What is the highest temperature that the test tube can withstand?

Test tubes are made of glass. The main component of glass is silica (SiO2), with a density of 2.32g/cm3, a melting point of1723 5℃ and a boiling point of 2230℃. The glass production process mainly includes: ① raw material pretreatment. Bulk raw materials (quartz sand, soda ash, limestone, feldspar, etc. ) crushing, drying wet raw materials, removing iron-containing raw materials, and ensuring the quality of glass. (2) Batch preparation. (3) melting. The glass batch is heated at high temperature (1550~ 1600℃) in a tank kiln or crucible kiln to form uniform, bubble-free liquid glass that meets the molding requirements. ④ molding. Liquid glass is processed into products with required shapes, such as flat plates and various utensils. ⑤ Heat treatment. Through annealing, quenching and other processes, the internal stress, phase separation or crystallization of glass are eliminated or produced, and the structural state of glass is changed. Therefore, test tubes can generally withstand the high temperature of about 1500 degrees.