Characterization and Beneficiation of Indigenous Marble Waste to Remove Siliceous and Ferrous Impurities

ABSTRACT In this study, marble waste (MARWAS) beneficiation was done using thermal, physical, and chemical means. The MARWAS samples collected from dumping yards of Kishangarh and Revdar districts of Rajasthan (India) and Ambaji district of Gujarat (India) were characterized by chemical composition analysis, scanning electron microscopy with energy‐dispersive spectroscopy (SEM), thermogravimetric analysis (TGA), X‐ray diffraction (XRD), and Fourier transform infrared spectroscopy (FTIR). These were then subjected to different beneficiation schemes: (1) calcination followed by slaking and clarification, (2) cationic reverse floatation, and (3) acidulation followed by magnetic separation. These aim to enhance the calcite content by removing siliceous and ferrous impurities. The percentage removal of impurities (PRIs) of these schemes was calculated using chemical composition analysis of purified products. The acid dissolution method (PRI = 93.97%) was more efficient for eliminating siliceous than the reverse floatation method (PRI = 68–73%), while the magnetic separation (PRI = 99.32%) completely removed the ferrous impurities. Although the PRI is just about 45% in the calcination method, it is useful for decomposing the material to eliminate the impurities strongly entangled between the calcite matrix. Purified products (CaO, Ca (OH) 2 , and CaCl 2 ) obtained by these beneficiation schemes can be used to synthesize high‐grade CaCO 3 powder to serve as a feed supplement in poultry, filler in papermaking, and in toothpaste, etc.