Abstract Zeolites are extensively produced by hydrothermal treatment of different raw materials, such as kaolin. Sanitary ware (SW) is a kaolin-based ceramic ware usually found in sinks, urinals and bathtubs whose production is led by Spanish domestic clay product industry. SW production generates approximately 8% of solid waste in Spain, which increases landfills sizes and pose economic, social and technical problems. This study aims to evaluate the feasibility of solid waste of SW industry to produce zeolites once subjected to a conventional hydrothermal treatment during different times and temperatures. Ground SW was subjected to dissolution in a highly basic medium (NaOH 5 M) inside a Teflon-lined stainless steel reactors, at temperatures of 100, 150 and 200 °C for 1 to 30 days. X-ray powder diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM) were used to characterize both the raw material and resultant mineral phases. Quartz and mullite present in SW transform into zeolites, as temperature and time increase. Mineral assemblage at 100 °C includes zeolite P, Na-faujasite and sodalite as major component and analcime, natrolite, and zeolite A as minor, which behave as metastable phases and their relative abundance depends on aging time. Analcime and cancrinite crystallization is favored by high temperature (150 °C to 200 °C) and increasing aging time produces analcime disappearance. Cancrinite is the dominant mineral after 30 days. Conventional SW waste is an optimal raw material for zeolites synthesis under high alkaline hydrothermal conditions. Combining time and temperature it is possible to drive crystallization towards a target phase.

中文翻译：

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以卫生洁具废弃物为原料水热合成沸石

摘要 沸石广泛采用不同原料（如高岭土）水热处理生产。卫生洁具 (SW) 是一种高岭土陶瓷制品，通常用于水槽、小便池和浴缸，其生产由西班牙国内的粘土制品行业主导。在西班牙，SW 生产产生了大约 8% 的固体废物，这会增加垃圾填埋场的规模并带来经济、社会和技术问题。本研究旨在评估SW工业固体废物在不同时间和温度下进行常规水热处理后生产沸石的可行性。在特氟龙衬里的不锈钢反应器内，在 100、150 和 200 °C 的温度下，将研磨的 SW 在强碱性介质 (NaOH 5 M) 中溶解 1 到 30 天。X射线粉末衍射（XRD），傅里叶变换红外光谱 (FTIR) 和扫描电子显微镜 (SEM) 用于表征原材料和所得矿物相。随着温度和时间的增加，SW 中存在的石英和莫来石会转变为沸石。100 °C 下的矿物组合包括沸石 P、Na-八面沸石和方钠石作为主要成分，方沸石、钠沸石和沸石 A 为次要成分，它们表现为亚稳态，它们的相对丰度取决于老化时间。高温（150°C 至 200°C）有利于方沸石和钙沸石结晶，增加老化时间会导致方沸石消失。30 天后，Cancrinite 是主要矿物。常规 SW 废料是在高碱性水热条件下合成沸石的最佳原料。