Scrap Industry - Ironing Out the Difference

Scrap metal dealing was one of the earliest recycling industries. It probably began shortly after the invention of metallurgy, about 6000 years before it became a vogue term!

The modern industry broadly divides into ferrous and non ferrous processors.

Ferrous processors (Ferrous metals contain iron)

Breaking large, mainly low value scrap (such as structural steelwork, ships, industrial plant, vehicle shells, and 'white goods' casings) to produce graded material for British and overseas steel producers, and to a lesser extent, broken cast iron for direct foundry use.

Some 6 million tonnes per year (about half the new steel output) are recycled in this way, aided by the fact that 50 per cent scrap is necessary for the open hearth steel conversion process. Some overseas industries (notably Brazil) are based on 100 per cent scrap.

The major products of the ferrous industry are cast iron, low and medium alloyed steels and specialty steels such as tool steels and stainless steels. In the production processes used to manufacture these end products other important materials encountered are refractories, sinters and slags, and of course the starting raw materials iron ore together with limestone and coke.

Finally ferro alloys are employed in the high alloy steel making processes as a way of adding elements such as chromium nickel, molybdenum and silicon to the steels thereby completing an extremely varied spectrum of materials to be analyzed in the ferrous industry.

Non ferrous processors (Non ferrous metals do not contain iron)

Generally operating from secure premises, breaking smaller volumes of scrap products containing metals of higher value (brass, copper, zinc, lead, aluminium etc. including non-magnetic stainless steels) mainly for sale to refiners. Refiners although most common non ferrous metals have relatively low melting points, scrap is rarely used directly in foundries. Quality control usually demands the use of closely specified alloys which are supplied as standard ingots by secondary metal refiners (generally at prices around double that of equivalent scrap).

The non ferrous industries deal with a similar cross-section of material types in the production of metals such as copper, nickel, lead and zinc, but in these industries much more time and effort is spent in analyzing exploratory core body samples since these metals are generally present in much lower concentrations in the earths crust than is iron and more widely dispersed.

Aluminum and copper are widely used in high electrical conductibility applications where the presence of some elements at even a trace level can give rise to unacceptable high power losses in electrical transmission lines. For aluminum an added concern is the fact that the anodizing characteristics of the metal are strongly influenced by the presence of just a few ppms of certain elements.