A Life Cycle Assessment Of Environmental Impacts From The Production Of Rare Earth Oxides In China

The rare earths are a group of17elements that have gained in relevance over thepast few years. While the majority of studies have been on the supply of theseresources, only recently have its environmental impacts come to light. In2012, over90%of rare earths were produced in China, which also bore the majority of itsenvironmental impacts. Rare earth oxides are difficult to process, consuming largequantities of energy and chemicals. It also discharges large amounts of radioactivewaste, ammonia, and hydrogen fluoride to the environment. The Chinese governmenthas implemented several policy measures since2010to mitigate impacts. However, dueto a lack of studies, it has been difficult to determine how effective they have been.The focus for this thesis was a cradle-to-gate life cycle assessment on theenvironmental impacts of producing1tonne of rare earth oxide (REO) in China fromeach of the three primary production streams. Environmental impacts were assessed fora total of10characterization factors. Results of the study show that the four mostprevalent environmental impact categories associated with the rare earth industry are:abiotic resource depletion, global warming, acidification and eutrophication. Ionisingradiation, which has traditionally been a concern within the industry, was found to below, yet still significant given the parameters of this study. Baotou had the largestimpact of the three legal production streams, primarily due to the overwhelmingquantity of REO produced there. When disaggregated to its individual processes, theREO decomposition and separation processes contributed most to overall impacts. Anestimate was also made of environmental impacts from illegal mining, which had amuch larger marginal impact than that of the legal production streams.Using the LCA model to measure its efficacy, it was found that governmentmeasures to reduce impacts in the rare earth industry have had a positive impact. Whilethe policies themselves are well-developed, however, implementation and enforcementare still lacking. This study concludes with a series of5recommendations forimproving policies directed towards environmental impacts in the rare earth productionindustry. They focus on reducing illegal mining and production, improvement ofproduction efficiency, and implementation of waste treatment technologies.