China's Refractories

《中国耐火材料》英文版

China's Refractories ›› 2020, Vol. 29 ›› Issue (1): 31-35.DOI: 10.19691/j.cnki.1004-4493.2020.01.006

• Original article • Previous Articles     Next Articles

Influence of Setting Accelerating Agents on Properties of Colloidal Alumina Bonded Corundum Castables

ZHANG Xiaohui1,*(), YU Xingguo1,3, WANG Baoyu2, ZHU Boquan3   

  1. 1 Sinosteel Luoyang Institute of Refractories Research Co., Ltd., Luoyang 471039, China
    2 Jiangsu Chianaref Refractory Co., Ltd., Yixing 214266, China
    3 The State Key Laboratory of Refractories and Metallurgy, Wuhan University of Science and Technology, Wuhan 430081, China
  • Online:2020-01-10 Published:2020-01-10
  • Contact: ZHANG Xiaohui
  • About author:Zhang Xiaohui was born in 1979. She obtained her bachelor’s degree with the major of inorganic nonmetallic materials in 2001 and master’s degree with the major of materials science in 2004 from Xi’an University of Architecture & Technology. From 2004 to the end of 2005, she worked in Xi’an Qinxiang Technology Co., Ltd. Since 2006, she has been working in Sinosteel Luoyang Institute of Refractories Research Co., Ltd.

Abstract:

In order to improve the flow ability and early-stage strength of colloidal alumina bonded corundum castables, the colloidal alumina with 20% of solid content was used as the binder, and tabular corundum aggregates and fines, and active alumina micropowder CL370 as the main starting materials. Influences of setting accelerating agents (magnesia fines and sodium meta-aluminate) on the linear change rate, the modulus of rupture and the microstructure of corundum castables after different heat-treatments were researched. The results show (1) cement bonded corundum castables have the highest modulus of rupture after 24 h of demolding, and colloidal alumina bonded corundum castables have the lowest one; both magnesia fines and sodium meta-aluminate can improve the strength after 24 h of demolding; (2) after firing at 1 000 ℃ for 3 h, the modulus of rupture of all specimens decreases, even lower than that after 24 h of demolding; (3) after firing at 1 600 ℃ for 3 h, the castable specimen added with 0.1 mass% magnesia fines has the highest modulus of rupture; the tabular phases appear interwovenly in the specimen; (4) taking the comprehensive properties into account, 0.1 mass% of magnesia fines is appropriate, and the addition of sodium meta-aluminate shall be lower than 0.3%.

Key words: corundum, colloidal alumina, setting accelerating agent, magnesia fines, sodium meta-aluminate