建筑陶瓷固废模拟热液蚀变反应低碳制备陶瓷砖

Low-Carbon Preparation of Ceramic Tiles from Building Ceramic Solid Waste by Simulating Hydrothermal Alternation

陶瓷通常需要在1 000℃以上烧结,导致陶瓷工业约有60%的能耗用于烧成工序,降低陶瓷的烧成温度对于陶瓷行业的节能减碳具有重要意义。本文以陶瓷固废为原料提出了一种在200℃下模拟热液蚀变反应低碳制备陶瓷的方法。本研究先对废陶瓷进行球磨预处理,得到亚微米级粉体,再通过模拟热液蚀变反应,以陶瓷固废粉体为原料制备出陶瓷砖。在最佳实验条件下:陶瓷固废球磨6 h,粉体含水率25%,以硅酸钾水溶液作为蚀变溶液,在200℃温度下反应36 h,得到样品的抗折强度为(32.1±4) MPa,满足陶瓷砖的应用要求。利用X射线衍射、傅里叶红外光谱、扫描电子显微镜表征反应前后样品的物相组成、官能团结构和微观形貌,给出了可能的反应过程。确认在热液蚀变反应中产生了正长石和α-石英晶体,这两种晶体的生长有效地提高陶瓷砖的抗折强度。

Ceramics are usually sintered over 1000℃,which leads to 60%energy consumption of ceramic production process.Low temperature sintering is a key factor for energy saving and carbon reduction of ceramic industry.This article proposes a low-carbon method for preparing ceramics by simulating hydrothermal alteration reaction at 200℃using ceramic solid waste as raw material.Waste ceramics were firstly pre-treated by ball milling to obtain submicron powder.Ceramic tiles were prepared from ceramic powder by hydrothermal alteration simulation.Under the optimal condition of 6 h ball milling of ceramic waste solid,25%water content of submicron powder,K 2SiO_(3) solution and 36 h reaction at 200℃,the flexural strength of the final product can reach(32.1±4)MPa fitting application requirement of ceramic tiles.X-ray diffraction,Fourier infrared spectroscopy and scanning electron microscopy were used to characterize the physical phase composition,functional group structure,and microscopic morphology of the samples before and after the reaction,and a possible reaction mechanism was given.It is confirmed that orthoclase andα-quartz crystals are produced during the hydrothermal etching reaction,and the growth of these two crystals effectively improves the flexural strength of ceramic tiles.