| As global warming is becoming a major challenge for mankind,iron and steel enterprises should take measures to address the pressure of emission reduction immediately since they are carbon emission intensive companies,which enhances the development of short-range electric furnace steel-making process.EAF steelmaking is a remanufacturing process,which has the characteristics of short process flow and low energy consumption.However,apart from the general remanufacturing features,the uncertainty of the element content in the scrap steel and the variety of its finished steel make EAF steelmaking process more complex.Production decisions need to take both the uncertainty of general remanufacturing and the characteristics of raw and scrap steel into account.Reasonable production planning has a significant impact on the total cost and carbon footprint of scrap remanufacturing.Therefore,this paper studies the production planning of scrap steel remanufacturing under carbon emission policy.There are many studies on the general remanufacturing process,mainly considering the influence of uncertainties such as the quantity of recycled products,the quality of recycled products and the demand on production and recovery strategies.In addition,under the background of carbon emission reduction,the problem of steel-making remanufacturing production plan is special,mainly in the following aspects:(1)The classification of the scrap steel.Scrap steel is recycled from different sources which means there are various types with different contents in it,and classification can enhance the efficiency of remanufacturing while the process of classifying will result in cost;(2)The uncertainty of the content of alloy in scrap.In the process of EAF steelmaking,scrap steel can be used as both ferritic source and alloy source,and the uncertainty of alloy content will affect the utilization efficiency of scrap steel;(3)One-way alternative to different types of scrap steel.Since the alloying elements in the molten steel are difficult to extract,the alloy element which is induced to the steel and is unwanted by the product(ie impurity elements)will reduce the quality of steel products.So all types of scrap steel show a one-way alternative relationship.In summary,this paper analyzes the uncertainties and key characteristics of scrap steel remanufacturing process,and constructs the optimization model of scrap steel remanufacturing production plan under the carbon emission reduction environment.This paper includes the following three parts:(1)Considering the uncertain content of scrap steel.Electric furnace is mainly used for smelting the special steel or alloy steel whose requirements of alloying elements are more stringent.The effective use of scrap steel alloy elements can reduce the amount of alloy when refining,thereby reducing the refining time and the cost of raw materials.Since the impurity elements is difficult to extract,the introduction of them will reduce the quality of steel.However,even if the scrap steel is classified,the alloy content of scrap steel in the same category is usually within the specified range,and the alloy content of the steel product is usually interval,too.So this uncertainty must be taken into account when making a charge plan in order to achieve the optimal allocation of raw materials to reduce costs;(2)Scrap steel remanufacturing production plan based on steel matching.Recycled scrap steel is classified and preferentially allocated to the corresponding products that match the product alloy standard.The steel match can reduce the cost and energy consumption of the remelting process and can effectively reduce carbon emissions,while the classification will bring classification costs.As China’s electric furnace steelmaking started late,classification facilities are not perfect,which means there are classification and non-classification of the situation.This section will compare the classified and non-classified enterprises’ optimal production plan under the circumstances of carbon emissions policy and analyses the carbon emissions policy’s impact on the classification decision;(3)Scrap steel scrap remanufacturing production plan optimization with consideration the one-way replacement of scrap steel.As the alternative is unidirectional,and the proportion of various types of scrap iron and steel in the recovered product does not necessarily converge with the proportion of various types of steel products,there is a shortage of raw materials in some of the remaining scrap and some products.Therefore,to maximize profits,hot metal may be used to make up for the shortage of scrap or excess scrap steel is recovered to meet all the smelting needs.In addition,the use of hot metal will bring a lot of carbon emissions,so the impact of carbon emissions policy on optimal decisions is analyst.In addition to enriching the theory of manufacturing decision-making of scrap steelmaking,this paper can provide guidance for enterprise production decision and government carbon emission policy. |
