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将粉煤灰与固体氢氧化钠混合后焙烧活化,经酸浸、静置和聚合等步骤制备聚硅酸铝铁絮凝剂,研究了活化条件、静置时间和聚合条件等因素对合成的影响,并对洗煤废水进行处理。结果表明,当碱灰比1.2、活化温度750℃、活化时间1.5h,产物被盐酸完全溶解,静置15min,可获得聚合度较低、活性较强的聚硅酸。正交实验表明,聚合条件对高浊水去除率的影响顺序为:pH值>熟化时间>n(Si):n(Al)>熟化温度>n(Si):n(Fe),最佳聚合条件为:n(Si):n(Al)=1:0.9、n(Si):n(Fe)=1:0.3、p H=2、熟化温度80℃、熟化时间2.5h。洗煤废水处理结果表明,当pH=7,投加量为1g/L,搅拌时间为35min,COD去除率和氨氮去除率最高,分别为95.7%、94.2%,剩余浊度为17NTU,经处理后的废水达到洗煤废水污染物排放标准。
The fly ash was mixed with solid sodium hydroxide and then calcined to activate. After the steps of acid leaching, standing and polymerization, the flocculant was prepared. The influences of activation conditions, standing time and polymerization conditions on the synthesis , And coal washing wastewater treatment. The results showed that polysilicic acid with low degree of polymerization and strong activity could be obtained when the ratio of alkali to ash was 1.2, the activation temperature was 750 ℃ and the activation time was 1.5h. The product was completely dissolved with hydrochloric acid and allowed to stand for 15 minutes. The orthogonal experiment showed that the order of the influence of polymerization conditions on the removal rate of high turbidity water was as follows: pH value> aging time> n (Si): n (Al)> aging temperature> n : n (Si): n (Al) = 1: 0.9, n (Si): n (Fe) = 1: 0.3, p H = 2. The aging temperature is 80 ℃ and the aging time is 2.5h. The results of coal washing wastewater treatment showed that when pH = 7, dosage of 1g / L, stirring time of 35min, COD removal efficiency and ammonia nitrogen removal rate were the highest, 95.7%, 94.2% and the remaining turbidity 17NTU, after treatment Of the wastewater to reach coal washing wastewater pollutant discharge standards.