Study on recycling and leaching valuable elements from Bayan Obo tailings

2019 ◽  
Vol 116 (1) ◽  
pp. 114 ◽  
Author(s):  
Bo Zhang ◽  
Xiangxin Xue ◽  
Xiaowei Huang ◽  
He Yang ◽  
Gongjin Chen

A novel process for recovering iron, niobium and scandium from Bayan Obo tailings has been developed. In this paper, the treatment of Bayan Obo tailings by Ca(OH)2-coal roasting and sulfuric acid leaching process was investigated. In the Ca(OH)2-coal roasting process, niobium-bearing minerals are converted to CaTiO3 structure of Ca(Ti0.8,Fe0.1,Nb0.1)O3 and Ca2Nb2O7 which are soluble in sulfuric acid. The pyroxene and amphibole that are Sc-bearing silicates are mainly decomposed and reduced into metallic iron which can be recycled by weak magnetic separation. Scandium in the silicates is converted to Sc2O3. In the sulfuric acid leaching process, Ca(Ti0.8,Fe0.1,Nb0.1)O3 and Ca2Nb2O7 are converted to Nb(OH)5 that could easily dissolve in sulfuric acid by dissociating into Nb(OH)4+ and OH− when Sc2O3 is dissolved into heat sulfuric acid. Bayan Obo tailings were roasted with Ca(OH)2-coal at elevated temperature, followed by magnetic separation and sulfuric acid leaching. The optimized experimental parameters are proposed as follows: Ca(OH)2-coal-tailings mass ratio of 20: 5: 100; roasting at 1200 °C for 2 h; the magnetic field (magnetic separation) of 270 mT; the liquid-solid ratio of 4:1 (ml/g); leaching at 245 °C for 1 h. Iron concentrate with a grade of 88.39% and a recovery rate of 91.92% is obtained. The leaching results show that the leaching rates of niobium and scandium could achieve 95.52% and 95.75%, respectively.

Crystals ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 810
Author(s):  
Zhanyong Guo ◽  
Ping Guo ◽  
Guang Su ◽  
Fachuang Li

In this paper, nickel-containing residue, a typical solid waste produced in the battery production process, was used to study the cavitation characteristics of ultrasonic waves in a liquid–solid reaction. The ultrasonically-enhanced leaching technology for multicomponent and complex nickel-containing residue was studied through systematic ultrasonic-conventional comparative experiments. An ultrasonic leaching kinetics model was established which provided reliable technological guidance and basic theory for the comprehensive utilization of nickel-containing residue. In the study, it was found that ultrasonically-enhanced leaching for 40 min obtained the same result as conventional leaching for 80 min, and the Ni extraction degree reached more than 95%. According to the kinetic fitting of the leaching process, it was found that the sulfuric acid leaching process belonged to the diffusion-controlled model of solid product layers under conventional and ultrasonic conditions, and the activation energy of the reaction was Ea1 = 17.74 kJ/mol and Ea2 = 5.04 kJ/mol, respectively.


2011 ◽  
Vol 361-363 ◽  
pp. 628-631 ◽  
Author(s):  
Cheng Jun Liu ◽  
Jie Qi ◽  
Mao Fa Jiang

Utilizing Pakistan chromite as raw material, the rapid leaching of chromium and iron could be realized by the sulfuric acid leaching process on the condition of atmospheric pressure and the addition of oxidant A. And the leaching rate of chromium and iron would be 98.5% and 71.9%, respectively. The sulfuric acid leaching processes with different temperature were systematically studied by chemical analysis and phase analysis. The results showed that, with the increase of reaction temperature, the leaching rate of chromium would increase gradually, but the leaching rate of iron increased at first and then decreases and reached its maximum at 140°C. When the temperature > 160°C, the phases of the leaching residue were magnesium iron silicate and a few of silica, no chromohercynite, chrompicotite and magnesioferrite existed in the chromite. The leaching solution of sulfuric acid leaching process could be used for preparing the basic chrome sulfate, and there is no Cr6+ in the leaching residue and solution. The results would provide theoretical guidance for solving environmental pollution problem of Cr6+ in traditional chromate production process.


2014 ◽  
Vol 633 ◽  
pp. 169-172
Author(s):  
Li Jiao Yang ◽  
Nan Chun Chen ◽  
Xia Ping Zhong ◽  
Jun Gao ◽  
Yao Xiu Lang ◽  
...  

It is found that cuprous sulfite, zinc sulfate and zinc sulfide were the main phases of copper and zinc in zinc leach residue, through analyzing its composition and phase characteristics by XRF and XRD. The method that cooperate sulfuric acid leaching with oxidant was chosen. 60 g/L H2SO4 at 60 °C for 2 h with 4% KMnO4 and liquid/solid ratio of 5..1, 84.29 % of Cu and 92.02 % of Zn are extracted. The ion concentration of copper and zinc are tested by UV-VIS spectrophotometer and EDTA titration respectively. The results show that the amount of acid is sufficient for leaching at the condition of 60 g/L H2SO4 and liquid/solid ratio of 5..1. At the same time, copper change from low valence into high valence after adding KMnO4 which strengthen the leaching, and the chemical reaction can reach balance at 60 °C for 2 h. This method has good extraction effect on copper and zinc.


Processes ◽  
2021 ◽  
Vol 9 (11) ◽  
pp. 1922
Author(s):  
Anastasiia V. Dubenko ◽  
Mykola V. Nikolenko ◽  
Oleksandr O. Pasenko ◽  
Andrii Kostyniuk ◽  
Blaž Likozar

A new method of altered ilmenite processing has been studied. In this method, sulfuric acid is used as the reaction medium of the process, and fluoride ions are activators of the dissolving process of the rutile part of the ore raw material. The regression model of the sulfate–fluoride leaching process was developed and analyzed by using the response surface method of 23 matrix. The obtained model is adequate and well describes the studied process. The influence of Ti:F molar ratio, temperature, and sulfuric acid concentration on the leaching process are investigated in this work in order to optimize the studied process. It is experimentally proved that leaching at temperatures above 100 °C, at a molar ratio of Ti:F of more than 1:2, and the use of solutions of sulfuric acid with concentrations of more than 85 wt.% is not optimal because the extraction degree of titanium is reduced. The intensification of the process of sulfuric acid leaching by dividing the main stage of chemical dissolution of ilmenite into two stages was proposed. This method allows to leach up to 95.9% of titanium, which is 1.6–1.9 times higher in comparison with the classical technology of leaching altered ilmenite.


2019 ◽  
Vol 294 ◽  
pp. 86-91
Author(s):  
Hui Yang Gao ◽  
Tao Jiang ◽  
Ying Zhe Xu

In this study, microwave irradiation technology was used for the calcification roasting followed by sulfuric acid leaching process. The effect of roasting temperature, m (CaO)/m (V2O5), and roasting time on the leaching ratio of vanadium were investigated and the roasted samples were characterized by TG-DSC, XRD, and SEM. The leaching ratio of vanadium can be significantly enhanced with the increasing in roasting temperature, m (CaO)/m (V2O5), and roasting time. The leaching ratio of chromium decreased with roasting temperature and increased with m (CaO)/m (V2O5), and roasting time. The optimal roasting parameters were roasting temperature of 850 °C, the m (CaO)/m (V2O5) of 0.85, and roasting time of 90 min. Under the optimal roasting parameters, the leaching ratio of vanadium reached 88.81%. While the leaching ratio of chromium is 3.98%. During roasting process, vanadium is oxidized to acid-soluble CaV2O5, Ca2V2O7, and CaMgV2O7. After leaching, chromium mainly exists in form of chromohercynite (FeCr2O4) and chrome-manganese spinel (Mn1.5Cr1.5O4) in leaching residues.


2013 ◽  
Vol 826 ◽  
pp. 122-125 ◽  
Author(s):  
Jin Lin Yang ◽  
Hong Mei Zhang ◽  
Gui Fang Wang ◽  
Shao Jian Ma ◽  
Min Zhang

In this paper, sulfuric acid leaching was carried out to assess the effect of several parameters on metal extraction in a low grade complex gossan ore in which the grade of zinc and iron is 13% and 40.2%, respectively. Parameters, such as sulfuric acid concentration, liquid to solid ratio and leaching temperature, were studied. The results show that the zinc leaching rate is almost 80%, while the iron leaching rate is about 45% used strong acid with 200g/L. It can be seen from the results that sulfuric acid leaching could not effectively recover zinc from gossan ores studied in this paper because of iron dissolving greatly.


2013 ◽  
Vol 634-638 ◽  
pp. 3541-3544
Author(s):  
Shao Jun Bai ◽  
Shu Ming Wen ◽  
He Fei Zhao ◽  
Qin Bo Cao ◽  
Hai Ying Shen ◽  
...  

A craft of concentrated acid-heating reinforced leaching process is investigated for the treatment of a high arsenic pyrite cinder, a common by-product in vitriol industry. The pyrite cinder, containing 57.37% Fe, and 2.78% As, was conducted for the acid leaching process. The results demonstrated that iron concentrate with 60.57% Fe, 0.28% As and 96.23% of iron recovery was obtained under the optimal acid leaching conditions(Sulphuric acid concentration is a mass ratio of 20%, a leaching temperature of 60°C, a liquid-solid ratio of 2:1 and a leaching time of 120 min).This craft can be used to utilize pyrite cinder and produce qualified concentrate as iron-bearing feed for steel industry, which will help to solve the pollution of sulfuric acid residue and extend raw material sourcing for Chinese steel industry.


2018 ◽  
Vol 170 ◽  
pp. 1089-1101 ◽  
Author(s):  
Junyi Xiang ◽  
Qingyun Huang ◽  
Xuewei Lv ◽  
Chenguang Bai

2016 ◽  
Vol 5 (4) ◽  
pp. 1 ◽  
Author(s):  
XiaoMing Qu ◽  
YuFeng Guo ◽  
FuQiang Zheng ◽  
Tao Jiang ◽  
GuanZhou Qiu

<p class="1Body">The sulfuric acid leaching of titanium from titanium-bearing electric furnace slag (TEFS) was investigated under different experimental conditions. In the sulfuric acid leaching process, the M<sub>x</sub>Ti<sub>3-x</sub>O<sub>5</sub>(0≤x≤2) and diopside could react with sulfuric acid. The optimum conditions of sulfuric acid leaching process were particle size at &lt; 0.045mm, sulfuric acid concentration at 90 wt.%, acid/slag mass ratio at 1.6:1, feeding temperature at 120 °C, reaction temperature at 220 °C, reaction time at 120minute, curing at 200°C for 120 minute. The [TiO<sub>2</sub>] concentration of the water leaching was 150 g/L, and leaching temperature at 60℃for 120 minute. Ti extraction could reach 84.29 %. F of titanium-bearing solution was 2.15, and the Ti<sup>3+</sup>/TiO<sub>2</sub> of the titanium-bearing solution was 0.068. The TiO<sub>2</sub> content of the leaching residue was 18.32 wt.%. The main mineral phases of the leaching residue were calcium sulphate, spinel, diopside and little M<sub>x</sub>Ti<sub>3-x</sub>O<sub>5</sub>.</p>


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