At present, environmental problems have become increasingly prominent, and countries all over the world pay more attention to the pollution problem of traditional manufacturing industry. Sand casting, as a traditional metal forming process, not only occupies a pivotal position in the manufacturing industry, but also is an important source of resource consumption and environmental pollution. According to statistics, China’s casting output in 2020 has reached 51.95 million tons, with a year-on-year growth of 6.6%, ranking first in the world for 21 consecutive years. However, the development mode of sand casting industry is still extensive, and environmental protection and safety production are still relatively weak.
In order to reduce the impact of sand casting process on resources and environmental load and improve the green level of sand casting industry, scholars at home and abroad have explored the environmental impact of sand casting process from energy saving and emission reduction, environmental impact, dust removal and purification and other aspects. J Zheng proposed a carbon emission prediction model for sand casting, which saved 21%~24% of process carbon emissions on average through process optimization design. Zhu Ying has designed and reformed the waste gas purification system of sand mold casting and applied it as an example. Wang Tingting carried out research on the particulate matter emission in each production process of sand casting enterprises, and summarized the potential of cleaner production and emission reduction of sand casting enterprises. Xiong Xiaoqi studied the emission characteristics and control measures of air pollutants in Shanxi sand casting industry. At present, the relevant research mainly focuses on the environmental impact of a certain type of sand casting process, lacking comprehensive impact research on resources and environmental load of sand casting process, and insufficient data on the comprehensive impact of resources and environmental load between different sand casting processes.
Aiming at two typical sand casting processes, an evaluation index system of sand casting process resources and environmental loads was established, and the index weights were calculated. The data of two sand casting process resources and environmental loads were calculated using the life cycle assessment method, and the comprehensive evaluation of resources and environmental loads was conducted according to the evaluation index system. The evaluation results further improved the understanding of the comprehensive impact of sand casting process resources and environmental loads, Identify the key links of sand casting process, and provide a solid foundation for green improvement of sand casting process.
Taking the static pressure casting process and V-method casting process in sand mold casting as the research object, the casting process was analyzed and summarized into four processes: smelting, molding, pouring and cleaning. The environmental impact factors of each process were studied. Based on the theory of life cycle assessment, nine assessment indicators including climate change (GWP), abiotic resource consumption potential (ADP), primary energy consumption (PED), acidification impact (AP), water resource consumption (WU), water eutrophication (EP), photochemical ozone synthesis (POCP), human toxicity potential (HTP), and inhalable inorganic substances (RI) were selected, and an assessment indicator system of typical foundry process resources and environmental load was established. The comprehensive impact assessment of typical casting process resources and environmental loads was carried out from three aspects of resource consumption, environmental load and human health impact, and quantitative comparative analysis was carried out according to the assessment results. The smelting process is the main process that generates resources and environmental loads, and the process should be greenized; From the perspective of workers’ occupational health, it is necessary to strengthen the treatment of waste gas emission in the molding process and cleaning process.