Biorock sea water mineral accretion technology
March 14, 2010 at 9:00 pm #9856
Here is some food for thought on seacrete. Cement is concreet without aggregate seacrete has no aggregate just a metal frame so it should be called fero seament. Seacrete is seament with aggregate. if Concreet structures were made with pure cement they wouldent be cost efective either…August 16, 2011 at 4:03 am #14661
I’m not super knowledgeable on any of this but I’ve always been fascinated by (and wondered why we don’t already have several examples of, I mean, the ultimate tax haven if nothing else!) floating cities, and I guess I’ve read a lot about the tech involved over the years. I’ve always loved the seacrete idea because… well, I’m sure all of you like the idea for the same reason as well even if you don’t think it can be economical, It’s basically growing sea-shell structures. What I was thinking was why should you lose heat due to decreasing conductivity? Steel’s pretty much dirt cheap as far as metals go, especially if you buy scrap steel – which would, I shoudl think, be perfect for being pushed through wire extruders or turned into powders. Couldn’t you simply sprinkle your structure with either conductive powders or tiny conductive filaments as it goes, constantly refreshing the surface magnetic layers? Perhaps for a cylindrical log-raft type individual floatation unit you create your wire mesh cylinder like you were doing ferrocement, put it on an axle, give it a slow spin, and put a stream sprinkler for fine steel thread sections above it. Calculate the speed so that as it goes you get the most possible accretion – cementing the strands to the structure before they are on the unerside of the spinning surface, assuming the magnetic field wouldn’t do so? but also decreasing the amt of wire needed – without too much interference, or less conductive materials bound up between the previous layer of wire and the new one.
That’s one idea anyway, another I suppose could be as simple as dispensing an iron powder over the structure gradually as you go. The higher end of this basic idea would be to skip the mesh overall. Make your framing structure out of whatever you will so long as its tough, doesn’t need to be conductive. Then get you a whole load of steel wire, probably the thinner the better. Let’s say your basic structure is again a cylinder, you set it up with a spinning mechanism (imagine your own mechanism, it doesn’t necessarily have to be fast, it can probably be tidal powered, possibly even mechanically tidally powered without any electronics inbetween) that runs the wire down the structure with less than a centimeter’s spacing, really with whatever you calculate to be optimal – the gap and how quickly the accretion will cross the gap, the cost of using more wire to lessen the amt of accretion the electricity has to go through vs the cost of using more electricity for less accretion, etc – and then spin the wire up and down the length of the drum frame for your float.
I’m sure you get the idea. As you go you are constantly exposing a new layer of metal to the ocean’s minerals, and no matter how large your structure gets, how thick, you’re always controlling power due to conductivity loss. How? Well, you’ve got a drum of line you’re winding out around the structure for your constantly renewing metal meshing (and btw, probably also pretty structurally sound) and the electrodes are at either end of this length of wire, and there’s no reason you can’t shorten it at any given time. The stuff that’s already buried within the accreted zone, there’s not really any reason you have to keep on powering that and wasting your electricity as heat reaching through the calcium buildup. You can snip the wire at any time, will switch it whenever you replace drums of wire, and reattach the leads much closer to each other.
As far as I can see this should more or less keep you right up near the optimal power per kilo of accreted materials, possibly a bit above what they calculated as optimal (unless they just assumed superconducting wire in their calculations then only powering one itsy bitsy section of the structure’s metal skeleton at a time is going to lower energy loss). Where would that put you, if you had a method for keeping conductivity as high as possible like this? How about if you’re powering it through these deep water heat exchange plants (otec, opec, whatever they’re called) and you’re using their byproducts to dope the water with excess calcium carbonate (presumably lowering kwh/kg)?
Dunno, the method just seems to simple and brilliant, too direct of an exchange of electricity for work, to not have some workable solution to just make it awesome. If nothing else I should think perhaps this method of using wire to reinforce it combined with perhaps rotating it under a sream of descending calcium and sand or rubble (to get stuck in the pockets and spaces and serve as a cheap aggregate) would make it doable. I mean, making hulls out of straight up steel’s already profitable, and that takes way more energy than we’re talking here (casting plate and welding it all together vs pressing or pulling out wire and running a low current through it for a while) and we’re talking about basicaly adding a couple cm3 of agregate for each cm3 of metal even for quickish building, and without very much labor or more than a few simple machines, all running on relatively low power, possibly even mechanical and electrical power harvested from the factory itself.
Seems doable. Wish I had the cash to experiment with this Perhaps I will attempt to rebuild atlantis in my fish tank.August 16, 2011 at 5:16 am #14663
in a fish tank. It looks like shit. Don’t waste your cash on that.August 16, 2011 at 8:22 pm #14669
I too have been interested in Hibbertz’s mineral accretion for a long time. I would be happy to kick in on the development of the dome pilot study you speak of.
Of course, with mineral accretion, as with ferro-cement, the shape is no longer an issue unless you are dealing with external forces (underwater, or earth-sheltered). You can build it any way you want.
Glad to see it brought up here.
BenAugust 16, 2011 at 8:38 pm #14672
As soon as I find my hard copies of Eric Lee’s experiments debunking mineral accretion as a viable building method I’m gonna scan ‘em and post ‘em to the wiki so we don’t have to keep having these conversations.
Best I can do is post a bunch of links to some old Living Universe Foundation discussions where they explain why mineral accretion, or seacrete, is not going to work for building floating structures.
Basically, it takes way too long and costs way too much money to accrete minerals on a structure. Plus the material you end up with is not what you think it is. Give up on mineral accretion.August 17, 2011 at 1:22 am #14681
Don’t be harsh on them :), guys if you want seacreate as your primary construction material along with necessary iron first thing you must to is to find a way produce electricity really cheap, if you simply produce electricity by available means seacrete is a waste of time and money ofc you might prove Tesla(harness lightning for example) and prove us wrong perhaps…August 17, 2011 at 2:38 pm #14700
It’s not so much the cost of the electricity as the cost of the other materials and the time. True, it does require a TON of energy and that energy is not free. But you need to build a wire mesh so dense that it will end up costing you FAR more than just building the structure out of normal materials.
Plus you need to accrete at such an incredibly slow rate that it would take you decades before you had anything resembling an actual structure, let alone a floating habitat.
Mineral accretion is fine for making coral reefs, but it is in no way a viable means for building a seastead.
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