Properties and Uses of Washed Silica Sand

نشر بتاريخ 2024-06-24 12:30:41

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Silica sand deposits are mostly found in heavily eroded sandy soil areas rich in quartz and other rock and mineral deposits. Cleaning and processing the extracted silica sand removes impurities and minerals to produce washed quartz sand suitable for various industrial applications.

Composition and Physical Properties

Washed quartz sand is nearly pure silicon dioxide (SiO2) in powder or granular form. It consists of well-rounded, polished grains that give it a characteristically smooth, glass-like feel. The grains are mostly colorless, transparent to translucent, and predominantly in the size range of 0.1-2.0 mm in diameter.

Washed quartz sand has a loose bulk density averaging around 1.5 g/cm3, a true density of approximately 2.65 g/cm3, and a Mohs hardness of 7. It is chemically inert, non-toxic, and odorless. Due to its high silica content (usually over 99%), washed quartz sand displays excellent chemical resistance, high melting point (approx. 1610°C), good insulation and low thermal conductivity.

Processing

Raw silica sand from deposits undergoes various cleaning and processing steps to remove unwanted materials and refine the mineral content. Initially, excavated sand undergoes screening to separate coarse and fine fractions. Magnetic and electrostatic separation removes magnetic (iron) and conductive (metallic) contaminants.

The sand is then boiled in acid or alkaline solutions to dissolve and leach out carbonates, clay, and other soluble impurities. Further washing and scrubbing rinses away remaining soil and contaminants trapped within pores or cavities. Drying and sieving ensures uniform particle size distribution for different industrial specifications. Final analysis tests guarantee the high purity of Washed Silica Sand .

Industrial Applications

Due to its purity and consistent physical properties, washed quartz sand finds widespread use in various industries:

- Glassmaking: As the primary raw material, it constitutes over 90% of flat, container, and specialty glass compositions.

- Foundry: It is used as aggregate in metal casting molds and cores for ferrous and non-ferrous alloys. The rounded particles minimize pinholes.

- Abrasives: Silica sand garnet blasting grit is employed for blast cleaning and surface preparation applications.

- Hydraulic Fracturing: Proppant sand is used to maintain fractured shales in oil and gas wells. High crush resistance is essential.