🔍 Key Concepts

• Behavior of slag in oil-fired boilers when fuel is contaminated with salt water • Purpose and vulnerability of furnace refractory and furnace walls • Difference between protective coatings and damaging deposits in high-temperature areas

💭 Think About

• Think about what happens to the brick or lining of a furnace when very hot, molten material runs down over it repeatedly. • Consider whether melted glassy slag acts more like an insulation/protection, or like something that attacks or erodes the surface it touches. • Which of the listed effects would be the most direct and immediate result of molten slag flowing over the furnace wall, rather than a later structural consequence?

✅ Before You Answer

• Identify what glassy slag actually is (molten, glass-like deposits) and whether it is usually considered protective or destructive to furnace materials. • Recall the primary function of refractory: what it does and what types of conditions cause it to fail. • Ask whether cracks in the furnace floor are a direct, immediate effect of slag on the wall, or more of a secondary/indirect structural problem.