High-Alumina Runner Brick — Teeming Hollow Ware for Ingot Pouring

Where Ingot Quality Is Actually Decided

Bottom-pour teeming looks like a simple operation: steel leaves the ladle, runs through a set of hollow refractory channels, and fills a mould. Everything that can go wrong with ingot cleanliness happens in those channels.

If a bore is rough, the metal stream becomes turbulent and picks up refractory particles. If two joints do not align, the stream spills at the step — picking up air and reoxidising. If the set is cold, the first stream cracks the bore wall. And if the brick itself carries enough iron oxide to form low-melting phases at pouring temperature, the bore surface softens and erodes, feeding inclusions straight into the ingot. None of this shows up on a chemistry certificate, which is why it is so often misdiagnosed as a melting problem.

The Two Grades and What Separates Them

XZK teeming hollow ware comes in two grades, both from the same high-alumina body family:

• XZK-TR65 — 65% Al₂O₃, Fe₂O₃ ≤ 2.0%, bulk density ≥ 2.40 g/cm³, CCS ≥ 40 MPa, refractoriness ≥ 1750 °C, thermal shock ≥ 8 cycles. The economical choice for plain carbon ingots and short sequences.
• XZK-TR75 — 75% Al₂O₃, Fe₂O₃ ≤ 1.5%, bulk density ≥ 2.55 g/cm³, CCS ≥ 50 MPa, refractoriness ≥ 1770 °C, thermal shock ≥ 10 cycles. Specified for alloy and special grades where inclusion count drives rejection, and for runner systems expected to run repeated sequences.

The step between them is not just alumina content. The lower iron limit on TR75 is the property that matters most for cleanliness, followed by the higher strength and the better thermal shock figure.

Why Thermal Shock Gets Tested Per Batch

Every set takes a hard thermal transient when the first stream arrives. A brick that survives eight 1100 °C water quench cycles and one that survives ten may look equivalent on paper, but on a multi-sequence set that difference compounds.

We test thermal shock per production batch rather than only at type approval, because it is the property most sensitive to firing curve drift. If a kiln runs slightly cool one week, thermal shock is where it shows up first — and the certificate is where you should be able to see it.

Matched Sets, Not Loose Pieces

A runner system is a fitted assembly: well block, collector nozzle, straight runners, branches, elbows and mould gates. When these come from different suppliers, each piece is individually within tolerance and the assembly still does not seal — because the tolerances stack across the interfaces.

We supply matched sets with bore alignment checked before shipment, and diamond grind the seating faces where it matters. Ordering the set as one package removes the interface problem and, in our experience, saves more platform time than any other single change.

What We Need to Quote

Steel grade or grades, pouring temperature range, number of ingots per sequence, whether the set is single-use or reused, and a layout drawing if you have one. If you are replacing an existing set, the dimensions of the current one are enough.

If you are chasing an inclusion or surface-finish problem rather than buying to print, tell us what the rejection looks like. Bore erosion, joint aspiration and thermal cracking leave different signatures, and the fix is different in each case. We would rather diagnose first than sell you a higher grade that does not address the actual mechanism.

Where This Grade Sits in the Lining System

Corundum and high-alumina grades earn their place on hot strength and creep resistance, and those properties only pay back if the surrounding zones survive as long as they do. Putting the strongest brick into the harshest zone and leaving the rest to habit is how most of the refractory budget is actually lost.

XZK supplies high-alumina runner brick (teeming hollow ware) as one zone of a zoned package rather than as a standalone item: the grades normally zoned alongside it — among them high-alumina brick — are documented on the corundum and high-alumina 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 steel ladle and RH/VD and tundish flow control pages.

Campaign data measured on this class of lining — including the wear profile that drove grade selection — is published in the JFE Steel RH degasser snorkel and ladle flow control programme project reference.