We report an alternative technology for the mineralization of CO2 and production of soluble potash fertilizer via thermal activation of the insoluble K-feldspar with industrial waste of CaCl2 with lower energy consumption since the activation temperature was about 800-900 degrees C compared with the conventional temperature of 1300 degrees C. A remarkable K-extraction and CO2 mineralization ratio could be obtained at an appropriate activation temperature and content of additive CaCl2, which possessed the exchange of skeletal K+ with dissociative Ca2+ to form soluble K+ species, the collapse of K-feldspar framework, and the formation of intermediates (e.g., anorthite, pseudowollastonite, and wollastonite) to react with CO2. Characterization results (e.g., XRD, EDS, and SEM) indicated that pseudowollastonite and wollastonite were the major species to fix CO2. Moreover, the reaction principles of the K-extraction and CO2 mineralization were discussed, and a possible mechanism was proposed.