Reduction behavior of boron-bearing iron concentrates by bituminous coal and its magnetic separation

•Effects of temperature and time on the reduction behavior of boron-bearing iron concentrate briquettes were studied.•Temperature played a crucial role in the selective reduction of iron minerals in boron-bearing iron concentrate briquettes.•Boron is not volatile if the reduction temperature is controlled below 2609 K.•Microstructure features of briquettes reduced at diverse temperatures and times are investigated.

In this study, the effects of temperature and time on the reduction behavior of boron-bearing iron concentrate briquettes were studied by using X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy dispersive spectrometer (EDS). Results indicated that reduction temperature played a crucial role in the selective reduction of iron minerals in boron-bearing iron concentrate briquettes with bituminous coal as a reducer. The increase in reduction time facilitated the generation of metallic iron and the grain growth of the metallic phase in the reduced briquettes, which had a beneficial effect on the separation of iron and boron in the subsequent low-intensity magnetic separation process. The magnetic material contained 92.81% Fe with a recovery of 95.58%, while in the boron-rich non-magnetic material, the grade and recovery values of B2O3 were 14.11% and 89.59%, respectively. In addition, the efficiency of extraction of boron of the non-magnetic material was 80.76%. The magnetic material and boron-rich non-magnetic material were good raw materials for steel-making and borax production.