1
|
LCA-Based Carbon Footprint Accounting of Mixed Rare Earth Oxides Production from Ionic Rare Earths. Processes (Basel) 2022. [DOI: 10.3390/pr10071354] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
At present, there are significant knowledge gaps in the research on the resource and environmental effects of rare earth exploitation, especially the carbon emission coefficient. This study applies the life cycle assessment approach to calculate the carbon footprint of producing mixed oxide rare earths using ionic rare earth resources and analyze the sources and influencing factors of the carbon footprint. The results show that the carbon footprint of producing 1 kg of mixed oxide rare earths using ionic rare earths is 17.8~24.3 kg CO2 eq, but its uncertainty is 15.54%; the total carbon footprint from 2012 to 2017 reaches 1.6 × 108~2.19 × 108 kg CO2 eq/year, and after 2018, the carbon footprint decreases to 1.51 × 108~2.07 × 108 kg CO2 eq /year. The total carbon footprint of illegal mining is around 1.50 × 108~1.59 × 108 kg CO2 eq/ year. In principle, the higher the recovery rate, the lower the carbon footprint of 1 kg REO production, but with the increase in the recovery rate, the carbon footprint reduction benefit brought by the increase in the unit recovery rate shows a downward trend. Finally, the new generation of magnesium salt leaching technology, while alleviating ammonia nitrogen pollution in ionic rare earth mines, will increase the carbon footprint of the product.
Collapse
|
2
|
Ou X, Chen Z, Chen X, Li X, Wang J, Ren T, Chen H, Feng L, Wang Y, Chen Z, Liang M, Gao P. Redistribution and chemical speciation of rare earth elements in an ion-adsorption rare earth tailing, Southern China. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 821:153369. [PMID: 35077788 DOI: 10.1016/j.scitotenv.2022.153369] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/22/2021] [Revised: 01/19/2022] [Accepted: 01/20/2022] [Indexed: 06/14/2023]
Abstract
Mining is an activity that will change the distribution and chemical speciation of rare earth elements (REEs), thus posing a serious threat to the natural environment. However, the distribution and chemical speciation of REEs in ion-adsorption rare earth tailings remain poorly understood. In this study, we investigated the contents and forms of REEs and associated geochemical behavior in rare earth tailings in southeast China. Total rare earth elements (TREEs) contents were lower while the ratios of light REEs (LREEs) to heavy REEs (HREEs) were higher in tailings than in an unmined area. In the unmined area, the distribution characteristics of TREEs and LREEs remained consistent, whereas HREEs differed with increasing depth. However, in the tailing area, the distribution characteristics of TREEs, LREEs and HREEs tended to be consistent, reflecting the outcomes of mining activities on vertical distribution characteristics of REEs. The REEs were dominated by residual and exchangeable forms in the unmined area, while residual and exchangeable REEs accounted for 80% and 20% of the TREEs, respectively, in the three tailings. Additionally, the exchangeable and carbonate-bound REEs increased but Fe/Mn oxide-bound and organic-bound REEs declined in the unmined area, whereas their distribution characteristics were irregular in the tailings. These results suggest that mining activity could curtail REEs contents and redistribute their chemical speciation, further altering geochemical behaviors in the tailings and posing serious risks to adjacent environments.
Collapse
Affiliation(s)
- Xiaolin Ou
- Key Laboratory for Humid Subtropical Eco-Geographical Processes of the Ministry of Education, Fujian Normal University, Fuzhou, China; School of Geographical Sciences, Fujian Normal University, Fuzhou, China
| | - Zhibiao Chen
- Key Laboratory for Humid Subtropical Eco-Geographical Processes of the Ministry of Education, Fujian Normal University, Fuzhou, China; School of Geographical Sciences, Fujian Normal University, Fuzhou, China.
| | - Xiuling Chen
- Key Laboratory for Humid Subtropical Eco-Geographical Processes of the Ministry of Education, Fujian Normal University, Fuzhou, China; School of Geographical Sciences, Fujian Normal University, Fuzhou, China
| | - Xiaofei Li
- Key Laboratory for Humid Subtropical Eco-Geographical Processes of the Ministry of Education, Fujian Normal University, Fuzhou, China; School of Geographical Sciences, Fujian Normal University, Fuzhou, China
| | - Jian Wang
- Key Laboratory for Humid Subtropical Eco-Geographical Processes of the Ministry of Education, Fujian Normal University, Fuzhou, China; School of Geographical Sciences, Fujian Normal University, Fuzhou, China
| | - Tianjing Ren
- Key Laboratory for Humid Subtropical Eco-Geographical Processes of the Ministry of Education, Fujian Normal University, Fuzhou, China; School of Geographical Sciences, Fujian Normal University, Fuzhou, China
| | - Haibin Chen
- Key Laboratory for Humid Subtropical Eco-Geographical Processes of the Ministry of Education, Fujian Normal University, Fuzhou, China; School of Geographical Sciences, Fujian Normal University, Fuzhou, China
| | - Liujun Feng
- Key Laboratory for Humid Subtropical Eco-Geographical Processes of the Ministry of Education, Fujian Normal University, Fuzhou, China; School of Geographical Sciences, Fujian Normal University, Fuzhou, China
| | - Yikai Wang
- Key Laboratory for Humid Subtropical Eco-Geographical Processes of the Ministry of Education, Fujian Normal University, Fuzhou, China; School of Geographical Sciences, Fujian Normal University, Fuzhou, China
| | - Zhiqiang Chen
- Key Laboratory for Humid Subtropical Eco-Geographical Processes of the Ministry of Education, Fujian Normal University, Fuzhou, China; School of Geographical Sciences, Fujian Normal University, Fuzhou, China
| | - Meixia Liang
- Key Laboratory for Humid Subtropical Eco-Geographical Processes of the Ministry of Education, Fujian Normal University, Fuzhou, China; School of Geographical Sciences, Fujian Normal University, Fuzhou, China
| | - Pengchang Gao
- Key Laboratory for Humid Subtropical Eco-Geographical Processes of the Ministry of Education, Fujian Normal University, Fuzhou, China; School of Geographical Sciences, Fujian Normal University, Fuzhou, China
| |
Collapse
|
3
|
Zhang T, Zhuo X, Shi G, Zhang M. Colorimetric recognition of lanthanide ions with a complexometric indicator array. Analyst 2021; 146:4441-4445. [PMID: 34136890 DOI: 10.1039/d1an00710f] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A colorimetric sensor array based on complexometric indicators is proposed for pattern recognition of lanthanide ions. The complexometric indicators have abundant functional groups and can act as a platform for chromogenic reaction with various metal ions, including lanthanide ions. The subtle difference of the lanthanide ions' structure results in the difference of absorbance response between lanthanide ions and two chromogenic indicators (Alizarin Red and Erichrome Black T) in Tris-HCl buffer with two different pHs (i.e., pH 7.4 and pH 8.5, colorimetric sensor array). Fourteen lanthanide ions were distinguished well with the newly designed colorimetric sensor array. The sensor array has the potential to distinguish between different concentrations of lanthanide ions and their mixtures. Moreover, the results in actual samples indicate the future practical applications of this sensor array in environmental analysis.
Collapse
Affiliation(s)
- Tiantian Zhang
- School of Chemistry and Molecular Engineering, Shanghai Key Laboratory for Urban Ecological Processes and Eco-Restoration, Shanghai Key Laboratory of Multidimensional Information Processing, Engineering Research Centre for Nanophotonics and Advanced Instrument (Ministry of Education), East China Normal University, 500 Dongchuan Road, Shanghai 200241, China.
| | - Xiuzhi Zhuo
- School of Chemistry and Molecular Engineering, Shanghai Key Laboratory for Urban Ecological Processes and Eco-Restoration, Shanghai Key Laboratory of Multidimensional Information Processing, Engineering Research Centre for Nanophotonics and Advanced Instrument (Ministry of Education), East China Normal University, 500 Dongchuan Road, Shanghai 200241, China.
| | - Guoyue Shi
- School of Chemistry and Molecular Engineering, Shanghai Key Laboratory for Urban Ecological Processes and Eco-Restoration, Shanghai Key Laboratory of Multidimensional Information Processing, Engineering Research Centre for Nanophotonics and Advanced Instrument (Ministry of Education), East China Normal University, 500 Dongchuan Road, Shanghai 200241, China.
| | - Min Zhang
- School of Chemistry and Molecular Engineering, Shanghai Key Laboratory for Urban Ecological Processes and Eco-Restoration, Shanghai Key Laboratory of Multidimensional Information Processing, Engineering Research Centre for Nanophotonics and Advanced Instrument (Ministry of Education), East China Normal University, 500 Dongchuan Road, Shanghai 200241, China.
| |
Collapse
|
5
|
Zhou H, Chun X, Lü C, He J, Du D. Geochemical characteristics of rare earth elements in windowsill dust in Baotou, China: influence of the smelting industry on levels and composition. ENVIRONMENTAL SCIENCE. PROCESSES & IMPACTS 2020; 22:2398-2405. [PMID: 33237075 DOI: 10.1039/d0em00273a] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Smelting is one of the main sources of rare earth elements (REEs) in large scale smelting regions that have been neglected before. To provide experimental evidence on the influence of smelting processes on REEs in windowsill dust, this study investigated the concentration, chemical fractions, and spatial distribution of 14 REEs in windowsill dust and assessed the possible influence of smelting processes on the geochemical behavior of these REEs. A total of 46 windowsill dust samples were collected from different locations in Baotou, a typical industrial city for large-scale smelting. The fractions of REEs were analyzed by Tessier sequential extraction analysis. The enrichment factor (EF) was adopted to assess the contribution of anthropogenic emissions of REEs. The loess-normalized REE patterns of windowsill dust are similar to those of the iron ore of the Bayan Obo mine, but differ from those of the local soil. The concentrations of La, Ce, Pr, Nd, and ∑REEs in the residual fraction and total digestion decrease gradually with the increase in distance from the smelter in the downwind direction. These results suggested that the accumulation and fractionation of REEs in windowsill dust are considerably influenced by smelting. The emission of smelting is the main source of REEs for windowsill dust in Baotou.
Collapse
Affiliation(s)
- Haijun Zhou
- Inner Mongolia Key Laboratory of Mongolian Plateau Environment and Global Change, Inner Mongolia Normal University, Hohhot 010022, China and Inner Mongolia Repair Engineering Laboratory of Wetland Eco-environment System, Inner Mongolia Normal University, Hohhot 010022, China and College of Geographical Sciences, Inner Mongolia Normal University, Hohhot 010022, China
| | - Xi Chun
- Inner Mongolia Key Laboratory of Mongolian Plateau Environment and Global Change, Inner Mongolia Normal University, Hohhot 010022, China and Inner Mongolia Repair Engineering Laboratory of Wetland Eco-environment System, Inner Mongolia Normal University, Hohhot 010022, China and College of Geographical Sciences, Inner Mongolia Normal University, Hohhot 010022, China
| | - Changwei Lü
- School of Ecology and Environment, Inner Mongolia University, Hohhot 010021, China
| | - Jiang He
- School of Ecology and Environment, Inner Mongolia University, Hohhot 010021, China
| | - Dagula Du
- Environmental Monitoring Center of Inner Mongolia, Hohhot 010011, China
| |
Collapse
|