Integrated production of potash fertilizer and formed coke via carbonated consolidation technique

Abstract

Transforming potassium feldspar (PF) into water-soluble potassium fertilizer traditionally requires high-temperature conditions, a significant challenge in sustainable agriculture. Addressing this, our study innovatively employed the carbonated consolidation process using low-rank semi-coke (SC). By introducing PF and alkaline earth metal salts, we produced high-strength formed coke (FC). Crucially, the combustion heat from FC facilitated the desired transformation in the coke ash. Our findings highlight that FC with PF addition yields a calorific value of 20.8 MJ/Kg, aligning with industrial standards, and significantly curtails emissions of sulfur, nitrogen compounds, and dust, emphasizing its eco-friendly nature. Remarkably, a 96.5% potassium leaching rate was achieved within 4 h at 25 °C. Further analyses showcased the FC's carbonate content's role in drastically reducing the transformation temperature of potassium in PF to a mere 570 °C. This research not only offers a cleaner approach to SC utilization but also paves the way for cost-effective and eco-friendly PF transformations, bearing significant implications for future sustainable agricultural practices.