The potential for mining trace elements from phosphate rock

Several dozen trace elements are present in phosphate rock, and could potentially be mined as by-products. We have reviewed information on elemental presence and typical concentrations so as to assess the desirability and feasibility of extracting trace elements in order to contribute to global supplies. We generate as well a material flow analysis for the phosphate rock processing chain, examine potential recovery technologies, and assess economic viability. Trace element abundances vary widely among different phosphate rock deposits, but a number of median element concentrations in phosphate rock are more than ten times elemental crustal abundances. When the total content of the trace elements in annual phosphate rock production is compared to the annual production of those elements from traditional sources, sixteen elements have ratios >10, making them potential candidates for extraction. We view the more promising trace element candidates for extraction from phosphate rock to be scandium, hafnium, beryllium, gallium, germanium, and several of the rare earth elements. (C) 2014 Elsevier Ltd. All rights reserved.