Classification of carbon sources in sand casting

The production process of sand casting will directly produce carbon emissions, such as alcohol combustion in flow coating liquid and slag making operation of molten iron smelting, which will directly produce carbon dioxide emissions (carbon emissions for short). However, it is unscientific to simply take the carbon emissions directly generated on site as the total carbon emissions of sand casting system. The research content of this paper aims to calculate the carbon emissions in the whole life cycle of casting products, such as power consumption and pig iron do not directly produce carbon emissions, but will produce carbon emissions in the process of power generation, pig iron production and transportation.

In the molding process of sand casting, natural gas spray gun will be used to bake the sand mold whose coating is not completely dry. In the process, the combustion of natural gas will directly emit carbon dioxide into the atmosphere, and carbon emissions will also be generated in the process of natural gas production, transportation and storage. This part of carbon emissions will also be included in the calculation range. In the carbon emission calculation method of sand casting based on process carbon source proposed in document [57], five types of carbon sources for carbon emission in sand casting have been proposed. On this basis, in order to calculate the carbon emission of sand casting based on process parameters, this paper puts forward material carbon source, energy carbon source and unexpected carbon source.

The process parameters of sand casting affect the carbon emission in the process. Materials and energy are consumed and waste and products are produced in the process of casting. The conversion of casting carbon emission is based on materials, energy and waste pollutants. Waste pollutants are called unexpected carbon sources. Then the carbon emission of sand casting is mainly composed of material carbon sources, energy carbon sources Undesired carbon sources are the three types of carbon sources.

The carbon emission of material carbon source includes the indirect carbon emission in the material production process, including the production process of casting raw materials (scrap steel, pig iron, etc.), auxiliary materials (sand, alcohol, etc.), transportation, sales and product related processes, as well as the direct carbon emission generated by chemical reaction in the process of material use; The carbon emissions of energy carbon sources include the carbon emissions directly generated by enterprises’ consumption of energy in production, as well as the indirect carbon emissions generated by various energy sources in their own manufacturing process; The carbon emission of undesired carbon source refers to the carbon emission generated in the process of treating the waste and waste products formed in the production of casting process, including the carbon emission directly generated in the process of waste treatment and the indirect carbon emission formed by the consumption of energy and materials such as electricity in the process of treatment.