Preparation of ultrafine-grain graphite by liquid dispersion technique for inhibiting the liquid fluoride salt infiltration. (June 2016)

• Record Type: Journal Article
• Authors: Lian, Pengfei; Song, Jinliang; Liu, Zhanjun; Zhang, Junpeng; Zhao, Yanling; Gao, Yantao; Tao, Zechao; He, Zhoutong; Gao, Lina; Xia, Huihao; Guo, Quangui; Huai, Ping; Zhou, Xingtai
• Is Part Of: Carbon. Volume 102(2016)
• Page Start: 208
• Page End: 215
• Publication Date: 2016-06
• Subjects: Carbon -- Periodicals; Carbone -- Périodiques; Koolstof; Toepassingen; Electronic journals; 546.681
• DOI: 10.1016/j.carbon.2016.02.018
• Languages: English
• ISSNs: 0008-6223

Abstract

Abstract: In this work, the mixtures of coke aggregates and coal tar pitch were used as starting materials to prepare ultrafine-grain graphites (UGG) by a liquid mixing method for the inhibition of molten salts in molten salt reactor (MSR). The average diameters of coke aggregates for UGG-1 and UGG-2 were respectively 10 and 5 μm. The liquid dispersion technique could effectively prevent fine particles of raw materials from being conglomerated. Microstructure, thermophysical and other properties of the obtained graphite were studied. A high-pressure reactor was constructed to evaluate the molten salt penetration in the graphite. Compared to isostatic graphite (IG-110, TOYO TANSO CO., LTD.), UGG-2 possessed excellent properties such as high bending strength of 81.0 ± 2.5 MPa, compressive strength of 133 ± 3 MPa, low porosity of 14.0 ± 0.1% and an average pore diameter of 0.52 ± 0.01 μm. The fluoride salt volume occupation of IG-110 and UGG-1 under 1.5 atm was 14.4% and 3.7%, respectively. While the volume occupations of UGG-2 under 1.5 atm was only 0.17%, and continued to be steady even up to 5 atm with the increase of 0.45%, less than the critical index proposed for MSR of 0.5%. The UGG-2 could effectively inhibit liquid fluoride salt infiltration and was a promising candidate as neutron moderator or reflector materials for MSR.