粉煤灰与煤矸石协同焙烧陶粒填料及其 SBR 应用研究

文章通过对粉煤灰、煤矸石固体废物的协同焙烧并对其制备工艺进行深度优化, 最终得到性能较好的陶粒填料, 采用 X 射线衍射仪 (X-ray diffractometer, XRD)、扫描电子显微镜 (scanning electron microscope, SEM)、比表面积检测法 (Brunauer-Emmett-Teller, BET) 等表征手段分析其性能。结果表明: 陶粒材料制备的原料最佳配比 (质量分数) 为煤矸石 45%、粉煤灰 25%、膨润土 20%、氧化铁 5%、氧化钙 4%、氧化镁 1%; 最佳工艺条件为 400 ℃ 下预热 20 min 并在 1100 ℃ 焙烧 30 min, 制备出的陶粒吸水率为 30.2%, 表观密度为 1546.4 kg/m³, 比表面积为 70.1 m²/g, 抗压强度为 328.9 N, 酸损失率为 0.25%, 碱损失率为 0, 该陶粒符合 CJ/T 299—2008 标准; 将所得陶粒投加至序批式活性污泥反应器 (sequencing batch reactor, SBR) 内, 有利于提高微生物挂膜速率, 进而提高反应器处理氨氮和化学需氧量 (chemical oxygen demand, COD) 的效果。该陶粒制备思路可实现煤矸石、粉煤灰固废的大掺量高值化利用, 为解决煤矸石、粉煤灰固废堆积、环境污染等问题提供了理论基础和实验依据。

In this paper, through the synergic roasting of fly ash and coal gangue solid waste and the deep optimization of its preparation process, the ceramsite filler with good performance was finally obtained. X-ray diffractometer (XRD), scanning electron microscope (SEM), Brunauer-Emmett-Teller (BET) and other characterization methods were used to analyze its properties. The results show that the best mass fractions of ingredients are 45% coal gangue, 25% fly ash, 20% bentonite, 5% iron oxide, 4% calcium oxide and 1% magnesium oxide. The optimum conditions are preheating at 400 °C for 20 min and roasting at 1 100 °C for 30 min. The water absorption rate of the resulting ceramite is 30.2%, the apparent density is 1 546.4 kg/m³, the specific surface area is 70.1 m²/g, the compressive strength is 328.9 N, the acid loss rate is 0.25%, and the alkali loss rate is 0. The ceramite conforms to CJ/T 299-2008 standard. The addition of the ceramite into the sequencing batch reactor (SBR) is beneficial to increasing the microbial membrane adhesion rate, thus improving the effect of the reactor in the treatment of ammonia nitrogen and chemical oxygen demand(COD). This idea of ce