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Effect of carbon sources on the properties of lightweight corundum‐spinel refractory with density gradient
Author(s) -
Wan Qifa,
Yin Hongfeng,
Tang Yun,
Yuan Hudie,
Ren Xiaohu,
Xin Yalou,
Liu Yuchi
Publication year - 2019
Publication title -
international journal of applied ceramic technology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.4
H-Index - 57
eISSN - 1744-7402
pISSN - 1546-542X
DOI - 10.1111/ijac.13437
Subject(s) - materials science , corundum , spinel , graphite , particle size , refractory (planetary science) , carbon fibers , carbothermic reaction , carbon black , particle (ecology) , metallurgy , composite material , chemical engineering , oceanography , natural rubber , composite number , engineering , geology , carbide
Abstract Lightweight refractories are expected to have excellent performance in high and room temperature in addition to energy consumption reduction. Lightweight corundum‐spinel refractory was fabricated by carbothermal reduction of MgO, the oxygen diffusion rate controlled oxidation of Mg vapor, and subsequent reaction between MgO and Al 2 O 3 . The lightweight corundum‐spinel refractory was characterized by X‐ray diffraction and scanning electron microscopy. Effects of flaky graphite particle size and carbon black content on the properties of lightweight corundum‐spinel refractory were investigated. The results showed that flaky graphite particle size had great effect on the stacking density of green compacts and the properties of refractory. When flaky graphite particle size was 42.44 µm, the refractory possessed bulk density 2.68 g/cm 3 , compressive strength (CS) 63.5 MPa, and refractoriness under load 1641°C fired at 1550°C for 4 hours. With the decrease of carbon black content, the properties of refractory increased, but the CS was low due to the generation of structure defects including large pores and cracks when compared with the samples using graphite as carbon source. In order to obtain lightweight refractory with good performance, the carbon particle size and content should be chosen properly in addition to firing temperature and holding time.