Research Information System
Minerals Engineering, vol.232, 2025 (SCI-Expanded)
Marble slab cutting residue, known as marble dust, is discharged in the form of sludge in marble processing plants to such an extent that it threatens sustainability in marble mining in terms of environmental concerns. This rejected marble dust has a similar size distribution and mineralogical composition to the commercially available ground calcium carbonate, and therefore has a great potential for evaluation as a value added product. This study investigates the preparation of coated calcium carbonate from marble dust by flotation method. Key variables tested in the coating process included conditioning time and oleic acid (OA) collector concentration. Experimental results showed that recovery of calcite, the sole mineral forming marble dust, in the froth phase increased up to 99 % with longer conditioning time and higher OA concentrations. However, a linear relationship between the active ratio, a measure of coating success, and flotation recovery was not seen. It was found that the active ratio reached its maximum (∼72 %) at a collector concentration around the concentration of critical micelle formation at an optimum conditioning time. The shorter conditioning and lower OA concentration resulted in reduced active ratios due to lower rates of occupation of the suitable surface sites by OA and insufficient interaction between reagent and marble dust particles. It also decreased at higher OA concentrations and by extended conditioning due to physical adsorption as multilayer formation on mineral surface and the oxidation of double bond containing H-C chain.