The　nature　of　copper　slag　flotation　is　unique　due　to　the　high　temperature　in　the　flotation　pulp　and　high　metallic　copper　content　in　the　feed.　Despite　its　great　potential　for　valorizing　slag,　copper　slag　flotation　remains　challenging　due　to　the　deactivation　of　traditional　dithiocarbonate　(DTC)　collectors　(e.g.,　butyl　xanthate)　under　high　temperatures.　DTC　collectors　also　respond　poorly　to　the　metallic　copper　due　to　the　difficulty　in　forming　stable　chemical　adsorption.　In　this　work,　possible　deactivation　mechanisms　of　DTC　collectors　are　proposed,　i.e.,　decomposition,　oxidation　and　thermal　desorption.　A　novel　furfuryl　trithiocarbonate　(FTTC)　collector　was　designed　and　synthesized.　Spectral　characterization　using　FT-IR,　H-NMR　and　ion　trap　MS　confirmed　the　molecular　structure　of　the　synthesized　collector　and　its　decomposition,　oxidation　and　polymerization　products　at　55　°C.　The　novel　collector　features　high-temperature　resistance　and　high　metallic　copper　recovery,　as　revealed　by　the　single　mineral　flotation　experiments　of　chalcopyrite,　pyrite　and　metallic　copper　at　both　25　°C　and　55　°C.　The　high　collecting　ability　and　selectivity　of　our　collector　were　explained　by　EHOMO　and　ELUMO　values　using　first-principles　calculations.　Our　work　provides　guidance　for　the　design　of　collectors　exhibiting　high-temperature　resistance　for　copper　slag　flotation,　aims　at　constituting　a　meaningful　contribution　for　unlocking　potential　copper　resources　in　copper　slag.　©　2023　Elsevier　Ltd