Dissolution Mechanism of Basalt Crystals and Glass in Alkaline Solution
As a new supplementary cementitious materials (SCMs), basalt has a certain pozzolanic activity and has been widely studied and applied in cement and concrete.In order to explain the origin and reaction mechanism of volcanic ash activity of basalt, the dissolution of silica and aluminite elements in recrystallized basalt and amorphous basalt in distilled water, saturated lime water and sodium hydroxide solution have been discussed in this paper, and also the microstructure and composition of the filter slag after hydrothermal reaction were tested and analyzed.The results show that the increase of pH value will significantly accelerate the disintegration of the basalt structure, and the dissolved silicon ions can react with the calcium ions in the solution to produce the new phase, according to dissolution law of silicon element.No matter in distilled water, saturated lime-water or sodium hydroxide solution, the content of silicon in recrystallized basalt samples is about twice as high as that of amorphous basalt, indicating that the former is easier to disintegrate in alkaline environment, and difference in mineral composition and crystal structure is the root cause.The results of electron scanning microscopy(SEM), energy spectrum analysis(EDS) and X-ray diffraction(XRD) show that flocculating aluminum gel and thin layer calcium silicate hydrate gel are formed in the solid of recrystallized basalt and amorphous basalt after the reaction, respectively.
basalt dissolution mechanism pozzolanic activity supplementary cementitious materials
Laibao Liu Kaijing Tang Lihua Zhang Fuping Mao
School of Materials Science and Engineering, Southwest University of Science and Technology, Mianyan Chengdu Jinmoer New Material Technology Co., Ltd, Chengdu, 611130, China
国际会议
福州
英文
351-360
2018-11-04（万方平台首次上网日期，不代表论文的发表时间）