It’s no secret that we find steel an absolutely fascinating material – not only does it have almost endless possibilities, it’s also almost endlessly recyclable! Some materials have a limited number of times that they’re suitable for recycling; paper, for instance, can only be recycled around 6 times due to its structure. The cellulose chains that paper is made from get shorter and shorter every time it’s recycled, meaning that after around 6 times, they’re too short to be reused for more paper.
Steel doesn’t have this problem; there’s no shortening of its structure and no problem with using the same piece of steel over and again to make new steel. Given the recycling steel uses a fraction of the energy that it takes to process ore into fresh material, it’s the more environmentally friendly option and prevents perfectly good material from being wasted or left to decompose.
There are times, however, where recycling steel is not only desirable but the best way of going about things. Sometimes trying to use a new steel – no matter how expertly it’s been crafted – is not a suitable option for the tools or equipment. Machines, such as medical scanners, need to be made from recycled steel – but why would that be?
There’s actually an incredibly accurate point for the date when new steel wasn’t the best option – July 16th, 1945. This was the date of the first atomic bomb detonation, which was quickly followed in the last days of World War II by the bombs dropped on Japan. Since then, there have been well over 1,000 nuclear weapons tests, each one having a lasting effect by throwing varying amounts of radioactive material up into the air, slightly increasing the levels of background radiation all across the globe.
This doesn’t pose any problem in general, but when you take iron and combine it with air to make steel, you end up with a final metal that’s slightly radioactive. Now imagine that you need to build a Geiger counter or a medical scanner that’s capable of picking up radiation levels – if the metal the machine is made from is slightly radioactive, it’s constantly going to be reacting to itself and will be less sensitive. If the scanner is large enough, it could prevent it from registering levels of radiation that it needs to, which poses a problem.
Luckily, we have an abundant source of steel from pre-1945. Today’s Geiger counters and medical scanners are generally made from massive battleships that were sunk prior to July 1945. Recycled steel doesn’t use the same process as that used to forge or create fresh steel, so it can be reused without contaminating it with the background radiation contained in the air. The tens or hundreds of metres of water above a sunken ship act as a barrier, meaning it’s much less likely to show background radiation.
Technology has come up with a solution to radioactive steel, but it’s very expensive and energy intensive and there’s such an abundant source of suitable recyclable material available, we should be making every effort to supply the world’s steel needs from it. Besides, we’re sure that people are always fascinated by learning that some of the most advanced medical equipment in the world used to be a giant warship!