Smelting furnace ancient

The extraction of the common metals from their ores in antiquity was based mainly on relatively simple equipment and processes. Lumps of copper or iron ore, for example, that may have formed part of a ring of stones around an ancient domestic fire and become embedded in its embers, could have been reduced to metal. It is quite reasonable to conjecture, therefore, that some prehistoric campfire became, quite accidentally, the first metallurgical furnace. All that is needed to convert a campfire into a smelting furnace is a small depression in the ground to receive the molten metal. A furnace of this type is illustrated in Figure 42 (Gowland 1912 Killick 2001). 

FIGURE 42 Ancient smelting furnace. A simulated ancient smelting furnace used to replicate ancient metallurgical processes (a) plan (b) cross section. 

Iron articles were probably made by the Egyptians twenty-five or thirty centuries before Christ, but because the metal is so readily corroded, iron objects of great antiquity are much rarer than similar ones made of gold, silver, or copper (25). Smelting furnaces for iron were used in ancient times, but the exact nature of the process is not known. 

The term coke brings an immediate reference to the blast furnace the evolution of the blast furnace reduction process occurred over a period of many centuries (ore smelting being known in the sixteenth century and documented in some detail) (Biringuccio, 1540) and most certainly had become well known in almost all areas of the ancient world two millennia ago (Forbes, 1950). By the early Middle Ages, a shaft blast furnace known in Germany as stuckofen was well established and iron making was a respected trade and not a sporadic part-time occupation. The fuel for these furnaces was provided by wood charcoal, and, consequently, the vitality of the iron and steel industry was controlled by the availability and cost of wood. 

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