:Ca5(PO4)3OH + 10 HNO3 -> 3 H3PO4 + 5 Ca(NO3)2 + H2O

The mixture is cooled to below 0 °C, where the calcium nitrate crystallizes and can be separated from the phosphoric acid.

:2 H3PO4 + 3 Ca(NO3)2 + 12 H2O -> 2 H3PO4 + 3 Ca(NO3)2.4H2O

The resulting calcium nitrate produces nitrogen fertilizer. The filtrate is composed mainly of phosphoric