粉煤灰旋转摩擦电选脱碳的试验研究

发布时间：2018-06-27 16:32

本文选题：粉煤灰 + 旋转摩擦电选　；参考：《中国矿业大学》2015年硕士论文

【摘要】：目前,火力发电厂多采用燃煤发电,产生大量粉煤灰,造成很大的环境污染。为降低粉煤灰大量堆积引起的污染,减少粉煤灰中包含的有用资源的浪费,其综合利用也越来越引起人们的关注,本论文用旋转摩擦电选对粉煤灰进行了脱碳加工方面的研究。摩擦电选能够有效地分选小于74μm不同性质的矿物颗粒,粉煤灰中碳和灰颗粒通过自摩擦以及与摩擦材料间的摩擦,分别带上不同极性的电荷,从而在静电场中可以实现分选。该方法干法操作、工艺简单、不需要庞大的废水处理及产品脱水系统,受到越来越多的研究人员关注。本论文综述了电选的理论基础和粉煤灰电选技术;对粉煤灰样品基本性质进行了测定,并对不同粒级的电性质进行了分析;进行了对粉煤灰脱碳分选效果有一定影响的包括给料速度、摩擦轮转速、进风风速、矫正流风速等7个因素的单因素试验;以单因素试验结果为基础进行了因素水平优化试验,确定了最佳试验条件。粉煤灰中未燃尽碳和灰的电性质研究证明:颗粒越小,未燃尽碳和灰的电阻率越大、介电常数越小,摩擦带电过程中电子回流小,摩擦带电荷质比大,有利于实现分选;反之,则不利于实现摩擦电选。单因素试验表明:充电电压对分选效果影响最不明显,给料速度影响较明显,其余的进风风速、摩擦轮转速、矫正流风速、极板电压及收集室宽度5个因素则影响明显,各因素最佳水平按前面介绍顺序为,0KV、1.38g/s、2.0m/s、4400r/min、3m/s、-35KV、(1,2,3cm);分析优化试验结果认为:负极板产物产率、烧失量及脱碳效率指数三个响应值都适宜采用二次方程模型进行拟合,模型中同一因素对不同响应值的显著性有所差别,但E始终是对各响应值影响最显著的,最佳试验条件为(由A到E)1.2m/s、5050r/min、2.0m/s、-35KV、(1,2,3cm)。
[Abstract]:At present, coal-fired power generation is mostly used in thermal power plants, resulting in a large amount of fly ash, resulting in great environmental pollution. In order to reduce the pollution caused by mass accumulation of fly ash and to reduce the waste of useful resources contained in fly ash, the comprehensive utilization of fly ash has attracted more and more attention. Friction electroseparation can effectively separate mineral particles with different properties less than 74 渭 m. Carbon and ash particles in fly ash can carry different polarity charges through self-friction and friction with friction materials, thus the separation can be realized in electrostatic field. This method has been paid more and more attention because of its simple process and no need for large wastewater treatment and product dehydration system. In this paper, the theoretical basis of electroseparation and the technology of fly ash electroseparation are summarized, the basic properties of fly ash samples are determined, and the electrical properties of different particle levels are analyzed. The single factor tests including feed speed, friction wheel speed, inlet wind speed and corrected flow velocity were carried out on the basis of the results of the single factor test, and the factor level optimization tests were carried out based on the results of the single factor test, which had certain influence on the decarburization effect of fly ash, including feed speed, friction wheel speed, inlet wind speed and rectified flow velocity. The optimum test conditions are determined. The study on the electrical properties of unburned carbon and ash in fly ash shows that the smaller the particle size, the greater the resistivity of unburned carbon and ash, the smaller the dielectric constant, the smaller the electron reflux in the process of friction charging, and the larger the charge / mass ratio of friction band, which is beneficial to the separation. It is not conducive to the realization of friction electrical separation. The single factor test shows that the charge voltage has the least effect on the sorting effect, the feed speed is more obvious, and the other five factors, such as inlet wind speed, friction wheel speed, corrected flow velocity, plate voltage and collecting chamber width, have obvious effects on the separation efficiency. The optimum level of each factor is as follows: 1.38g / s = 2.0m / s / s = 4400r / min / min ~ 3m / min ~ (-3) KV, (1 / 2 ~ 3cm). The results of the optimization test show that the three response values of negative plate product yield, loss of burning and decarbonization efficiency index are all fitted by quadratic equation model. In the model, the same factor had different significance to different response values, but E always had the most significant influence on each response value. The best test condition was 1.2 m / s / s 50 ~ (50) r / min ~ (2.0) m / s ~ (-1) / s ~ (35) KV, (1 / 2 ~ (3) cm).
【学位授予单位】：中国矿业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TD94

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