Silica Fume as a kind of construction and other engineering industries commonly used in cement and concrete admixtures, mainly from the smelting process generated by a large number of volatile silicon monoxide gas and air quickly oxidized and condensed from the silica dust, its chemical composition in addition to silica there are many other iron oxide, ETC。, in order to make it better for the role of cement and concrete, the basic will be Silica Fume purification 过程. But in addition to purification, we can often hear densified, 或者 semi-densified silica fume, meaning to increase the density, so what is the reason for encryption of Silica Fume?

Reasons for encryption of Silica Fume

Reduce transportation cost

One of the reasons for encryption of Silica Fume is to reduce transportation cost, its physical properties are fine particles of easily dispersed dust, in the actual production is easy to produce a large amount of dust phenomenon, and it is difficult to capture, usually use the bag dust collector to collect the dispersed Silica Fumev, since this, in the transportation process will certainly appear dispersed phenomenon, then after encryption can effectively solve the Moreover, the volume of densified silica fume is much smaller than that of undensified silica fume under the same weight, so the same package can hold more Silica Fume, thus reducing packaging and transportation costs.

Improved performance in use

As the project requirements for cement and concrete become higher, the requirements for admixtures also become higher, and the properties of densified Silica Fume can just meet the demand. The encrypted silica fume can ensure its fluidity while it is easier to mix, so that the concrete can be mixed more evenly and each admixture can be filled in the molecular structure of the concrete, thus increasing the performance of the concrete.

Improve the use environment

In the past, in the concrete mixing site, the dust situation is very serious, the reason is that in addition to cement and lime powder, which is very easy to disperse, including Silica Fume and other concrete admixtures of the dispersion of flying, causing pollution to the air, but also seriously affect the physical and mental health of the staff, but also to a certain extent on the loss of consumers, and densified Silica Fume particles become coarse, dispersion becomes weaker, so that can effectively stop the The dust phenomenon, improve the indoor and outdoor working environment.

Encryption method of silica fume

Encryption principle

The density of silica fume before encryption is about 150 到 200 公斤/立方米, and after encryption, it can reach 700 公斤/立方米, which greatly reduces the volume and improves the particle size at the same time. The purpose of encryption is achieved.

Encryption Equipment

The encryption equipment of silica fume generally consists of five parts, which are as follows:

1. Conveying device: usually scraper type conveyor is used for conveying work, but due to the continuous maturation of pneumatic conveying process in recent years, there are also manufacturers who switch to pneumatic conveying equipment.
2. Storage device: The storage device for silica fume is a closed container, which can generally be divided into two types: 80m³ and 120m³, also called encryption tank.
3. Encryption device: generally refers to the fan installed at the bottom of the encryption tank, when the storage volume of silica fume in the encryption tank reaches a certain amount, the compressed air is blown into the tank through the fan for encryption work.
4. Air delivery device: usually the compressed air is provided by the air compressor, and the air energy is distributed through the air distribution plate to realize the encryption process.
5. Exhaust device: The encrypted silica fume needs to discharge the excess gas in the encryption tank to achieve gas-solid separation, otherwise a large amount of gas will make the silica fume overflow from the encryption tank, and the existing separation methods are inertial separation method and filtration separation method.

致密硅粉 is an essential concrete admixture in the field of engineering and construction nowadays, but it does not mean that every industry that uses silica fume needs to make silica fume densified , 例如, 未致密硅粉 is generally used in refractory materials, so different silica fume processing is needed for different industries.