|Specification||Ferrous scrap with less than 5% impurities|
Ferrous metals comprise the different grades of steel parts, including chrome steel, chrome-nickel steel and stainless steel. It is often difficult to differentiate the different types of steel, so that they are usually stored together. Knowing which type of steel is found in which component makes the segregation easier. Chrome steel and chrome-nickel steel are usually not painted, shiny and without rust.
In a computer ferrous metals of different types are generally found in protective tower, casings of the various drives, casings of the power supply and the loudspeakers. Some frame parts are also contained in other components.
Steel should be cleaned up to a degree where it is still viable. Steel with some plastic content is also accepted as plastic and can act as a burning facilitator.
Stainless steel, an alloy of iron and chromium, should be stored separately and not be mixed with ferrous scrap.
No special caution needs to be taken into account when storing or transporting ferrous metals.
In general, metal recycling is a pyramid industry with many small companies at the bottom feeding scrap to large multinationals at the top. Steel recycling involves some, or, all of the following steps:
- Sorting: Because magnets attract steel, this metal can be easily separated from other recyclables like paper in a recycling facility with magnetic belts. Different kinds of steel do not need to be separated.
- Shredding: Shredders incorporate rotating magnetic drums to extract iron and steel from the mixture of metals and other materials.
- Media separation: Further separation is achieved using electrical currents, high-pressure air flows and liquid floating systems. Other processes may be necessary in cases such as steel cans which have a protective layer of tin that must be removed and recycled separately.
- Shearing: Hydraulic machinery capable of exerting enormous pressure is used to cut thick heavy steel recovered from railways and ships. Other cutting techniques, such as the use of gas and plasma arch, are sometimes employed.
- Baling: Iron and steel products are compacted into large blocks to facilitate handling and transportation.
- Steel is ideal for recycling because it does not lose any of its inherent physical properties during the process, which can be repeated ad infinitum. Steel is 100% recyclable and therefore, recycled steel can be used for the same applications as steel produced from virgin material.
Ferrous metals can be sold to scrap metal merchants. Like other commodity prices, ferrous metals prices are fluctuating considerably.
Source of Information
Dismantling Guide for IT Equipment, which was elaborated within the SRI project and financially supported by SECO and UNIDO, June 2015