scholarly journals Characterization and Iron Removal Treatment of Ion-Adsorption Rare Earth Tailings in Southern China

2016 ◽  
Vol 04 (02) ◽  
pp. 127-134
Author(s):  
Yongqing Wang ◽  
Xin Nie ◽  
Qibing Chang ◽  
Huayin Liang ◽  
Xiaozhen Zhang ◽  
...  
Author(s):  
Yongqing Wang ◽  
Huayin Liang ◽  
Qibing Chang ◽  
Xiaozhen Zhang ◽  
Jian’er Zhou

2017 ◽  
Author(s):  
Huizhong Lu ◽  
Longxi Cao ◽  
Yin Liang ◽  
Jiuqin Yuan ◽  
Yayun Zhu ◽  
...  

Abstract. Rare earth mining has led to severe soil erosion in southern China. Furthermore, the presence of the mineral leaching chemical ammonium sulfate in runoff and sediment poses a serious environmental threat to downstream water bodies. To study the transport characteristics of mineral leaching chemicals, soil on rare earth tailings was sampled in different positions, and runoff and sediment samples were collected along flow routes during three typical rainfall events. The results demonstrated that the NH4+ contents in the surface sediment deposits increased from the top of the heap (6.56 mg/kg) to the gully (8.23 mg/kg) and outside the tailing heap (13.03 mg/kg). The contents of SO42− in the different locations of the tailing heaps ranged from 27.71 to 40.33 mg/kg. During typical rainfall events, the absorbed NH4+ concentrations (2.05, 1.26 mg/L) in runoff were higher than the dissolved concentrations (0.93, 1.04 mg/L), while the absorbed SO42− concentrations (2.87, 1.92 mg/L) were lower than the dissolved concentrations (6.55, 7.51 mg/L). The dissolved NH4+ and SO42− concentrations in runoff displayed an exponentially decreasing tendency with increasing transport distance (Y=1.02*exp(-0.00312X), Y=3.34*exp(-0.0185X)). No clear trend with increasing distance was observed for the absorbed NH4+ and SO42− contents in transported sediment. The NH4+ and SO42− contents had positive correlations with the silt and clay ratio in transported sediment but negative correlations with the sand ratio. These results provide a better understanding of the transport processes and can be used to develop equations to predict the transport of mineral leaching chemicals in rare earth tailings.


Solid Earth ◽  
2017 ◽  
Vol 8 (4) ◽  
pp. 845-855 ◽  
Author(s):  
Huizhong Lu ◽  
Longxi Cao ◽  
Yin Liang ◽  
Jiuqin Yuan ◽  
Yayun Zhu ◽  
...  

Abstract. Rare-earth mining has led to severe soil erosion in southern China. Furthermore, the presence of the mineral-leaching chemical ammonium sulfate in runoff and sediment poses a serious environmental threat to downstream water bodies. In this paper, the characteristics of mineral-leaching chemicals in surface soil samples collected in the field were studied. In addition, NH4+ and SO42− transport via soil erosion was monitored using runoff and sediment samples collected during natural rainfall processes. The results demonstrated that the NH4+ contents in the surface sediment deposits increased from the top of the heap (6.56 mg kg−1) to the gully (8.23 mg kg−1) and outside the tailing heap (13.03 mg kg−1). The contents of SO42− in the different locations of the tailing heaps ranged from 27.71 to 40.33 mg kg−1. During typical rainfall events, the absorbed NH4+ concentrations (2.05, 1.26 mg L−1) in runoff were significantly higher than the dissolved concentrations (0.93, 1.04 mg L−1), while the absorbed SO42− concentrations (2.87, 1.92 mg L−1) were significantly lower than the dissolved concentrations (6.55, 7.51 mg L−1). The dissolved NH4+ and SO42− concentrations in runoff displayed an exponentially decreasing tendency with increasing transport distance (Y = 1. 02 ⋅ exp( − 0. 00312X); Y = 3. 34 ⋅ exp( − 0. 0185X)). No clear trend with increasing distance was observed for the absorbed NH4+ and SO42− contents in transported sediment. The NH4+ and SO42− contents had positive correlations with the silt and clay ratio in transported sediment but negative correlations with the sand ratio. These results provide a better understanding of the transport processes and can be used to develop equations to predict the transport of mineral-leaching chemicals in rare-earth tailings, which can provide a scientific foundation for erosion control and soil management in rare-earth tailing regions in southern China.


2021 ◽  
Vol 13 (16) ◽  
pp. 9460
Author(s):  
Weiying Wang ◽  
Yanqiong Xu ◽  
Riming Yan ◽  
Zhibin Zhang

Ion adsorption-type heavy rare earths found in southern China are important ore resources, whose yttrium(Y)-group rare-earth elements account for 90% of the total mass of rare earths known on the planet. At present, ammonia-nitrogen wastewater from extraction of rare earths pose threats to the environment. A bacterial strain (Bacillus sp. ZD 1) isolated from the “Foot Cave” mining area was used for adsorption of Y3+. Its adsorption capacity reached 428 μmol/g when the initial concentration of Y3+ was 1.13 mM. Moreover, 50 mg of Bacillus sp. ZD 1 (converted to dry mass) could completely adsorb Y3+ in the mother solution of mixed rare earths from the rare-earth mining area. Ammonia nitrogen in the remaining solution after adsorption was removed through denitrification using a fungus named Galactomyces sp. ZD 27. The final concentration of ammonia nitrogen in wastewater was lower than Indirect Emission Standard of Pollutants for Rare-earth Industry (GB 26451-2011). Furthermore, the resulting fungal cells of Galactomyces sp. ZD 27 could be used to produce single cell proteins, whose content accounted for 70.75% of the dry mass of cells. This study offers a new idea for integrated environmentally-friendly extraction and ecological restoration of the mining area in southern China.


Rare Metals ◽  
2018 ◽  
Author(s):  
Wan-Fu Huang ◽  
Hao Wu ◽  
Xin-Dong Li ◽  
Jia-Cai Ou ◽  
Xiao-Lin Huang

2021 ◽  
Vol 31 (1) ◽  
pp. 288-296
Author(s):  
Bo FAN ◽  
Long-sheng ZHAO ◽  
Zong-yu FENG ◽  
De-peng LIU ◽  
Wei-Qiang YIN ◽  
...  

2020 ◽  
Vol 20 (9) ◽  
pp. 3351-3357
Author(s):  
Qin Zhang ◽  
Guangyue Wan ◽  
Caiyun Zhou ◽  
Jie Luo ◽  
Jianping Lin ◽  
...  

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