Mechanical Process Technology
Like a long, quiet River
At the Core
Lucrative development potential currently exists in the recovery of raw materials in the form of “urban mining”. There was no role here for mechanical process engineering 20 years ago — before rare earths became the game changers they are today. Due to the protectionist measures of a few — although vital — raw material manufacturing states (such as China), attention in research and development has now shifted to the recycling of strategic materials such as rare earths and precious metals, as well as other high-grade mineral commodities.
When you consider that one ton of PB motherboards contains 30 times more gold than a ton of material extracted from a gold mine, you start to see the mechanical processing of such materials in a different light. However, recovering metals, especially rare earths as well as gold, silver and copper, is a very complicated process and requires high levels of energy, and so specially adapted crushing and sorting processes for extracting metals aim to provide a solution. If the motherboard, for example, is not removed before shredding, it is very difficult — if not impossible — to get at the essential trace elements. In this case, it means losing 75 % of the gold.
Mechanical process engineering with its traditional crushing and sorting disciplines is the starting point for this process chain and has a decisive influence on the subsequent stages in the process, i.e. in dictating whether or not an urban mining operation is even worthwhile. The topic has been flagged up as an issue for the future in a Dechema position paper in 2013.
These examples, whether they involve the handling of minimal flows of material mass where the task pushes the physics to its outer limits or the search for potential future raw materials held in crude flows of recyclable material, demonstrate the huge potential of mechanical process engineering. Although the traditional workhorses of process engineering have performed perfectly well for many years, it’s time for the industry to tackle new challenges.