The　preparation　of　high-grade　schleelite　concentrates　from　calcite　containing　ores　despite　significant　research　progress　remains　an　important　commercial　challenge.　In　this　study,　Fe(II)　was　selected　as　an　assistant　depressant　and　combined　with　sodium　silicate　(SS)　to　improve　the　flotation　separation　of　scheelite　from　calcite.　Micro-flotation　experiments　of　the　individual　minerals　and　artificially　mixed　minerals　using　oleic　acid　as　a　collector　were　conducted　to　evaluate　the　selective　depression　effect　of　the　SS/Fe(II)　depressant　(the　mixture　of　SS　and　Fe(II)).　The　results　showed　that　the　depressant　mixture　had　a　better　selective　depression　effect　on　calcite　than　SS　alone,　and　the　optimum　mass　ratio　of　SS　to　ferrous　sulphate　was　4:1.　Flotation　tests　using　ore　from　a　commercial　mine　showed　that　a　concentrate　with　a　WO3　grade　of　more　than　62%　and　recovery　greater　than　89%　could　be　achieved　using　SS/Fe(II)　as　the　depressant.　The　depression　mechanism　of　the　SS/Fe(II)　was　investigated　in　detail　using　zeta　potential　measurements　and　X-ray　photoelectron　spectroscopy.　The　results　showed　that　silicate　species　are　more　likely　to　adsorb　on　the　surface　of　calcite　and　produce　a　selective　depression　effect.　The　improved　depression　effect　could　be　attributed　to　the　Fe(II),　which　not　only　increased　the　adsorption　of　the　silicate　species　on　the　calcite　surface,　but　also　improved　the　formation　of　polymeric　silicate　species.　©　2017　Elsevier　Ltd