Cost Optimization On Purcurement Logistics Of Iron Ore Considering Carbon Emissions Based On "Port Before Factory"

As a big country of crude steel production and consumption,domestic iron ore is of low grade and high cost of beneficiation,which needs to rely heavily on imports.However,foreign high-quality iron ore are monopolized by a few suppliers,and factors such as distance,ore reserves and national policies cause China to be restricted by the seller's market for a long time,and the bargaining power of iron ore and route selection are restricted,as a result,the procurement cost remains high.In addition,iron and steel enterprises are.facing some challenges such as high proportion of logistics costs,increasing environmental pressure.As a necessary node in the supply chain of imported iron ore,port is very important 'for the cost optimization of steel enterprises.At the same time,in order to pursue high-speed development,port is also facing the challenge of environmental change.In response to the need for green transformation of enterprises of both sides of "port-steel",the "Port before Factory" mode of cooperation between ports and steel mills was born:the imported raw materials(fuel)or finished products to be sold are stored directly in the special port yard,waiting for the production or sales instructions to be transported from the port to the steel mills or sales destination.In this way,a closed-loop operation system consisting of purchase,produce and sale is formed.Therefore,based on the "Port before Factory" mode,this paper constructs a combined optimization model,which takes the selection of ship type,vehicle type,supplier and unloading port as variables and aims at minimizing the purchasing logistics cost and carbon emission cost of iron ore.The NSGA-? algorithm(Pareto Optimization)and the weight coefficient method are selected to verify and compare the cost and transportation scheme before and after signing the contract of "Port before Factory".The results show that the total cost,unit cost,carbon reduction optimization rate are higher and the NSGA-? algorithm optimization results are better,under the condition of "Port before Factory".Through the cooperation of upstream and downstream enterprises in the supply chain,the two sides of"Port-Steel" can achieve a fair profit state,improve the utilization rate of port resources,and save the investment of steel yard construction.This paper provides a theoretical basis for the application of "Port before Factory" mode in enterprise practice.