On the vast stage of modern industry, there is a material that seems inconspicuous but contains huge energy - silica. It is like a bright pearl. With its unique performance, it shines in many fields and becomes an indispensable key force in promoting industrial development.

1. The unique appearance in the microscopic world
White carbon black, whose chemical name is silica and whose molecular formula is often written as silica, belongs to the family of white powdery X-ray amorphous silicic acid and silicate products. Exploring from a microscopic perspective, it presents many fascinating properties.
In terms of physical properties, silica black appears as white amorphous fine powder and has a light texture. The density of precipitation silica is roughly 2.0 - 2.6g/cm³, and the density of gas phase silica is slightly lower, about 1.8 - 2.2g/cm³. The particle size distribution is significantly different. The particle size of the products produced by the precipitation method is mostly 5 - 40μm, while the particle size of the products produced by the gas phase method can be as fine as nanometer level, often in the range of 7 - 40nm. Such a small particle size gives it a very high specific surface area, and the gas phase method white carbon The black specific surface area can even reach 380 - 400m²/g, and the precipitation method generally has 100 - 300m²/g.
Its chemical properties are also outstanding. It has super chemical stability. It is insoluble in water and most acids in daily environment. Only hydrofluoric acid can "compete" with it. When the two meet, they will react: Its surface is covered with a large number of hydroxyl groups. These hydroxyl groups are like pairs of "invisible hands", giving silica black strong adsorption and surface activity, allowing it to "shake hands" closely when in contact with other substances, strengthening interactions.

2. Multiple preparation processes create diverse characteristics
The excellent performance of silica is inseparable from the exquisite preparation process behind it. The precipitation method and the gas phase method are like two magical "keys", opening the door to different properties.
The precipitation method is like a simple craftsman, using water glass (sodium silicate) and acids such as sulfuric acid or hydrochloric acid as basic raw materials. During production, the water glass solution is first acidified to promote the generation of silicic acid. The silicic acid polymerizes rapidly in the solution and precipitates into a gel form. After subsequent processes such as filtration, washing, drying, and crushing, precipitation method silica was born. Taking the reaction between water glass and sulfuric acid as an example, the chemical equation clearly demonstrates its principle. The precipitation method is relatively simple and cost-effective, so it is suitable for large-scale industrial mass production. However, the product is slightly inferior to the gas phase method in terms of fine indicators such as purity and particle size uniformity.

The gas phase method is like a master who pursues the ultimate. Silicon tetrachloride or methyltrichlorosilane is often used as the starting material, and the gas phase reaction journey is started under the synergistic effect of high temperature and hydrogen, oxygen or air. For example, when silicon tetrachloride meets hydrogen and oxygen at high temperatures, it transforms into silicon dioxide and hydrogen chloride. The silica produced by the gas phase method is like a carefully carved work of art, with extremely high purity, tiny particle size and uniform distribution, large specific surface area, excellent dispersion, and top-notch performance. But behind this are complex and expensive production equipment, high investment costs and huge energy consumption, making fumed silica expensive.