The mineral crystalline morphology of foundry natural silica sands has been investigated, which can be divided into two groups:single crystal and polycrystalline gather.
考查了铸造用天然硅砂的矿物晶体形态， 可将其大致分为单晶体和多晶集合体两类。
2
The silica bricks of high refractoriness, high loading and heavy melting point made of large crystalline quartz have already increased the life to 5 times.
用大结晶脉石英制成高耐火度、高荷重软化点硅砖，使用寿命提高5倍以上。
3
For example, both crystalline and glassy forms of silica (SiO,) have structures with each si surrounded by four oxygen atoms, and each o by two si.