Glass furnaces · 2026-10-25
Chrome-corundum at the regenerator crown under petroleum-coke firing
Petroleum coke brings vanadium and sulphur into the flue gas. Low-melting silicates and vanadates can form between MgO crystals, and the volume change on melting and solidification cracks and spalls the checkers. Chrome-corundum takes this crown duty with resistance to V₂O₅ and SO₂, and with excellent thermal shock.
Replacing heavy oil with petroleum coke changes the chemistry at the crown of a glass-furnace regenerator. V₂O₅ and SO₂ in the flue gas rise; if sand carryover is then joined by cullet or batch preheating, the top checkers are in the most severe class of duty.
In magnesia-chrome checkers, the molten reagent forms low-melting silicate and vanadate phases between MgO crystals. Those phases melt on heating and solidify on cooling; the repeated volume change opens cracks and spalls, and the attack accelerates. In an alumina-chrome material, an alumina-chrome solid solution can envelop the alumina particles and limit contact with the low-melting liquid, which improves corrosion resistance. Chrome-corundum, built on high-purity corundum and chromium oxide, has high strength, excellent thermal shock and strong resistance to acidic species such as V₂O₅ and SO₂, and is prepared for exactly this crown duty.
When the furnace is not fired with petroleum coke, the acidic load at the crown is different, and magnesia-zirconia is the more suitable brick. The fuel is the first question in choosing a crown material.