Effects　of　common　ions,　namely　hydroxyl　ions　and　carbonate,　on　the　adsorption　and　flotation　of　malachite　with　salicylaldoxime　as　a　collector　was　investigated,　making　use　of　solubility,　micro-flotation,　zeta　potential,　contact　angle,　FTIR,　and　XPS　measurements.　The　results　suggested　that　hydroxyl　and　carbonate　ions　affect　malachite　recovery　through　altering　solubility　of　this　mineral.　Under　conditions　of　lower　solubility,　more　stable　copper　atoms　acted　as　adsorption　sites　for　retaining　salicylaldoxime　on　the　malachite　surface,　and　the　collector　consumed　by　copper　species　in　slurry　was　reduced.　This　allowed　more　collectors　to　get　adsorbed　onto　malachite　surface,　resulting　in　improved　malachite　recovery.　Zeta　potential,　FTIR,　and　XPS　measurements　indicated　that　salicylaldoxime　chemically　adsorbs　onto　malachite　by　forming　copper　salicylaldoxime　chelates,　in　which　two　salicylaldoxime　molecules　react　with　one　copper　atom　by　N　atom　and　the　O　atom　combined　with　benzene　ring.　©　2019　Elsevier　B.V.