| Abstract |
With the growing low-carbon economy, the demand for copper resources is increasing, and Taiwan, which is highly dependent on imports, is potentially vulnerable to future copper resource shortages. In this context, the copper resource loss through industrial waste flows is a significant issue that must be addressed effectively. This study aims to implement a systematic approach to in-plant copper recycling in Taiwan's printed circuit board (PCB) manufacturing industry, to support copper recovery rates and improve waste management efficiency. Using material flow analysis, this study assesses copper resource utilization and identifies potential recycling opportunities. Material-flow cost accounting approach is employed to assess the economic benefits associated with in-plant copper recycling. Four representative plants, along with two recycling programs and eight rate scenarios, which recycle copper from various waste streams, are considered to evaluate their effects on each plant's economic health and waste management efficiency. The results indicate that the costs of material loss mainly affect the hidden costs of waste, accounting for over 80 % of these costs in the material-flow cost accounting. The study also demonstrates significant waste management benefits from in-plant copper recycling across both recycling programs, drastically reducing the costs for outsourced treatment of copper-containing waste while achieving a high copper recovery rate of over 95 % for each plant. The copper content in waste streams influences recycling process costs and the value derived from recycled products. Therefore, a processoriented copper recycling program is advisable, especially for plants seeking to repurpose copper into products for external sale. This model helps determine benefits and provides recommendations for effective in-plant copper recycling programs. For instance, prioritizing the recycling of copper-containing waste from specific processes such as sheet cutting, lamination, soldering mask, and wastewater treatment is recommended, considering factors like process similarity, copper content, and waste proportions. It may serve as a valuable reference for both government and industry stakeholders seeking to promote future copper resource circulation in Taiwan and countries with PCB industries. However, further research is needed to address data gaps and integrate life cycle assessment methodologies for environmental evaluation. |