高级检索

煤矸石香蕉型等厚筛粒群时空透筛分布规律及适配特性研究

Research on the distribution law of spatio-temporal permeability screening and adaptation characteristics of banana-type equal-thickness classification of coal gangues

  • 摘要: 筛分是减少环境污染和资源浪费,促进煤矸石固废资源综合利用的一项重要技术。单一倾角振动筛在煤矸石分级过程中,容易导致物料在入料端集中堆积,松散和分层困难,分级效果恶化。利用变倾角筛面代替单一倾角筛面,用于研究煤矸石的分级。采用高速动态测试分析系统及Image-Pro Plus(IPP)图像分析系统研究变倾角和单一倾角筛面的料群时空透筛分布特征,发现变倾角筛面给料端与排料端位移与运动速度幅值差值大于单一倾角,变倾角筛上煤矸石的吸光度是单一倾角的1.5倍,筛下吸光度是相对应数值的2.5倍,说明变倾角筛面更利于煤矸石的松散分层,且物料分布更加均匀。采用多段采样多层分级法对筛分产品进行分析,将筛面从入料端至排料端划分为Ⅰ、Ⅱ、Ⅲ、Ⅳ、V段,发现颗粒在单一倾角与变倾角筛面上的透筛位置均居于中部,但变倾角筛面透筛量更大;筛下各段产品主导粒级为6~3 mm和−3 mm,−3 mm粒级的煤矸石占产品产率在单一倾角和变倾角筛分过程中的顺序依次为Ⅱ>Ⅰ>Ⅲ>Ⅳ>V,Ⅱ>Ⅲ>Ⅰ>Ⅳ>V,透筛率均依次为Ⅱ>Ⅲ>Ⅰ>Ⅳ>V。再者,与单一倾角相比,变倾角的筛分效率和总错配物百分比分别提高2.24%与1.74%,分配粒度更接近6 mm。此外探索了煤矸石处理能力与筛面倾角的适配特性及对筛分效果的影响规律。当>6 mm的粗颗粒占比55%时,应选择较小的筛面倾角梯度,比如3°和4°,相应的生产能力为18 t/h,此时能保证获得最佳的筛分性能与处理能力。本研究将提高煤矸石的分级效果和固废资源的综合利用率,为煤矸石的定向转化与固废资源的高附加值综合利用提供新途径和技术支撑。

     

    Abstract: Screening is an important technological challenge to alleviate environmental contamination and resource waste and enhance the large-scale synthesis of coal gangue solid waste resources. Single inclination vibrating screen for coal gangue grading process can easily cause concentrated accumulation of materials at the infeed end, loosening and stratification difficulties, and deterioration of grading effect. A single inclination screen surface is replaced by a variable inclination (banana-type) for coal gangues classification and separation. High-speed camera testing and IPP image analysis system was used to study the spatio-temporal permeability distribution characteristics of material groups on the screen surface with variable and single inclination. It is found that the difference in displacement and motion velocity amplitudes between the feeding end and the discharging end of the variable inclination is greater than that of single inclination. The integrated optical density (IOD) of gangue on the screen surface with variable inclination is 1.5 times that of single inclination, and the gangue under the screen with variable inclination is 2.5 times that of single inclination. It indicates that the inclined screen surface is more conducive to the loosening and stratification of the coal gangue, where the material distribution is more uniform. Multi-stage sampling and multi-layer classification method was adopted to analyze the screened products. It shows that the penetration position of particles on single and variable inclination screen surfaces are both located in the middle, while the penetration amount of the latter is more significant. The dominant particle sizes of the undersized products are 6−3 mm and −3 mm, and the order of the proportion of coal gangue of −3mm in the product yield during the single and variable inclination screening processes is II>I>III>IV>V and II>III>I>IV>V, and the penetration rate are both II>III>I>IV>V. Moreover, the screening efficiency and the whole misplaced content are increased by 2.24% and 1.74% compared with the single inclination, respectively. At the same time, the distribution size is closer to 6 mm. Besides, the gangue and screen inclination angle adaptation characteristics are studied. When the coal gangue >6 mm accounts for 55%, a smaller screen inclination gradient should be selected, such as 3° and 4°, matching the productivity of 18 t/h, achieving the best screening performance and processing capacity. This study will improve the classification effect of coal gangue and the comprehensive utilization rate of solid waste resources, providing new ways and technical support for the directional transformation of coal gangue and the high value-added comprehensive utilization of solid waste resources.

     

/

返回文章
返回