About Ladle Filler Sand
Ladle filler sand is commonly used in smelting industry. The Ladle filler sand has the advantages of good fluidity, good permeability, fast flow rate and resistance to molten steel erosion. The Ladle filler sand is mainly used in the smelting process of metallurgical industry to improve the quality and output of steel and reduce the product cost. The Ladle filler sand is an essential refractory for the tapping of eccentric furnace.
Silicon-based stuffing sand and chromite-based stuffing sand are two kinds of most popular sands for ladles. But in comparision, the silion sand's performace is quite hard to meet the requirements, while the chromite based stuffing sand was developed using chromite as main starting material and lubricant, sintering aider and reducer as additives. The application result revealed that the sand was safe for ladle performance and had as high self open rate. However, it cause a lot of pollution.
Advantages of Fused Ceramic Sand as Stuffing Sand
1. High refractoriness: the main component is aluminum oxide, so the fire resistance is ≥ 1800 ℃, and the thickness of the sintered layer can be reduced without excessive sintering at a certain molten steel temperature.
Because the Fused ceramic sand is spherical and the particles in the sintering layer are in point contact, the strength of the sintering layer can be effectively reduced, so that the Ladle filler sand can be used for open casting.
2. Spherical particle shape: the particle shape is close to the true circle, the surface is smooth, without concave convex veins, and its fluidity is good, which is conducive to pouring.
3. Low thermal expansion rate: it has low thermal conductivity and small expansion after heating, which can prevent shed materials; Contact with molten steel can form a uniform protective layer, which can prevent the drainage from floating up and the molten steel from penetrating.
Application of Fused Ceramic Sand as Stuffing Sand
Fused ceramic sand is used as Ladle filler sand. Its specification is 30 mesh, the particle shape is spherical, the surface is smooth, and the fluidity is good, which is conducive to pouring; According to the proportion, fused ceramic sand can be used completely or partially to replace chromite sand, but its price is far lower than chromite sand; Attention shall be paid to during use. During tapping, the steel flow shall be prevented from directly impacting the ladle shape and affecting the gravity flow rate of open casting. The added drainage agent shall be stacked into a small ladle, and the center of the ladle shall be aligned with the ladle outlet.
Advantages of Fused Ceramic Sand over Chromite Sand in the Application of Ladle Filler Sand
1. the bulk density of Fused ceramic sand is less than that of chromite sand.
2. the high self opening rate can effectively reduce the strength of the sintered layer, which is conducive to the stuffing sands’ opening rate.
3. the thermal expansion rate is low, and the expansion rate after heating is low, which can prevent spraying.
4. the most important thing is the low price of fused ceramic sand. The cost is 40% of the cost of chromite sand, which can greatly reduce the production cost of ladle filler sand.