Al4C3 Hydration Thermochemical Analysis for Burned Carbon-Containing Refractories with Al

In this paper,X-ray diffractogram analysis and SEM observation of Al4C3 formed at high temperature from carbon-containing refractories with Al have been carried out.Aluminum added to carbon-containing refractories reacts with C(s) to form Al4C3(s) gradually during heating from 600℃ to 1200℃，It is considered that the interlocked structure of Al4C3 plate crystals promotes the outstanding increase of hot modulus of rupture of carbon-containing refractories with Al.The HMOR of carbon-contatining refractories with Al.The HMOR of carbon-containing refractories added with Al additive from 0 to 5wt% increases by 2.8 times being from 6.5MPa to 18.2MPa.After a thermochemical Calculation for hydration reaction Processes of Al4C3 and H2O(g),the equilibrium partial pressure chart of H2O(2)in H2O-Al4C3-Al(OH)3 system vs various temperatures has been attained.The H2O(g) partial pressure in the air needed for the Al4C3 hydration reaction is no more than 10-18 atm at the temperature below 120℃。It is considered that the temperature below 120℃. It is considered that the burned carbon-containing refractories with Al is extremely easy to hydrate and the cracking of buurned carbon-containing refractories is generated because that the hydration expansion is 2.11 times during transforming from Al4C3 to Al(OH)3.The fundamental measure against hydration of the refractories is to insulate the refractories from H2O(g) by various means such as pitch impregnatiion or other sealing materials.

Al4C3 Hydration Thermochemical Analysis for Burned Carbon-containing Refractories with Al

In this paper, X-ray diffractogram analysis and SEM observation of Al4 C3 formed at high temperature from carbon-containing refractories with Al have been carried out.Aluminum added to carbon-containing refractories reacts with C(s)to form Al4 C3(s) gradually during heating from 600 ℃ to 1200℃.It is considered that the interlocked structure of Al4 C3 plate crystals promotes the outstanding increase of hot modulus of rupture of carbon-containing refractories with Al. The HMOR of carbon-containing refractories added with Al additive from 0 to 5wt％ increases by 2.8 times being from 6.5MPa to 18.2MPa.After a thermochemical calculation for hydration reaction processes of Al4 C3 and H2O(g), the equilibrium partial pressure chart of H2O(g)in H2O-Al4C3-Al(OH)3 system vs various temperatures has been attained . The H2O (g) partial pressure in the air needed for the Al4 C3 hydration reaction is no more than 10～18 atm at the temperature below 120℃.It is considered that the burned carbon-containing refractories with Al is extremely easy to hydrate and the cracking of burned carbon-containing refractories is generated because that the hydration expansion is 2.11 times during transforming from Al4 C3 to Al(OH)3.The fundamental measure against hydration of the refractories is to insulate the refractories from H2O(g)by various means such as pitch impregnation or other sealing materials.