In the iron and steel industry, direct reduction is a set of processes for obtaining iron from iron ore, by reducing iron oxides without melting the metal. The resulting product is pre-reduced iron ore.
Historically, direct reduction was used to obtain a mix of iron and slag called a bloom in a bloomery. At the beginning of the 20th century, this process was abandoned in favor of the blast furnace, which produces iron in two stages (reduction-melting to produce cast iron, followed by refining in a converter).
However, various processes were developed in the course of the 20th century and, since the 1970s, the production of pre-reduced iron ore has undergone remarkable industrial development, notably with the rise of the Midrex process. Designed to replace the blast furnace, these processes have so far only proved profitable in certain economic contexts, which still limits this sector to less than 5% of world steel production.
- ^ (fr) Emmanuel-Louis Grüner, Traité de métallurgie - métallurgie générale, t. 2 (procédé de métallurgiques, chauffage et fusion, grillage, affinage et réduction), Dunod, 1878 [details of editions] (read online), part I, pp. 240; 250-254; 257.
- ^ (fr) Adolf Ledebur (trans. Barbary de Langlade revised and annotated by F. Valton), Manuel théorique et pratique de la métallurgie du fer, Tome I et Tome II, t. 2, Librairie polytechnique Baudry et Cie éditeur, 1895 [details of editions], pp. 350-352.