Influence Of Surface Dissolution On The Flotability Of Ilmenite And Titanaugite

The surface dissolution of fine ilmenite in pulp will change its surface properties and the solution chemistry environment thanks to its large specific surface area, that effects the flotation separation efficiency of ilmenite and titanaugite. The high fine mineral content of Panzhihua ilmenite (-19μm size frcation is about 35%) leads to its complex dissolution behaviour, which will worsen the flotation separation of ilmenite from other silicate gangues sharply. The solubility behaviour of ilmenite and titanaugite surface metal ions was investigated in this paper. The influence of pH regulators type, mineral surface dissolution and solvent ions on the flotation behaviour of ilmenite and titanaugite and its influence mechanism were also researched. The influence factors of flotation separation of ilmenite from titanaugie, the adsorption mechanism of sodium oleate on ilmenite and titanaugite surface were studied and explicated in the flotation system using sodium oleate as collector. The main conclusions and innovation spots of this paper show as follows:(1)Ilmenite shows better flotability than titanaugite. The flotability differences between ilmenite and titanaugite are most remarkable while using H2SO4 adjusting pulp pH value. There is possibility to separate ilmenite from titanaugite in the faintly acid pH range of 5.5-6 and the alkalescence pH range of 9-10.(2) In flotation process, Large numbers of Ca2+,Mg2+,Al3+,Fe (Fe2+, Fe3+) may dissolve into pulp from ilmenite and titanaugite surface, the dissolution rate will reduce with increasing pH, and the metal ions on ilmenite surface shows more solubility greatly than on titanaugite surface. The dissolution in unit of metal ions on mineral surface is Ca2+>Mg2+>Al3+>Fe (Fe2+, Fe3+)>Ti4+, Whereby Ca2+, Mg2+ have remarkable solubility when pH< 11, Al3+ and Fe (Fe2+, Fe3+) have a right amount of rease only when pH<6, Ti dissolves hardly.(3) Under acid condition sodium oleate react mainly with Fe3+ on ilmenite surface, while under alkalimity condition mainly with Ca2+ and Mg2+. For titanaugite, the main activated adsorption sites on its surface are Ca2+ and Mg2+ under acid and alkalinity condition.(4) In flotation process under faintly acid pH condition, the great dissolution of Ca2+ and Mg2+ on titanaugite surface can drastically decrease its flotability, Fe2+ on ilmenite surface dissolve hardly but can be oxidated to Fe3+ largely, that makes ilmenite keep preferably flotability. Under alkalinity condition, the degree of oxidation of Fe2+ on ilmenite surface decrease markedly, Ca2+ and Mg2+ on ilmenite and titanaugite surface which dissolve hardly, can react with sodium oleate more easily to product more steady chemical compounds compared to the reaction under acid condition.So it's necessary to separate ilmenite from titanaugite under faintly acid condition(5.5-6.0).