Herein a novel process for CO₂ capture and utilization suitable for small-medium scale applications is presented. The use of potassium and calcium wastes is proposed as an alternative low-energy path to CO₂ capture and waste valorization. In our work, CaCO₃ precipitation studies were performed to corroborate the feasibility of the novel process described. Reaction time, reaction temperature, molar ratio, and K₂CO₃ initial concentration were varied to analyse their effects on the precipitation efficiency. The purity and main characteristics of the obtained product were physicochemically characterized to evaluate the potential cost of the final solid product by means of Raman spectroscopy, X-ray diffraction, FTIR, and scanning electron microscopy. Results show that promising precipitation efficiencies are obtained in comparison with other waste-valorization and CO₂ capture process, even at room temperatures. High quality calcite was obtained as solid product. Overall our work confirms the technical viability of the proposed route to synergize CO₂ capture and saline waste utilization.