Geochemical Occurrence of Rare Earth Elements in Mining Waste and Mine Water: A Review

?ining waste, processing by-products and mine water discharges pose a serious threat to the environment as in many cases they contain high concentrations of toxic substances. However, may also be valuable resources. The main target current review is comparative study occurrence rare earth elements (REE) mining waste produced from exploitation coal, bauxite, phosphate rock other ore deposits. Coal combustion ashes, bauxite residue phosphogypsum present percentages critical REEs (up 41% total REE content) with ?REY content ranging 77 1957.7 ppm. different coal areas around globe are characterised by range 0.25 9.8 ppm 1.6 24.8 ppm, respectively. Acid their associated natural treatment precipitates seem promising sources if extraction coupled simultaneous removal pollutants.