Carbon or hydrogen used to remove oxygen from iron ore to produce iron and steel.

Reheat furnaces are used to ensure that partly worked steel, which has been allowed to cool, arrives at its next processing stage at the optimum temperature. The furnace heats metal ingots, billets and blooms in order to bring them to the temperature required for hot-working. 

Re-rollable scrap is a steel scrap metal that is already in such a condition that it is suitable for another application through rolling it into a saleable product. This differs from the more common processes seen in scrap recycling where the metal undergoes melting, casting and rolling. Re-rolling is more commonly used in emerging economies rather than in industrialised countries. 

Residuals are elements such as copper and tin, which are usually introduced into the steelmaking process in the form of unsorted or contaminated scrap. This can sometimes, however, impair the physical and mechanical properties of steel. Residuals are key concerns regarding the mini-mills’ recent entry into the flat-rolled market. High residuals can leave sheet steel too brittle for customer use causing problems in the mill.

A reversing mill is used to reduce material to gauge. The steel enters the rolling mill from one side, passes through the other side and then comes back through the mill again. Normally it will go left to right through the mill a number of times being rolled a little thinner each time it goes through.

This type of steel is produced during ingot casting, with the resulting ingot having a very pure surface layer, or rim. This feature is due to the absence or near absence of a deoxidising agent during steel production, which allows carbon monoxide to be formed from the oxygen and carbon in the melt. As this gas migrates to the surface, other elements (eg.carbon, phosphorus and sulphur) gravitate towards the centre of the ingot to leave a much purer layer or rim on the outside. After hot rolling this steel has a good surface finish which is low in carbon.

A machine which converts semi-finished steel (semis) into finished steel products by passing them through sets of rotating cylinders which squeeze the steel into the desired shape. Rolled steel products include bar, rod, plate, beams, coil etc.

Roughing mills are rolling mills which convert steel ingots into blooms, billets or slabs. The process enables the steel to go back-and-forth through the mill (multiple passes) until the desired dimensions are achieved.

Two heavy rolls that press the steel plate to reduce its thickness before hot rolling.

Obsolete scrap is derived from steel-containing goods at the end of their useful lives, while revert scrap is steel waste produced and recycled within a steelworks. New production scrap is generated when steel is cut and formed during the manufacturing of finished products or components.

Seamless tubes are made from solid blocks of steel that are pierced and drawn into tube shape. Seamless tubes have greater strength than welded tubes because of their homogenous microstructure, but are much more expensive to produce. They are made by rolling a preheated billet between offset rolls which is then pierced with a pointed bar or plug to create a tube shell. This is then elongated in a multi-stand rolling mill to achieve the desired thickness

Steelmakers use a secondary metallurgy vessel between the steelmaking and casting operations to allow molten steel to be brought to the required specification. Key operations can include deoxidation, desulphurisation and dephosphorisation. Not only does the use of secondary metallurgy enable a larger range of steel grades to be cast, but fine tuning steel composition in a separate furnace greatly improves the productivity of the main steelmaking unit. This is because with metallurgical adjustments taking place elsewhere, the time from steelmaking raw materials in, to tapped liquid steel out, is shortened.

Semis is short for semi-finished steel, which is the name given to large, uniform cast pieces that require further processing in order to be transformed into finished long, flat and tubular steel products.

Shredding transforms mixed metallic scrap into a more homogeneous product. It is done in a shredder, a powerful piece of enclosed equipment with rotating hammers which break down the incoming material. Shredded scrap’s regular consistency is attractive to electric arc furnace operators as it is easy to charge and offers uniform steel chemistry.

A process in which fine materials are combined into a porous mass that can be used in the blast furnace.