采用热重分析仪对O2/CO2气氛下碱金属对无烟煤燃烧特性的影响进行研究.研究结果表明NaCl、K2CO3能够改善无烟煤的燃烧性能，这主要由于Na、K对无烟煤着火后挥发分和固定碳的燃烧起促进作用，而K对无烟煤燃烧的促进作用更明显.通过TG-DTG切线法计算得出着火温度，与煤样相比分别降低了19.1℃和23.7℃，这主要由于Na、K催化剂在煤燃烧过程中，充当了氧的活性载体，促进氧从气相向碳表面扩散，从而降低了固定碳表面着火温度.同时，计算得到煤和Na、K负载样品的燃烧特性指数分别为4.39×10-6、11.14×10-6、17.22×10-6，可见Na、K负载样品优于煤的燃烧特性，其燃烧特性指数的提高主要在于着火温度的降低，表明Na、K均可降低无烟煤高温燃烧区的表观活化能，提高燃烧反应速度.%The effects of alkali metal salt on combustion property of anthracite were investigated by thermal analyses. The results show that K2CO3 or NaCl can improve the combustion characteristics of anthracite, which is mainly due to Na, K to promoting the volatile matter and fixed carbon combustion after anthracite ignition, especially to K. Compared with anthracite ignition temperature obtained by TG-DTG tangent method, the ignition temperature decreases at 19.1 ℃ and 23.7 ℃, respectively. This phenomenon is mainly caused by Na, K catalyst as the carrier of oxygen activity during combustion, which promotes the diffusion of oxygen from the gas phase to the surface of carbon, and reduces the surface ignition temperature of fixed carbon. The index of the combustion characteristics calculated by TG-DTG are 4.39×10-6, 11.14×10-6, 17.22×10-6, respectively, and the combustion characteristics of samples with Na, K is better as a result of the ignition temperature decrease. It indicates that Na and K can reduce the apparent activated energy of coal and improve the combustion reaction rate.
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