Effect of catalyst types on cold properties of low carbon MgO-C refractories

doi:10.3969/j.issn.1001-1935.2022.03.004

Abstract

Abstract:

Low carbon MgO-C refractories were prepared through in-situ catalytic pyrolysis of phenolic resin,using fused magnesia,flake graphite and silicon powders as raw materials,and phenolic resin added with iron nitrate,cobalt nitrate or nickel nitrate as the binder,firing in argon atmosphere at 800,1 100 and 1 400 ℃,respectively.The effects of the catalyst types on the cold properties of the low carbon MgO-C refractories were studied.The results show that iron nitrate is the best catalyst,which promotes the in-situ formation of CNTs and SiC_w and improves the mechanical properties of refractories.With the phenolic resin containing iron nitrate,the sample after heat treatment at 1 100 ℃ has the highest cold modulus of rupture and cold compressive strength.

Key words: low carbon magnesia-carbon refractories, carbon nanotubes, silicon carbide whisker, mechanical properties

摘要：

以电熔镁砂、鳞片石墨和Si粉为原料,以掺入硝酸铁、硝酸钴和硝酸镍的酚醛树脂为结合剂,通过原位催化热解酚醛树脂的方法,在氩气气氛下,分别经800、1 100和1 400 ℃热处理,制备了低碳MgO-C耐火材料。研究了不同催化剂对低碳MgO-C耐火材料常温性能的影响,结果表明:硝酸铁为最佳的催化剂,硝酸铁的引入促进了碳纳米管(CNTs)和SiC晶须的原位生成,提高了耐火材料的力学性能。含硝酸铁的酚醛树脂加入试样时,经1 100 ℃热处理后其常温抗折强度和常温耐压强度最高。

关键词: 低碳MgO-C耐火材料, 碳纳米管, 碳化硅晶须, 力学性能

CLC Number:

TQ175.75

Li Yage, Wang Junkai, Duan Hongjuan, Liang Feng, Zhang Haijun. Effect of catalyst types on cold properties of low carbon MgO-C refractories[J]. Refractories, 2022, 56(3): 197-201.

李亚格, 王军凯, 段红娟, 梁峰, 张海军. 催化剂种类对低碳MgO-C耐火材料常温性能的影响[J]. 耐火材料, 2022, 56(3): 197-201.

Figures/Tables 9

References 18

[1]	XIAO J L, CHEN J F, WEI Y W, et al. Oxidation behaviors of MgO-C refractories with different Si/SiC ratio in the 1 100-1 500 ℃ range[J]. Ceramics International, 2019, 45(17):21099-21107. DOI URL
[2]	RASTEGAR H, BAVAND-VANDCHALI M, NEMATI A, et al. Phase and microstructural evolution of low carbon MgO-C refractories with addition of Fe-catalyzed phenolic resin[J]. Ceramics International, 2019, 45(3):3390-3406. DOI URL
[3]	EWAIS M, MOHOAMED E. Carbon based refractories[J]. Journal of the Ceramic Society of Japan, 2004, 112(1310):517-532. DOI URL
[4]	CAO G L, DENG C J, CHEN Y, et al. Influence of sintering process and interfacial bonding mechanism on the mechanical properties of MgO-C refractories[J]. Ceramics International, 2020, 46(10):16860-16866. DOI URL
[5]	BAHTLI T, HOPA D Y, BOSTANCI V M, et al. Investigation of thermal shock behaviour of MgO-C refractories by incorporation of pyrolytic liquid as a binder[J]. Materials Chemistry and Physics, 2018, 213:14-22. DOI URL
[6]	HU S Y, ZHU R, LIU R Z, et al. Decarburisation behaviour of high-carbon MgO-C refractories in O₂-CO₂ oxidising atmospheres[J]. Ceramics International, 2018, 44(17):20641-20647. DOI URL
[7]	ZHU T, LI Y, SANG S, et al. Improved thermal shock resistance of magnesia-graphite refractories by the addition of MgO-C pellets[J]. Materials and Design, 2017, 124(6):16-23. DOI URL
[8]	LIU Z Y, YUAN L, YU J K, et al. Improvements in the mechanical properties and oxidation resistance of MgO-C refractories with the addition of nano-Y₂O₃ powder[J]. Advances in Applied ceramics, 2019, 118(5):249-256. DOI URL
[9]	CHEN J F, LI N, HUBALKOVA J, et al. Elucidating the role of Ti₃AlC₂ in low carbon MgO-C refractories: Antioxidant or alternative carbon source?[J]. Journal of the European Ceramic Society, 2018, 38(9):3387-3394. DOI URL
[10]	ZHANG J, LI C, GONG W, et al. First-principles simulation of the growth of in situ synthesised β-Sialon and its effects on the thermo-mechanical properties of Al₂O₃-C refractory composites[J]. Journal of the European Ceramic Society, 2019, 39(8):2739-2747. DOI URL
[11]	WANG J, DENG X, DU S, et al. Carbon nanotube reinforced ceramic composites:a review[J]. International Ceramic Review, 2014, 63(6):286-289.
[12]	LIJIMA S. Helical microtubules of graphitic carbon[J]. Nature, 1991, 354(6348):56-58. DOI URL
[13]	ZHU B Q, WEI G P, LI X C, et al. Preparation and growth mechanism of carbon nanotubes via catalytic pyrolysis of phenol resin[J]. Materials Research Innovations, 2014, 18(4):267-272.
[14]	WANG J K, DENG X G, ZHANG H J, et al. Synthesis of carbon nanotubes via Fe-catalyzed pyrolysis of phenolic resin[J]. Physica E, 2017, 86:24-35. DOI URL
[15]	YIN C F, LI X C, CHEN P A, et al. Thermo-mechanical properties of Al₂O₃-C refractories with in situ synthesized non-oxide bonding phases[J]. Ceramics International, 2019, 45(6):7427-7436. DOI URL
[16]	ZHU T, LI Y, SANG S, et al. Effect of nanocarbon sources on microstructure and mechanical properties of MgO-C refractories[J]. Ceramics International, 2014, 40(3):4333-4340. DOI URL
[17]	王军凯, 邓先功, 张海军, 等. 碳纳米管增强碳复合耐火材料的研究进展[J]. 耐火材料, 2016, 50(2):150-154.
[18]	WANG J Q, SHEN B X, LAN M C, et al, Carbon nanotubes (CNTs) production from catalytic pyrolysis of waste plastics:The influence of catalyst and reaction pressure[J]. Catalysis Today, 2020, 351:50-57. DOI URL

原料		加入量(w)/%
	≤1 mm	20
电熔镁砂	3~1 mm	13
	5~3 mm	35
镁砂细粉	≤0.088 mm	25
Si粉	10 μm	3
鳞片石墨	150 μm	4
含有催化剂的酚醛树脂(外加)		4

原料		加入量(w)/%
	≤1 mm	20
电熔镁砂	3~1 mm	13
	5~3 mm	35
镁砂细粉	≤0.088 mm	25
Si粉	10 μm	3
鳞片石墨	150 μm	4
含有催化剂的酚醛树脂(外加)		4

项目	试样C	试样F	试样N	试样W
常温耐压强度/MPa	53.6	49.0	60.5	56.9
常温抗折强度/MPa	7.7	7.6	9.4	8.3
体积密度/(g·cm^-3)	2.85	2.89	3.05	3.10
显气孔率/%	8.3	8.7	7.4	7.6

项目	试样C	试样F	试样N	试样W
常温耐压强度/MPa	53.6	49.0	60.5	56.9
常温抗折强度/MPa	7.7	7.6	9.4	8.3
体积密度/(g·cm^-3)	2.85	2.89	3.05	3.10
显气孔率/%	8.3	8.7	7.4	7.6

项目	试样C	试样F	试样N	试样W
常温耐压强度/MPa	17.7	21.2	21.4	21.5
常温抗折强度/MPa	2.1	2.5	2.4	2.0
体积密度/(g·cm^-3)	2.95	2.95	2.99	3.01
显气孔率/%	14.0	13.5	14.0	12.6
烧后线变化/%	0.14	0.21	0.29	0.21