| There are several types of casting furnaces which | | | | refractory-lined, and can easily be shaped into a |
| include Electric Arc furnaces, Blast furnaces, Cornwall | | | | spherical section or conical section (frustum). A |
| Iron Furnace, etc. Here's a quick review of some of | | | | refractory delta is also supported by the roof at its |
| them. | | | | center, by the way of which graphite electrodes make |
| Electric Arc Furnace: This furnace can be described | | | | an entry. |
| as a furnace heating charged materials by the way of | | | | The process of operation starts with delivery of scrap |
| an electric arc. These furnaces exist in all the | | | | metal to scrap bay which is located adjoining melt |
| sizes-right, from the smallest one having a capacity of | | | | shop. After that, the loading of scrap into huge buckets |
| around 1 ton to the largest one having a capacity of | | | | or baskets takes place. The next step is to carry this |
| 400 tons. The former one is used in foundries to | | | | basket to the melt shop. The charging takes place |
| produce cast iron products, whereas the latter one is | | | | here. After the completion of charging, let the |
| used for secondary steel making. The ones used by | | | | electrodes be allowed to enter and placed onto scrap. |
| dentists and in research laboratories might be having | | | | This causes the arc to be struck. Lower voltage is |
| capacity of a few grams only. The electric arc | | | | preferred for this part (of operation) to provide |
| furnace can have temperatures risen up to 1800 | | | | protection to the walls and roof against arc damage |
| Celsius. The first electric furnaces came into being in | | | | and excessive heat. After having the electrodes |
| 1907, at the hands of Paul Heroult of French origin. The | | | | reached the heavy melt, shielding of arcs by scrap |
| commercial part of these furnaces was established in | | | | takes place. This enables a rapid formation of molten |
| the United States of America. In the beginning, the | | | | pool, thereby decreasing tap-to-tap times. Oxygen is |
| specialty product used in the making of spring steel | | | | also allowed to enter. |
| and machine tools was electric steel. Calcium Carbide | | | | Blast Furnace: It can be referred to as a kind of |
| was also prepared in these arc furnaces. It (calcium | | | | metallurgical furnace, through which the process of |
| carbide) was used in carbide lamps. | | | | smelting takes place. This produces metals, normally |
| This furnace comprises of a refractory-lined vessel, | | | | iron. These furnaces trace their origin to China (around |
| normally water-cooled in huge sizes, having a covering | | | | 500 BC). They were also found in Belgium and England |
| of a retractable roof, through which the entry of | | | | later. They do not have any special mode of operation. |
| graphite electrodes takes place. They might be one or | | | | The metals get melted by heating only. Generally, iron |
| many in number. The furnace is divided into 3 sections: | | | | is melted in these furnaces. |
| the shell, consisting of lower steel bowl and sidewalls, | | | | The chemical reaction can be explained as follows: |
| the hearth, consisting of refractory lining the lower | | | | Fe2O3 + 3CO -> 2Fe + 3CO2. |
| bowl, and the roof, that can be water-cooled or | | | | |