Effect of carbon black on pore structure of lightweight homogenized bauxite

doi:10.3969/j.issn.1001-1935.2021.01.007

Abstract

Abstract:

Lightweight homogenized bauxite samples were prepared with homogenized bauxite raw powder and carbon black.The effects of the carbon black type (N990 and N774),the carbon black addition (0,4%,and 8%,by mass),and the heat-treatment temperature (1 450,1 500,and 1 550 ℃ for 3 h) on the pore structure of the lightweight homogenized bauxite were investigated.The results reveal that with the heat-treatment temperature increasing,the pore amount in the lightweight homogenized bauxite decreases but the average pore diameter increases;pores in the samples with N990 exhibit more uniform distribution and smaller average size since N990 is easy to disperse;while the average pore size distribution of the samples with N774 is less uniform and the average pore size increases with the rising N774 addition since N774 is not easy to disperse.

Key words: lightweight, homogenized bauxite, carbon black, pore structure

摘要：

以均化矾土生料和炭黑为主要原料,研究了炭黑种类(炭黑N990和炭黑N774)、加入量(加入质量分数分别为0、4%和8%)及热处理温度(1 450、1 500和1 550 ℃下保温3 h)对轻量均化矾土孔结构的影响。结果表明:随着温度的升高,轻量均化矾土气孔数量逐渐减少,平均孔径增大;炭黑N990易于分散,所制得的轻量均化矾土气孔分布均匀且孔径尺寸相对较小;炭黑N774粒子难以均匀分散,所制得的轻量均化矾土孔径分布不规律,且其平均孔径随加入量增加而明显增大。

关键词: 轻量, 均化矾土, 炭黑, 孔结构

CLC Number:

TQ175

Zhu Huiliang, Liu Yan, Ren Bo, Sang Shaobai, Zhu Huang. Effect of carbon black on pore structure of lightweight homogenized bauxite[J]. Refractories, 2021, 55(1): 30-34.

朱惠良, 刘燕, 任博, 桑绍柏, 朱煌. 炭黑对轻量均化矾土孔结构的影响[J]. 耐火材料, 2021, 55(1): 30-34.

Figures/Tables 9

Table 1 Chemical composition of raw bauxite

原料	w/%
原料	Al₂O₃	SiO₂	Fe₂O₃	CaO	MgO	K₂O	Na₂O	TiO₂	灼减
矾土	73.22	4.65	1.25	1.10	0.27	0.51	0.08	3.13	15.34

Fig.1 TEM image of carbon black

Table 2 Formulations of samples

原料	w/%
原料	Ref	C4	C8	N4	N8
均化矾土生料	100	96	92	96	92
炭黑(N990)	0	4	8	0	0
炭黑(N774)	0	0	0	4	8

Fig.2 Bulk density of samples

Fig.3 Apparent porosity,closed porosity and total porosity of samples

Fig.4 SEM images of bauxite fired at different temperatures

Fig.5 SEM images of samples fired at 1 500 ℃

Fig.6 Pore diameter analyse of samples fired at different temperatures

Table 3 Average pore diameter of samples fired at different temperatures

温度/℃	平均孔径/μm
温度/℃	Ref	C4	C8	N4	N8
1 450	4.8	2.2	3.9	7.5	12.5
1 500	5.9	4.1	4.3	9.4	17.6
1 550	17.4	15.3	10.8	17.7	28.8

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