Following back on your comments from the Mars colony thread...
Olivine weathering is so energetically favorable from that paper that, if you put enough of it into a sphere, and feed it enough pure CO2, it's actually a usable thermal energy source.
You can "burn" it like coal, except that it "burns" CO2 instead of oxygen.
To relate back to Mars, you can probably do similarly absurd things with the perchlorates in the soil there. You can "burn" perchlorates in a reducing atmosphere of e.g. methane from the sabatier process, and end up with salt and an explosion.
You can "burn" it like coal, except that it "burns" CO2 instead of oxygen.
That is a bit optimistic :-)
The potential energy per gram of mass is much lower than for coal burning in Earth's atmosphere -- worse, the kinetics are so sluggish that you would need a very large vessel with good insulation to build up a useful temperature differential.
You'd also need to concentrate perchlorates from the Martian soil before they would sustain combustion with methane. Assuming that was done, though, perchlorates plus hydrocarbons will combust with vigor.
I think the analysis I saw was that it's energetic enough that the entire mining + grinding + "burning" process is energetically favorable. Which I found pretty astounding, but I think that points more to the incredible efficiency of mining and industrial processes than anything.
I think that was also at elevated temperature in a carbonic acid solution, so basically the fastest possible "weathering".
Olivine weathering is so energetically favorable from that paper that, if you put enough of it into a sphere, and feed it enough pure CO2, it's actually a usable thermal energy source.
You can "burn" it like coal, except that it "burns" CO2 instead of oxygen.
To relate back to Mars, you can probably do similarly absurd things with the perchlorates in the soil there. You can "burn" perchlorates in a reducing atmosphere of e.g. methane from the sabatier process, and end up with salt and an explosion.