Exploration of hydrogen-based suspension magnetization roasting for refractory iron ore towards a carbon-neutral future: A pilot-scale study

In the iron and steel industry, magnetization roasting technology is one of the effective methods to realize the efficient development and utilization of refractory iron ores, but global warming requires us to reduce greenhouse gas emissions. Therefore, switching to the clean reducing agent for the magnetization roasting of iron ores is of significance. In this study, hydrogen was used as reductant for the pilot-scale study of suspension magnetization roasting of a refractory iron ore, and the roasted products were processed with magnetic separation. The results showed that the continuous stability experiments obtained a magnetic separation concentrate with an average iron grade of 65.68% and an average iron recovery of 91.64% under the optimal roasting conditions of temperature 470 degrees C, hydrogen concentration 22%, feeding rate 140 kg/h and total gas flow rate 18 m3/h. The phase composition and changes of the ore during roasting, as well as the magnetic characteristics, were analyzed by X-ray diffraction, Mo euro ssbauer spectroscopy, and vibrating sample magnetometer, respectively. Besides, the microscopic morphology and micro-area element content of the ore were observed by a field emission scanning electron microscope equipped with an EDS unit. This study provides a reference for the efficient and clean utilization of refractory iron ores towards a carbon-neutral future.

Automated summary

In this study, hydrogen was used as a clean reducing agent for the magnetization roasting of refractory iron ores. The results showed that using hydrogen as the reductant achieved a high iron recovery rate and a concentrate with high iron grade. The study also analyzed the phase composition, magnetic characteristics, and micro-area element content of the ore. This research provides valuable insights for the efficient and clean utilization of refractory iron ores in achieving a carbon-neutral future.