Reseach On The Ecological Cumulative Exergy Consumption Of The Production Environment In Ion-absorbed Rare Earth Based On LCA

The life cycle assessment(LCA)is considered as the most effective environmtal management tool and environmtal impact evaluation method in the 21 st century.It can qualitative and quantitative analysis the environmental load in the whole life process of the product caused by its production,promoting environment coordination of the product or the processes.It can help enterprises optimize process,improve technologies and choose the optimal processes.Besides,it would provided the theoretical basis for the the government to formulate environmental management policies and enterprises manage environmental.But the traditional LCA exist defects in the practical application.Ecologically based life cycle assessment(Eco-LCA)is a emerging LCA method based on the theory of energy.It is the development of the traditional LCA,which would assesses the ecological impact of industrial processes and its sustainability and identify the ultimate ecological impact of production.Eco-LCA would overcome the shortcomings of the traditional LCA method ignoring implicit contribution of the ecological system and the social economy factors for the sustainable development of the product.But the theoretical framework of Eco-LCA is still need to be studied.The ion-absorbed rare earth are important national strategic and non renewable resources.It will causes serious environmental problems in the process of the product.Through the study of traditional LCA method and ECEC measurement scheme of Eco-LCA,based on the basic framework of LCA and combined with the production environment of in the ion-absorbed rare earth,proposed target of this research and the system boundary about LCA.Besides,established the environmental load evaluation index system,cumulative model and environmental load sharing principle.This paper has established ecological cumulative exergy consumption(ECEC)evaluation model including natural resources consumption(NC),the social and economic investment(SC)and the harm of environmental pollution(EI).This evaluation model overcome the defect of traditional LCA ignoring implicit contribution of the ecological system and the social economy factors for the product.Additionally,it was a creation to establish ECEC of environmental impact categories combining with ECEC measurement method of Eco-LCA and environmental design of industrial products(EDIP)method in Denmark for the first time.This model quantitative the environmental load of each environment impact categories making it in the same unit(ECEC,sej)for comparison.It can reflect the ecological impact,sustainability and tke key environmental load factors in the production.This study take the production of an ion-absorbed rare earth as the research object and basethe 1t lanthanum oxide as a functional unit,carrying out the application study of its ECEC and ECEC of the type of environment impact.The results show that:(1)The most gaseous pollutant is the Carbon dioxide in order to product 1t lanthanum oxide.The most liquid pollutant and solid pollutant is COD and waste residue(2)The maximum ECEC is resource consumption,249.002×1016sej,which contribute 89.9% of total.Besides,the ECEC of environmental pollution harms are the secondly.(3)The influences on the global warming and eutrophication are more from the aspect of the type of environment impact.In which,the ECEC of global warming is 4.17 ×1016sej,while the ECEC of eutrophication is 2.28×1016sej.(4)The influence on the environment in the smelting separation stage is more serious,and its proportion reach 80.56%.The stage of smelting separation is the key of environment management and pollution control for the enterprise.At last,the optimization space and pollution control measures are put forward.