Novel Harmless Utilization of Bayan Obo Tailings: Separation and Recovery of Iron and Rare Earth

Abstract

In this work, the carbothermal reduction and hydrochloric acid leaching were utilized for separation and recovery of iron and rare earth from the Bayan Obo tailings. The effects of temperature, addition of calcium oxide, and reaction time on the metallization rate of iron during roasting were investigated. The results showed that the metallization rate of iron reached 99.67% and the loss rate of fluorine was less than 1% under optimum roasting conditions of a temperature of 1100 °C, a coal ratio of 6.77 wt %, a calcium oxide ratio of 10 wt %, and a roasting time of 2 h. The behavior of iron and rare earth in magnetic separation was found to be controlled by the particle size after grinding. Using ball milling, 98.2% of rare earth and 96.7% of Fe were separated. A hydrochloric acid solution with a low concentration of 3 mol/L was used to leach rare earth from the magnetic separation tailings. The results showed that the leaching recovery of rare earth exceeded 99%, and more than 80% of other valuable elements were also leached out. Finally, the leaching residue contained 52.38 wt % of pure calcium fluoride, which can be used as a raw material for the flotation of fluorite.

In situ separation and characterization of britholite crystals in RE‐bearing slag via supergravity

“…4 In recent decades, Baogang Steel has mainly treated Bayan Obo ore for iron making process, in which almost REEs were mainly transferred to the RE-bearing slag. 5,6 The composition of RE-bearing slag was varied with the composition of Bayan Obo ore and the smelting conditions, and the content of REEs was about 15 wt.%. 7 At present, a large amount of RE-bearing slag is stacked in the tailings dam and cannot be utilized efficiently.…”

“…Bayan Obo ore deposit in the Inner Mongolia region of North China is a rare multimetallic mine that accounts for 59.3% of the world's REEs reserves 4 . In recent decades, Baogang Steel has mainly treated Bayan Obo ore for iron making process, in which almost REEs were mainly transferred to the RE‐bearing slag 5,6 . The composition of RE‐bearing slag was varied with the composition of Bayan Obo ore and the smelting conditions, and the content of REEs was about 15 wt.% 7 .…”

Selective separation and crystal characterization of RE‐phases from RE‐bearing slag systems: Calcium cerite and cefluosil

“…The RE reserves of Bayan Obo mine in China rank first in the world. For a long time, the RE‐bearing (RE‐bearing) mine has mainly been utilized in iron‐making process for the recovery of iron, 2,3 where almost all the REs were transferred into the RE‐bearing slag with a high rare‐earth content of 15–20 wt.% 4 . In recent years, the recovery and utilization of REEs resources in RE‐bearing slag systems have attracted great interest 5–7 …”

“…For a long time, the RE-bearing (RE-bearing) mine has mainly been utilized in iron-making process for the recovery of iron, 2,3 where almost all the REs were transferred into the RE-bearing slag with a high rare-earth content of 15-20 wt.%. 4 In recent years, the recovery and utilization of REEs resources in RE-bearing slag systems have attracted great interest. [5][6][7] So far, the basic data for RE phases is seriously lacked and divergent, which brings many difficulties to effectively extract RE resources from RE-bearing slag systems.…”