This　study　presents　a　strategy　for　decreasing　cement-production-induced　CO2　emissions　and　achieving　comprehensive　utilization　of　copper　tailings　(CTs).　This　is　realized　by　preparing　Portland　cement　clinkers　dominated　by　calcium　silicate　minerals　with　a　low　Ca/Si　ratio　through　the　adjustment　of　the　siliceous　(CTs)　to　calcareous　(limestone)　material　ratio.　Differential　scanning　calorimeter　(DSC),　quantify　X-ray　diffraction　(QXRD),　scanning　electron　microscopy　(SEM),　29　Si　nuclear　magnetic　resonance　(NMR),　and　thermogravimetric　(TG)　analyses　were　employed　to　systematically　characterize　the　thermodynamic　behavior　and　mineral　composition　changes　during　the　formation　of　the　low-calcium　Portland　cement　clinker,　and　to　analyze　their　mechanical　properties,　carbonation　products,　and　microstructural　evolution　under　accelerated　carbonation　conditions　(high　pressures　and　CO2　concentration).　CTs　used　as　siliceous　raw　materials　enabled　the　preparation　of　the　low-calcium　Portland　cement　clinkers　with　wollastonite　(CS),　belite　(C2S),　and　rankinite　(C3S2)　as　the　main　mineral　phases　at　1200　degrees　C.　The　Ca/Si　ratio　and　calcination　temperature　markedly　influenced　the　clinker　minerals.　For　a　Ca/Si　ratio　of　＜=　1.0,　CS　was　the　main　clinker　mineral.　When　the　Ca/Si　ratio　was　between　1.0　and　1.4,　the　clinker　comprised　the　C2S-C3S2　system,　with　the　C3S2　content　increasing　as　the　calcination　temperature　increased.　The　prepared　clinker　achieved　a　compressive　strength　of　over　100　MPa　after　carbonation　when　calcined　at　1200　degrees　C　with　a　Ca/Si　ratio　of　1.4.　Carbonation　of　several　low-calcium-content　silicate　minerals　produced　CaCO3,　mainly　as　spherical　vaterite　crystals,　while　silica　in　the　system　formed　silica　gel,　which　formed　a　reticulated　structure　with　CaCO3.