The melting process of matte candle vessels is divided into five stages: silicate formation, glass formation, clarification, homogenization and cooling.
Formation of silicate: At this stage, the components of the batch undergo a series of physical and chemical changes during the heating process, and a solid-phase reaction mainly occurs. Part of the gaseous products escape from the batch. The final batch changes from silicate and dioxide. An opaque sinter of silicon.
Formation of candles: At this stage, the sinter begins to melt and the silicate and the remaining silica fuse together. The final sinter becomes a transparent glass with a large amount of bubbles and uneven chemical composition and properties.
Clarification: The molten glass continues to be heated to reduce the viscosity to reduce the amount of gaseous impurities and to eliminate visible bubbles.
Homogenization: The glass liquid is kept at a temperature for a long time, due to the effect of diffusion, the streaks in the glass are eliminated to the allowable limit and become homogeneous. Homogenization can be accomplished below the refining temperature.
Cooling: After clarification and homogenization, the temperature of the glass liquid is lowered by 200~300℃, so that the glass liquid has the necessary viscosity for molding.
