ABSTRACT

In this study, the rotary triboelectrification separation technology is applied to the separation of macerals for low rank coal, which has not been studied by previous researchers. The effects of air humidity and temperature on permittivity and specific-charge were tested to ensure that vitrinite and inertinite were effectively separated under obvious electrical differences. The best separation index of macerals was determined by single factor test, including airflow rate, feed rate, friction wheel speed, and plate voltage. The test results of specific-charge and permittivity showed that the difference is most reasonable when the air humidity is 20% and the temperature is 40°C. Single factor test showed that the optimal conditions are the feed rate of 1.5 g/s, the friction wheel speed of 3000 r/min, the plate voltage of 20 kV and the air flow rate of 6 m/s. Finally, this study obtained the best maceral separation indexes are vitrinite content of 72.03 vol%, vitrinite recovery of 67.86% and benefication ratio of 1.33. Comparison with other maceral separation technologies, the rotary triboelectrification technology is a clean dry and economical process technology, it has inherent advantages in the separation of macerals for low rank coal.

摘要

本研究将旋转摩擦带电分离技术应用于前人未研究过的低阶煤质料的分离。测试了空气湿度和温度对介电常数和比电荷的影响，以确保在明显的电差异下有效分离镜质体和惰性体。通过单因素试验确定最佳的微晶分离指标，包括气流速率、进料速率、摩擦轮转速和板电压。比电荷和介电常数测试结果表明，空气湿度为20%，温度为40℃时，差异最为合理。单因素试验表明，最佳条件为进给速度为 1.5 g/s，摩擦轮转速为 3000 r/min，板电压为 20 kV，空气流速为 6 m/s。最后，本研究得到最佳的微晶分离指标为镜质体含量为72.03 vol%，镜质体回收率为67.86%，选矿率为1.33。与其他煤渣分离技术相比，旋转摩擦带电技术是一种清洁干燥、经济的工艺技术，在低阶煤的煤渣分离中具有先天优势。