It depends on the contaminant. For example, if iron is polluted with carbon, carbon will dissolve and even react with iron to produce cementite. That’s how iron becomes steel.

And slag itself results in a metal loss. You can’t drain it off and not waste some of the material you’re recovering.

Basically there’s no such thing as 100% recovery of recycled material in an industrial setting. You can do it in the lab at astronomical costs, sure, but your local metalworks are not capable of that. But that doesn’t mean we should stop recycling.

Gardening on Reddit has 7.8m subs, that’s more than the whole Fediverse with all the bots.

Another issue is the quality of people. For example, I’m into kitchen knives. Dr. Larrin posts on Reddit about steels and related metallurgy. Does he post on Lemmy? No. Stroppy Stuff posts on Reddit about strops and sharpening. Does he post on Lemmy? No.

I’m also into mountain biking. Reddit is full of engineers, brand representatives and athletes, none of them is on Lemmy.

No one worth their salt gives a shit about Lemmy, that’s the hard truth. If you want to get quality hobby content - you go to Reddit.

Lemmy is for 15yo kids posting memes and US politics for those who got banned on Reddit. And for some devs to satiate their curiosity.

Normal people don’t give a shit about Lemmy. If you want to dive into hobbies, local news and other fun stuff - go to Reddit :)

Metals are also not 100% recyclable due to contamination. We just have plenty of use for low grade metal alloys.