作者：YANG Ding'ao;YU Zhiming;FAN Liuwu;

作者单位：Sanmenxia Polytechnic College, Sanmenxia, Henan 472000, China

刊名：China's Refractories

ISSN：1004-4493

出版年：2003-01-05

卷：12

期：1

起页：19

止页：22

分类号：TQ175

语种：英文

关键词：Aluminium carbide;Hydration;Thermochemical analysis;Carbon-containing refractory;Aluminium;

内容简介

In this paper, X-ray diffractograms analysis and SEM observation of Al_4C_3 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 Al_4C_3(s) gradually during heating from 600 deg C to 1200 deg C. It is considered that the interlocked structure of Al_4C_3 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 5 wt percent increases by 2.8 times being from 6.5MPa to 18.2MPa. After a thermochemical calculation for hydration reaction processes of Al_4C_3 and H_2O (g), the equilibrium partial pressure chart of H_2O (g) in H_2O-Al_4C_3-Al(OH)_3 system vs various temperatures has been attained. The H_2O (g) partial pressure in the air needed for the Al_4C_3 hydration reaction is no more than 10 approx 18 atm at the temperature below 120 deg C. 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 he hydration expansion is 2.11 times during transforming from Al_4C_3 to Al(OH)_3. The fundamental measure against hydration of the refractories is to insulate the refractories from H_2O (g) by various means such as pitch impregnation or other sealing materials.