Rare Earth Separation Process And Environmental Assessment

With the shortage of resources and environmental issues outstanding, the phenomenon of low value caused by lack of environment values in product prices is widespread. As a tool for environmental management and preventive measures, life cycle assessment is an important method of environmental assessment and it has been widely used in various fields. Although our skills of rare earth separation reach to the world advanced level, there are no research institutions and scholars to carry out life cycle assessment for rare earth separation in domestic through a variety of literature search.In this paper, it uses heavy rare earth separation process, which is only in Gannan of Jiangxi, as the research object, and makes life cycle assessment for each process of the production process: such as rare earth separation process; process of inventory analysis; and making clear the boundary, goals and second-rate index system of life cycle assessment. Resources factor, energy factor, waste factor, environmental noise factor, waste footprint and product performance factor will be the level indicators in the system, while mineral resources, water resources, recycling resources, raw materials, finished products, dust and waste will be the secondary indicators. Evaluation for environmental impact of rare earth separation process is mainly for resources, energy and waste factor. Integrated related environmental index model has been established and environmental load consolidated value of P507 and P204 has been calculated respectively, so we can analyze from the results that the environmental load is smaller when use the process of P507. Though the input/output method (I/O) analysis, we can deduce the accumulative environmental factor models such as resources, energy factor, mixed rare earth mine waste and other environmental factors. According to international standards or national standards with local standards, its resources factor equivalent coefficient is modified, and the accumulative environmental load models in rare earth separation process is calculated. The results show that P507 process could reduce the environmental load and reduce environmental emissions. In order to evaluate more scientific, multi-objective environmental load model which based on fuzzy theory has been optimized. The relationship between the cleaner production of rare earth separation process and environmental benefits has been cleared, and integrated environmental relative index of the whole rare earth separation process has been calculated(IREI=0.748). It is analyzed that environmental load of the rare earth separation can be reduced by 25.2% with the clearer production used. Waste factor reduces sharply by 95%; the environmental load of resources factor, energy factor, wastewater factor and waste factor reduces by 5%,12%,9%,5% respectively, which brings a strategy for cleaner production. This research provides new references for the improvement of the effect of the rare earth separation to the environment, and opens a new avenue for the application of research results of life cycle assessment.