Lime Bayer Process Production Of Alumina Desulfurization

This article studies new and economic high sulfuric bauxite production method from the perspective of the continuable development of bauxite and the construction of resource-saving society, which complies with increasingly competitive alumina industrial development. Exploiting high sulfuric bauxite mine, the paper proposes the topic of the lime Bayer producing desulfurization of oxide-aluminum. This article studies new and economic high sulfuric bauxite production method.This topic through preparation of sodium aluminates solution, discussing NaOH and Al(OH)₃ ratio of 1:1,1.5:1,2:1,2.5:1,3:1 sodium aluminates solution stability and the concentration of alkali to the effecting of desulphurization, the experiment proved that when the originally preparation of sodium aluminates solution to dilute 3～4 times, the desulphurization effect is more better, the desulphurization rate reaches about 78%.Discussing lime additive on the desulfurization efficiency simultaneity, it is proved by experiments that lime is good additive. The desulphurization rate reaches about 83.5%When the lime is added to 8～8.5g around. Through the XRD diffraction analysis, the reaction products are not Ca4Al₂SO₁₀·12H₂O and Ca₆Al₂(SO)₃(OH)₁₂, the desulfurization product has only CaSO₄.The reaction temperature is main influencing factors of the Ca₄Al₂SO₁₀·12H₂O synthesis; increasing temperature is propitious to improving reaction speed of the Ca4Al₂SO₁₀·12H₂O synthesis, when the reaction temperature is 70-75℃, the desulphurization rate reaches about 85%, through the XRD diffraction analysis, the reaction product of Ca₄Al₂SO₁₀·12H₂O content of 78%.Reaction time is one of the important factors desulfurization efficiency, when the reaction time is about 40⁵0min, the desulfurization is the best; the desulphurization rate reaches about 85%. Through the XRD diffraction analysis, the reaction product of Ca₄Al₂SO₁₀·12H₂O and Ca₆Al₂(SO)₃(OH)₁₂ contents of 96.4%, the desulfurization efficiency significantly.Through the design orthogonal experiment on the factors of desulfurization effect, through analyzing of the experimental found the best desulfurization conditions: sodium aluminates solution concentration is 30.40g/L, lime additive is 8.5g, the reaction temperature of 70℃, reaction time of 50 min, the desulphurization rate reaches about 87.42%.Through X-ray diffraction and differential thermal infrared spectral method proved reaction product of Ca₄Al₂SO₁₀·12H₂O and Ca₆Al₂(SO)₃(OH)₁₂ presence, at the same time providing theoretical basis for desulfurization efficiency in Bayer lime method.