Life Cycle Assessment Of Copper Tailings Resource Recycling Process In Jiangxi Province

Copper tailing refers to the solid waste left after the mining of copper ore,which contains abundant reusable materials.The resource treatment of copper tailings is a new research field and has a broad development prospect.The content of SiO₂ in copper tailings in a certain place of jiangxi province is high,which can be used to substitute siliceous raw materials for building materials.In recent years,there have been more domestic and foreign scholars on copper tailings resource-oriented utilization in building materials production,in order to make greener copper tailings utilization technology,need to use the scientific method,from the Angle of resource consumption and pollution emissions to evaluation process of copper tailings building materials production,achieve the goal of energy conservation and emissions reduction.Therefore,this study introduced the life cycle theory to analyze the potential environmental impact of copper tailings in the process of resource utilization in the production of building materials.In this study somewhere for jiangxi copper tailings resource utilization in the production of cement clinker,autoclaved aerated concrete and foam microcrystalline heat preservation material process,on the basis of site investigation and the actual data collection,combining CLCD data quality assessment methods,on eFootprint online system of copper tailings composite building materials and common building materials life cycle assessment of the whole manufacturing process,through the various stages in the process of quantitative resource,energy consumption and pollutant emissions and the cumulative environmental impact contribution value,etc.,comparative analysis of both the size of the production process of environmental impact index,The most serious stages and environmental categories of the production process were determined,and the impact of the copper tailings recycling process on natural resources and the ecological environment was determined.The main conclusions of this study are as follows:Compared with the production of ordinary Portland cement clinker,the values of various environmental impact types in the production of copper tailings composite cement clinker are all reduced to different degrees,with the PED（Primary Energy Demand）decrease up to 10.25%.The main types of environmental impacts caused by the production process of copper tailings composite cement clinker are PED>WU>GWP:the coal powder preparation process contributes the most to PED,accounting for 80.04%of the total PED.The preparation of iron powder and the process of tap water contributed significantly to the WU（Water Use,WU）,accounting for45.05%and 30.77%of the total WU,respectively.The clinker calcining stage contributed the most to GWP（Global Warming Potential,GWP）,accounting for 89.31%of the total GWP.These processes are the key links of energy conservation and emission reduction control.In addition,the production of copper tailings replacing clay for cement clinker not only avoided the possible ecotoxicity,human toxicity and the impact of land occupation caused by the accumulation of copper tailings,but also reduced the ecotoxicity and human toxicity produced in the production of copper tailings composite clinker,of which the ecotoxicity was reduced by 5.7%.Compared with the traditional autoclaved aerated concrete production,the values of various environmental impact types in the production of copper tailings autoclaved aerated concrete all decreased to different degrees,with the GWP decreasing as much as 19.51%.Copper tailings autoclaved aerated concrete production process caused by the major types of environmental impact for PED>WU>GWP:autoclaved curing process consumes a lot of steam and gas,resources and environment impact,the largest is an important part of the energy conservation and emissions reduction control,main types of environmental impact for PED,GWP and WU,It accounted for57.31%,51.37%and 38.30%of the total value of each environmental impact type respectively.In addition,the copper tailings instead of 10%35%of the sand and cement is used in the production of the autoclaved aerated concrete avoids copper tailings storage may produce toxic ecological toxicity,and the influence of the occupation of land,but also reduces the copper tailings autoclaved aerated concrete production process of ecological toxicity and human toxicity,including ecological toxicity reduced 54.5%,toxic value by 5.6%.Compared with the production of ordinary foam microcrystalline insulation materials,the values of each environmental impact type in the production of copper tailings foam microcrystalline insulation materials were all reduced to different degrees,with WU’s decrease as high as 70.35%.Copper tailings foam microcrystalline heat preservation material production process of the main environmental impact type for WU>PED>GWP:borax belongs to high purity material,its upstream production process influence on resources and environment is the largest,is an important part of the control of energy saving and emission reduction,the major types of environmental impact for the GWP,PED and WU,It accounted for 75.33%,70.07%and39.38%of the total value of each environmental impact type respectively.In addition,the copper tailings instead of quartz sand and bauxite is used in the production of the foam microcrystalline thermal insulation material not only avoid the copper tailings storage of toxic ecological toxicity,and the influence of occupation of land,but also reduces the copper tailings foam microcrystalline heat preservation material production process of ecological toxicity and human toxicity,including ecological toxicity reduced 29.3%,toxic value by 25.85%.