Physics and Chemistry of Minerals ( IF 1.4 ) Pub Date : 2021-02-04 , DOI: 10.1007/s00269-020-01127-1 Francesco Di Benedetto , Andrea Giaccherini , Maurizio Romanelli , Giordano Montegrossi , Elena Belluso , Silvana Capella , Alfonso Zoleo , Giulio Arcangeli , Alessandro Marinaccio , Ottorino Gottardo , Fabio Capacci
We report the results of an experimental multianalytical characterisation of industrial cristobalite powders, used as raw materials for artificial stone production. Cristobalite is considered a serious threat to human health. The study was carried out through X-ray diffraction (XRD), scanning electron microscopy with energy dispersive microanalysis (SEM/EDS), continuous-wave (cw) and pulse electron paramagnetic resonance (EPR) spectroscopy. Our results point out a sub-micrometric size of the structural coherence in cristobalite, associated with numerous stacking defects. Moreover, the material was found characterised by the presence of superoxide radicals, whose persistence appears conceivably long. Radicals in a material synthesized through a high-temperature treatment were generated during the grinding step in the industrial production of cristobalite. During this process, in fact, both superoxide generation and structural defectivity are induced. Indeed, cristobalite powders already result activated by a radical population, before any kind of process in artificial stone production.
中文翻译:
工业生方石英粉中自由基的研究
我们报告了工业方石英粉(用作人造石生产原料)的实验多分析表征结果。方石英被认为是对人类健康的严重威胁。该研究是通过X射线衍射(XRD),具有能量色散显微分析(SEM / EDS)的扫描电子显微镜,连续波(cw)和脉冲电子顺磁共振(EPR)光谱进行的。我们的结果指出了方石英中结构相干的亚微米尺寸,并伴有大量堆积缺陷。此外,发现该材料的特征在于存在超氧化物自由基,其持久性似乎很长。在方石英工业生产中的研磨步骤中,产生了通过高温处理合成的材料中的自由基。实际上,在此过程中,会同时产生超氧化物生成和结构缺陷。的确,在人造石生产中的任何形式的加工之前,方石英粉已被自由基活化。