CAJ | 학술논문

根据煤粉中煤和伴生矿物的摩擦荷电特性来设计摩擦荷电系统，使煤和伴生矿物充分异性荷电，是强化煤粉摩擦荷电过程、提高分选效率的关键。以石英、高岭土、方解石这3种煤粉中的主要伴生矿物作为研究对象，利用铜管中气力输送过程使颗粒摩擦荷电，并使用法拉第筒和静电计测量铜管出口颗粒的荷电量，研究了气速、给料速度、管道长度对其摩擦荷电特性的影响。结果表明，石英、高岭土、方解石与铜管摩擦均带负电；各伴生矿物的荷质比均随气速增大而增大，随给料速度增大而减小，随管道长度增加而增加；相同实验条件下，方解石与铜管摩擦后荷质比最大，高岭土荷质比次之，石英荷质比最小，功函数大小为方解石＞高岭土＞石英＞铜。基于连续碰撞荷电机理，同时考虑气速、给料速度、管道长度的影响，建立了稀相气力输送过程颗粒摩擦荷电模型。3种伴生矿物颗粒荷质比的模型计算值与实验值的相关系数均大于0.95，平均相对偏差均小于10%。实验结果表明模型具有较高的预测精度，可以为摩擦荷电系统的设计提供指导。
근거매분중매화반생광물적마찰하전특성래설계마찰하전계통，사매화반생광물충분이성하전，시강화매분마찰하전과정、제고분선효솔적관건。이석영、고령토、방해석저3충매분중적주요반생광물작위연구대상，이용동관중기력수송과정사과립마찰하전，병사용법랍제통화정전계측량동관출구과립적하전량，연구료기속、급료속도、관도장도대기마찰하전특성적영향。결과표명，석영、고령토、방해석여동관마찰균대부전；각반생광물적하질비균수기속증대이증대，수급료속도증대이감소，수관도장도증가이증가；상동실험조건하，방해석여동관마찰후하질비최대，고령토하질비차지，석영하질비최소，공함수대소위방해석＞고령토＞석영＞동。기우련속팽당하전궤리，동시고필기속、급료속도、관도장도적영향，건립료희상기력수송과정과립마찰하전모형。3충반생광물과립하질비적모형계산치여실험치적상관계수균대우0.95，평균상대편차균소우10%。실험결과표명모형구유교고적예측정도，가이위마찰하전계통적설계제공지도。
Triboelectrification system should be designed based on the understanding of triboelectrification characteristics of coal and its associated minerals. Making minerals fully charged of different polarities is the key to strengthening triboelectrification process and enhancing separation efficiency. Pneumatic triboelectrostatic experiments were performed in a copper pipe, and a Faraday cup connected with an electrometer was used to measure the charge-to-mass ratios of particles at the pipe outlet. The effects of air velocity, solid feed rate and pipe length on the specific charge of quartz, kaolinite and calcite were investigated. Quartz, kaolinite and calcite were negative charged when rubbing against the copper pipe. The specific charge of each associated mineral increased with increasing air velocity and pipe length, but decreased with increasing solid feed rate. Under the same experimental condition, calcite acquired the largest specific charge, while quartz got the smallest, and kaolinite got the second place. The work function in order was calcite>kaolinite>quartz>Cu. Based on these results, a triboelectrification model of associated mineral particles during dilute phase pneumatic conveying in the pipe was developed. The correlation coefficient calculated from predicted results and experimental data were all larger than 0.95, and the average relative errors (ARE) were all less than 10%, which indicated that the model could accurately predict the specific charge of associated minerals during dilute phase pneumatic conveying. Therefore, the model can provide guidance for triboelectrification system design.