To　recycle　industrial　wastes　sufficiently,　this　work　innovatively　proposed　a　mixture　of　desulfurization　gypsum　and　carbide　slag　as　skeleton　material　to　fabricate　phase-change　composites　with　NaNO3　as　phase　change　material　in　a　mass　ratio　of　5　to　5.　Four　phase-change　composites　were　fabricated　with　different　ratio　of　desulfurization　gypsum　to　carbide　slag　by　the　cold　compression-hot　sintering　method,　and　then　key　thermal　and　mechanical　properties,　microscopic　morphology　and　chemical　compatibility　between　components　were　investigated　in　detail.　Results　show　that　the　mixture　of　desulfurization　gypsum　and　carbide　slag　as　skeleton　material　is　feasible　and　reliable　and　an　optimal　mass　ratio　of　desulfurization　gypsum　to　carbide　slag　was　obtained　to　be　3.5　to　1.5;　the　phase-change　composite　with　the　optimal　mass　ratio　possesses　good　mechanical　strength　of　up　to　134.116　MPa　and　an　energy　storage　capacity　of　483.151　J/g　in　the　range　of　100　to　400　°C,　as　well　as　excellent　thermal　stability　and　chemical　compatibility　between　components,　inside　which　the　NaNO3　is　well　encapsulated.　Moreover,　the　phase-change　composites　fabricated　in　this　work　have　far　low　energy　consumption　and　carbon　dioxide　emission.　©　2024　Elsevier　Ltd