微波辐照辅助煤泥水沉降试验的研究

发布时间：2019-02-13 08:37

【摘要】：目前我国选煤厂煤泥水的处理方式主要是絮凝沉降法。但是,由于我国煤炭质量总体来说比较差,高灰分煤炭占比很大；而且煤炭在洗选时有严重的泥化现象,使煤泥难以沉降。因此,在处理煤泥水时所需添加的药剂量也越来越大,购买絮凝剂的费用也愈来愈高。本试验将微波技术和絮凝沉降技术联合起来组成微波-絮凝技术来处理煤泥水,以降低药剂的使用量,节省药剂的使用费用。论文对淮南市望峰岗选煤厂的煤泥水进行了试验研究。试验首先研究了煤泥水的一些基本性质。通过振动筛等设备对煤泥水进行小筛分,分析-0.5mm煤泥的粒度和灰分分布；用X射线衍射仪分析了煤泥水的矿物组成成分；用激光粒度分析仪分析了-0.045mm煤泥的粒度组成。试验结果表明：-0.045mm粒级的煤泥占86.94%,灰分为56.48%,属于高灰细煤泥。而在-0.045mm粒级的煤泥中又有78.37%的煤泥粒度小于O.01mm,在煤泥水中难以沉降。煤泥中含有高岭石、蒙脱石和石英等粘土矿物,煤泥水的Zeta电位达-25.1mV,使煤泥水中各粘土矿物颗粒互相排斥,形成相对稳定结构,难以沉降。然后,试验又分别研究了单一絮凝剂和单一凝聚剂对煤泥水的处理效果,并确定在不同条件下煤泥水的最佳药剂添加量。之后试验研究了煤泥水在经过微波预处理后加入絮凝剂、凝聚剂后的沉降效果,对药剂添加量、微波辐照功率和微波辐照时间进行三因素三水平的正交试验,试验结果以煤泥水的透光率、初始沉降速度以及澄清后的沉积物高度作为评价指标,通过直观分析确定各因素影响的主次顺序,并确定在不同条件下的最佳因素组合。之后进一步探讨研究了絮凝机理和微波辅助絮凝技术处理煤泥水的机理。实验结果表明：(1)当使用阴离子型聚丙烯酰胺(APAM)絮凝剂处理煤泥水,单一絮凝剂作用时,最佳絮凝剂添加量为1.2ml(0.0048g/L),沉降20min后透光率为86.7%。当使用微波絮凝组合技术时,絮凝剂添加量可以减至0.7ml (0.0028g/L)此时煤泥水的沉降效果与单一絮凝剂添加量为1.2ml (0.0048g/L)时的效果基本一致。(2)当使用明矾(12H2O.KA1(SO4)2)凝聚剂处理煤泥水,单一凝聚剂作用时,最佳凝聚剂添加量为14m1(0.56g/L),沉降20min后透光率为92.4%。当使用微波凝聚组合技术时,凝聚剂添加量可以减至10ml(0.4g/L),此时煤泥水的沉降效果与单一凝聚剂添加量为14ml (0.56g/L)时的效果基本一致。(3)合适的微波功率和辐照时间确实可以改善煤泥水的沉降效果,减少药剂的添加量,降低药剂的使用费用；但微波功率过高或辐照时间过长,又会降低煤泥水的沉降效果。(4)微波加热与絮凝剂组合技术对煤泥水的沉降效果比普通加热与絮凝剂组合技术对煤泥水的沉降效果要好。
[Abstract]:At present, flocculation sedimentation is the main treatment method of coal slurry in coal preparation plants in China. However, because of the poor quality of coal in our country, the high ash content coal accounts for a large proportion, and there is a serious mudding phenomenon in the coal washing and separation, which makes the coal slime difficult to settle. Therefore, the amount of medicament needed to treat coal slurry is increasing, and the cost of buying flocculant is becoming higher and higher. In this experiment, microwave technology and flocculation sedimentation technology are combined to form microwave-flocculation technology to treat coal slime water, in order to reduce the dosage of medicament and save the cost of using medicament. In this paper, the slurry of Wangfenggang Coal preparation Plant in Huainan City was studied. At first, some basic properties of coal slurry are studied. The coal slurry is sifted by vibrating screen, and the particle size and ash distribution of 0.5mm slime are analyzed, and the mineral composition of coal slurry is analyzed by X-ray diffractometer. The particle size composition of-0.045mm slime was analyzed by laser particle size analyzer. The test results show that-0.045mm grain-grade slime accounts for 86.94 and the ash is divided into 56.48 and belongs to high ash and fine slime. However, 78.37% of the slime size in-0.045mm grade slime is less than 0. 01 mm, so it is difficult to settle in the slurry. Clay minerals such as kaolinite, montmorillonite and quartz are found in the slime. The Zeta potential of the slime water is -25.1mV, which makes the clay mineral particles in the slime water repel each other and form a relatively stable structure, which is difficult to settle. Then, the effect of single flocculant and single coagulant on the treatment of coal slime water was studied, and the optimum dosage of slurry water was determined under different conditions. After that, the effect of flocculant and coagulant on the sedimentation of coal slime water after microwave pretreatment was studied. The orthogonal experiments were carried out on three factors and three levels: dosage, microwave irradiation power and microwave irradiation time. The experimental results take the transmittance of coal slime water, the initial settling velocity and the sediment height after clarification as the evaluation indexes, and determine the primary and secondary order of each factor by intuitionistic analysis, and determine the best combination of factors under different conditions. The mechanism of flocculation and microwave assisted flocculation were studied. The results showed that: (1) when the anionic polyacrylamide (APAM) flocculant was used to treat coal slime water, the optimum addition amount of flocculant was 1.2ml (0.0048g/L), and the transmittance after settling 20min was 86.7%. When microwave flocculation combination technology is used, When the addition of flocculant was reduced to 0.7ml (0.0028g/L), the settling effect of slime water was basically the same as that of 1.2ml (0.0048g/L). (2) when 12H2O was used. KA1 (SO4) 2) coagulant for treating coal slime water, The optimum coagulant addition amount is 14m1 (0.56g/L), and the transmittance after settling 20min is 92.4%. When microwave coagulation combination is used, the amount of coagulant added can be reduced to 10ml (0.4g/L), The sedimentation effect of slime water is basically the same as that of 14ml (0.56g/L). (3) the appropriate microwave power and irradiation time can improve the sedimentation effect of slime water and reduce the dosage of medicament. Reduce the cost of using the medicament; However, if the microwave power is too high or the irradiation time is too long, the sedimentation effect of coal slime water will be reduced. (4) the effect of the combination of microwave heating and flocculant is better than that of common heating and flocculant.
【学位授予单位】：安徽理工大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：TD94

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