Material Flow Cost Accounting Modeling and Life Cycle Analysis of Zinc Smelting Industry Concentrate Unit in Iran to Reduce Environmental Pollution

In developing countries, Material Flow Cost Accounting (MFCA) offers numerous benefits, including the identification of hidden costs, waste reduction, improved environmental outcomes, enhanced product quality and competitiveness, and increased process and resource productivity. The zinc mining industry and related activities, such as concentrate production and zinc smelting, require process life cycle analysis due to the extensive pollution they generate, including contamination of surface and underground water from heavy elements in the leachate. Through the use of MFCA modeling, it is possible to accurately evaluate the inputs and outputs of current processes in this field and analyze them for environmental effects.

This study involved visits to industrial smelting units, expert opinions, and integration with the Sima Pro software database to prepare a life cycle model and network of the product life cycle and its environmental effects. By analyzing the life cycle of Iran's zinc smelting industry, green product productivity was used to calculate the cost-material flow in the selected sample unit, track the material flow, and present a model for the life cycle of zinc. This involved utilizing information from Iran's zinc smelting industry, data from the Sima Pro software database, and the implementation of the MFCA model on information related to zinc smelting and concentrate products. In this model, zinc smelting and zinc concentrate production processes were treated as input and greenhouse gas emissions as output.

Based on the material balance relationship, the combination of calcine with sulfuric acid produces leach cake, silver, lead, and air pollution. The research estimates that for the production of one ton of zinc ingot, the amount of air pollution generated is 7 kg. MFCA analysis of the leaching unit of the industrial research complex indicates that the cost of 5070 kilograms of input materials is 12,350,000 Tomans, the cost of the system is 30,000,000 Tomans, and the cost of energy is 1,950,000 Tomans. The study also found that 3549 kg of product is obtained for 9,100,000 Tomans, while 1536 kg of waste is produced at the cost of 3,250,000 Tomans. This highlights the input values, the primary product, and the secondary product.

Through the provision of comprehensive life cycle models for the zinc smelting process, especially the zinc smelting concentrate process, the inputs and outputs of the production chain were evaluated. By accurately determining the flow cost of these materials, the process of zinc smelting concentrate production can be optimized to minimize losses, reduce environmental pollution, lower direct costs, and increase economic output, thereby leading to the growth and development of the industrial complex.