The　activation　of　ground　granulated　blast　furnace　slag　(GGBFS)　using　NaCl,　gypsum,　and　quicklime　frequently　results　in　inadequate　precursor　aluminum　phases,　while　high-carbon　ferrochrome　slag　(HCFS),　despite　its　aluminum　richness,　remains　underutilized.　This　research　addresses　these　challenges　through　the　synergistic　incorporation　of　HCFS　into　GGBFS-based　geopolymers　as　an　aluminum　phase　supplement.　Optimized　mix　designs　were　tested　for　mortar　strength　to　enhance　binder　properties,　ensuring　soundness　and　water　stability.　Hydration　mechanisms　were　investigated　using　XRD,　SEM-EDS,　and　TG-DTG.　Key　findings　include:　(1)　HCFS　sourced　from　Inner　Mongolia　complies　with　safety　standards　for　leaching.　Cr　present　in　Kuzel＇s　salt　within　hydration　products　suggests　further　reduction　of　HCFS＇s　leaching　toxicity;　(2)　The　optimal　mix　achieved　compressive　strengths　of　20.5　MPa,　28.9　MPa,　31.8　MPa,　and　33.6　MPa　at　3,　14,　28　and　60　days,　respectively,　surpassing　Level　II　requirements　for　solid　waste-based　cementitious　materials.　Additionally,　the　geopolymer　exhibited　excellent　soundness　and　achieved　a　high　bend-press　ratio　of　0.30,　and　remarkable　stability　in　freshwater　and　brine　conditions;　(3)　The　primary　hydration　mechanism　involves　aluminum　phases　reacting　with　Ca(OH)2　to　form　C-A-H,　subsequently　reacting　with　gypsum　to　generate　AFt,　promoting　early　strength.　In　alkaline　environments,　C-A-H　reacts　with　NaCl　to　form　Friedel＇s　salt,　which,　at　low　Cl-　concentrations,　transitions　to　Kuzel＇s　salt,　ensuring　longterm　strength;　(4)　Partial　replacement　of　GGBFS　with　HCFS　enhances　HCFS＇s　valorization　while　reducing　costs　by　20.6　%　compared　to　GGBFS-based　geopolymers,　with　strength　reaching　92.9　%　of　32.5　slag　cement　while　manufacturing　cost　is　only　58.1　%　of　those　slag　cement,　demonstrating　engineering　potential.