Preparation of Advanced Materials by Hydrothermal Hot-pressing from Waste Shells

珍珠养殖后的珍珠牡蛎壳、牡蛎壳、扇贝壳等废弃贝类很难带入处理过程，因此将废弃贝壳作为一种没有任何水泥生产价值的零件材料来使用。本研究的目的是关注水热条件下的硬化反应，对这些闲置的天然碳酸钙粉末进行固化，在阐明固化反应过程的同时，形成坚固的板型体，为新的设施从应用研究到建材等方面获取基础信息。当无机化合物在高温高压溶液体系中与水混合并在低于300℃的温度下机械加压时，研究代表发现硬化反应与烧结体一样发生。在这里，利用各种壳粉的水热硬化反应制作出先进的型体，并对未使用的废物进行升级回收。在生物材料方面，以碳酸钙粉末和磷酸根离子溶液为原料，通过水热反应，使生物材料与生物体材料发生水热反应，制备出羟基磷灰石。通过水热条件的选择，可以制备出致密致密或多孔的材料，通过模拟体液检测和细胞培养检测，部分样品表现出较好的效果。认为这种在30 0℃以下获得羟基磷灰石材料的方法比目前的高温加热方法(如90 0℃)要好，在未来的能源成本和环境保护方面有可能成为一种强有力的手段。

It is difficult for waste shellfishes such as pearl oyster shells after pearl culture, oyster shells and scallop shells to be carried into disposal process, therefore waste shells are used a part material without any values for the cement manufacturing. The purpose of this research tries to pay attention to the stiffiening reaction under the hydrothermal condition, to solidify these unused natural calcium carbonate powders, and makes to a strong board molding body at the same time as clarifying the process of the solidification reaction, and to obtain basic information for new establishment from the applied research to the building material etc.When inorganic compounds were mixed with water and pressurized mechanically in the high temperature high-pressure solution system at the temperature below 300℃, the research representatives found the stiffening reaction being caused as well as the sintered compact. Here, it was done to make an advanced molding body by using the hydrothermal stiffening reactions of various shell powders, and to assume a help of the upgrade recycling of unused waste. Especially, preparation of advanced materials with high functions by addition of organic matters was researched.In the case of biomaterials, hydoxyapatite was able to be prepared as development with the living body material by hydrothermal reactions from calcium carbonate powders and solutions with phosphate ions. The dense compact or the porous material could be prepared by the selection of hydrothermal conditions, and a part of samples showed an excellent result by the simulated body fluid examination and the cell culture examination. It was thought that this method of obtaining hydroxypatite materials at the temperature below 300℃ is better in comparison with the current method using high temperature heating such as 900℃ and was able to become a powerful means in the future in the energy cost and the environment.