high alumina spinel castable refractories were examined for their wear resistance against steel ladle slag under laboratory conditions. The influences of mechanical properties and chemical composition on the wear mechanism are discussed.
Get Price
High Alumina Castables A Comparison Among Various Sol
A comparison among various sol-gel bonding systems has been done for high alumina castable refractory. Four different sol systems namely alumina boehmite mullite and spinel have been synthesized and used individually as sole binder in high alumina castable system with particle size distribution coefficient of 0.23 as per Dinger and Funk model.
Get Price
Effect of CaO Content on the Hot Strength of Alumina
· The modulus of rupture of Al 2 O 3-spinel castables containing 20 wt Al 2 O 3-rich MgO-Al 2 O 3 spinel and 1.36-2.04 wt CaO generally increases with an increase in both CaO content and temperature from 1300° to 1500°C but it remains virtually constant from 1000° to 1300°C. Microscopic observation of the castable fired at 1500°C for 3 h reveals the growth of some CA 6 crystals out of
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
Effect of spinel content on slag attack resistance of high
Abstract High alumina refractory castables based on the Al 2 O 3 -MgO-CaO diagram ternary system were prepared using tabular alumina white electrofused corundum calcined alumina synthetic spinel dead-burned magnesia dolomite and calcium aluminate cement as starting raw materials. Two kinds of slags with 9.02 and 4.14 CaO/SiO 2 ratios were studied for slag resistance by means of crucible
Get Price
Optimization of Properties for Alumina-Spinel Refractory
Aiming at optimizing properties of alumina-spinel refractory castables coarse corundum particles were replaced partially with the particles of a novel porous multi-component CMA (CaO-MgO-Al2O3) aggregate in the same size. Properties including the bulk density apparent porosity strength slag corrosion resistance thermal shock resistance and thermal fatigue resistance of alumina-spinel
Get Price
Effect of CaO Content on the Hot Strength of Alumina
· The modulus of rupture of Al 2 O 3-spinel castables containing 20 wt Al 2 O 3-rich MgO-Al 2 O 3 spinel and 1.36-2.04 wt CaO generally increases with an increase in both CaO content and temperature from 1300° to 1500°C but it remains virtually constant from 1000° to 1300°C. Microscopic observation of the castable fired at 1500°C for 3 h reveals the growth of some CA 6 crystals out of
Get Price
BEHAVIOUR OF ALUMINA-SPINEL SELF-FLOWING
· time. Hence the alumina-spinel castables must have cold crushing strength values above 60 60 and 150 MPa at 110 1000 and 1500°C respectively. With respect to results if the nano-alumina particles content in castable com- position be used higher than 0.5 wt. the high-strength alumina-spinel castable will be obtained. By using of Figure 3.
Get Price
Study of Spinel-Containing High Alumina Castable with
· High alumina castable with presynthesized and in situ spinel formation is studied using two different lime-containing high alumina cements. Vibratable castable compositions were studied by conventional processing using a distribution coefficient of 0.29 and heat treatments at 110 900 and 1500°C. Slightly lower density and strength values were
Get Price
Effect of spinel content on slag attack resistance of high
· High alumina refractory castables based on the Al 2 O 3-MgO-CaO diagram ternary system were prepared using tabular alumina white electrofused corundum calcined alumina synthetic spinel dead-burned magnesia dolomite and calcium aluminate cement as starting raw materials.Two kinds of slags with 9.02 and 4.14 CaO/SiO 2 ratios were studied for slag resistance by means of crucible tests.
Get Price
(PDF) Post mortem study of alumina-spinel castables of an
When Al 2 O 3 contains spinel the strength after firing at 1500ºC largely increase 1 . Two refractory materials are used in the roof alumina-spinel in the critical region and high alumina in the other parts. The following report deals with the alumina- spinel only. In table 1 the chemical composition of the alumina-spinel castable is given.
Get Price
FORMATION OF HEXA-ALUMINATE SOLID SOLUTION
· Refractory castables based on Tabular alumina T60/T64 (C1) and white fused alumina (WFA) (C2) were prepared in addition to the synthetic raw mixtures. As shown in Tab. 2 the castables contain 12 wt. pre-formed spinel AR 78 which is a sintered spinel with a phase composition of 100 alumina-rich non-stochiometric spinel.
Get Price
Development of spinel sol bonded high pure alumina
· Spinel formation was confirmed by phase analysis from 600 °C. The developed sol was solely used as binder at 5 and 7 level for making high alumina castables with two different particles size distributions. Conventional castable processing technique was
Get Price
Effect of spinel content on slag attack resistance of high
· There have been numerous studies on the effects of spinel on refractory castable properties including the influence of spinel grain size 6 7 chemical composition 8 density 9 spalling resistance 5 and hot strength.10 11 Recently the alumina-spinel castable normally used on the sidewall of secondary steelmaking ladles has gradually been replaced by an alumina-magnesia type.12 13 The reason is that fine spinel
Get Price(PDF) Microstructure and phase evolution of alumina–spinel
Comparison between Fig. 4. XRD results of alumina–spinel refractory castable containing different XRD results of Figs. 3 and 4 reveals that the content of CA2 amounts of nano-alumina particles after firing at 1500 8C. C corundum S phase is decreased with the increase of firing temperature and spinel
Get Price
High alumina castables a comparison among various sol-gel
· A comparison among various sol-gel bonding systems has been done for high alumina castable refractory. Four different sol systems namely alumina boehmite mullite and spinel have been synthesized and used individually as sole binder in high alumina castable system with particle size distribution coefficient of 0.23 as per Dinger and Funk model.
Get Price
(PDF) Microstructure and phase evolution of alumina–spinel
Comparison between Fig. 4. XRD results of alumina–spinel refractory castable containing different XRD results of Figs. 3 and 4 reveals that the content of CA2 amounts of nano-alumina particles after firing at 1500 8C. C corundum S phase is decreased with the increase of firing temperature and spinel
Get Price
Microstructure and phase evolution of alumina–spinel self
· For the study of nano-alumina addition on the microstructure phase composition and other properties of these refractory castables reactive alumina is substituted by nano-alumina powder in 0–4 wt . range.The particle size distribution was calculated from the Andreasen s equation as (1) CPFT = 100 d D q where CPFT d D and q indicate the cumulative percentage finer than particle size
Get Price
Evolution in properties of high alumina castables
Unlike the findings reported by X. Wang et al. and O.H. Borges et al. ZA spinel could be observed in Zn(OH) 2-containing castables in previous study . After heat-treating at 1550 °C ZA spinel grains were isolated among CA 6 plates and no sintering neck and/or ceramic bonding was detected between ZA spinel and CA 6 plates.
Get Price
Study on The Effect of Different Sols on High Alumina
The sol systems were chosen in such a way that they generate high temperature withstanding refractory oxides on firing (alumina mullite and spinel). These synthesized sols are used as a sole binder in high alumina castable systems with two different particle size distributions containing no cement.
Get PriceMicrostructure and phase evolution of alumina–spinel self
· As it can be seen present phases in the alumina–spinel refractory castables contains alumina tabular and spinel aggregate that linked together by refractory castable matrix. The matrix of these refractory castables comprising of calcium aluminate cement hydrates with reactive alumina together with fine grains of spinel.
Get Price
Characteristics of Refractory Castables Containing Mullite
· The performance of high alumina castables containing mullite and spinel coated graphites was investigated to explore their commercial application in carbon containing refractory composites. It was compared in terms of thermal shock resistance refractoriness under load static slag resistance test pore size distribution and physical properties e.g. apparent porosity and cold crushing strength.
Get PriceHydration of refractory oxides in castable bond systems—I
· The crystal structure of magnesium aluminate spinel can accommodate high levels of deleterious elements such as Fe and Mn from slags without loss of structural integrity. 3 Static cup tests dynamic rotary slag tests and field trials in steel ladles have shown that spinel-based alumina-rich castables have excellent slag resistance.4 5 Spinel (MgAl 2 O 4) is easily formed in situ from mixtures of fine reactive magnesia and hydratable alumina included in the formulation of castable
Get PriceStudy on The Effect of Different Sols on High Alumina
The sol systems were chosen in such a way that they generate high temperature withstanding refractory oxides on firing (alumina mullite and spinel). These synthesized sols are used as a sole binder in high alumina castable systems with two different particle size distributions containing no cement.
Get Price
