Automated recycling is coming along well. Here's a typical modern plant in the UK.[1] Sorting is mechanized, with tumble drums, vibratory sorters, and magnets doing most of the work. Permanent magnets pull ferrous metal out. AC magnets pull aluminum out. Vision systems, often multispectral, look at the presorted materials as they go by on a fast belt and use air jets to kick out certain types of items. This is standard technology.
There's still some manual picking involved in most plants. Robots are taking that over at a few plants.[2]
Aluminum is the moneymaker. Plastic bottles can go to a plant that turns them back into pellets for making new bottles.[3] A huge plant now serves southern California. Not clear this makes money.
Waste paper isn't that valuable. "Peak paper" was a while back, and US paper mills have been closing for years. It's not that sorting is hard, it's that the product is so low-value.
Plain white office paper might not be so valuable, but cardboard remains valuable enough that in Eastern Europe you can see marginalized communities like the Roma collecting it daily. I have seen recycling centers advertise payments like 0.50€/kg in exchange for cardboard, which seems pretty high.
We still burn tens of millions of tonnes of essentially recyclable material that isn't recycled thanks to market prices.
The burning isn't relevant (it's better than landfill in a lot of circumstances), it's that introducing virgin materials to the waste pool is cheaper than reuse, for many materials.
There's still some manual picking involved in most plants. Robots are taking that over at a few plants.[2]
Aluminum is the moneymaker. Plastic bottles can go to a plant that turns them back into pellets for making new bottles.[3] A huge plant now serves southern California. Not clear this makes money.
Waste paper isn't that valuable. "Peak paper" was a while back, and US paper mills have been closing for years. It's not that sorting is hard, it's that the product is so low-value.
[1] https://www.youtube.com/watch?v=SIVKmwzWSuc [2] https://www.youtube.com/watch?v=2gjUpDnJrZA [3] https://www.youtube.com/watch?v=vAr4BZM_Tzk