when I hear of industrial uses of phosphorus my ears prick up since phosphorus is a key limiting factor for life.

A world where this actually became industrially very successful combined with a lack of recycling could potentially add large new sink for phosphorus.

In general, be careful when creating a process which locks meaningful amount of phosphorus out of the biosphere.

I can't imagine this approaches how much is used in agriculture for fertilizer.

When a general study was made back in the 1970s of the limits of substitutability and recyclability of mineral resources, it was found phosphorus likely dictates the minimum amount of mining needed in steady state. It occurs at an average concentration of about 0.1% in the continental crust.

I worry just a bit about this in reference to LFP batteries.

I think that was a core plot point of a series of books by Niven I think. Humans are on a planet that has almost no phosphorus or maybe potassium in it's biosphere. Humans have to take it artificially by sprinkling a special salt on every meal. But it's very limited and expensive and so a significant part of the population are mentally handicapped to lesser or greater degrees, generation after generaion.

Ah, Destiny's Road, and it was Potassium.

"...dooming humanity to a slow mental extinction."

Great.