Beneficiation and Characterization of High-Purity Nano Calcite from a Carbonaceous Mineral

This study investigated the beneficiation of calcite ore to obtain a high-purity nano calcite suitable for industrial applications using the froth flotation process. The physicochemical properties of untreated and treated calcite were analyzed and compared with Nigeria Industrial Standards (NIS). X-ray fluorescence (XRF) analysis was employed to assess the elemental composition of the purified calcite across varying pH levels. The results showed significant improvements in treated calcite, including increased purity (72.5%) and higher calcium oxide content (25.5%), surpassing NIS requirements. These improvements were attributed to the effectiveness of the froth flotation process in removing impurities, yielding a higher-grade product. The treated nano calcite displayed a pH value of 8.4, meeting the NIS range of 7.5–10.5, and a density within the standard range of 1.5–1.6 g/cm³. The XRF analysis revealed pH-dependent trends, such as increased elemental concentrations at lower pH levels, while variations in scavenger and cleaner concentrations showed no distinct patterns. Additionally, particle size analysis revealed a bimodal distribution, with two dominant size distributions: smaller nanoparticles (~1–10 nm) and larger particles (~100 nm), with the latter dominating the volume distribution. X-ray diffraction (XRD) analysis confirmed calcite as the primary mineral phase, evidenced by sharp, well-defined peaks indicative of excellent crystallinity. Minor phases such as quartz, lime, and muscovite were also identified. This study emphasizes the potential of local calcite deposits to reduce import dependency, lower production costs, and drive economic growth.