What is Steel Scrap?

• March 25, 2022
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Steel Scrap

Steel scrap consists of discarded steel or steel products, generally segregated by composition and size or ‘grade’ suitable for melting. Three main types of scrap are used by the steel industry as feedstock. These are (i) internal scrap, (ii) prompt scrap, and (iii) obsolete scrap.
Internal scrap is also known as revert or home scrap. It refers to the rejected metal within the steel plant which gets generated during steelmaking, steel casting, and steel finishing activities within the steel plant. Prompt scrap is also known as process scrap and it is the waste generated during the product manufacturing by the steel plant’s customers i.e. the manufacturing industries. Obsolete scrap consists of that scrap that is recovered from discarded industrial and consumer items i.e. from ships to refrigerators and from construction beams to automobiles.
The first two categories of scrap can be returned to the steel making process with little or no pretreatment, obsolete scrap needs to be separated from contaminants, sorted, and prepared for steel making. Due to the large improvements which have taken place in steel manufacturing, steel casting, steel finishing, and product manufacturing technologies in the recent past, the amount of generation of the first two types of scraps has reduced a lot. On the other hand with resources of obsolete scrap are increasing as the world is becoming more industrialized and due to larger quantity of discarded consumer durables and worn-out industrial equipment etc.
Another way of classifying steel scrap is to classify it according to the products in which the steel was used before it became scrap. The main steel scrap sources in this sense are automobiles, ships, railroads, construction buildings, machinery, white goods, packaging, electric and electronic equipment, etc.
Steel scrap is considered to be free of alloys if the residual content of the following elements contained in steel does not occur at levels consistent with the purposeful creation of alloy steel. The residual level of elements contained within the scrap shall not exceed chromium 0.20 %, nickel 0.45 %, manganese 1.65 %, and molybdenum 0.10 %. The combined residuals other than manganese shall not exceed a total of 0.60 %. A scrap is considered to be off-grade if it fails to meet (i) applicable size limitations, (ii) applicable requirements for the type of scrap, and (iii) applicable requirements concerning scrap quality.
Steel scrap in itself does not pose any risk to the environment, i.e. there are no environmental risks in transportation and storage of metal itself. However, if the steel scrap is contaminated with oil or mixed with other waste, this may be considered hazardous for transportation or storage. For example, oil or any other liquid attached to scrap metal, when exposed to rain, may cause contamination to its surrounding environment.

Facts regarding recycling of steel scrap

The following are the facts associated with steel scrap and its recycling:

• Almost 40 % of the global steel production is made from steel scrap. Around 500 million tons of steel scrap are being used annually for the production of steel.
• Recycling one ton of steel saves 1.4 tons of iron ore, 0.40 tons of coal, and 0.055 tons of limestone.
• CO2 emissions are reduced by 58 % through the use of steel scrap.
• Recycling one ton of steel scrap saves 2.3 Cu m of landfill space.
• Recycling of el scrap uses 75 % less energy compared to creating steel from raw materials.
• Steel scrap recycling uses 90 % fewer virgin materials and 40 % less water. It also produces 76 % fewer water pollutants, 86 % fewer air pollutants, and 97 % less mining waste.
• Steel automobile frames contain at least 25 % recycled steel scrap and a typical electrical appliance will usually be made of 75 % recycled steel scrap. Steel cans consist of at least 25 % recycled steel scrap.

Specifications and standards

Currently, specifications and standard classifications for steel scrap exist at all levels, international, European, national, as well as between individual parties. It is clear that for the reason of marketing and trading, standards and specifications are needed not only to set the price but also uses as a reference for classification and controlling of the quality. In many cases based on the production need, steel scrap is processed according to the bilateral specifications agreed upon between the scrap processor and smelters.

Institute of Scrap Recycling Industry (ISRI) of USA has developed specifications for steel scrap which are known as ISRI specifications. This American standard provides the norms for the classification of steel scrap and is used internationally. EFR and EUROFER have developed the European steel scrap specifications. These specifications cover the requirements from the safety perspective, the excluded elements for all grades from a cleanliness point of view, and the tolerance for residual and other metallic elements. These also provide a detailed description of the specifications by category, which corresponds to the type of scrap. National industry associations of some countries such as the UK, Spain, Belgium, France, Germany, etc. have developed their specifications for steel scrap. There are also bilateral contracts/specifications made as agreements or contracts in trade between two parties. Such a specification is usually based on a standard classification with additional requirements suitable for the desired production process or product.

Basic loss of electric steelmaking, heavy melting scrap (HMS) is used. It is industrial or commercial scrap steel greater than 6 mm thick, such as plates, beams, columns, channels, etc. It also contains scrap machinery or implements or certain metal stampings. HMS is usually broken into two categories namely HMS 1 and HMS 2. The difference between the two is that HMS 1 does not contain galvanized and blackened steel while HMS 2 does contain galvanized and blackened steel.