煤质在线检测技术可对煤中矿物元素进行直接检测，为煤炭洗选生产实现灰分自动回控提供关键数据支撑。文章在介绍并对比了用于煤质在线检测的X荧光分析（XRF）技术、激光诱导击穿光谱（LIBS）技术和瞬发γ射线中子活化分析（PGNAA）技术的基础上，详细阐述了PGNAA多元素在线检测技术的原理、检测设备的组成，重点介绍了PGNAA技术在矿井型选煤厂和中央型选煤厂的应用情况，并对PGNAA在线检测设备得到的煤质检测结果与实验室化验结果进行了对比。PGNAA在线检测设备在矿井型选煤厂和中央型选煤厂的应用表明：在不同的生产条件和产品需求下，PGNAA在线检测设备对灰分检测的标准偏差能够控制在0.15%以内，相关系数在0.91以上；对全硫检测的标准偏差为0.032%，相关系数达到0.995；对煤中Fe₂O₃含量检测的标准偏差仅为0.025%，相关系数为0.950；可见PGNAA多元素在线检测技术对于灰分、全硫、Fe₂O₃含量的检测结果与实验室化验结果之间有很好的相关性。随着选煤厂智能化建设的深入，对煤质在线检测设备的要求越来越高，未来PGNAA多元素在线检测技术以其高精度、强适用性等特点，将在原煤均质、分选控制、精准配煤、商品煤出厂快速检测等方面发挥作用。

Online detection of mineral elements contained in coal provides a crucial data support for realizing control of ash of products with feedback ash data. Following an introduction to and comparison of the XRF, LIBS and PGNAA techniques for online detection of mineral constituents contained in coal, the paper goes to elaborate on the working principle, make-up and structural design of the PGNAA online muti-element detection technique and particularly the effects obtained in field application of this technique in mine and central coal preparation plants, as well as the comparison of the actually measured and analysis data. Practice shows that under varying operating conditions and quality requirements of products, compared with the analytical data, the standard deviation of the ash values actually measured with the PGNAA technique can be controlled within 0.15%, with a correlation coefficient being over 0.91; and for the detection of total sulfur and Fe₂O₃, the standard deviations and correlation coefficients are 0.032% and 0.995, 0.025% and 0.950, respectively. It can be seen that the actually measured ash, total sulfur and Fe₂O₃ data are in good agreement with the analytical data. With the ongoing development of intelligent coal preparation plants, an ever stricter requirement is placed online coal analysis units. Looking ahead, the high-accuracy and high-adaptability PGNAA technology will play an ever bigger role in raw coal homogenization, separation control, accurate coal blending and rapid determination of quality of delivered commercial coal.