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This reads like an advert. The whole "carbon-negative" thing relies on the assumption that steel dust is a waste product, which seems highly dubious to me. Stee
by mrob 8y ago
This reads like an advert. The whole "carbon-negative" thing relies on the assumption that steel dust is a waste product, which seems highly dubious to me. Steel is commonly recycled, including steel in very small pieces such as machining chips. It's hard to believe that anybody producing steel dust in quantities sufficient for use as construction material would just throw it away. The fair comparison would include the energy needed for steel making, which needs even higher temperatures than the "staggering 2,800 degrees Fahrenheit" needed to make cement.
- JulianMorrison 8y agoLow grade iron scrap can probably be diverted from landfill, or reclaimed from it?
- CapitalistCartr 8y agoIron and steel are not normally put in landfills. Due to the ease of extraction, iron is the most recycled material on the planet.
- Animats 8y agoLow grade iron scrap goes to Nucor Steel. Nucor started in steel making rebar from scrap. Then they figured out how to continuous-cast better steel from scrap. Now they're the biggest steelmaker in the US. If it's steel or iron and you can get it to a scrapyard, it's going to be recycled. If it was a car, it's going to be recycled. If the magnets at the recycling center can pull it out of trash, it's headed for a steel mill.
- nerdponx 8y agoIf people don't do this already, the technology to do it cost-effectively probably doesn't exist.
- Animats 8y agoYes. It checks all the green boxes (CO2, Native American nations, EPA, etc.) but not the structural engineering boxes. Now if the tensile strength were 5x greater, that would be something. An alternative to concrete with rebar would be useful. Rebar corrosion is a huge problem and the limiting factor on the life of modern concrete buildings. Some way to use up recycled glass cullet has potential. There's a glut of that.
- DannyBee 8y agoWasn't CLT supposed to be the green answer to concrete?
- lazyjones 8y agoOr, Roman Concrete: https://newscenter.lbl.gov/2013/06/04/roman-concrete/ https://newscenter.lbl.gov/2013/06/04/roman-concrete/
- occamrazor 8y agoOne problem with Roman concrete is the very long curing time, which makes it less suitable for very tall buildings, because they require that the lower floors are almost fully cured before the upper floors are erected above them.
- bmer 8y agoThey do mention that it is less brittle (more flexible) than concrete. This would mean that less cracks might form, which would be very helpful in increasing rebar lifetime.
- neltnerb 8y agoMy first thought when I read it's more flexible was that this would be applied to road surfaces where crack prevention was the only way to prevent damage from weather. I agree, though this is also clearly an ad =)
- Accujack 8y agoBasalt rebar looks pretty good. It's too new to be in wide use yet, and prices aren't lowered by wide use either. Non corroding, though.
- radicalbyte 8y agoThat was my view too whilst researching the subject. The only information I could find on Ferrock was very hopeful marketing material. We need new materials here urgently. Ideally something which, like plants, would pull the carbon from the air during the curing process. Whoever creates such a material is going to get very very rich..
- tyingq 8y agoThey linked out to a company called IronKast as an example of commercial development. The site isn't encouraging: http://ironkast.com http://ironkast.com
- dkarl 8y agoYep. The article compares it throughout to cement instead of to concrete. People don't build large structures out of cement. Is it supposed to be used as binder to replace cement in concrete? Or is the comparison to cement simply more favorable than if they made a realistic comparison to a functionally similar mix of concrete?
- thinkcontext 8y agoMuch (most?) concrete construction already includes steel in the form of rebar. It's not clear how much this new process uses compared to traditional concrete. Or if the fact that steel dust can be used versus rebar represents a carbon advantage. We'd have to see a fuller lifecycle analysis of a variety of construction scenarios.
- mc32 8y agoAlso wouldn't steel make the concrete less effective over time as the steel rusted and made the concrete weaker?
- semicolon_storm 8y agoThe article claims that the steel rusting is actually an integral part of the process. The iron in the steel reacts with CO2 to rust, which sets the material.
- neltnerb 8y agoI actually read the carbon negative claim as implying they're forming an iron carbonate. I'm not sure why it would be carbon negative if it's just iron to rust, rust doesn't have any carbon in it.
- justinclift 8y agoWatching the YouTube video (mentioned further down) which covers in-development concrete alternatives (https://youtu.be/wOE4UegzJ_M?t=190 https://youtu.be/wOE4UegzJ_M?t=190), apparently this forms FeCO3 + H2. The C in that would be the carbon sequestration. :)
- d--b 8y agoYes, I’m pretty sure you could make cement from waste clay as well...