A blast furnace is a large structure in which iron ore is heated under pressure so that it melts and the pure iron metal separates out and can be collected.
blast furnace in British English
noun
a vertical cylindrical furnace for smelting iron, copper, lead, and tin ores. The ore, scrap, solid fuel, and slag-forming materials are fed through the top and a blast of preheated air is forced through the charge from the bottom. Metal and slag are run off from the base
blast furnace in American English
a towerlike smelting furnace for separating metal, esp. iron, from the impurities in the ore: a blast of air is forced into the furnace from below to produce the intense heat needed
Examples of 'blast furnace' in a sentence
blast furnace
A blast furnace at the site was halted after a walkout by workers amid failed pay talks.
Times, Sunday Times (2010)
Another executive who worked on the deal said Britain must accept its days of making molten steel in blast furnaces are numbered.
Times, Sunday Times (2016)
At one point there were 100 blast furnaces on Teesside.
The Sun (2010)
For example, limestone is used as a flux in the blast furnace to allow the removal of iron from the ore in the presence of heat.