How to effectively improve the explosion-proof performance of castables

1, add a bonding agent to adjust the hardening time

The rapid hardening of the castable is essential for rapid demolding after construction. By adding a hardening aid, the castable has sufficient construction time and must be hardened quickly after casting to facilitate demolding in time. bake. The hardening time of the castable is also highly dependent on the bulging and bursting of the cast body. If the castable is too hard and too hard, the problem of swelling and bursting of the cast body will occur. Therefore, by adding an appropriate amount of the co-bonding agent, the hardening time of the castable can be effectively controlled, and in turn, bulging and cracking due to gas generation can be prevented. The castable with the gas generating agent and the bonding agent can be baked immediately after pouring, and the demoulding can be cured in about 1 hour, and the solidified sample is directly placed in the furnace at 450 ° C without bursting.

2, add organic fiber to improve anti-burst

It is not difficult to see from the relationship between the vapor pressure of water and the temperature that the vapor pressure rises rapidly when the water is above 100 °C. When the cast body is baked, the water in the castable is rapidly vaporized by heat. The main reason for the cracking and bursting of castables is that the rapidly formed water vapor cannot be discharged out of the body in time, and the water vapor pressure in the pouring body is too high.

Adding explosion-proof fiber is one of the most effective explosion-proof measures for castables. The principle of fiber explosion-proof is that the fiber shrinks or decomposes rapidly after being heated, and at the same time, a pore passage is formed in the castable, so that the water vapor generated by the heat of the castable is rapidly diffused and volatilized. The water vapor in the castable diffuses out in time without accumulating in the casting body to form a large pressure, and the cast body does not burst. However, there are many varieties of fibers, and reasonable selection of varieties, diameters, lengths and dosages are essential for the explosion-proof effect of castables. In this study, after reasonable selection, the appropriate variety and quantity of fiber were added to the castable. The cast sample was directly baked in a high temperature furnace at 200 ° C. The surface of the sample was intact and no burst occurred.

3. Add alkali emulsion anti-explosive agent

The alkali emulsion anti-explosive agent is a new type of anti-explosive agent which has been reported in recent years, and its composition is a multi-nuclear complex formed by ion polymerization of hydroxide, which can be effectively dissolved in an aqueous solution. It is described in the literature that the explosion-proof mechanism is: when the castable is heated and dried, the dehydration gelation of the alkali emulsion forms a mesh-like microcrack passage in the matrix, thereby increasing the gas permeability of the castable. It is also said that the basic emulsion can inhibit or delay the formation of CAH10, and can also increase the cracking temperature of the castable. In order to further improve the explosion-proof effect of the castable, the application research of the alkali emulsion anti-explosion agent was carried out. Through the matching of the dosage, the anti-burst temperature of the castable was increased from the original safety explosion-proof temperature of 400 °C to 600 °C, so that the quick-drying explosion-proof castable Have a safer use performance.

4, the use of high efficiency water reducer

The bursting of the castable is mainly caused by the fact that the water vapor generated by the vaporization of the water cannot be discharged out of the caster in time, so reducing the amount of water added to the castable is also a necessary method. The traditional castable water reducer is mainly used in combination with sodium tripolyphosphate or sodium hexametaphosphate, but the amount of water added to the castable material containing C is generally more than 6%. Later, we used a superplasticizer to obtain a better dispersion effect. The amount of water added was controlled at 5%, which was 20% lower than that of sodium tripolyphosphate and sodium hexametaphosphate.

The above-mentioned method is applied to modify the castable, which effectively solves the problem of quick-drying demoulding, rapid baking and preventing bursting of the cast iron in the iron slag of the blast furnace, so that it can be applied to the small and medium-sized blast furnace of single iron tapping for integral pouring. , achieved very satisfactory results.