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Electric arc furnace
The sequence of operations is similar to that in the BOS furnace, except that, after charging, the charge must be melted down.The furnace charge melts when an electric arc passes between the electrodes and the scrap metal. The temperature around the arc rises to 1200oC and a 100 tonnes charge can be melted in about 60 minutes.

The four main stages are (roll over the highlighted word to see the pictures):

Diagrams of electric arc furnace sequence that change on rollover
Photographs of electric arc furnace sequence that change on rollover
1. Chargingwith a mixture of metal and lime.

2. Melting the metal and scrap using electric arcs from the graphite electrodes. After this some more lime is added to clear out the oxides in the next step.

3. Blowing with oxygen to oxidise elements such as carbon, silicon and manganese in the scrap metal. As in the BOS furnace, carbon monoxide escapes as a gas. The oxides of the other elements are acidic and combine with the basic lime to make a neutral slag, which is poured off the surface.

4. Tappingthe metal itself by running it out through the furnace spout into a ladle. The liquid in the ladle is now ready for secondary steelmaking and casting. Further treatments of the metal from the EAF take place in much the same way as steel from the BOS plant.

The future for EAF steelmaking
The global output of steel from EAF furnaces is increasing. Many countries that cannot make iron by the traditional Blast Furnace route but have sufficient supplies of scrap have developing steel industries based on the EAF process.
The output of iron from Blast Furnaces is likely to decline in the future because of diminishing supplies of coking coal and other raw materials. This means that steel recycling in the EAF will grow in importance. The EAF could also develop in the near future as a means of processing directly reduced iron (DRI). You can learn more about this alternative route to iron in the next section.
Question 17

Why do the acidic oxides that are formed in the EAF combine with lime?

Question 18
2. Suggest reasons why some countries are unable to produce iron by the Blast Furnace route.