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But that's not the same, the above process would be like melting the steel and glass and concrete from the building and hope future chemistry allows us to separ
by jgtrosh 4y ago
But that's not the same, the above process would be like melting the steel and glass and concrete from the building and hope future chemistry allows us to separate them
- WJW 4y agoCurrent chemistry allows us to do that just fine. Glass melts at a much lower temperature and is much less dense than steel. Concrete is not as dense as steel, but melts at a much higher temperature. So, if you heat up the whole mixture to steel melting temperatures, the glass and steel will melt and can be poured off, while the concrete will stay solid. Then the molten mixture of steel and glass will naturally separate because the steel part is so much heavier than the glass part and they don't naturally mix all that well. (Fun fact, glass pane manufacturing is often done by floating the molten glass on a bath of molten metal so that the surface tension will make it flat. AFAIK they don't usually use molten steel as the metal though.)
- jopsen 4y agoBut if you can pull out the steel beams without all the concrete, melting it will be a lot cheaper. Imagine grinding up a bridge or tunnel and trying melt all the steel out of the concrete. That sounds expensive.
- WJW 4y agoIt does "sound" expensive, but so does separating out all the steel beams from the concrete of a tunnel. That kind of thing is pretty labor intensive and people cost a lot of money. If you have a big enough grinding machine, it may well be cheaper overall if it only needs a single operator.
- rimunroe 4y agoI'm not a chemist, but this is something we're already very good at, and have been for quite some time. Silicon oxides occur very commonly in iron ores, and are a major component of slag.