Distribution, occurrence mode, and extraction potential of critical elements in coal ashes of the Chongqing Power Plant

Insights into the rare earth element potential of coal combustion by-products from western Canada

“…These findings are similar to previous studies which found that REE were primarily hosted in the residual phase of CCBs. 22,49,61,82,83…”

“…Geochemical data from previous CCB studies 20,21,23,24,26,27,30,34,39–63 was compiled to compare REE contents of western Canadian CCBs with other localities and to identify elemental indicators of REE enrichment using unsupervised machine learning. Where available, major oxide, trace element, REE, coal rank, country, and sedimentary basin information was compiled for FA and BA samples from around the world.…”

“…These ndings are similar to previous studies which found that REE were primarily hosted in the residual phase of CCBs. 22,49,61,82,83 Typical crystalline mineral phases present in CCBs can include quartz, mullite, hematite, magnetite, kaolinite, illite, periclase, anhydrite, lime, pyrite, calcite, and calciummanganese oxides, 34,44,55,84 with the aluminosilicate minerals being the most abundant components in Class F y ash. 25 SHRIMP-RG ion microprobe analysis of CCBs from the United States indicated that REE were mainly present in aluminosilicates, while acid leaching experiments on the same CCBs showed poor REE recovery in all samples except those from the Powder River Basin.…”

Separation of coal combustion residue for critical element extraction and other bulk uses

“…In terms of critical elements, the larger surface area of unburnt carbon aids in the adsorption of volatile elements on the ash surface. 15 The fly ash was slightly acidic (pH 5.75–6.6) (ESI Table 1†). The pH of the ash influences its reactivity, environmental impact, and suitability for use in construction, agriculture, environmental remediation, and other industries.…”

Ecological and Health Risks Attributed to Rare Earth Elements in Coal Fly Ash

“…Coal fly ash (CFA), a byproduct of coal burning in thermal power plants, has recently gained attention as a potential resource for REYs [ 9 , 10 , 11 ]. While challenges exist regarding low concentrations and extraction complexities since REYs are encapsulated within glassy particles [ 12 ], ongoing research and technological advancements are making it increasingly feasible to recover REYs from this unconventional source [ 13 ].…”