新型墙材用工业废渣中天然放射性核素分布研究

Distribution of Natural Occurring Radionuclide in Some Industries Residue Used in New Type Wall Materials

目的研究在新型墙体材料中大量使用的粉煤灰、煤矸石以及各种炉渣中的天然放射性核素分布特点,为降低公众受照剂量提供科学依据。方法使用高纯锗γ谱仪分析各种工业废渣的核素分布。结果镭当量浓度从高到低依次为粉煤灰(279.13Bqkg-1)、炉渣(225.69Bqkg-1)、煤矸石(141.26Bqkg-1)均不超过OECD规定的限值。226Ra、232Th、40K的活度浓度平均值,粉煤灰分别为127.88,93.83,221.75Bqkg-1;炉渣分别为73.89,97.13,293.44Bqkg-1;煤矸石分别为47.85,45.21,413.56Bqkg-1。同一电厂,不同时间采集的粉煤灰的放射性核素活度浓度会有很大差异,最大值可达到最小值的2倍以上。结论粉煤灰和炉渣在掺入比例上要严格控制在合理的范围,不宜将掺入量超过70%。煤矸石的平均放射性水平与黏土相当,一般在生产过程中掺入比例可以不受限制。新型墙材企业在生产过程中应经常性的检测废渣的放射性水平,使生产的产品中放射性核素达到合理的近可能低的水平。

Objective To study the natural radioactive nuclide distribution characteristic of fly ash , gangue and various kinds of slag used in the new-type wall material and offer scientific basis for reducing the radiation dosage that the public suffers. Methods The activity concentrations of the content of natural radioactive nuclide of different industry waste residue have been determined by HPGe gamma-my spectrometry. Results The mean Racq is successively fly ash （279.13 Bq kg^-1 ）, slag （225.69 Bq kg^-1） , gangue（ 141.26 Bq kg^-1 ） from high to low and all of the samples is lower than the limit set in the OECD. The arithmetic mean activities of ^236Ra.^232Th.^40K in fly-ash samples are 127.88,93.83,221.75 Bq kg^-1; for coal slag samples are 73.89,97.13, 293.44 Bq kg^-1 and for coal gangue samples are 47.85,45.21,413.56 Bq kg^-1. For the same power plant, the radioactive nuclide activity of the fly ash gathered in different time may have very great differences, the maximum can reach more than 2 times of the minimum. Conclusion The fly ash and slag should be controlled strictly on rational proportion, which should not exceed 70% of the total mass. The mixing of the average radioactive level of the gangue is nearly equal that of to clay, it can be unrestricted in the mixing proportion in process of production. The manufacturer of new-type wall materials should often measure the radioactive level of the industrial waste residue in production. Make the content of radioactive nuclide in the products reach the rational level as low as possible.