Chromium and vanadium incorporation in sulfate-containing sodium aluminoborosilicate glass
Chromium and vanadium incorporation in sulfate-containing sodium aluminoborosilicate glass
复制标题
含硫酸盐铝硼硅酸钠玻璃中铬和钒的掺入
作者：
Natalie Smith;Jason M. Lonergan;J. McCloy
在汉福德低活性核废料玻璃的组成空间中，某些配方的废物装载量受到硫酸盐掺入不足的限制。特别是，在以前的研究中确定的某些元素往往会提高或降低硼硅酸盐玻璃中的硫酸盐溶解度。目前研究的目的是了解钒和铬如何各自影响含硫酸盐的钠铝硼硅酸盐玻璃结构。测量玻璃化转变温度、质量密度、可见光吸收和拉曼散射以研究玻璃结构的变化。在含铬玻璃中发现Cr 6+（CrO 42-）和Cr 3+，而在含钒玻璃中钒主要以5+氧化态存在。电子探针微量分析确定元素组成，以评估保留的成分。Cr2 O3的增加导致玻璃中Cr浓度饱和，并形成结晶状的铁钾长石（Cr2 O3）。另一方面，所有目标V都被掺入玻璃中。批料S的一小部分未掺入任何玻璃中，推测是由于熔化期间的挥发。显然，掺入Cr的细节以及在一定程度上V是不同的，这取决于硫是如本研究中那样添加还是如文献中所述在过饱和条件下添加，其中Cr分配到含硫酸盐的盐相中。
In the composition space for Hanford low-activity nuclear waste glass, the waste loading of some formulations is limited by poor incorporation of sulfate. In particular, certain elements identified in previous studies tend to raise or lower sulfate solubility in borosilicate glass. The aim of the current study is to understand how vanadium and chromium each affect a sulfate-containing sodium aluminoborosilicate glass structure. Glass transition temperature, mass density, visible absorption, and Raman scattering were measured to investigate changes in the glass structure. Both Cr6+ (CrO42−) and Cr3+ were found in the chromium-containing glasses while vanadium primarily existed in the 5+ oxidation state in the vanadium-containing glasses. Electron probe microanalysis determined elemental compositions to assess retention of components. Increasing Cr2O3 caused saturation of Cr concentration within the glass and formation of crystalline eskolaite (Cr2O3). On the other hand, all the targeted V was incorporated into the glass. A fraction of batched S was not incorporated in any glass, presumably due to volatilization during melting. Apparently, the details of incorporation of Cr, and to an extent V, are different depending on whether sulfur is added as in this study or in oversaturated conditions as described in the literature, where Cr partitions to a sulfate-containing salt phase.