无水氟化铝与湿法氟化铝的危险特性差异分析及运输风险评估

采用TG、EDS、XRD、氟离子选择电极等方法，研究了无水氟化铝和湿法氟化铝两种样品的主要物相组成、热稳定性、水溶性、腐蚀性及其与苛性碱混合发生化学反应的情况，并对其在运输过程中可能存在的安全风险进行了分析评估。结果表明：无水氟化铝在加热至200℃之前具有优良的热稳定性，含有β-AlF₃·3H₂O的湿法氟化铝在加热至110℃以上时才开始发生脱水及析出HF的反应；湿法氟化铝在水中溶解饱和时氟可达300mg/L左右，高出我国污水排放标准10倍以上，存在轻度污染水环境的毒害性安全风险，无水氟化铝在水中达饱和时的氟<10mg/L，低于我国污水排放标准，在运输时基本无毒害性风险；无水氟化铝和湿法氟化铝对碳钢无腐蚀性，其饱和水溶液对A3钢的腐蚀速率为0.078~0.22mm/a，在运输时基本无腐蚀性风险；当湿法氟化铝与固体NaOH混合或无水氟化铝与含水NaOH混合时，均有生成NaF的反应发生，应避免混运混放。

Hazard analysis and risk assessment in the transport of anhydrous and hydrated aluminum fluoride

Hazard analysis and risk assessment in the transport of anhydrous and hydrated aluminum fluoride have been evaluated based on the thermal stability, solubility in water, causticity and the reactivity with NaOH which were studied using TG, EDS, XRD and an ionic selective electrode (ISE). It was found that most of the water in hydrated aluminum fluoride was lost quickly below a temperature of 110℃, and the AlF₃reacted with H₂O to evolve HF gas. In contrast, anhydrous aluminum fluoride was stable even up to 200℃. The concentration of F was more than 300 mg/L in a saturated aqueous solution of hydrated aluminum fluoride, which is 10 times more than the limit for the direct release of waste water. On the other hand, the concentration of F in a saturated aqueous solution of anhydrous aluminum fluoride was less than 10mg/L, which has less effect on the environment. The corrosion rate of steel (A3) in aqueous solutions of both aluminum fluoride materials was in the range 0.078-0.22 mm/a, which means there is limited corrosion, which should not cause any risk in transport. When aluminum fluoride reacts with NaOH, NaF is generated. 