Glass has a wide range of applications throughout the world, but just how does it get manufactured? The process involves combining the main components, which are soda, limestone, and, of course, silica sand. The higher the quantity and chemical purity of silica in the sand for glassmaking, the better the quality of the glass produced, both in terms of appearance and function. Let’s take a deeper look into the role that silica sand plays in the glass manufacturing industry.
What is Silica Sand?
Silica sand, which can also be called industrial sand, white sand, or quartz sand, is mainly made up of oxygen and silica. In glass manufacturing, it can simply be called “sand” for making glass, since this is its main use. Sand must have at least 95% SiO2 and less than 0.6% iron oxide to be classified as silica sand. The sand in issue will be labelled as ordinary sand and won’t be used in the glass-making process if these requirements aren’t satisfied.
Apart from glassmaking, silica sand has a number of applications, including:
- On sports fields and on golf courses to support proper drainage
- In industrial blasting as a mineral abrasive
- In water filtration systems
- In coatings and paints, to improve the durability and appearance of the coating
- To construct and glaze ceramics like floor tiles, tableware, and more
Difference Between Silica Sand and Regular Sand
Silica sand must contain a specific quantity of iron oxide and SiO2 to qualify as silica sand. Regular sand is also called brown sand, feldspathic sand, or construction sand since its most common application is in the construction industry. Typically, brown sand will have a considerable percentage of silica, sometimes up to 80%, as well as potassium, carbonate, iron, and other trace minerals.
These additional elements make regular sand more reactive than silica sand, which is relatively inert. Regular sand will also typically be a darker color in comparison to silica sand, and depending on the geographic aspect of where it’s found, some shades are black, green, and pink. It’s therefore easy to differentiate between regular sand and silica sand by judging its appearance.
Why is Silica Sand Used in the Glass Making Industry?
Silicon dioxide is necessary for glass manufacturing. Since silica sand has a high percentage of silicon dioxide, it’s one of the most important materials in glassmaking. Note that not all sand deposits will be of the required purity to be used in glassmaking, with less than 1% of the 50 billion tonnes of sand extracted annually meeting the required standards.
The degree of purity of the silica sand used is going to have a direct impact on qualities such as the durability, strength, and transparency of the glass that’s produced. For products like vehicle windshields, it’s of the utmost importance to only use the highest-quality silica sand. That’s because this glass will meet the optimal vision requirements that vehicle windshields have. Along the same lines, only building glass that’s made of silica sand that’s high quality meets the thermal or light transmittance specifications necessary while maintaining safety and durability.
How is Glass Manufactured Using Silica Sand?
The process of manufacturing glass with silica sand is a rather straightforward one that involves mixing the basic ingredients and then melting them. The primary ingredients are limestone, soda ash, and silica sand. Depending on the color or purpose of the glass produced, other ingredients may be added, such as pigment.
These ingredients are melted together in a furnace at temperatures that can reach 1600°C until they are all molten. This molten glass is then stirred to make its thickness consistent and remove any air bubbles trapped within it. At this point, chemicals like sodium sulfate may be added to help with the process.
The next step, which is molding the molten glass, also depends on the required product. If the outcome is a glass item with a simple shape like a lens, the molten glass is simply placed into the necessary mold and allowed to cool. If the requirement is glass panes, the molten glass will be placed into a bath of molten tin and shaped with pressurized nitrogen. Typically, this includes drawing it through rolling machines to flatten it evenly.
The glass product is then annealed, which involves placing it in an oven or kiln at temperatures between 750°F and 1,000°F to remove stress points that may have formed and strengthen it. After this, the glass is ready to be put into use in its final application.
Sodimate’s Role in the Glassmaking Industry
For the process to be carried out successfully to the end, it’s important to have the necessary industrial equipment. This will help streamline the process, and it’s something that Sodimate can help you with. Sodimate has a storage, discharge, and feed system which can be used to handle silica sand.
Depending on your specific requirements, we can customize the equipment to offer you the number of injection points you need, your required feed rate, and other details.
Sodimate also has systems for treating emissions that result in air pollution which are created during the process of manufacturing. We have, for example, dry absorbent injection systems that can easily handle two of the most commonly-used reagents in glass manufacturing, hydrated lime, and soda ash. Speak to one of our experts today and we will help you give your glass manufacturing industry the right equipment.