Comprehensive analysis and relevant developments of cadmium removal technologies in fertilizers industry

The fertilizers industry is mainly developing its activities by processing phosphate, phosphoric acid and ammonia. The cadmium (Cd) is one of the most challenging materials, which is existed naturally in the heterogeneous mixture of phosphate ore as the main source of phosphate (feed of fertilizer production). The legal limits for cadmium in fertilizers is 60 mg/kg in different regions, guidelines and standards such as European Union (EU), China, Canada, and International Fertilizer Association (IFA). Therefore, the cadmium removal from wet phosphoric acid that is produced from the Wet Process Acid (WPA) is today a massive challenge to the fertilizers industry to face environmental, economic, financial, political and other legal constraints. These constraints have committed to develop significant research and innovation interests on cadmium removal technologies from the phosphate ore as feedstock and the produced phosphoric acid. The research reported in the present article aims to give a comprehensive overview and relevant developments of cadmium removal technologies in phosphoric acid industry, with a specific focus on technical feasibility, complexity, cost evaluation and sustainability of the main technologies that could present a potential application at the industrial scale.

Automated summary

The fertilizers industry mainly processes phosphate, phosphoric acid, and ammonia. Cadmium, a challenging material, naturally exists in the heterogeneous mixture of phosphate ore, which serves as the main source of phosphate for fertilizer production. The legal limits for cadmium in fertilizers are set at 60 mg/kg by different regions, guidelines, and standards such as the European Union (EU), China, Canada, and the International Fertilizer Association (IFA). The removal of cadmium from wet phosphoric acid poses significant challenges for the fertilizers industry due to environmental, economic, financial, political, and legal constraints. This article reviews the developments of cadmium removal technologies in the phosphoric acid industry, focusing on technical feasibility, complexity, cost evaluation, and sustainability of potential industrial-scale applications.