利用煤矸石制备莫来石陶瓷

Preparation of Mullite Ceramics From Coal Gangue

以煤矸石为原料,分别引入α-Al_(2)O_(3)、工业氧化铝、氢氧化铝调整原料配比,以干压成型法制备莫来石陶瓷,研究了铝源和煅烧温度对莫来石陶瓷性能的影响。研究表明:铝硅比对莫来石生成量及制品比热容具有重要作用;随着煅烧温度的提高,试样致密化程度高,力学强度增大,比热容升高;适当延长保温时间会促进晶体发育。以氢氧化铝为铝源,铝硅比为1.85,1600℃烧结保温2 h时,试样综合性能最优,体积密度为2.03 g/cm^(3),耐压强度和抗折强度分别为47.75和6.9 MPa,热震循环3次后,抗折强度为1.96 MPa,热震循环5次后,抗折强度为0.47 MPa。

Using coal gangue as a raw material,the ratio of the raw material was adjusted by introducing α-Al_(2)O_(3),industrial alumina and aluminum hydroxide to prepare mullite ceramics by dry pressing method.The effects of aluminum sources and calcination temperature on the properties of mullite ceramics were investigated.The results show that the ratio of aluminum to silicon has an important effect on the synthesis of mullite and specific heat capacity of the samples.The degree of densification is escalated with raising temperature.At the same time,the mechanical strength and specific heat capacity of ceramics are escalated.Properly prolonging the holding time is conducive to crystal development.When aluminum hydroxide is used as the aluminum source,the ratio of aluminum to silicon is 1.85,the comprehensive performance of samples sintered for 2 h under 1600℃ is the best.Its bulk density is 2.03 g/cm^(3),the compression strength and the flexural strength are 47.75 and 6.9 MPa,respectively.After 3 thermal shock cycles,the flexural strength is 1.96 MPa.And even after 5 thermal shock cycles,the flexural strength is 0.47 MPa.