大宗固体废弃物煤矸石的堆存带来严重的环境问题，因而综合利用与高值高效利用煤矸石十分紧迫与重要。煅烧是煤矸石资源化利用的重要加工手段。针对煅烧法存在能耗高、效率低的问题，通过研究钠盐种类及煅烧工艺对煤矸石增白效果的影响，得出了煤矸石煅烧前后样品的物相组成、微观形貌、孔结构及化学键变化情况，并在此基础上采用同步热分析与红外−质谱(TG−FTIR−MS)联用系统对NaCl煅烧过程中的气相产物与除杂增白机理进行了分析。结果表明：当煅烧温度为860 ℃时，NaCl煅烧煤矸石样品白度由原矿的38.5%提高到86.0%；碳质全部被氧化，黄铁矿(FeS₂)脱硫转变为赤铁矿(Fe₂O₃)，赤铁矿和金红石(TiO₂)总质量分数下降到0.27%；当煅烧温度为800～860 ℃时，样品孔结构特性变化较小；当升高温度到950 ℃时，片层状的偏高岭石转变为圆球状的莫来石，比表面积和孔体积分别由原矿的12.91 m²/g和0.056 cm³/g显著下降到6.58 m²/g与0.031 cm³/g。当煅烧时间超过30 min后，煅烧产物的白度增加幅度变小，煅烧时间超过90 min后，煅烧产物的白度基本不再增加(86.6%～86.7%)。NaCl的加入对于煅烧产物化学键的影响较小，煅烧阶段的易挥发矿物质成分质量分数较低，主要气体产物为H₂O、HCl、CO₂和H₂S；NaCl与H₂O、SiO₂发生作用高温分解生成HCl气体，并与Fe₂O₃、TiO₂等杂质反应，生成气相氯化产物从料层表面逸出，实现了煤矸石除杂增白。

The accumulation of coal gangue results in serious environmental pollution, it is urgent and necessary to comprehensive, high value and efficient utilization of coal gangue. The resource utilization of coal gangue by calcination is important. In terms of the problems of high energy consumption and low efficiency, the use of sodium salt types and calcination process for coal gangue whitening has been investigated. Raw and calcined coal gangue were thoroughly characterized with respect to phases constituent, microstructures, pore structures and chemical bonds.Based on above investigations, the whitening mechanism and volatile products obtained from sodium chloride calcined coal gangue process were further analyzed by simultaneous thermogravimetry-Fourier transform infrared spectroscopy-Mass spectrometer (TG-FTIR-MS). Results show that after being calcined with sodium chloride at 860 ℃, the whiteness of raw coal gangue was upgraded from 38.5% to 86.0%. All the carbon and pyrite (FeS₂) contained in coal gangue was oxidized and correspondingly converted into hematite (Fe₂O₃) by desulfurization and the total amount of hematite and rutile (TiO₂) was reduced to 0.27%. The pore structural characteristics changed little at calcination temperature between 800 and 860 ℃. However, the calcination at 950 ℃ resulted in generation of spherical mullite, and a significant decrease in specific surface area and pore volume from 12.91 m²/g and 0.056 cm³/g for raw coal gangue to 6.58 m²/g and 0.031 cm³/g, respectively. The whiteness increased slightly at calcination time between 30 and 90 min (85.3% to 86.6%). Meanwhile, the whiteness changed little at calcination time between 90 and 150 min (86.6% to 86.7%). The addition of NaCl had little impact on the chemical bonds of calcined coal gangue. The evolution of mineral components in the calcination stage was relatively low, and the main volatile products were H₂O, HCl, CO₂ and H₂S. Moreover, NaCl reacted with SiO₂ and H₂O to decompose into HCl gas, which removes iron and titanium by the volatilization of the respective chlorides. The chlorinated products escaped from the surface of the material layer and discharged, resulting in a purified and whitened coal gangue.