Solidification of Waste Glass Powder with Utilizable Functionality by Hydrothermal Hot pressing for recycling

在目前的废玻璃回收工艺中，废玻璃被研磨成碎玻璃，碎玻璃可用作玻璃瓶原料，然后被回收。近年来，由于当地社区积极努力进行部分回收，碎玻璃利用率已提高到约80%。然而，每年约有40万吨未使用的碎玻璃，另一个严重的问题是处理通过废玻璃的研磨作为残余产品产生的超细玻璃粉末。因此，除了玻璃瓶原料以外，还需要考虑其他的使用方法。本研究以利用玻璃瓶原料以外的玻璃碎片或玻璃粉末，通过水热热压法制造建筑材料用人造石为目标进行了研究。水热热压法是一种在低温下（低于300℃）即可烧结的方法，具有成本低、环境友好等优点。本文研究了水热热压法处理后玻璃碎片的水化速率和晶化行为。通过SEM、XRD、IR等手段对产物表面的影响层形貌进行了分析，为废玻璃粉在水热条件下的固化提供了基础知识。此外，对来自玻璃粉末的产物的相同分析还为我们提供了关于玻璃碎片和玻璃粉末之间的反应性差异的另一个基础知识。将水热热压低温烧结技术应用于废玻璃粉，可制得具有很高抗拉强度的固化物。

In the present recycling process of waste glass, the waste glass are triturated to make glass cullet, which are useful as glass bottle raw materials, and then are recycled. Recently, the glass cullet utilization ratio has increased to about 80% because local communities have made positive efforts to fractional recovery. However, there is about 400,000 tons of unused glass cullet a year, and another serious problem is the handling of ultrafine glass powder that are yielded as residual-products by the trituration of the waste glass. For the above reasons, it is necessary to think up other ways to use the glass cullet and the glass powder besides glass bottle raw materials.In this research, we have been studying with a goal of producing artificial rocks, which are available as building materials, from the glass cullet or the glass powder by application of hydrothermal hot pressing. Hydrothermal hot pressing readily produces a sintered material at low temperature (below 300℃), so the methods is possible at reduced cost and environmentally-friendly.We investigated the velocity of hydration and the crystallization behavior in a piece of broken glass that was treated by hydrothermal hot pressing process. The morphology of the affected layer on the surface of the products was analyzed by SEM, XRD, IR, and etc. Then, we had basal knowledge for solidification of the waste glass powder under hydrothermal conditions. Furthermore, the same analysis of the products from the glass powder also gave us another basal knowledge about the reactivity difference between in the glass cullet and in the glass powder. When the sintering technology at low temperature by hydrothermal hot pressing was applied to the waste glass powder, the solidified substances with the very high tensile strength were able to be produced.