hope this helpsthis info came from the Camfield...

hope this helps

this info came from the Camfield function.

alternate feed was from Australia ( no more details given)

we use the same process to get 4N and 5N

the difference is the purity or the lack of contamination in the feed material,

basically strip material from the top and use or store for 4N production, use the lower depth resource into the same process and you get 5N, only talking a few metres.

I ask the question about building two separate plants or a split stream or extra steps to get 5N, the above was my answer