Effect of organosilicon phosphate binders on physicomechanical properties of corundum-carbon refractories

Krotikov, V. A.; Buslaev, G. S.; Zhukovskaya, A. E.; Kozelkova, I. I.

doi:10.1007/s11148-006-0054-5

Cited by 4 publications

(4 citation statements)

References 4 publications

(1 reference statement)

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“…Active carbon formed can take part in phase formations of secondary compounds. 23) Iron was supplied by LECO Australia in the form of rings weighing 1 g each; the weight of iron used was kept constant for all experimental runs. The composition of iron was analysed using ICP elemental analysis with details given in Table 2.…”

Section: Methodsmentioning

confidence: 99%

Chemical Interactions in Al2O3^|^ndash;C/Fe System at 1823 K: Implications for Refractory Recycling

et al. 2012

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An investigation was carried out on recycling spent refractories comprising of Al2O3-12.9%C refractory substrate after 30 minutes of interactions with molten iron at 1 823 K. XRF results showed that the spent refractory was contaminated with iron (0.798 wt%). Spent refractories in 10, 20 and 30 wt% proportions were mixed with virgin refractory composition of Al2O3-10%C. High temperature interactions of recycled refractory substrates with liquid iron were investigated at 1 823 K to understand chemical reactions occurring in the metal/refractory interface as well as in the bulk of the refractory. The sessile drop technique was used to determine the interfacial wetting behaviour and the phase transformations during interactions with molten iron were determined using SEM and EDS. These investigations determined the role of spent refractory constituents which contains degraded alumina, carbon and iron. The presence of iron and reactive alumina in the refractory substrates was seen to affect both physical and chemical interactions, contact angles and carbon pick-up. The drop in contact angles was in direct correspondence with an increase in carbon pickup. The structural integrity and bonding of the recycled refractory was also compromised, and interfacial cracks were observed along with increases in the interfacial area of contact of metal droplet with refractory. Video images also showed whisker formation on metal droplets during 30 minutes of reaction time. The results from this study have shown that metal contaminated spent refractories tend to enhance refractory degradation during recycling and therefore may be unsuitable for steelmaking applications.

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Section: Methodsmentioning

confidence: 99%

Chemical Interactions in Al2O3^|^ndash;C/Fe System at 1823 K: Implications for Refractory Recycling

et al. 2012

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“…29) During heat treatment at 800-1 200°C, the resin undergoes devolatalisation to form a reinforcing carbon framework over the entire volume of the component. The active carbon thus formed takes part in phase formations of secondary compounds, 30) which could influence the interfacial reaction mechanisms. Iron for these experiments was supplied by LECO Australia in the form of rings weighing 1 g each.…”

Section: Methodsmentioning

confidence: 99%

High-temperature Interactions of Alumina–Carbon Refractories with Molten Iron

et al. 2010

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IntroductionRefractory degradation is a complex phenomenon involving chemical wear (corrosion) and physical/mechanical wear (erosion/abrasion). Refractory corrosion results in the recession of "hot face" (working surface) due to chemical reactions and molten metal penetration. 1) Alumina-carbon refractories are commonly used in steelmaking applications due to their excellent high-temperature strength and thermal shock resistance. [2][3][4][5] The corrosion resistance of Al 2 O 3 -C refractories is influenced by its reactions with liquid iron, which leads to the dissolution of refractory constituents into the melt. 6) Carbon in the form of graphite is used in refractories since it enhances corrosion resistance and thermal shock resistance. 7) However, the degradation of carbon-based refractories occurs through carbon depletion, resulting in decreased refractory resistance to chemical attack, increased carbon pickup by steel and extensive metal penetration within the refractory. 8) Material inhomogeneity and porosity can promote corrosion and allow corrosive agents to penetrate and cause erosive damage, resulting in severe degradation. 9) Iron oxide formed can react with alumina to form hercynite (FeO-Al 2 O 3 ), which builds up in the refractory over time, eventually causing uncontrolled expansion of saturated refractory and hot face spalling. 10) The corrosion of alumina-carbon refractories is primarily influenced by their chemical reactions with molten iron/steel, which proceed through a direct contact with the metal. The composition of the refractory, its physical texture, the nature of the bonding phases, and the characteristics of melt and reaction products are known to influence reaction kinetics. 11) Refractory-iron reactions lead to molten metal penetration; the penetration depth is believed to be influenced by the chemical composition of the refractory, metal and physical properties like porosity of the refractory. The penetration depth may range from a few microns to several millimetres depending upon these factors, and the quantity of molten metal. 1) Carbon is picked up by Fe resulting in carbon dissolution from the refractory and the alumina left behind tends to resist Fe penetration. The regions which experience carbon depletion are subsequently filled with molten iron, which contributes to the corrosion. In the liquid iron/alumina-graphite system, carbon transfer from graphite to liquid iron is a well known phenomena, while alumina is considered to be unreactive to iron at steelmaking temperatures (1 550°C). 12) The influence of wettability on carbon dissolution into molten iron suggests that the rate of dissolution is significantly affected by the contact area available for the carbon-transfer. 13) The depth of penetration of molten iron into the refractory and the strength of bonding between the metal and the refractory 804 © 2010 ISIJ ISIJ International, Vol. 50 (2010), No. 6, pp. 804-812 The interfacial behaviour of alumina/carbon refractories with liquid iron was investigated at 1 550°C, w...

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“…There are three types of commonly used inorganic binders that are phosphates, silicates, and cement . Among them, aluminum phosphate binders, also commonly named aluminum phosphate salt binders, have many excellent properties such as strong bonding strength, low coefficient thermal expansion, good thermal shock resistance, and excellent mechanical properties at medium‐high temperature, and are widely used for bonding of high‐temperature materials such as refractory materials, ceramics, and airborne wave‐transmitting materials. However, unfortunately, there are few studies on the composition and structure of the aluminum phosphate binders.…”

Section: Introductionmentioning

confidence: 99%

Study of composition and structure of aluminum phosphate binder

Wei

Wang

Zhang

et al. 2019

J Chinese Chemical Soc

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In this article, theoretical analysis and different testing techniques were used to study the reaction pathways and synthesized products of phosphoric acid and aluminum hydroxide at different Al/P molar ratios. The results show that: (a) When the molar ratio of phosphoric acid/aluminum hydroxide is 1:3, the reaction will produce stoichiometric aluminum dihydrogen phosphate (Al(H 2 PO 4 ) 3 ); (b) when Al(OH) 3 is excessive, an intermediate, monohydroxy aluminum dihydrogen phospate (HO-Al-(H 2 PO 4 ) 2 ), will appear, which is unstable and will continue to react according to two reaction pathways, one is intramolecular dehydration to form phosphoric acid hydrogen-dihydrogen aluminum diphosphate (H 2 PO 4 )Al(HPO 4 ); the other is intermolecular dehydration cross-linking to form a polymeric macromolecular aluminum phosphate H-((HPO 4 )(H 2 PO 4 )Al-O-HPO 4 -Al(H 2 PO 4 )-O)n H. The ratio of the two pathways is affected by the excess of Al(OH) 3 . When the excess of Al(OH) 3 continues to increase, the ratio of the second reaction path begins to increase and the viscosity of the product gradually increases. Adhesion experiments show that the aluminum dihydrogen phosphate has the best bonding performance benefiting from its lower viscosity. K E Y W O R D SAl/P molar ratio, aluminum phosphate binder, bonding performance, composition, reaction route

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Effect of organosilicon phosphate binders on physicomechanical properties of corundum-carbon refractories

Cited by 4 publications

References 4 publications

Chemical Interactions in Al2O3^|^ndash;C/Fe System at 1823 K: Implications for Refractory Recycling

Chemical Interactions in Al2O3^|^ndash;C/Fe System at 1823 K: Implications for Refractory Recycling

High-temperature Interactions of Alumina–Carbon Refractories with Molten Iron

Study of composition and structure of aluminum phosphate binder

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