`Separation of aqueous lead on francolite surface’.

The separation of aqueous Pb2� onto a low-grade (�15% P2\ud O5) carbonate-substituted rock phosphate (Francolite) mineral from Madhya Pradesh (India) was investigated. The effects of different parameters such as initial concentration of Pb2�, particle size of Francolite, and amount of substrate on lead-ion separation were studied\ud under natural conditions by equilibrating different amounts of Francolite with aqueous lead solutions of different concentrations. Francolite was found capable of leadion separation at par with hydroxyapatite or high-grade (�25% P2\ud O5) rock phosphate. Francolite was found very effective in removing Pb2� with a minimum lead removal of 82–99.9% and a maximum LRC (lead removal capacity) of 0.082 g of lead/g of\ud Francolite