Automatic sorting spectrometer for phosphate rocks?

[sswats]

I think thats what I'm looking for.

Basically we are trying to separate rocks with high phosphate percentages from rocks with low percentages.

Or at least a portable detector which we can use on site and manually separate the different rocks.

this is for a very unsophisticated plant, so the most basic cheap device you know, or know the name of, please tell.

thank you