As one of the most recycled materials in the world, we have been recycling steel for over a century and a half; resulting in what is now one of the most effective, efficient and widespread recycling process. Steel is a ferrous metal, meaning that it is made primarily from iron, the single most common element found in the earth, so considering its abundance why has so much time and research been invested into the recycling of steel?
The reason why is unsurprisingly simple, in that compared to the process of mining iron, having to remove the impurities in a blast furnace and then converting it into one of many possible steel alloys, recycling that which has already been processed is considerably easier, cheaper and less time consuming.
As you can see, recycling steel is incredibly practical, especially as it does not lose any of its strength or durability after having gone through the process of being recycled, which cannot be said for quite a number of other materials which will diminish in quality or content as a direct result of being recycled.
The actual means by which we recycle steel is extremely simple in principle: we melt it and have it recast. However there are many kinds of steel, which are made by combining iron, carbon, and sometimes another element, in various proportions. Depending on the content percentage of the elements used, the melting point of the alloy will naturally be affected, and the components will eventually separate and need to be filtered out.
Since steel is always majority iron however, the melting points of the various alloys never vary too much, with most being somewhere between 1370°C & 1510°C, or 2500°F & 2750°F. The filtering out of the various additions, such as zinc, chromium, nickel, copper, etc., is also undertaken during the same process if needs be, and these too can be used toward recreating alloys or possibly used independently.
Once melted all that needs to be done to the steel, before it can be reused, is for it to be recast and moulded into whatever form is chosen; whether that form be suited to a particular purpose right away or made into ingots to be saved for a later date. It is also important to note that steel does not have to be recycled and can be reused easily, with little or no processing being required; though this is only really practised in the construction industry, as it is impractical in most other areas.