4 ms·

Maybe it's about the buring needed to make the coke.

qbrass 8y ago
Steel is an alloy of iron and carbon. They mix coke with the iron to add carbon to it. The article is talking about the CO2 released from that coke, and not the coke used to fuel the furnace.
- cauldron 8y ago
  You sound like confused, from my limited knowledge, the making of steel is exactly opposite of what you said, they extract carbon atoms from iron, that makes carbon monoxide into carbon dioxide.
  - SomeAmerican 8y ago
    Iron ore has no appreciable carbon in it before it enters the blast furnace.
- hexane360 8y ago
  Actually it's 100% the opposite. Look at your iron-carbon phase diagram: https://www.tf.uni-kiel.de/matwis/amat/iss/kap_9/illustr/fe_c_phase_diagram_cast_iron.gif https://www.tf.uni-kiel.de/matwis/amat/iss/kap_9/illustr/fe_... Cast iron contains a high concentration of carbon, which makes it brittle. To make steel you need a heavy oxidizer to extract the (reduced) carbon. This is usually done using a "basic oxygen furnace", which is basically injecting a high pressure, very high velocity stream of oxygen into the metal to game thermodynamics into combusting the carbon without combusting the iron.
  - foobarian 8y ago
    Wow, TIL. This has some details at "5 year old level:" https://www.quora.com/What-is-the-difference-between-iron-and-steel https://www.quora.com/What-is-the-difference-between-iron-an... The phase diagram is very interesting too. Very little carbon is needed to go from elemental iron to steel, looks like about 0.008%. Thanks for posting that!
- testrun 8y ago
  This is correct, and the carbon is a byproduct. The reason is to get rid of the oxide in the iron-oxide compound. The way I understand it, is that when mined they get iron-oxide, Fe(2)O(3), or Fe(3)O(4), so there is no carbon present. They use the coke to make carbon monoxide (CO). And this process removes the oxide and adds carbon to iron to create pig iron. From there it will be further processed to create different steels, alloys and iron products. Wikipedia (https://en.wikipedia.org/wiki/Iron_ore https://en.wikipedia.org/wiki/Iron_ore) under the smelting paragraph describes the oxide removal process.
- SomeAmerican 8y ago
  The coke that is mixed with the iron ore is the coke that heats the furnace. As the coke (carbon) reacts with oxygen, some of the carbon monoxide then strips oxygen from the iron oxide in the iron ore.

Steel is an alloy of iron and carbon. They mix coke with the iron to add carbon to it. The article is talking about the CO2 released from that coke, and not the coke used to fuel the furnace.

cauldron 8y ago
You sound like confused, from my limited knowledge, the making of steel is exactly opposite of what you said, they extract carbon atoms from iron, that makes carbon monoxide into carbon dioxide.
- SomeAmerican 8y ago
  Iron ore has no appreciable carbon in it before it enters the blast furnace.
hexane360 8y ago
Actually it's 100% the opposite. Look at your iron-carbon phase diagram: https://www.tf.uni-kiel.de/matwis/amat/iss/kap_9/illustr/fe_c_phase_diagram_cast_iron.gif https://www.tf.uni-kiel.de/matwis/amat/iss/kap_9/illustr/fe_... Cast iron contains a high concentration of carbon, which makes it brittle. To make steel you need a heavy oxidizer to extract the (reduced) carbon. This is usually done using a "basic oxygen furnace", which is basically injecting a high pressure, very high velocity stream of oxygen into the metal to game thermodynamics into combusting the carbon without combusting the iron.
- foobarian 8y ago
  Wow, TIL. This has some details at "5 year old level:" https://www.quora.com/What-is-the-difference-between-iron-and-steel https://www.quora.com/What-is-the-difference-between-iron-an... The phase diagram is very interesting too. Very little carbon is needed to go from elemental iron to steel, looks like about 0.008%. Thanks for posting that!
testrun 8y ago
This is correct, and the carbon is a byproduct. The reason is to get rid of the oxide in the iron-oxide compound. The way I understand it, is that when mined they get iron-oxide, Fe(2)O(3), or Fe(3)O(4), so there is no carbon present. They use the coke to make carbon monoxide (CO). And this process removes the oxide and adds carbon to iron to create pig iron. From there it will be further processed to create different steels, alloys and iron products. Wikipedia (https://en.wikipedia.org/wiki/Iron_ore https://en.wikipedia.org/wiki/Iron_ore) under the smelting paragraph describes the oxide removal process.
SomeAmerican 8y ago
The coke that is mixed with the iron ore is the coke that heats the furnace. As the coke (carbon) reacts with oxygen, some of the carbon monoxide then strips oxygen from the iron oxide in the iron ore.