ソーダ石灰硝子向け代替原料の探索的研究（1）

-カルシウム原料の可能性-

抄録

Soda lime glass constitutes 70% of SiO₂, 15% of CaO, and 15% Na₂O. Silica sand (SiO₂), lime stone (CaCO₃), and soda ash (Na₂CO₃) were procured from local sources as well as from abroad. These compounds are chemically stable and found abundantly on earth, hence, they are widely used as raw materials. However, they are carbonate, and their use leads to the production of CO₂. Therefore, it is necessary to explore alternative raw materials such as biological raw materials, which are carbon neutral. Here, we focused on seashell because they mainly constitute CaCO₃ and are disposed as a by-product from marine products. The purpose of this study was to make flint glass using seashell. We developed two types of CaCO₃ materials from seashell via heat treatment and substituted for lime stone to make glass. As a result, we obtained two distinct soda lime glasses types: one was amber, while the other was flint. We analyzed the compositions of the materials, glasses, and their color tone. Thereby, we found that the organic compounds in seashell were responsible for the color change of the glass.