石灰拜耳法生产氧化铝的脱硫研究

【作者】 蒋洪石；

【导师】 吴贤熙；

【作者基本信息】 贵州大学 ， 化学工艺， 2007， 硕士

【摘要】 本文从铝土矿资源的可持续性发展、加快构建资源节约型社会角度出发，顺应竞争日趋激励的世界氧化铝工业发展的要求，寻求使用的高硫低铝硅比铝土矿研究简单的、经济的氧化铝生产方法，提出石灰拜耳法生产氧化铝的脱硫研究的课题。本课题首先通过配制铝酸钠溶液，论述了NaOH与Al（OH）₃摩尔比分别为1：1、1.5：1、2：1、2.5：1和3：1配制的铝酸钠溶液的稳定性和碱液浓度对脱硫效果的影响，实验证明：当配制铝酸钠溶液稀释3～4倍时，脱硫效果较好，脱硫率达75％左右；同时讨论石灰添加量对脱硫效果的影响，通过实验证明选择最佳的石灰添加量，是获得较好的脱硫效果的前提条件，当石灰的添加量达到8～8.5g左右，脱硫率最佳达到83％。通过对反应产物XRD分析发现，反应产物中均没有一元型含水硫铝酸钙和三元型含水硫铝酸钙，脱硫产物只有CaSO₄。反应温度是铝酸钠溶液脱硫效果的主要影响因素，同时也是制约水合硫铝酸钙生成的影响因素，当反应温度为70～75℃左右时，脱硫率最佳达到85％，通过XRD衍射分析，反应产物中水合硫铝酸钙的含量为78％左右。反应时间也是影响脱硫效果的重要因素之一，当反应时间在40～50min左右时，脱硫效果最好，脱硫率达86％左右，通过XRD衍射分析，反应产物中一元型含水硫铝酸钙和三元型含水硫铝酸钙的含量为96.4％，脱硫效果显著。通过正交实验对铝酸钠溶液脱硫效果影响的因素进行研究，当铝酸钠溶液中SO₄^2-浓度为24g／L，通过实验的极差分析给出最佳脱硫工艺条件：铝酸钠溶液中碱液浓度为30.40g／L，石灰添加量为8.5g、反应温度为70℃、反应时间为50min，其最佳脱硫率为87.42％。通过X射线衍射、差热分析、红外光谱分析等方法研究，证明了水合硫铝酸钙的存在，为石灰拜耳法高效脱硫提供理论依据。更多还原

【Abstract】 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.更多还原