{"id":13047,"date":"2020-11-30T11:01:46","date_gmt":"2020-11-30T05:31:46","guid":{"rendered":"https:\/\/cbselibrary.com\/?p=13047"},"modified":"2020-11-30T18:11:30","modified_gmt":"2020-11-30T12:41:30","slug":"glass-produced-raw-materials","status":"publish","type":"post","link":"https:\/\/cbselibrary.com\/glass-produced-raw-materials\/","title":{"rendered":"How is glass produced from raw materials?"},"content":{"rendered":"
Glass<\/strong><\/p>\n People also ask<\/strong><\/p>\n Table summarises the composition, properties and uses of the four types of glass.<\/p>\n How is glass produced from raw materials? Glass The raw material for making glass is sand (silicon dioxide or silica) which is abundant in the Earth\u2019s crust. Glass is formed when silicon dioxide is melted and mixed with other substances like lead(II) oxide, boron oxide, sodium carbonate or calcium carbonate. Generally, glass can be made … Read more<\/a><\/p>\n","protected":false},"author":3,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"spay_email":""},"categories":[84],"tags":[4647,4644,4655,4649,4652,4648,4646,4645,4656,4651,4650,4653,4654],"yoast_head":"\n\n
\n(a) When sodium carbonate and calcium carbonate are heated to a high temperature, they decompose to form oxides.
\n
\n(b) The metal oxides then combine with silicon dioxide to form the respective metal silicates.
\n
\n(c) The overall reaction is as follows:
\n
\n(d) Thus, glass is actually a metal silicate or a mixture of metal silicates such as sodium silicate and calcium silicate.<\/li>\n
\n<\/li>\n
\n(a) Transparent
\n(b) Hard but brittle
\n(c) Impermeable to liquid
\n(d) Heat insulator
\n(e) Bad conductor of electricity
\n(f) Chemically inert<\/li>\n
\n(a) Fused glass is made from pure silicon dioxide<\/strong> by heating it to a temperature above 1700\u00b0C until it becomes molten and then cooled quickly.
\n(b) During fast cooling, the SiO4<\/sub> tetrahedral do not have time to crystallise out to form regular structure. Thus, the structure resembles that of a liquid state. Hence, glass is a super-cooled liquid.
\n(c) Fused glass is expensive because exceptionally high temperature is required during its manufacture.
\n(d) Fused glass consists mainly of silica. Thus, it is the simplest glass<\/strong>.<\/li>\n
\n(a) Soda-lime glass is made by heating a mixture of sand, SiO2<\/sub> (silica) with limestone, CaCO3<\/sub>, sodium carbonate, Na2<\/sub>CO3<\/sub> and recycled glass (sodium silicate, Na2<\/sub>SiO3<\/sub> and calcium silicate, CaSiO3<\/sub>) at around 1500\u00b0C and cooling it quickly.
\n
\n(b) The presence of sodium silicate makes the glass melts at a much lower temperature.
\n(c) It is the most common and earliest used glass.<\/li>\n
\n(a) Borosilicate glass is obtained when boron oxide (B2<\/sub>O3<\/sub>) is added to soda-lime glass.
\n(b) Borosilicate glass has a higher melting point and a lower coefficient of expansion and can withstand a wider range of temperature change due to the presence of borosilicate.
\n(c) The less alkali content makes it more resistant to chemical attack than soda-lime glass. This explains why borosilicate glass is excellent for chemical and electrical uses.<\/li>\n
\n(a) Lead crystal glass is made by substituting lead oxide with calcium oxide and often with part of the silica used in soda-lime glass.
\n(b) The presence of lead(II) silicate makes the glass denser, has higher refractive index and is much more expensive than soda-lime glass.
\n(c) Lead crystal glass is normally called crystal or lead glass.<\/li>\n<\/ol>\n\n
Composition, Properties and Uses of Glass<\/strong><\/h2>\n
\n\n
\n Type of glass<\/strong><\/td>\n Composition<\/strong><\/td>\n Properties<\/strong><\/td>\n Uses<\/strong><\/td>\n<\/tr>\n \n Fused glass<\/td>\n \n \n
\n \n
\n \n
\n Soda-lime glass<\/td>\n \n \n
\n \n
\n \n
\nWindowpanes
\nMirrors
\nLight bulbs<\/li>\n\n Borosilicate glass<\/td>\n \n \n
\n \n
\n \n
\n Lead crystal glass<\/td>\n \n \n
\n \n
\n \n