亚洲综合另类小说色区色噜噜,亚洲va久久久噜噜噜久久,国产乱沈阳女人高潮乱叫老,AAAAA级少妇高潮大片免费看,欧美性猛交内射兽交老熟妇,午夜欧美精品久久久久久久,精品国产乱码久久久久久郑州公司,欧美黑人又粗又大又爽免费,国产精品久久久久9999高清,国产精品污WWW在线观看

K2O acts like Na2O, which extends the frit and enhances the gloss and transparency of the glass. When the colored glass is melted, the coloration is more vivid. The K2O in the glass is usually introduced by a potassium base (K2CO3) having a specific gravity of 2.29, which often contains a small amount of impurities such as Na2CO3, K2SO4, KCl or the like. Potassium is easily absorbed by water and deliquesces and must be placed in a dry and ventilated warehouse. Because the price of potash is higher than that of soda ash, it is only used in optical glass and lead-potassium glass. The amount of pot glass is very small, generally below 3%.