Initial evaluation of waste phosphogypsum for its use as a precursor for bioceramic materials

In this study, the phosphogypsum waste taken from various places in the factory dump located in Kėdainiai (Lithuania) was reinspected and characterised by different physico-chemical characterisation methods. The results of X-ray diffraction analysis, thermogravimetric analysis and differential scanning calorimetry, Fourier transform infrared spectroscopy, energy-dispersive X-ray analysis, elemental analysis using inductively coupled plasma optical emission and X-ray fluorescence spectroscopy confirmed that the main crystalline phase of the phosphogypsum waste is gypsum (CaSO4·2H2O). The surface morphology of the investigated materials was analysed using scanning electron microscopy. The specific surface area was determined by the Brunauer–Emmet–Teller method. The pore size distribution of the material produced was obtained using the Barrett–Joyner–Halenda method. This study also demonstrated that the phosphogypsum waste could be successfully used as a precursor for the dissolution-precipitation synthesis of high quality bioceramic calcium hydroxyapatite.