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，对废玻璃进行研磨，制成玻璃碎料，可用作玻璃瓶原料，再进行回收利用。近年来，由于当地社区在部分回收方面做出了积极的努力，玻璃碎片的利用率已提高到80%左右。然而，每年约有40万吨未使用的玻璃碎片，另一个严重的问题是处理超细玻璃粉，这些超细玻璃粉是由废玻璃营养产生的残余产品。基于以上原因，除了玻璃瓶原料之外，有必要考虑其他方法来使用玻璃碎料和玻璃粉末。在本研究中，我们一直在研究利用水热热压技术将玻璃碎料或玻璃粉制成人造岩石，作为建筑材料。热液热压在低温（300℃以下）下可快速制备烧结材料，具有成本低、环境友好的优点。研究了水热压制破碎玻璃的水化速度和结晶行为。采用扫描电镜（SEM）、x射线衍射（XRD）、红外光谱（IR）等分析了产物表面影响层的形貌。对废玻璃粉在水热条件下的固化有了基本的了解。此外，对玻璃粉中产物的相同分析也使我们对玻璃碎片和玻璃粉中的反应性差异有了另一个基本的认识。将低温水热压制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质。

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.