煤基炭素的超细粉碎研究

发布时间：2018-06-02 21:52

本文选题：煤基炭素 + 超细粉碎　；参考：《中国矿业大学》2015年硕士论文

【摘要】：煤基炭素主要以优质无烟煤作为原料,经过无烟煤的超纯制备,低温炭化处理以及超细粉碎,最终获得满足技术要求的产品。而煤基炭素的超细粉碎作为整个生产流程的最后一环对最终产品的性能有着重要的意义,本文主要研究煤基炭素的结构性质、超细粉碎工艺参数以及干法助磨等问题。采用激光粒度仪、扫描电镜以及透射电镜等先进仪器设备对煤基低温炭化材料进行物理化学性质表征。主要开展了粒度分析、颗粒形貌结构观测、表面元素官能团分析以及石墨化程度分析,发现其中位径D50为5.14μm,颗粒形状以不规则多角形状为主,化学结构以芳香族C-C结构为主,主体结构周围含有酚羟基C-OH、羰基C=O以及羧基COOH等官能团,碳结构以无序的无定形碳为主并含有少量石墨微晶。在干法粉碎条件下,研究了行星球磨机的主要工艺参数对煤基炭素超细粉碎的影响规律及作用机理。超细粉碎的试验研究表明:(1)在一定的粉碎时间内,粉体的D50随着粉碎时间的延长不断降低,而粉碎时间超过30min以后粉体颗粒会出现团聚现象,不利于颗粒的粉碎;(2)粉碎介质的直径越小,其比表面积越大,与粉体颗粒的接触效率越高,对煤基炭素的粉碎效果越好;当采用5mm直径的粉碎介质时,粉体的D50达到最小值3.11μm;(3)随着磨机转速的增大,粉碎介质对粉体施加的粉碎力越强,但粉体的D50的减小程度并不明显;(4)随着球料比的不断升高,粉体的D50显著减小,当球料比为50:1时,粉体的D50达到2.45μm;(5)在粉体质量一定的条件下,粉碎介质的填充率与粉体的D50并没有很好的相关性。因此,在煤基炭素的超细粉碎中,粉碎时间、粉碎介质的直径以及球料比是能够促进粉体颗粒粒度的不断降低的重要因素。综合以上分析,煤基炭素超细粉碎的合理工艺参数:超细粉碎不锈钢球的直径为3mm,超细粉碎时间为30min,行星球磨机自转转速260r/min,球料比20:1,不锈钢球体积填充率为10.25%。在助磨剂的“强度削弱理论”和煤基炭素表面性质分析的基础上,表面改性剂能够改变煤基炭素颗粒的表面性质以阻止颗粒的团聚和改善粉体的流动性,而高硬度助磨剂能够降低煤基炭素颗粒的强度。超细助磨的试验研究表明:(1)在助磨剂种类的试验中,表面改性剂对粉体的改性作用不能有效促进煤基炭素的超细粉碎,而高硬度助磨剂能够有效降低煤基炭素颗粒的强度,实现颗粒粒度的进一步降低;(2)在助磨剂用量的试验中,助磨剂石英砂的添加量为1.4g时,粉体的中位径达到最小值;(3)助磨剂石英砂的三种添加方式:粉碎前的一次性添加、粉碎过程中每隔10min添加相同质量的石英砂、粉碎过程中每隔10min添加不同质量的石英砂,其中石英砂粉碎前的一次性添加对煤基炭素的助磨效果更好。
[Abstract]:Coal based carbon is mainly made of high quality anthracite as raw material, through the preparation of anthracite, low temperature carbonization and ultrafine pulverization, finally the products which meet the technical requirements are obtained. The ultrafine pulverization of coal based carbon is of great significance to the performance of the final product as the last link in the whole production process. This paper mainly studies the structural properties of coal based carbon, the technological parameters of ultrafine pulverization and dry grinding. The physical and chemical properties of coal based low temperature carbonization materials were characterized by laser particle size analyzer, scanning electron microscope and transmission electron microscope. The particle size analysis, particle morphology observation, surface element functional group analysis and graphitization degree analysis were carried out. It was found that the potential diameter D50 was 5.14 渭 m, the particle shape was irregular polygonal shape, and the chemical structure was aromatic C-C structure. The main structure contains functional groups such as phenolic hydroxyl C-OH, carbonyl Con O and carboxyl COOH. The carbon structure is mainly disordered amorphous carbon with a small amount of graphite microcrystals. Under the condition of dry grinding, the influence of the main technological parameters of planetary ball mill on coal based carbon ultrafine grinding and its action mechanism were studied. The experimental results of ultrafine grinding show that the D50 of the powder decreases with the prolongation of the grinding time, and the agglomeration of powder particles will occur when the crushing time exceeds 30min. The smaller the diameter of pulverizing medium is, the larger the specific surface area is, the higher the contact efficiency with powder particles is, the better the comminuting effect of coal based carbon is, when the pulverized medium with 5mm diameter is used, The D50 of powder reaches the minimum value of 3.11 渭 m ~ (3) with the increase of grinding speed, the comminuting force is stronger, but the decrease of D50 of powder is not obvious.) with the increasing of the ratio of ball to material, the D50 of powder decreases significantly. When the ratio of ball to material is 50:1, the D50 of the powder reaches 2.45 渭 m ~ (5) under the condition of certain powder quality, the filling ratio of the comminuted medium has no good correlation with the D50 of the powder. Therefore, in the ultrafine pulverization of coal based carbon, the grinding time, the diameter of comminuted medium and the ratio of ball to material are the important factors to promote the decreasing of particle size. According to the above analysis, the reasonable technological parameters of coal based carbon ultrafine grinding are as follows: the diameter of ultrafine pulverized stainless steel ball is 3 mm, the crushing time is 30 minutes, the rotation speed of planetary ball mill is 260 r / min, the ratio of ball to material is 20: 1, and the volume filling ratio of stainless steel ball is 10.25. Based on the "strength weakening theory" of grinding aids and the analysis of the surface properties of coal based carbon, the surface modifiers can change the surface properties of coal based carbon particles to prevent the agglomeration of coal particles and improve the fluidity of powders. High hardness grinding aids can reduce the strength of coal-based carbon particles. The experimental study of ultra-fine grinding shows that the surface modifier can not effectively promote the ultrafine pulverization of coal based carbon, while the high hardness grinding aid can effectively reduce the strength of coal based carbon particles in the experiment of the type of grinding aids, and the surface modifier can not effectively promote the ultrafine pulverization of coal based carbon, while the high hardness grinding aid can effectively reduce the strength of coal based carbon particles. In the experiment of grinding aid dosage, when the addition amount of grinding aid quartz sand is 1.4 g, the medium diameter of powder reaches the minimum value of 3) three kinds of adding ways of grinding aid quartz sand are as follows: one time addition before comminution, Quartz sand of the same quality was added at intervals of 10min during crushing and quartz sand of different quality was added at every interval of 10min during the grinding process.
【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】：TQ127.11

【参考文献】