> What I'm somewhat surprised about is that we've not seen synergies with desalination and ocean mineral extraction.

I think these guys are basically using desalination tech to make lithium extraction cheaper: https://energyx.com/lithium/#direct-lithium-extraction

As I understand it (which is far from perfectly) it's still not using ocean water, because you can get so much higher lithium concentration in water from other sources. But it's a more environmentally friendly, and they argue cheaper, way to extract the lithium from water than just using the traditional giant evaporation pools.

Do you know how much magnesium you find with silicon and iron as olivine? It's just the silicon that we haven't yet tamed for large scale mechanical usage that makes them uneconomical to electrolyze.

likely a matter of location. desal tends to be on the coast and near cities which tends to be pretty valuable land, making giant evaporation ponds a tough sell.