Occurrence of scandium and rare earth elements in Jamaican bauxite waste

Jamaica has been a major world producer of bauxite and alumina for the past three decades. The extraction of alumina from bauxite is carried out by the Bayer process, in which bauxite is digested at high temper-atures (140ø-250øC) in a caustic soda solution. Alu-mina dissolves in the solution and is recovered by crystallizing it, while the residue is pumped out in waste ponds. As a result, for each ton of alumina pro-duced, an equal amount of slimy caustic waste known as red mud is generated (Wagh et al., 1982). In Ja-maica this has been disposed of in containment dams, mined-out pits, or in several cases, natural valleys. Several such impoundment areas exist in a region near the center of the island, where literally hundreds of acres of land are occupied in storage of this waste.