Abstract: Palygorskite as an excellent adsorbent material shows a predominant performance on the adsorption of small gaseous polar molecules, which can be remarkably improved by suitable thermal treatment. In this study, the SO₂ removal from the flue gas is investigated with the palygorskite treated at different temperatures. The structural transformation of palygorskite desulfurizer during the heat treatment process was characterized by XRD，BET and TPD. A correlation between structural characteristics and desulfurization performance of palygorskite adsorbent was discussed. Results indicate that, as the heat treatment temperature increases, the micro-crystal structure of palygorskite displays significant step changes, which is suggested to be closely related to the removal of water in different forms from palygorskite surface. The adsorption capacity of SO₂ on palygorskite first increases and then decreases as the heat treatment temperature increases. Based on these results, it can be deduced that the water adsorbed on the surface and that in the pores of palygorskite inhibit the adsorption of SO₂, but the crystalline water is favorable for SO₂ adsorption.

Key words: palygorskite, SO₂, heat treatment, flue gas desulfurization

摘要： 凹凸棒石是一种性能优良的吸附材料，对小分子极性气体具有很好的吸附性，适宜的煅烧处理可以提高其吸附活性。考察了凹凸棒石经过不同条件热处理后对烟气中SO₂吸附性能的变化行为。利用XRD、BET和TPD等方法表征了凹凸棒石脱硫剂在热处理过程中的结构变化。探讨凹凸棒石脱硫剂的结构特性与其脱硫性能的内在关系。研究发现：凹凸棒石的微观晶体结构随热处理温度的升高呈现显著的阶段性变化，而SO₂吸附实验结果表明，这种结构变化的程度与凹凸棒石表面不同形态水分子的脱除密切相关。随着热处理温度的升高，凹凸棒石对SO₂的吸附量呈现先增大后减少的趋势；凹凸棒石的表面吸附水和沸石水的存在占用大量的吸附位，对SO₂的吸附是不利的；而结晶水的存在对SO₂的吸附是有利的。

关键词: 凹凸棒石, SO₂, 热处理, 烟气脱硫