V and Cr substitution in dicalcium silicate under oxidizing and reducing conditions – Synthesis, reactivity, and leaching behavior studies

The Influence of Boron Doping on the Structures and Composition of Dicalcium Silicate: A Research Study

“…At the same time, excess B 3+ partially substitutes for Ca 2+ , following a similar mechanism to the substitution of Al 3+ in olivine by Mg 2+ [29]. This forms a structure of Ca 2−x B x (SiO 4 ) 1−x (BO 4 ) x , consistent with the proposed structure for single boron doping into the C 2 S structure by Cuesta et al [33]. The difference is that they represent [BO 3 ] 3− , which is derived from the triangular structure formed after B 3+ replaces Ca 2+ .…”

“…These elements include Na + , K + , As 2+ , Sr 2+ , Ba 2+ , B 3+ , Fe 3+ , P 5+ , V 5+ , and Cr 6+ [22,23]. The elements K + [24], Ba 2+ [25,26], B 3+ [27][28][29][30][31], P 5+ [32], and V 5+ [33] can stabilize both the β-type and α ′ -type belite.…”

Air granulated basic Oxygen furnace (BOF) slag application as a binder: Effect on strength, volumetric stability, hydration study, and environmental risk

“…The Ca 3 (VO 4 ) 2 and CaCrO 4 are the dominant chemical species at pH >12. Usually, calcium vanadate is insoluble, and calcium chromate is soluble >20 g/L at room temperature which indicates that Cr is immobilized by the hydration products [ 69,70]. Moreover, the barium leaching increases in mortar samples as compared to raw material (5.5 mg/kg CEM I).…”

Quantitative analysis and phase assemblage of basic oxygen furnace slag hydration

“…The BOF slag used in this study contains chromium and vanadium (see Table 1), implying a potential risk of leaching when applying the material. Cr is mostly incorporated in the wüstite and brownmillerite phases, while V is incorporated into brownmillerite and C 2 S [22,26], as shown in Table 3. The one-batch leaching test was performed to evaluate the environmental impact and capacity of the hydration products to immobilize the heavy metals.…”

“…These phases should be considered to participate in the reaction of BOF slag with water. Furthermore, it is known that C 2 S phases incorporate V, which may be immobilized in the C-S-H gel after hydration [26]. Literature also shows that heavy metals can be immobilized in hydrogarnets [22].…”