Zhao, Zong Wen, Chai, Li Yuan, Peng, Bing, Liang, Yan Jie, He, Yinghe, and Yan, Zhi Hao (2017) Arsenic vitrification by copper slag based glass: mechanism and stability studies. Journal of Non-Crystalline Solids, 466. pp. 21-28.

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Abstract

In the present work, the (100 - x)(58SiO(2)-20Fe(2)O(3)-10B(2)O(3)-12Na(2)O) - xAs (x = 0, 2, 4, 6, 8 wt%) glasses, which are main constituents of the copper slag based glasses, were produced by conventional melting method to study the arsenic vitrification mechanism and stability. X-ray diffraction (XRD), Fourier transform infrared spectrum (FTIR) and X-photoelectron spectroscopy (XPS) were used to investigate the mechanism of arsenic vitrification. The XRD analysis for the x <= wt 8% samples shows that all the samples form homogeneous glasses and the arsenic is compatible with the copper slag based glass. The FTIR spectrum of the glasses have revealed that the arsenic exists in the form of AsO4 tetrahedra and the Q(n) structure of the copper slag based glass has been strengthened with the increase addition of arsenic. The changes of the binding energies of Si2p, O1s, As3d and Fe2p directly indicate the formation of Si-O-As and Fe-O-Si/As bonds in the glass, which strengthens the chemical stability of the glass. Lastly, USEPA toxicity characteristics leaching procedure (TCLP) and differential scanning calorimetry (DSC) tests were used to study the chemical durability and thermal stability of the glasses containing arsenic. The leaching concentrations of As, B, Fe, Na, and Si are under safety thresholds and the increase addition of arsenic into the glasses can decrease the leaching concentrations, indicating that the arsenic can improve the chemical stability of the glass. The arsenic added into the glass can improve the AT, which strengthens the thermal stability of the glasses.

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