基于酸性强化的煤粉燃前高梯度磁选脱硫实验研究

发布时间：2018-01-20 19:57

本文关键词： 煤粉新型高梯度磁选机酸性体系磁性强化脱硫　出处：《河南理工大学》2015年硕士论文　论文类型：学位论文

【摘要】：煤粉所含的煤系黄铁矿燃烧过程产生大量二氧化硫,是导致我国环境污染的主要原因。此外,约占我国煤炭储量1/3的高硫煤燃烧又加剧了污染程度。因此,煤粉脱硫意义重大。本文采用燃前干法高梯度磁选技术分别对重庆煤、甘肃煤和洛阳煤进行脱硫实验研究,通过研发新型高梯度磁选机以及在酸性体系下强化煤粉磁性质,以提高煤粉脱硫效果。针对一般磁选机磁场梯度低、聚磁介质堵塞问题,本文研发的新型高梯度磁选机,设计了矩形磁钢-锥形磁介质体系,优化锥角为60°、极距为0.005m;采用旋转盘式结构,可以带动磁介质进入、进出磁场区域,便于分选过程的实施;磁系的装配采用了矩形磁钢同极挤压、异极间隔的装配工艺及工装夹具,避免了磁体的损坏。本文设定酸性体系强化煤粉磁性以提高脱硫率。通过调节溶液的pH值和控制反应温度,依次考察了硫酸浓度、温度、充气速度、氯化铁浓度以及氯化亚铁浓度对煤炭脱硫率的影响,优化了最佳脱硫率下各参数的取值。之后,选用新型高梯度磁选机对磁性强化前后的重庆煤、甘肃煤、洛阳煤进行对比实验。在磁选机最佳参数下,考察了不同粒级煤粉磁选脱硫率,对比分析了磁性强化前后原煤、精煤脱硫率与粒度之间的关系,优化了最佳粒级的选取。重庆煤、甘肃煤以及洛阳煤在粒度为0.074mm时,磁性强化前后煤粉脱硫率分别提高了22.77%,16.93%、19.99%。通过XRD对比分析了磁性强化前后黄铁矿物性变化,实验结果证实了新型高梯度磁选机处理磁性强化煤粉技术的可行性。再者,采用了PFC2D离散元软件,从颗粒水平考察系统量的变化,形象记录磁选过程,揭示梯度磁选机理。最后提出了基于该技术体系下,煤粉干法磁选在火电厂应用的可能性。
[Abstract]:The combustion process of coal pyrite contained in coal powder produces a large amount of sulfur dioxide, which is the main cause of environmental pollution in China. In addition, the combustion of high-sulfur coal, which accounts for about 1/3 coal reserves in China, has aggravated the pollution. Desulfurization of pulverized coal is of great significance. In this paper, the desulfurization experiments of Chongqing coal, Gansu coal and Luoyang coal were carried out by dry high gradient magnetic separation before combustion. In order to improve the desulfurization effect of pulverized coal, a new type of high gradient magnetic separator was developed and the magnetic properties of pulverized coal were strengthened in acid system. A new type of high gradient magnetic separator is developed in this paper. The rectangular magnetic steel-cone magnetic medium system is designed. The optimum cone angle is 60 掳and the polar distance is 0.005 m. With the structure of rotating disk, the magnetic medium can be driven in and out of the magnetic field area, which is convenient to carry out the sorting process. The assembly technology and fixture of rectangular magnetic steel are used in the assembly of magnetic system, such as the same pole extrusion of rectangular magnetic steel and the interval between different poles. In order to improve the desulfurization rate, the acid system was set up to strengthen the magnetic properties of coal powder to improve the desulfurization rate. By adjusting the pH value of the solution and controlling the reaction temperature, the concentration of sulfuric acid, the temperature and the charging rate were investigated in turn. The influence of the concentration of ferric chloride and ferrous chloride on the desulfurization rate of coal was optimized. After that, the new type of high gradient magnetic separator was used to treat the coal of Chongqing and Gansu before and after the magnetic strengthening. Under the optimum parameters of magnetic separator, the desulphurization rate of different particle grade coal powder was investigated, and the relation between the desulfurization rate and particle size of raw coal and clean coal before and after magnetic strengthening was compared and analyzed. When the particle size of Chongqing coal, Gansu coal and Luoyang coal is 0.074 mm, the desulfurization rate of pulverized coal before and after magnetic strengthening is increased by 22.77% and 16.93% respectively. 19.99. the physical properties of pyrite before and after magnetic strengthening were compared and analyzed by XRD. The experimental results confirmed the feasibility of treating magnetically enhanced pulverized coal by a new type of high gradient magnetic separator. The PFC2D discrete element software is used to investigate the change of the system quantity from the particle level, to record the magnetic separation process vividly, and to reveal the gradient magnetic separation mechanism. Possibility of coal dry magnetic separation in thermal power plant.
【学位授予单位】：河南理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TD457

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