0 引言
1 实验部分
1.1 材料、试剂及仪器
1.2 低品位凹凸棒石酸改性方法
1.3 性能评价及表征测试方法
2 结果与讨论
2.1 双酸改性对凹凸棒石白度和脱色率的影响
Fig. 1 Effect of acid activation on the whiteness and the decolorization rate of soybean oil图1 酸活化工艺对凹凸棒石白度和脱色率的影响 |
2.2 微观形貌的分析
Fig. 2 SEM pictures of attapulgite clay (left) and acid activated attapulgite (right)图2 凹凸棒石原矿(左)和酸化凹凸棒石(右)的SEM图片 |
2.3 物相结构特征与化学成分的分析
Fig. 3 XRD patterns of attapulgite clay and acid activated attapulgite图3 凹凸棒石原矿和酸化凹凸棒石的XRD图谱 |
Table 1 Chemical composition, whiteness and decolourization rate of the attapulgite表1 不同活化条件下得到的凹凸棒石的化学组成、白度和脱色率 |
Sample | Content / % | Whiteness / % | Decolourization rate / % | ||||||||
---|---|---|---|---|---|---|---|---|---|---|---|
SiO2 | MgO | Al2O3 | Fe2O3 | CaO | K2O | TiO2 | MnO | P2O5 | |||
ATP | 14.13 | 20.35 | 1.82 | 1.31 | 36.45 | 0.18 | 0.15 | 0.40 | 0.16 | 78.4 | 6.94 |
ATP-S | 43.57 | 4.29 | 4.95 | 2.62 | 17.38 | 0.62 | 0.46 | 0.03 | 0.02 | 75.7 | 22.35 |
ATP-SH | 72.64 | 5.85 | 7.54 | 3.88 | 0.31 | 1.00 | 0.74 | 0.03 | 0.02 | 71.8 | 76.38 |
ATP-H | 65.37 | 10.17 | 9.29 | 5.37 | 0.34 | 1.24 | 0.73 | 0.07 | 0.03 | 64.3 | 78.82 |
ATP-HS | 77.02 | 4.70 | 7.16 | 3.39 | 0.29 | 0.96 | 0.78 | 0.02 | 0.01 | 69.9 | 54.93 |
ATP-T | 76.88 | 4.55 | 6.44 | 2.67 | 0.82 | 0.88 | 0.73 | 0.02 | 0.02 | 72.2 | 12.55 |
2.4 吸附-脱附等温线及比表面积分析
Fig. 4 The N2 ad/desorption isotherms (a) and pore distribution analysis (b) of attapulgite clay and acid activated attapulgite图4 凹凸棒石原矿和酸化凹凸棒石的N2吸附-脱附等温线(a)和孔径分布图(b) |
Table 2 The textural properties of attapulgite clay and acid activated attapulgite表2 凹凸棒石原矿和酸化土的比表面积和孔容积 |
Sample | Surface area / (m2/g) | Pore volume / (cm3/g) | Dp / d | |||||
---|---|---|---|---|---|---|---|---|
SBET | Smicroa | Sextb | Vtotalc | Vmicroa | Vmeso | |||
ATP | 3.90 | 0.77 | 3.13 | 0.012 | 0.000 | 0.012 | 3.41 | |
ATP-H | 262.81 | 88.73 | 174.08 | 0.662 | 0.040 | 0.622 | 3.82 | |
ATP-S | 163.58 | 40.06 | 123.52 | 0.500 | 0.019 | 0.481 | 3.42 | |
ATP-T | 281.91 | 112.10 | 169.82 | 0.795 | 0.048 | 0.747 | 3.42 | |
ATP-SH | 280.96 | 63.84 | 217.12 | 0.732 | 0.029 | 0.703 | 3.83 | |
ATP-HS | 309.58 | 111.31 | 198.27 | 0.739 | 0.050 | 0.689 | 3.41 |
Note: a from t-plot method; b${{S}_{\text{BET}}}={{S}_{\text{micro}}}+{{S}_{\text{ext}}}$; c ${{V}_{\text{total}}}={{V}_{\text{micro}}}+{{V}_{\text{meso}}}$, from the amount adsorbed at the relative pressure of 0.97. |