Stabilization of hazardous ash waste with newberyite-rich chemically bonded magnesium phosphate ceramic

Abstract

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Magnesia-Based Cements: A Journey of 150 Years, and Cements for the Future?

“…This began in the early 1990s with research on the use of MPCs that can tolerate ash- and salt-bearing wastes, combined with radioactive and heavy-metal contaminants. Typically, these wastes might include pyrophoric materials, requiring a low-temperature encapsulation process, as well as salts or materials that are unsuitable for cementation in conventional PC blends. − …”

Effect of Calcined MgO-rich Byproduct from the Extraction of Li₂CO₃ on the Performance of Magnesium Phosphate Cement

“…In addition, MPC pastes prepared with dead burnt magnesia and phosphates have short setting times; consequently the use of retardants such as borax or boric acid is required (Hall, et al2001;Yang, et al2010). However, it has been suggested that the phenomena involved in the retardation process, such as the adsorption of B(OH) 3 on the surface of MgO grains, or the precipitation of a coating layer of lünebergite (Mg 3 B 2 (PO 4 ) 2 (OH) 6 ·6H 2 O) on the surface of cement grains, slow down their dissolution (Wagh et al 1995). Therefore, because of the high energy consumption associated with the production of dead burnt MgO, local magnesite-reserve limitations, and the need for the addition of retardants, the cost of MPC remains high and limits its use in large-scale applications.…”