Research On The Material Flow And Value Flow Analysis Of Secondary Zinc-recovery Enterprise Based On Circular Economy

The development of zinc smelting industry is being restricted by problems of extensive production management and low resources utilization rate.Most enterprises pay more attention to end control,such as terminal discharge of pollutants.But during production,the zinc loss flow and cost loss of each process is not clear makes it difficult to determine the key control process.And it seriously affects the enterprises’circular economy construction.In order to promote the circular economy construction of secondary zinc enterprise,this paper takes the typical production process of the secondary zinc recovery enterprise as the research object,and construct the substance-value flow analysis and evaluation framework.In this paper,substance flow analysis and material flow cost accounting analysis method are used as research methods to draw the substance flow chart and cost allocation map of the enterprise production system,and quantitatively evaluate the zinc loss flow and process cost loss during production process.At the same time,JEPIX method is adopted to evaluate the environmental impact of enterprises based on the environmental impact point（EIP）to clarify the priorities of pollutant control.Finally,according to the evaluation results,suggestions can be put forward to improve resource efficiency,reduce cost loss and promote the construction of enterprise circular economy.The main research results are as follows:（1）The zinc resource efficiency in the production system was 86.11%,leading to the system’s zinc loss of 13.89%.Most of the zinc loss flow out of system in the form of by-products such as leaching slag and kiln slag.Therefore,improving recycling efficiency of the leaching slag and kiln slag in the production system is the key to further improve the zinc resource efficiency.（2）The value flow analysis indicated that the positive and negative product cost accounts 82.24%and 17.58%respectively of the total input cost in the system.Among negative product cost of the system,material loss cost and waste disposal cost account for 44.65%and 54.27%respectively.And both are the key control point for cost reducing.（3）The pollution control of production system mainly focuses on particulate matter,SO₂ and NO_x in exhaust gas.Among them,NO_x has the highest environmental impact point.So improving the denitration efficiency of production system is the focus of pollution prevention and control.（4）In order to promote the construction of circular economy,enterprises should optimize the production process by means of recycling middle leach residue and improving the zinc volatilization rate of rotary kiln to improve the zinc resource efficiency.In this way,negative product cost can be reduced while resource efficiency is improved,and waste disposal cost and pollution discharge can both be reduced.In the aspect of reducing environmental impact,the enterprise should focus on optimizing denitration process to reduce NO_x emissions.