The　theoretical　simulations　and　experiments　on　metal　separation　in　complexation-precipitation　system　of　Me(Ni,　Co,　Mn)-OH--NH3-CO32-　were　carried　out.　The　Gibbs　free　energy　change　Delta　G　for　metal　precipitation　reactions　was　calculated.　The　Delta　G-pH　curves　showed　that　the　precipitation　difficulty　order　was　Mn　＞　Co　＞　Ni　at　pH　range　of　8-11.　Separation　experiments　indicated　that　Mn　and　Co　were　able　to　precipitate　successively　in　solution　of　different　compositions　mainly　in　the　forms　of　carbonates.　pH,　initial　carbonate　concentration　[C]　and　initial　ammonia　concentration　[N]　had　different　influence　on　Ni,　Co　and　Mn　precipitation　behaviors:　the　separation　effect　was　best　at　about　pH　10;　[C]　had　little　effect　on　the　metal　separation　in　the　[C]　range　of　0.05-0.4　mol/L;　changing　[N]　could　regulate　precipitation　step　by　step,　as　Ni　in　solution　and　Mn/Co　in　precipitate　at　[N]　1　mol/L,　and　Ni/Co　in　solution　and　Mn　in　precipitate　at　[N]　2.5　mol/L.　The　experimental　results　basically　consisted　with　the　theoretical　predictions.　The　Ni　solution　after　Mn/Co　precipitation　could　be　electrodeposited　to　obtain　Ni　metal.　Finally　a　separation　process　in　complexation-precipitation　system　of　Me(Ni,　Co,　Mn)-OH--NH3-CO32-　characterized　by　the　theoretical　simulation　was　proposed,　of　which　the　Ni,　Co　and　Mn　precipitation　could　be　predicted　or　controlled　by　flexibly　importing　parameters　of　[C],　[N],　pH,　etc.　The　process　can　provide　a　reference　to　metal　comprehensive　recovery　from　similar　nickel-cobalt　secondary　resources.　(C)　2013　Elsevier　B.V.　All　rights　reserved.