Silica Sand Data Sheet: A Comprehensive Overview
Silica sand, often referred to as industrial sand, is a crucial component in various industries, including glassmaking, foundry, and construction. This data sheet provides a detailed look into the properties, applications, and specifications of silica sand.
Physical Properties
Silica sand is primarily composed of silicon dioxide (SiO2), which is the main constituent of quartz. The physical properties of silica sand can vary depending on its source and processing. Here are some key physical properties:
– Color: Typically white, but can range from light yellow to dark brown.- Hardness: 7 on the Mohs scale, indicating its resistance to scratching.- Specific Gravity: Approximately 2.65, which is higher than that of water.- Particle Size: Ranges from fine powder to coarse grains, depending on the application.- Shape: Angular or sub-angular, which is beneficial for filtration and foundry applications.
Chemical Properties
The chemical composition of silica sand is relatively consistent, with a high percentage of SiO2. Here are some key chemical properties:
– Chemical Formula: SiO2- Crystal Structure: Trigonal- Crystal System: Hexagonal- Crystal Lattice Constant: a = 0.5418 nm, c = 0.874 nm- Thermal Conductivity: 7.9 W/m路K at room temperature- Thermal Expansion: 0.5% (25-300掳C)
Applications
Silica sand is used in a wide range of industries due to its unique properties. Here are some of the primary applications:
– Glassmaking: Silica sand is the main raw material for glass production, accounting for about 70% of the total sand used.- Foundry: Silica sand is used as a molding material in the foundry industry, providing strength and stability to the molds.- Construction: Silica sand is used in concrete, mortar, and asphalt to improve their properties and durability.- Water Filtration: Silica sand is used in water filtration systems to remove impurities and contaminants.- Chemical Industry: Silica sand is used as a raw material in the production of various chemicals, such as sodium silicate and silicon metal.
Grain Size Distribution
The grain size distribution of silica sand is an essential factor in determining its suitability for specific applications. Here is a table showing the grain size distribution for different grades of silica sand:
| Grade | Particle Size Range (micrometers) |
|---|---|
| Extra Fine | 0.0625 – 0.125 |
| Fine | 0.125 – 0.25 |
| Medium | 0.25 – 0.5 |
| Coarse | 0.5 – 1.0 |
| Extra Coarse | 1.0 – 2.0 |
Processing and Purification
Silica sand is typically processed and purified to meet the specific requirements of its intended application. Here are some common processing steps:
– Washing: To remove impurities and fines, silica sand is washed using water.- Screening: To separate the sand into different grain sizes, it is screened using a sieve.- Desliming: To remove clay and other fine particles, desliming processes are employed.- Drying: The sand is dried to reduce its moisture content, which is crucial for certain applications.- Grinding: In some cases, the sand is ground to achieve a finer particle size.
Environmental Impact
The mining and processing of silica sand can have environmental implications