I. Production Processes

1. Fumed Silica:
   • Production Principle: Generated through the gas-phase hydrolysis of silicon tetrachloride and air (or hydrogen, oxygen) at high temperatures (approximately 1800°C).
   • Characteristics: The particles are extremely fine, forming an aerosol with the gas, which is difficult to collect. Aggregation, separation, and deacidification steps are required to produce the final product. The preparation process is complex, but the product boasts high purity and small particle size.
2. Precipitated Silica:
   • Production Principle: Primarily produced using sodium silicate (water glass) and sulfuric acid as basic raw materials through a chemical reaction that precipitates silicon dioxide.
   • Classifications: Includes traditional precipitated silica and special precipitated silica. The former uses sulfuric acid, hydrochloric acid, CO2, etc., as precipitants, while the latter employs special methods such as high-gravity technology and sol-gel methods.
   • Characteristics: The production process is relatively simple, but the product's fineness is lower than that of fumed silica, typically 300-400 mesh.
3. Silica Micropowder:
   • Production Principle: Derived from natural quartz (SiO2) or fused quartz through multiple processes including crushing, ball milling, flotation, acid washing and purification, and high-purity water treatment.
   • Characteristics: Uniform particle size, high purity, excellent insulation, corrosion resistance, and wear resistance.

II. Physical and Chemical Properties

1. Fumed Silica:
   • Form: Normally a white, amorphous, flocculent, translucent solid nano-particle colloidal material with a particle size less than 100nm.
   • Purity and Surface Area: Product purity can reach 99%, with a large specific surface area (100-400m²/g).
   • Characteristics: High chemical purity, excellent dispersion properties, outstanding thermal and electrical resistance.
2. Precipitated Silica:
   • Form: White powder or flocculent powder, also available in granular form.
   • Particle Size and Density: Original particle size below 0.3μm, with a relative density of 2.319-2.653.
   • Characteristics: Heat-resistant, non-flammable, odorless, tasteless, and with excellent electrical insulation properties.
3. Silica Micropowder:
   • Form: Powder form with uniform particles.
   • Physical Properties: Refractive index of 1.54-1.55, Mohs hardness of approximately 7, density of 2.65g/cm³, and a melting point of 1750°C.
   • Characteristics: Excellent insulation, corrosion resistance, wear resistance, and reasonable particle size distribution, reducing and eliminating sedimentation and layering.

III. Application Fields

1. Fumed Silica:
   • Primary Uses: Widely used as an additive in optics, petrochemicals, rubber, plastics, inks, cosmetics, pharmaceuticals, and other industries. Particularly in optics, it is used to produce high-pressure sodium lamps and new organic glass additives, enhancing light transmittance and UV resistance.
2. Precipitated Silica:
   • Primary Uses: Primarily used as a reinforcing agent for natural and synthetic rubbers and as an abrasive in toothpaste. It is also widely applied in rubber, plastics, papermaking, coatings, and inks, especially in the rubber industry for its superior reinforcing and transparency properties.
3. Silica Micropowder:
   • Primary Uses: Widely used as a filler in copper-clad laminates, epoxy resin potting compounds, coatings, plastics, and other industries. It enhances materials' insulation, thermal conductivity, wear resistance, flame retardancy, and reduces product costs.