Glass is an amorphous inorganic non-metallic material, generally made of a variety of inorganic minerals, such as quartz sand, borax, boric acid, barite, barium carbonate, limestone, feldspar, soda ash, etc. as the main raw materials, and a small amount of auxiliary raw materials are added. Yes, its main components are silica and other oxides.
The chemical composition of ordinary glass is Na2SiO3, CaSiO3, SiO2 or Na2O·CaO·6SiO2, etc. The main component is silicate double salt, which belongs to mixture and is an amorphous solid with irregular structure.
The earliest glass makers in the world were ancient Egyptians.
More than 3,000 years ago, a European Phoenician merchant ship, loaded with the crystalline mineral “natural soda”, sailed on the Belus River on the coast of the Mediterranean Sea. Due to the ebb, the merchant ship ran aground, so the crew members went to the beach. Some crew members also carried cauldrons, brought firewood, and used a few pieces of “natural soda” as the supports for the cauldron to cook on the beach.
When the crew finished their meal, the tide began to rise. When they were about to pack up and board the ship to continue sailing, someone suddenly shouted: “Everyone, come and see, there is something crystal bright and sparkling on the sand under the pot!”
The crew brought these glittering things to the ship to study them carefully. They found that the shiny things had some quartz sand and melted natural soda stuck to them.
It turned out that these shiny things were the natural soda used to make the pot holder when they were cooking. Under the action of the flame, the substance produced by the chemical reaction with the quartz sand on the beach was the earliest glass.
Around the 4th century, the ancient Romans began to apply glass to doors and windows, and by 1291, Italian glass manufacturing technology had been very developed.
In the 12th century AD, commercial glass appeared and began to become an industrial material.
In 1688, a man named Nave invented the process of making large pieces of glass, and since then, glass has become a common object.
Silicate glass is usually made of quartz sand, soda ash, feldspar and limestone, etc., after mixing, high temperature melting, homogenization, processing and forming, and then annealing. mainly include:
⒈ Raw material preprocessing. The bulk raw materials (quartz sand, soda ash, limestone, feldspar, etc.) are crushed, the wet raw materials are dried, and the iron-containing raw materials are subjected to iron removal treatment to ensure the quality of the glass.
⒉ batch preparation.
⒊ Melting system. The glass batch is heated at high temperature (1550-1600°C) in a pool kiln or crucible kiln to form a uniform, bubble-free liquid glass that meets the molding requirements.
⒋ molding. The liquid glass is processed into products of the required shape, such as flat plates, various utensils, etc.
⒌ heat treatment. Through annealing, quenching and other processes, the stress, phase separation or crystallization inside the glass is eliminated or generated, and the structural state of the glass is changed.