Anders Cassel and Elisabeth Henriksson, Akzo Nobel Surface Chemistry AB
P.O. Box, Stenungsund, S-444 85, Sweden

Akzo Nobel Surfactants and Rajasthan State Mines & Minerals Ltd, Rajasthan, India are developing a process for the dolomitic Jhamarkotra low-grade ore as an alternative to the presently used acidic reversed bulk flotation process.

In a paper presented at the conference “Beneficiation of Phosphates V” in Rio de Janeiro 17-22 February, 2008, laboratory results were presented from experiments using an amphoteric apatite collector working directly, without de-sliming, on a fine ground Jhamarkotra ore feed, in a neutral or slightly alkaline water, producing a high-grade apatite concentrate with relatively low MgO, and generating process water with a good re-circulation potential.

The goal is to develop a process producing an apatite concentrate of higher P2O5 grade and recovery and with lower MgO content than today and being suitable for use in the wet phosphoric acid manufacturing process.

This picture demonstrates Jhamarkotra low-grade ore mining: