Extracting Minerals
When I worked at a large mobile phone manufacturing company we had a talk on upcoming re-use recycling initiatives. Once the battery (and possibly the display - 20 odd years ago) the remains would be crushed and put into essentially a bessemer converter and the metals seperated out. The casing would burn and the released heat would count as oil-reuse. I didn't get a clear answer on my question of how the toxic fumes from the burning plastic would be dealt with.