模拟放射性废树脂与纯树脂裂解行为对比研究

Comparative Study of Pyrolysis Behaviors of Simulated Radioactive Spent Resin and Pure Resin

在热重分析仪上对比研究了模拟放射性废树脂和纯树脂的热失重规律,结果表明,分别含有浓度为0.1 g/L Co、Cs和Sr核素的模拟废阳离子交换树脂在氮气氛围下裂解时,与纯阳离子交换树脂具有相同的裂解规律;在含20%(体积分数)氧气的空气氛围下裂解时,Cs、Co和Sr对阳离子交换树脂裂解过程影响较小,与纯阳离子交换树脂比,裂解温度略有降低,残渣量不变;含有浓度为13 g/L硼(B)元素的模拟废阴离子交换树脂分别在氮气和空气氛围下裂解时,硼元素对废阴离子交换树脂的裂解过程均有抑制作用,与纯阴离子交换树脂比,裂解反应结束温度升高,残渣量增大4%~5%(质量分数)。研究还发现,空气氛围中的氧气降低了阴阳离子交换树脂的裂解残渣量和阳离子交换树脂的裂解温度,但却使得阴离子交换树脂的裂解温度有所升高。

The pyrolytic weightlessness characteristics of simulated radioactive spent resin and pure resin were compared by the thermogravimetric analyzer.The simulated spent cation exchange resin containing 0.1 g/L Co,Cs and Sr respectively had the same pyrolysis pattern as pure cation exchange resin under nitrogen atmosphere.Under air atmosphere with 20%oxygen(volume fraction),Co,Cs or Sr had little effect on the pyrolysis of cation exchange resin.Compared with the pure cation exchange resin,the pyrolysis temperature of simulated spent cation exchange resin was slightly decreased while the amount of residue didn’t change.Under nitrogen or air atmosphere,Boron(B)at the concentration of 13 g/L hindered the pyrolysis of simulated spent anion exchange resin.Compared with the pure anion exchange resin,the pyrolysis temperature increased and the amount of residue increased by 4%-5%(mass fraction).It was also found that oxygen in air atmosphere reduced the amount of residue of resin and decreased the pyrolysis temperature of cation exchange resin,but increased the pyrolysis temperature of anion exchange resin.