I personally think most of the people that commented so far lack creativity. The first thing that came to mind for me when reading this, was easy mass storage of items. For instance, imagine having a overflow of iron. You can then turn that into underground belts, and then fast underground belts. fast underground belts is 57.5 iron for 2, stack size 50, making a stack of underground belts contain 1437,5 iron. Filling a steel chest like this would then contain 69.000 iron, that you could then later recycle into your system. Now this was items only containing iron, you could do the same with express underground belts and you would get 165.000 iron per chest. Now these are simple items, you could do this with Centrifuges. Now you are packing 650 iron and 500 copper per item, giving a stack 32.500 iron and 25.000 copper. A chest would then contain 1.560.000 iron and 1.200.000 copper.

This would of cause be assuming that a recycle plant gives plates and not ore. Also that it would discard any component non metal related.

Now would this be abusing the Recycling plant, sure, but isnt that all we do in this game?