Alumina-SiC-C Casthouse Castable for Blast Furnace Runners

Alumina-SiC-C (ASC) casthouse castables are the single largest refractory cost in a blast furnace casthouse, and they are also the item most often bought as a single product for what is actually four different duties. A main runner, an iron branch runner, a slag runner and a slag-only line do not wear the same way, and one castable cannot be optimal for all of them.

Grade by Position

• XZK-Main-Runner — 75% Al₂O₃, 10% SiC, density 2.92 g/cm³, CCS 43 MPa after firing. Highest alumina and hot strength for the highest iron throughput.
• XZK-Iron-Runner — 59% Al₂O₃, 30% SiC. Maximum silicon carbide for the highest abrasion at the iron line.
• XZK-Slag-Runner — 61% Al₂O₃, 13% SiC. Balanced for slag chemistry with less iron contact.
• XZK-Slag-Line — 62% Al₂O₃, 15% SiC. Dedicated grade for slag-only runners.

Permanent linear change is held within ±1.0% at 1450 °C, which is what keeps the runner geometry stable instead of cracking open or shrinking away from the sides.

Installation Quality Outweighs Product Grade

This is the part that decides campaigns, and it is worth stating plainly. With brick, performance is largely fixed at the factory. With castables, a large share of final performance is created on site:

• Water addition — deviating by even one percentage point measurably reduces strength and erosion resistance.
• Mixing time and equipment — under-mixing leaves dry pockets; over-mixing breaks down the grain structure.
• Vibration — determines density and the absence of voids.
• Curing and heat-up — a rushed heat-up drives out moisture faster than it can escape, and the result is spalling or explosive spalling.

We issue all of these with the material, and for larger projects we will dispatch an engineer. On a first installation that is usually the highest-return item in the whole package.

Precast vs Cast In Situ

Precast runner shapes are produced under controlled factory conditions, which removes most of the site variability above. Installation is faster and quality is more consistent. The trade-off is logistics and mould cost, so precast usually suits high-volume repeat geometries while site casting suits one-off or highly variable profiles.

Supply

Minimum order 5 metric tons for standard grades and 10 metric tons for custom formulations, shipping in 7–14 days. Precast shapes are quoted to drawing. Batch test data covering density, strength after drying and firing, permanent linear change and grain size distribution ships with every lot.

Where This Grade Sits in the Lining System

Monolithic materials fail more often on installation than on specification. Water demand, mixing time, vibration and the first heat-up curve decide the outcome before the lining ever sees metal — which is why installation parameters are issued with the material instead of being left to site practice.

XZK supplies casthouse asc castable as one zone of a zoned package rather than as a standalone item: the grades normally zoned alongside it — among them waterless taphole clay — are documented on the monolithic refractories page, and the vessel-level architecture — where each zone starts and ends, and which mechanism actually limits the campaign — is set out on the blast furnace and casthouse and torpedo car pages.

The MMK Magnitogorsk No.10 BF and 375 t ladle programme reference documents how this class of material performed in full service, with the measured campaign figures rather than datasheet values.