Microsilica fume is also called silica fume or condensed silica fume. When non-ferrous metals are smelting ferrosilicon and industrial silicon, a large amount of highly volatile SiO2 and Si gas are produced in the submersible furnace. After the gas is discharged, it is rapidly oxidized with the gas. It is formed by the accumulation of cold suspicion. It is a by-product of industrial smelting. The entire process must be collected with ash removal machinery. Because of its relatively low density, it also needs to be encrypted with encryption equipment.
Microsilica powder is used in cement mortar and concrete: high-rise residential buildings, ports, water conservancy dams, water conservancy projects, drainage gates, railway lines, highways, highway bridges, subway stations, tunnel construction, airport runways, concrete floors and other Reinforcement of underground bolt-blasting structures in coal mines, etc.
Microsilica powder is used in industry. The actual operation methods are mainly:
1. Incorporation method
Silica fume cement concrete and refractory castables should be constructed in a laboratory for mortar mix proportions. Construction shall be carried out strictly in accordance with the mortar mix ratio. In the mixing tank of silica fume cement concrete, silica fume should be added to the mixer immediately after the stone is added. There are two procedures for adding methods:
(1) Add stone, then add silica fume and cold mix concrete, then add water and other concrete admixtures.
(2) Add coarse bone, 75% water, silica fume, and 50% fine stone, and mix for 15-30 seconds. Then add concrete, admixtures, 50% fine stone, and 25% water, and mix until uniform. The mixing time is 20-25% or 50-60 seconds longer than that of cement concrete. Never add silica slag to mixed cement concrete.
2. Construction method
There is no important difference in the working methods of silica fume concrete and cement concrete, but good arrangement and vibration density during the construction process are very necessary. The early strength characteristics of silica fume cement concrete will advance the final setting time, so you need to pay attention when closing the surface. At the same time, adding silica fume will increase the viscosity of cement concrete and significantly reduce bleeding, making it slightly difficult to plaster the surface.
3. Safe construction
The construction of silica fume concrete should be carried out strictly in accordance with the relevant Chinese construction techniques for cement concrete projects. However, because silica fume is relatively light, it is prohibited to throw materials at high places to avoid flying silica fume.
As long as the above requirements and methods are followed, microsilica powder will be better used in industry.
