from the conferences organized by TANGER Ltd.
Calcium carbide (CaC₂) is a vital industrial chemical, central to acetylene production, metallurgy, and chemical synthesis. South Africa, leveraging its coal reserves and metallurgical expertise, has recently entered the global market as a calcium carbide producer. However, the sector faces a major challenge: South Africa’s energy crisis. Calcium carbide production, conducted in electric arc furnaces (EAFs) at 2000–2200 °C, is highly energy-intensive, consuming over 3-4 kWh per kilogram. With rising tariffs and unstable supply forcing many energy-intensive industries to shut down, therefore innovation is required. Recently, substituting anthracite with low-rank coals which offer greater reactivity, usage of lime-coal pellets are amongst several strategies to reduce energy consumption without compromising product quality. The addition of fluxes such as CaO to lower the effective reaction temperature is a plus. This study investigates the combined effects of low rank coal as a reductant, flux addition and pelletized feed for calcium carbide production. Using controlled carbothermal reduction experiments, supported by X-ray fluorescence (XRF), X-ray diffraction (XRD), and Scanning electron Microscopy (SEM), the work evaluates reduction kinetics, slag behaviour, and carbide yield. Response Surface Methodology (RSM) is applied to optimize variables and quantify their impact on energy efficiency. Preliminary insights emphasize slag chemistry as a critical factor in lowering thermal demand while preserving product purity. Results obtained demonstrate that the formation of CaC₂ was effective at relatively low temperature and that the reactivity of the low-rank coal used is good enough to replace generic high-quality coal. By addressing the energy constraints, this research supports industrial resilience while contributing to Sustainable Development Goals (SDG 9 and SDG 12). It advances the case for greener, more sustainable pathways in one of the world’s most energy-intensive industries.
Keywords: Metallurgy, Calcium Carbide, production, review, Low-Rank coal© This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.