Rodin Alexander, Ermakov Anatoly, Erofeeva Irina, Erofeev Vladimir
Faculty of Architecture and Construction Engineering, National Research Mordovia State University, 430005 Saransk, Russia.
Materials (Basel). 2022 May 2;15(9):3268. doi: 10.3390/ma15093268.
Porous glass-ceramic materials are used in the construction engineering and repair of various objects. The article investigates the method for obtaining porous glass ceramics from siliceous rock with a high calcite content. To obtain samples with an even fine porous structure, a small amount (≤0.386%) of chloride (NaCl, KCl, MgCl·6HO, CaCl) was added to the charge mixture. At the first stage, mechanochemical activation of raw materials was carried out. Siliceous rock, NaCO and additives (chlorides) were grinded together in a planetary ball mill. The resulting charge was annealed at a temperature of 850 °C. The influence of the type and amount of chloride on the properties of the charge mixture and glass ceramics has been defined by thermal analysis (TA), X-ray diffraction (XRD), scanning electron microscopy (SEM), etc. The chlorides in the charge mixture decreased the calcite's decarbonization temperature and had an effect on the macro- and microstructure of the material. As a result, samples of glass ceramics with an even finely porous structure in the form of blocks were obtained. The samples consist of quartz, wollastonite, devitrite, anorthoclase and an amorphous phase. On average, 89-90% of the resulting material consists of with small pores. The apparent density of the samples is in the range of 245-267 kg/m. Bending and compressive strength reaches 1.75 MPa and 3.8 MPa, respectively. The minimum thermal conductivity of the modified samples is 0.065 W/(m∙°C). The limiting operating temperature is 860 °C, and the minimum thermal shock resistance is 170 °C. The material has a high chemical stability. They can be used as thermal insulation for some types of industrial and civil facilities.
多孔玻璃陶瓷材料用于各种物体的建筑工程和修复。本文研究了从高方解石含量的硅质岩中获得多孔玻璃陶瓷的方法。为了获得具有均匀细孔结构的样品，在装料混合物中加入少量（≤0.386%）的氯化物（氯化钠、氯化钾、氯化镁·6H₂O、氯化钙）。在第一阶段，对原料进行机械化学活化。硅质岩、碳酸钠和添加剂（氯化物）在行星式球磨机中一起研磨。所得装料在850℃的温度下退火。通过热分析（TA）、X射线衍射（XRD）、扫描电子显微镜（SEM）等确定了氯化物的类型和用量对装料混合物和玻璃陶瓷性能的影响。装料混合物中的氯化物降低了方解石的脱碳温度，并对材料的宏观和微观结构产生影响。结果，获得了块状的具有均匀细孔结构的玻璃陶瓷样品。样品由石英、硅灰石、透辉石、钠长石和非晶相组成。所得材料平均89 - 90%由小孔组成。样品的表观密度在245 - 267 kg/m³范围内。弯曲强度和抗压强度分别达到1.75 MPa和3.8 MPa。改性样品的最小热导率为0.065 W/(m∙°C)。极限工作温度为860℃，最小抗热震性为170℃。该材料具有高化学稳定性。它们可用于某些类型的工业和民用设施的隔热。
