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

Abstract

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. This study replaces a single inclination screen surface with a variable inclination (banana-type) for coal gangues classification and separation. After studying the spatio-temporal permeability distribution characteristics of the screen surface with variable and single inclination, it is found that the integrated optical density (IOD) of gangue on the screen surface with variable inclination is 1.5 times of single inclination, and the gangue under the screen with variable inclination is 2.5 times that of a single inclination. The particle penetration position on the variable inclination’s screen surface is in the middle, while the penetration is significant. Moreover, the screening performance and the whole mismatch content are increased by 2.24 and 1.74% points compared with the single inclination, respectively. At the same time, the distribution size is closer to 6 mm. In addition, the range and screen inclination angle adaptation characteristics are studied. When >6 mm, gangue accounts for 55%, a smaller screen inclination gradient should be selected, such as 3° and 4°, matching the productivity of 18t/h, achieving the best screening performance and processing capacity.