Teacher Guide to Student Worksheet 3 – The Blast Furnace
Name: ______
Directions: Using the diagram of the cold-blast furnace, answer the following questions with complete sentences.
1)What materials do you think are loaded into the furnace through the tunnel head?
The iron ore, limestone, and charcoal were all added into the furnace through the tunnel head.
2)Why does the temperature in the furnace need to reach 2600-3000 degrees Fahrenheit? How hot is 2600-3000 degrees Fahrenheit? Compare it to the temperature of another object that you know.
The temperature needs to reach that high in order to melt the iron ore into a liquid, as well as to allow the necessary chemical reactions to occur. Impurities in the iron ore are drawn off by the limestone (to create “slag” or waste).Sometimes people preheat their ovens to 350 degrees. This is 8 ½ times less than the furnace temperature. The sun is 9,944 degrees Fahrenheit on its surface. That is slightly less than a third the sun’s temperature. Our body temperature is 98 degrees Fahrenheit, or thirty times less than the furnace.
3)Why is an air duct needed in the process of smelting iron?
The air duct was needed in order to bring air into the furnace to fuel the fire. The air came through the air duct and was then used to help keep the fire burning. The fire needed to burn continuously to aid in the process of smelting iron.
4)What materials are combined in the furnace in order to produce the molten iron and slag? What is slag? How is it produced? Is it heavier or lighter than molten ore? Explain.
Iron ore, limestone, and charcoal (or coke or coal) are combined to produce molten iron and slag. Slag is the material that is produced when the impurities of the iron ore combine with the limestone. The limestone draws away the impurities from the iron ore. Slag is lighter than molten iron because it rises to the top and is siphoned off.
5)Why does the furnace require a chimney at the top?
Since the furnace was fueled by a giant fire, there needs to be a way for the smoke and fumes to get out of the furnace. The furnace needed a chimney just like a fireplace needs a chimney.