Talk:Blast furnace

This process was made obsolete in 1856 by Henry Bessemer's invention of the blast furnace ....

which appears to contradict this article. Or is it that the 1865 invention is the steel blast furnace, as opposed to the iron blast furnace? -- Tarquin 10:10, 25 Aug 2003 (UTC)

The two processes are basically unrelated, although admittedly very similar. The blast furnace creates pig iron by mixing iron oxide with coke and burning it, resulting in slag and high-carbon iron. The iron is not useful on it's own. The bessemer process then takes this iron and blasts it again, without coke, to burn off the carbon and produce steel. The advantage is that the bessemer reactors can be fed with the hot pig iron from the blast furnace, thereby dramatically reducing the total amount of fuel needed to keep the process running. Most steelmills consisted of an assembly line starting with a blast furnace, then feeding a number of convertors.

Low and high blast furnaces ?

Hello,

in French, we make the difference between

the "low" blast furnace (bas-fourneau): used until the end of the Middle-Age, they can only produce solid stuf (high-carbon content) ,the temperature is too low to melt; the stuff is then processed (heated and beaten) to remove the carbon; they have the size of a human;
the "high" blast furnace (haut-fourneau): 7-10 m high, the metal melts and they produce cast iron (fonte).

Is there in English a specific vocabulary to separate the high and low blast furnaces ?

Cdang 15:28, 25 Oct 2004 (UTC)

What you're describing as a bas-fourneau, where liquid slag is beaten out of a solid mass of hot iron, is called a bloomery in English (because the spongy masses of iron produced by this method are called blooms). I have never heard "blast furnace" used to describe anything but an iron smelter hot enough to produce molten iron. Shimmin 18:34, Oct 25, 2004 (UTC)

Thanks. Well, all that's left is to create the Bloomery article... However, in the history part, is the blast furnazce so old (5-1st century BC)? I thought at that time there was only bloomery. Cdang 12:32, 28 Oct 2004 (UTC)

Yes, the blast furnace is that old ... in China. Chinese furnace technology, originally developed for large-scale pottery works, reached the melting point of iron perhaps as early as 1000 BC, although it was not immediately applied to iron-working. In the west, no one built furnaces that hot until the 1200s. The Han dynasty established iron production as a state monopoly and built several large blast furnaces. You can read an article about one of the better-preserved archaeological sites here.[1] Shimmin 13:26, Oct 28, 2004 (UTC)