| Baotou Iron&Steel co., Ltd is processing on election of niobium with many scientific research units recently. Taking tailings as raw materials, the concentrated niobium’s grade is about4%. This low-grade niobium concentrate is further enriched by high temperature reduction and removal of iron, it is called Nb-rich slag. In this paper, the processes of extraction and separation of niobium from Nb-rich slag as raw materials were studied.According to the experiments, there are two processes can be used for the recycling of niobium.Firstly, Nb-rich slag was mixed with A, and then they were decomposed by high temperature, at last Nb ions was leaching by hydrochloric acid. The process conditions are as follows:mass of Nb-rich slag:mass of A=1:0.6, the calcination temperature is800℃, calcination time is3h, the concentration of hydrochloric acid is6mol/L, and the leaching time is3h. The sedimentation rate of niobium and titanium is more than99%when the acidity of hydrochloric acid leaching solution is lower than1.1mol/L. And the total mass of niobium and titanium is above80%to the quality of the precipitate; it can be taken as raw material for extraction of niobium, and utilized in the production of niobium-titanium alloy. Secondly, Nb-rich slag was mixed with A, and then decomposed by high temperature, at last leached by sulfuric acids. The process conditions are as follows: mass of Nb-rich slag to mass of A is1:0.6, the calcination temperature is800℃, calcination time is2h, the concentration of sulfuric acids is6mol/L, and the leaching time is3h. It is found that the sedimentation rate of scandium is above91%and the sedimentation rate of rare earths is more than99%when the adding amount of hydrofluoric acid is VHF:VR=1:4and the reaction precipitation time is0.5h in the sulfuric acids leaching solution. TBP has good performance for extraction of niobium. Morevoer, the purity of the Niobium pentaoxide can be up to98.31%by a single-stage extraction, washing and anti-extraction. |
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