activated silica

White carbon black should be counted. The main component of diatomite is silica, but it has a skeleton structure.

Silica is widely found in nature and forms rocks together with other minerals. Naturally occurring silica, also called silica, is a hard, refractory solid. The main component of quartz is also silica. Transparent quartz crystals are what we often call crystals. One of the chemical formulas of silica is SiO2, also known as silica. It is widely distributed in nature, such as quartz, quartz sand, etc. Colorless or white crystal, light yellow when containing iron, density 2.20~2.66g/cm3, melting point of tridymite is 1670℃, melting point of cristobalite is 1710℃, boiling point is 2230℃, insoluble in water and acid (except hydrofluoric acid). Can react with molten alkali. Used for making glass, pottery, refractory materials, etc. Silica is a hard and insoluble solid. Natural silica is divided into two categories: crystalline and amorphous. ； The main component of quartz is silica crystal. The naturally transparent hexagonal columnar quartz crystal is crystal. ； Silicon dioxide is an atomic crystal, so its melting point is very high and its hardness is very high ； It is chemically stable and can react with alkaline anhydrides, alkalis and certain salts. It is insoluble in water and does not react with water. Chemical properties of silica Silica is chemically inactive and does not react with water or acids (except hydrofluoric acid), but it can react with alkaline oxides or bases to form salts. For example: High temperature 2NaOH+SiO2===Na2SiO3+H2O CaO+SiO2===CaSiO3 Chemical properties and characteristics of silica: SiO2 is an acidic oxide and an anhydride of silicic acid. However, SiO2 has some special properties compared with other acidic oxides. (1) Most acidic oxides can directly combine with water to form acid, but SiO2 cannot directly combine with water. Its corresponding hydrate, silicic acid, can only be produced by reacting the corresponding soluble silicate with acid (silicic acid is insoluble in water and is a weak acid, and its acidity is weaker than carbonic acid). (2) Acidic oxides generally do not react with acids, but SiO2 can react with hydrofluoric acid to generate gaseous silicon tetrafluoride. SiO2+4HF==SiF4↑+2H2O The main component of ordinary glass and quartz glass is silica. Therefore, hydrofluoric acid can be used to corrode glass. Hydrofluoric acid is used to carve patterns on glass. Hydrofluoric acid cannot be stored in glass, ceramics, porcelain, or pottery containing silica in the laboratory. Plastic bottles are generally used. (3) SiO2 reacts with a strong alkali solution to produce water glass, which is a mineral glue commonly used as an adhesive. Therefore, reagent bottles containing alkaline solutions in the laboratory do not use glass stoppers, but rubber stoppers. Uses of silica Silica has a wide range of uses. The main raw material of optical fiber, a high-performance communication material that is currently used, is silica. Generally, purer quartz can be used to make quartz glass. Quartz glass is often used to manufacture high-temperature chemical instruments. Crystal is often used to make important components in the electronics industry, optical instruments, and also used to make high-end industrial products and spectacle lenses. It can also be widely used in ordinary rubber, paint, ink, defoaming agent, toothpaste, papermaking, pesticides, food, feed, medicine and other fields.

Thank you very much to the friend upstairs, but I feel that it did not give me the results I want. What is the difference between active silica and inactive silica? Is it that it is easy to react? Why is this happening? How to quantitatively measure the activity? ? ? ? ? ? ?

Activated silica is a silica residue with strong activity. For example, it can be dissolved in hot sodium hydroxide solution, and its reduction temperature by carbon is much lower than that of silica.