【作者】 苏继成；

【导师】 衣守志；

【作者基本信息】 天津科技大学 ， 化学工艺， 2004， 硕士

【摘要】 本文从粉煤灰的活化，即提高粉煤灰中铁铝酸溶活性入手，在总结他人方法的基础上，提出了用Na₂CO₃融熔来提高粉煤灰酸溶活性，并得到了较为理想的结果。在粉煤灰活化的基础上，本文重点就粉煤灰无机絮凝剂的制备进行了系统的实验研究，并将其用于造纸废水的处理，取得了满意的效果。主要研究内容和结论如下： 1．研究了以一定浓度的盐酸为溶剂，助溶剂NaCl、NaF的加入量对粉煤灰中Al₂O₃浸出率的影响。结果表明，以盐酸为溶剂，助溶剂NaCl的加入量对粉煤灰中铝铁的浸出率没有影响；而助溶剂NaF的加入量对粉煤灰中铝铁的浸出率有明显的影响，随加入量的增加先使浸出率增加，当NaF的加入量超过15.8％以后，又有所下降。Al₂O₃最高浸出率为20.45％。 2．研究了用CaO与粉煤灰高温烧结，再用一定浓度的盐酸浸取，来提高粉煤灰中Al₂O₃浸出率的方法，结果表明，在850℃条件下CaO的加入量对浸出率提高有一定影响，Al₂O₃浸出率为14.3％。 3．研究了用Na₂CO₃与粉煤灰高温融熔，再用一定浓度的盐酸浸取，来提高粉煤灰中Al₂O₃浸出率的方法，结果表明，在850℃条件下Na₂CO₃能明显提高粉煤灰中铝铁的浸出率，Na₂CO₃加入量在25％时，Al₂O₃浸出率为53.2％。 4．在粉煤灰活化的基础上，研究了以粉煤灰、硫铁矿烧渣为主要原料通过一系列的碱浸和酸浸制备无机高分子絮凝剂聚硅酸铝铁（PAFSi）。在粉煤灰碱浸过程中反应温度和碱灰比为主要影响因素，实验结果表明，在碱灰比为0.74：1（OH／（0.5Si+Al）=1：1.5），控制温度150℃，恒温1h，Al的浸出率高达60.9％。在硫铁矿烧渣的酸浸过程中反应温度为主要影响因素，随反应温度的提高，铁的酸浸出率也明显提高，用6M盐酸106℃下回流30min，铁的浸出率可达99％以上。 5．在粉煤灰无机絮凝剂的制备实验中，通过单因素实验研究了Al、Fe和Si的不同配比、制备絮凝剂的pH值、熟化温度、熟化时间等对絮凝剂絮凝性能的影响。通过正交试验，确定了制备粉煤灰无机絮凝剂PAFSi的优化工艺条件，即Si：Al：Fe=1：0.7：0.5、絮凝剂的pH值为1.1、熟化温度为60℃、熟化时间为1h。 6．用制备的絮凝剂与市售聚合氯化铝和聚合硫酸铁进行了絮凝效果对比实验，结果表明，在模拟水样絮凝实验中，粉煤灰制备的PAFSi絮凝剂具有很强的除浊能力；在处理造纸废水时，粉煤灰无机絮凝剂的色度、浊度、COD_Dr去摘要Abstract除率分别达到99.1%、98.5%和65.6%。更多还原

【Abstract】 The activation of the coal fly ash was studied in this paper firstly. And the activation methods of other researchers were summarized. The Na2CO3 melting methods which are used to increase the acid lixiviate property of fly ash were put forward. Based on the activation of the fly ash, series experiments of synthesis and application in papermaking wastewater of the fly ash coagulant were studied. And satisfied results were obtained. The main studies and conclusions were as followed:1. The influence of the quantity of solubility promoter, NaCl and NaF, to solubilization ratio of Al2O3 from fly ash was studied when the HC1 is used as solvent. The results suggested that the quantity of NaCl, which was added to the fly ash, has no effect on the solubilization ratio of aluminum. But the quantity of NaF has obvious influence on the solubilization ratio of aluminum. The trend is that with the quantity’s increasing of NaF the solubilization ratio of aluminum also increased. The highest solubilization ratio is 20.45%. When the quantity is over 15.8%, the ratio begins to decline.2. Hydrochloric acid is used to solubiliz the fly ash after it is baked with CaO in the muffle. The aluminum chloride is obtained. The results suggested that the quantity of CaO has influence on the solubilization ratio of aluminum under the temperature of 850 C. The highest solubilization ratio is 14.3%.3. The fly ash is baked with Na2CO3 in the muffle, and then the sinter is solubilized by hydrochloric acid. The aluminum chloride is obtained at last. The results showed that the quantity of Na2CO3 has distinctly influence to the solubilization ratio of aluminum under the temperature of 850 C. When it was added, to 25%, the highest solubilization ratio is obtained by 53.2%.4. By using fly ash and pyrite roasting residue as primary raw materials, the polymeric aluminum ferric silicate (PAFSi) is synthesized by a series of sodium dissolves and acid dissolves procedure on the base study of the activation of fly ash. During sodium dissolves process, the sodium hydroxide to fly ash ratio and the reaction temperature are the main effects of the solubilization ratio of silicon and aluminum. Experiment results indicated that the optimum condition is alkali/ash =0.74:1 (OH/(0.5Si+Al))=2:3, molar ratio), temperature=150 C, reaction duration =lh. A highest solubilization ratio is obtained by 60.9% under the optimum condition. During pyrite roasting residue acid dissolves process, the main reaction factor is temperature, with the temperature’s increase, so do the ferric solubilization ratio. When the reaction temperature is up to 106 C, by using 6M hydrochloric acid. The ferric solubilization ratio will rapidly increased to 99% within 0.5 hour.5. During the study of the synthesize of the inorganic flocculants made from fly ash, the ratio between Al, Fe and Si, the pH value of the flocculants, the ageing temperature and duration and so on were studied by single factor experiments. Through orthogonal experiments, the optimums conditions of synthesize of the inorganic flocculants (PAFSi) are found. They are as follows, Si:Al:Fe=1: 0.7:0.5, pH value of the flocculants=1.1, ageing temperature=60 C, ageing time=1hour.6. A series jar tests were take by using the synthesized flocculants (PAFSi), polymeric aluminum chloride (PAC) and polymeric ferric sulfate (PFS). The results suggested that compared with PAC and PFS, PAFSi has the strongest turbidity removal ability during the treatment to the simulative wastewater. The fly ash inorganic flocculants (PAFSi) also has excellent manifest in treating papermaking wastewater, and the removal ratio of chroma, turbidity and CODcr is respectively up to 99.1%, 98.5%, and 65.6%.更多还原