SiTration uses silicon wafers to reclaim critical minerals from mining waste

Azolla SiTration

Brendan Smith didn’t intend to be in the critical minerals business. He initially thought his high-tech filters would be good at desalination. But it was hard to beat existing systems, so he and his adviser, MIT professor Jeffrey Grossman, quickly ruled it out. After a few years “where we sort of intentionally meandered,” they found themselves in a very different industry: mining.

Producing critical minerals is not a pretty business. Take copper, for example: The world uses around 25 million tons of copper per year, and more buildings, electronics, and electric vehicles mean that demand is expected to grow 24% over the next decade. Each ton of copper ore recovered leaves behind around 100–150 tons of waste.


That’s a lot of waste, so much so that some mines have run out of room for tailings ponds, which hold the toxic chemicals and byproducts that remain after valuable minerals are removed.