Technological breakthroughs

Under pressure from increasingly strict regulations on food safety and environmental protection—particularly in the European Union (EU) market—the removal of heavy metals from phosphoric acid is becoming a vital requirement for fertilizer manufacturers worldwide.

Pressure from Technical Barriers and International Regulations

The demand for phosphate fertilizers and animal feed is rising sharply alongside global population growth. However, phosphate rock—the primary raw material—often contains cadmium (Cd) and other heavy metals, which are toxic and mutagenic to humans.

Since July 2022, the European Union's Fertilising Products Regulation (FPR) has officially limited cadmium content to below 60 mg/kg P₂O₅. Furthermore, products seeking a "Green Label" must reach a threshold below 20 mg/kg P₂O₅.

Beyond the EU, many environmental organizations globally are pushing for similar tightened regulations, creating significant pressure on producers to find viable technological solutions for purifying phosphoric acid.

Limitations of Traditional Methods

For decades, the scientific and industrial communities have tested various "decadmiation" techniques. However, most have exhibited significant drawbacks:

• Calcination: Consumes massive amounts of energy and causes severe equipment corrosion.
• Co-crystallisation: Results in low acid recovery efficiency and produces large quantities of contaminated gypsum that is difficult to process.
• Ion Exchange: Requires complex pre-treatment processes and high operating costs.
• Solvent Extraction: Highly effective but requires very large initial capital expenditure (CAPEX).

The slow adoption of these technologies is primarily due to high costs, operational complexity, and the risk of generating new hazardous waste streams.

ACCO-PHOS®: A Breakthrough "Bolt-on" Solution from Syensqo

In this context, Syensqo’s ACCO-PHOS® chemical line (introduced by experts John Carr, Lei Zhang, and Yu Zheng) has emerged as a breakthrough solution. This is a "bolt-on" technology, allowing for direct integration into existing production lines without the need for massive investment in new infrastructure.

The core differentiator of ACCO-PHOS® lies in its ability to form insoluble complexes with heavy metals directly within the acidic environment. These complexes then attach to the surface of solid phases (such as gypsum) and can be easily removed through standard filtration systems.

Outstanding Advantages of ACCO-PHOS®

• High Selectivity: Especially effective for cadmium (Cd) and arsenic (As).
• Flexibility: Operates stably across a wide range of temperatures (from room temperature to 80°C) and various acid concentrations.
• Reasonable Cost: Does not require structural plant changes; dosage is proportional to the concentration of impurities to be removed.

Evidence from Industrial Production

Deployment results at five industrial-scale plants have confirmed the effectiveness of ACCO-PHOS® technology. At certain facilities, arsenic content was reduced by up to 97% and cadmium by over 90% in concentrated phosphoric acid.

The Future of the "Clean" Fertilizer Industry

The application of heavy metal removal technologies is no longer just about legal compliance; it is becoming a commercial competitive advantage. Manufacturers with "clean" products can more easily access premium markets where both added value and technical requirements are high.

With Syensqo’s strong R&D foundation, ACCO-PHOS® technology is opening a new path for the phosphate industry: safer for human health, friendlier to the environment, and more economically sustainable.