What is the significance of tracking the use of wet injection in blast furnace linings?

Answer 1

As a technical researcher who has worked in China's Speed Steel supply chain for 8 years, he is relatively familiar with this technology. The blast furnace lining wet injection technology can complete a 5500m³ blast furnace lining repair in a very short time (48h). And the service life can reach more than 1.5 years. This rapid maintenance mode has been fully recognized by most blast furnace users and plays a huge role in China's green ironmaking technology.

The core of wet injection technology is "injection" rather than "spray". "Injection" means pouring without mold, and the effect of pouring is achieved by spraying. At present, the market is flooded with various wet spraying technologies and products, most of which are the dry spraying model, and the work is completed by spraying the material on the inner wall. In fact, concrete spraying technology has been developed in the construction industry for more than 100 years, and the spraying of unshaped refractory castables is not more complicated than building materials. It's easy to "spray out and stick to the wall" material, but it goes against the idea of wet injection of blast furnace linings. For the non-slab wall combined with the blast furnace cooling stave, the inner lining basically fell off during the middle repair, and there are still residual materials in the brick-inlaid groove of the cooling stave. Even if the smooth metal lining is not repaired, it can still keep going straight after the furnace is opened. The success of injection lining of a blast furnace is not simply to observe whether the blast furnace runs straight after opening, nor whether the surface is smooth or not after injection lining, but the actual data reflected after opening the furnace. The role of the blast furnace lining is to protect the cooling stave, and it is also the key to preventing excessive energy loss in the blast furnace. Under normal circumstances, the coke ratio and the comprehensive fuel ratio of the blast furnace will drop significantly after the injection lining is opened. Based on a large amount of practical experience, this reduction rate is about 15% to 18%; and the judgment of the life of the injection lining can also be inferred from these data.

In order to achieve the effect of wet injection, a uniform stirring material and a stable pumping speed are required. The distance and angle between the gun head and the wall surface, the feeding amount, the feeding speed, the gas feeding amount and the coagulation accelerator amount, etc., the output will be stable when the injection material has the characteristics of the casting body. In the actual implementation process, the operator needs to be flexibly adjusted, so the early business training is very important. A good spray interface is not as smooth as a plastered surface, but rough and the particles are clearly visible. The steps of wet spraying can only be done from bottom to top like pouring, and cannot be sprayed piece by piece. Furnace shape, not longevity.

The energy saving and consumption reduction of blast furnace is not simply to choose low-cost refractory materials. The development direction of wet injection technology is still more efficient, energy saving and longevity. Only by respecting research and development, technology, and market, rather than blindly imitating, can we promote the progress of core technology and obtain good market applications. Even if the smooth metal lining is not repaired, it can still keep going straight after the furnace is opened. The success of a blast furnace injection lining.