Here is a break from our normal articles; this requires projection into the far future. Imagine a time when all the easily accessible metals deposits have been exploited and scarcity is pushing prices ever higher. Living standards could be compromised by a lack of vital metals, some countries could begin hoarding reserves as sovereign assets – what would we do? Not a comfortable thought is it and fortunately it is an entirely avoidable scenario if some of the ideas explored in a fascinating article in Chemical and Engineering News this month are developed in the meantime.
The gist of the argument is that while we are consuming the earth’s metallic resources at a rapacious rate if we recycled the metals in a closed loop we could continue to develop metal applications almost indefinitely with the resources we have already identified. The key phrase here is closed loop. At the moment, most recycling is open loop; that is if it occurs at all it is not as a result of the original design and many parties take ownership of the metal throughout its life. Consequently most of the metal originally mined is lost in the total life cycle process and even for well developed recycling industries like aluminum only a fraction is retained. An example of a closed loop would be where the product using the metal is designed for recycling after use. The metal is owned by one party who supplies the part, takes it back after use, recycles the metal and uses it to make a new part with just a small addition of new metal to make up for process losses. Platinum used in catalysts is an example of a metal where this is very successfully practiced. The chemical, petroleum, and pharmaceutical industries already have set the standard for recycling metals when it comes to platinum group metal (PGM) catalysts, which include platinum, palladium, rhodium, ruthenium, and iridium. These are all high-value commodities with relatively long life cycles. Thomas Graedel of Yale University says in some cases there is more metal already in use above the ground than there is left in the ground. Copper, zinc and platinum are all metals Graedel feels could be in trouble this century and others suggest gallium, indium and hafnium potentially could run short next decade. So may be there is an imperative to look more closely at this now.
Metals that have already been consumed are locked up in the mostly now defunct products they went into. The EPA estimates in the US only 18% of electronics and 10% of cell phones are currently recycled to recover gold, silver and other metals. Potentially those un-recycled products represent an urban mine that could be exploited as a valuable resource but to develop true closed loop systems requires products to be designed from the outset for recycling and for the re-cycler to be an integral part of the supply chain. This is easier for PGM’s where the amount of material in use is comparatively small. The article states 2,700 tons are used in cars and 1,000 tons in catalysts and other applications. Only some 500 tons of new PGM’s are produced each year making the process easier to manage. Maybe new technologies are a good place to start. Lithium consumption could grow exponentially if demand for car battery packs takes off as some would like to see. This has the potential for a re-cycler to become an early part of the supply chain and take up a critical role in the life cycle of the metal. In reality though there is so much lithium potentially available in Chile, Argentina and Bolivia the price may remain below the level where recycling in a closed loop is viable.
In reality there are still natural sources for metals that have not been exploited and will postpone the point at which the world appears to be running out of metals. Sub-sea vents and manganese nodules are two sources that we have written about before and combined represent vast untapped reserves. But logic should prompt us to ask should we be consuming ever diminishing grades of land based deposits or potentially damaging the ocean floor environment? When there is a vast untapped resource available that with more forward planning and cooperation between design engineers, consuming manufacturers, closed loop specialist recyclers and yes governments we can make better use of what we have.