Use of Marble Waste to Obtain Biphasic Bioceramics Based on Calcium and Magnesium Phosphates

The ornamental stone industry generates a huge amount of marble waste around the world, which requires sustainable disposal. This investigation aimed to synthesize a new biphasic calcium phosphate-magnesium phosphate bioceramic using marble waste as an alternative carbonate precursor. The phosphate bioceramic was synthesized using a wet chemical precipitation method in different Ca/P ratios. After the synthesis step, the resulting powders were characterized in terms of X-ray diffraction (XRD), scanning electron microscopy (SEM), thermogravimetric analysis (TG), Fourier transform infrared spectroscopy (FTIR) and average crystallite size. For the conditions studied, the results showed that the use of marble waste allowed the obtaining of binary mixtures of the type ß-calcium pyrophosphate (ß-Ca2P2O7)/magnesian whitlockite ((CaMg)3(PO4)2). The new biphasic phosphate powders presented average crystallite size in the range of 42.56 nm to 57.55 nm. Thus, marble waste can be recycled to obtain biphasic phosphate bioceramic for medical applications with relevant repercussions on the circular economy.