Separation of lead ions on francolite surfaces

The separation of aqueous Pb2+ onto a low-grade (<15% P2O5) carbonate-subst ituted rock phosphate (Francolite) mineral from Madhya Pradesh (India) was investigated. The effects of different parameters such as initial concentra tion of Pb2+, particle size of Francolite, and amount of substrate on lead- ion separation were studied under natural conditions by equilibrating diffe rent amounts of Francolite with aqueous lead solutions of different concent rations. Francolite was found capable of lead-ion separation at par with hy droxyapatite or high-grade (>25% P2O5) rock phosphate. Francolite was found very effective in removing Pb2+ with a minimum lead removal of 82-99.9% an d a maximum LRC (lead removal capacity) of 0.082 g of lead/g of Francolite.