★熔渣; 【连】保护渣(【参】关于在一定的语境下 slag 可作"保护渣"解， • ① Slag subsides down the blast furnace; being lighter than iron, it then floats above the layer of molten metal which is accumulating at the bottom. 炉渣在高炉中下行，由于它比铁水轻，因而会浮在不断积聚于炉底的铁水层之上。 ②Oxygen is injected with coal into furnace to foam up the slag by producing CO gas in the slag. 向炉内喷氧和加煤，通过炉渣中产生的一氧化碳气体使炉渣起泡。)
