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《稀土》2020,(1)
为研究稀土尾矿库周边植物碱蓬对4种稀土元素(La、Ce、Pr、Nd)的吸收和富集特征,以广泛分布于稀土尾矿库周边的碱蓬及其根区土壤为研究对象,用ICP-MS法分析土壤中La、Ce、Pr、Nd、Sm、Gd的含量和碱蓬各器官中La、Ce、Pr、Nd的含量,并对土壤进行了污染评价。结果表明,土壤中6种稀土元素的平均含量顺序为:CeLaNdPrSmGd,其数值分别为7826.9 mg/kg、4117.8 mg/kg、2251.0 mg/kg、1393.3 mg/kg、240.1 mg/kg、217.0 mg/kg,且稀土尾矿库周边土壤受到了严重的稀土元素复合污染;碱蓬对La、Ce、Pr、Nd的吸收没有特别的选择性;碱蓬对La、Ce、Pr、Nd的转移能力和耐受力较强,且碱蓬植物体内积累了较多的稀土元素,所以碱蓬在一定意义上可用于该地区稀土元素污染土壤的修复;在采样点GW-1~GW-11中,碱蓬各器官中La、Ce、Pr、Nd的含量水平为根叶茎;在采样点GW-12~GW-18中,碱蓬各器官中La、Ce、Pr、Nd的含量水平为根茎叶,即La、Ce、Pr、Nd主要分布于碱蓬根部;相关性分析表明,碱蓬各器官中的稀土元素大部分来源于其根区土壤;在采样点GW-1~GW-18中,碱蓬对La、Ce、Pr、Nd转移系数的平均值分别为0.976、1.013、0.897、0.944,说明稀土尾矿库周边的碱蓬对稀土元素的转移能力顺序为:CeLaNdPr;碱蓬对La、Ce、Pr、Nd富集系数的平均值分别为0.117、0.153、0.108、0.149,说明稀土尾矿库周边的碱蓬对稀土元素富集能力顺序为:CeNdLaPr。 相似文献
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为阐明在南方花岗岩红壤侵蚀区植被恢复对稀土迁移的影响,探讨稀土迁移的植物阻控效应,本研究以空间序列代替时间序列法选取不同治理年限下的典型样地,深入剖析其稀土含量特征,旨在量化评估生态林草措施下不同治理年限内阻控稀土迁移的生态效应。结果表明,水土流失样地随着生态恢复年限的增加,植被覆盖度的提高,植物种类的丰富,水土流失地土壤环境得到了改善,表层稀土流失也呈现出下降的趋势;土壤-芒萁系统中,稀土元素生态富集系数Ax呈现出先增加后下降的趋势,说明了土壤中稀土含量的增加短期内促进了稀土元素向芒萁植物叶片的迁移。芒萁植物叶片优先富集土壤中的轻稀土元素,充分体现出超累积植物芒萁一定程度上可阻控稀土元素向下游迁移,有可能达到生物调控环境中稀土污染的目的。研究成果可为拓展南方红壤侵蚀区稀土迁移的生物阻控提供科学依据。 相似文献
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准格尔矿区黑岱沟露天煤矿燃煤中含有丰富的稀土元素,且在其燃烧产物粉煤灰中进一步富集,使得粉煤灰成为潜在的稀土资源。而研究粉煤灰中的稀土浸出特性,是从粉煤灰中提取稀土必不可少的环节,对于粉煤灰中稀土的提取具有重要的参考价值。文章研究了黑岱沟露天煤矿燃煤及燃煤产物粉煤灰的特性,以及采用盐酸浸出粉煤灰中的稀土元素的规律。研究结果表明,黑岱沟露天煤矿燃煤主要由硅、铝、铁等组成,其中氧化铝含量为18.66%,氧化硅含量为12.79%,稀土元素含量为144.93×10-6,灰分为32.74%。燃烧后产生的粉煤灰中氧化铝含量可达50%,稀土氧化物含量则富集到939.12×10-6,其中轻稀土主要存在于粉煤灰中的非晶态物中或以独立的化合物形式存在,少量存在于晶体矿物,而重稀土则主要存在于晶体矿相中,较难溶于酸,在150℃、150 min、盐酸浓度为25%,固含为18.62%的条件下,轻稀土与重稀土的平均溶出率分别为90%与60%。 相似文献
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贵州织金含稀土生物屑磷块岩稀土元素赋存状态研究 总被引:6,自引:0,他引:6
对贵州织金新华含稀土磷矿床进行的稀土元素分析结果表明,磷块岩中含稀土总量ΣREE较高,LREE/HREE比值较大,富集La、Nd、及Y等轻稀土及重稀土元素.普遍具Ce、Eu的负异常,稀土分配模式等显示海相沉积源区继承性及热水源加入特征.生物碎屑、白云石及胶磷矿的单矿物微量元素分析证明,稀土元素含量与胶磷矿密切相关.胶磷矿中稀土元素含量大于其它矿物中稀土含量.扫描电镜及电子探针分析研究表明,稀土元素主要不是以独立矿物形式存在.化学物相分析研究证明,稀土元素多以类质同象形式存在于磷灰石中,少量被粘土矿物相吸附.解决了该类型矿床稀土元素赋存状态长期未解决的问题.综合研究表明,稀土元素赋存状态主要以类质同象形式存在于磷灰石晶格中,稀土元素的含量与胶磷矿密切相关. 相似文献
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研究了天然放射性元素钍、铀、镭在稀土冶炼过程中转移情况。使用X-射线荧光(XRF)对渣样分析以及电感耦合高频等离子光谱仪(ICP)对冶炼过程产生的水样分析,结果表明,得到稀土矿中的钍、镭元素主要富集于酸溶渣;铀元素富集于中和渣。通过伽马谱分析计算酸溶渣中钍含量为426.47 mg/kg,中和渣中铀的含量为281.82 mg/kg;并且酸溶渣的放射性活度要高于中和渣。最后分析稀土生产工艺流程得到渣中的主要物相组成:酸溶渣中主要含有硫酸钡、二氧化硅、稀土难溶氧化物和稀土复盐;钍元素以二氧化钍、磷酸钍、镭元素以硫酸镭等难溶盐的形式富集于酸溶渣。中和渣中主要含草酸钙、氯化钠、少量碳酸盐和稀土草酸盐;铀元素以重铀酸盐、氢氧化四铀的形式富集于中和渣。 相似文献
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应用ICP-MS测定了海南中部山区野生枫香中稀土元素的含量,讨论了其分布区间尺度,稀土元素总含量中占有最大比值的是Ce,为33.14%,其次是La\,Nd.绘制了含量区间谱图.枫香中稀土元素的含量区间位于4.5~7.0μg/g之间,波形平缓,波幅小,可推断其为辛味药性. 相似文献
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Flos Sophorae and Fructus Sophorae are two kinds of traditional Chinese medicines. In this work, the two kinds of traditional Chi-nese medicines collected from eleven areas of Dezhou, were analyzed by inductively couple plasma-mass spectrometry (ICP-MS) to compare the content and distribution of 14 kinds of rare earth elements (REEs). The method was verified by analyzing GBW07605 certified reference material. The results showed that ICP-MS is an accurate, sensitive and reliable technique for determining REEs in traditional Chinese medi-cine. There were big differences in contents for REEs in Flos Sophorae and Fructus Sophorae from different areas. The contents of total REEs in Flos Sophorae samples from different areas ranged from 1.0785 to 2.2659 g/g, while those in Fructus Sophorae from 0.6826 to 1.0527 g/g. The contents of total REEs in Flos Sophorae samples from different areas were obviously higher than those in Fructus Sophorae of the same area and there was big difference between various Flos Sophorae samples. Interestingly, the higher the content of total REEs in Flos Sophorae samples, the lower the content of total REEs in Fructus Sophorae samples of the same area. The plots of normalized element con-centration versus atomic number showed some characteristic distribution trends. The distribution trend of light REEs (La-Gd) was relatively flat except a positive Eu anomaly, however, that was steep and discrepant for heavy REEs (Tb-Lu). The results could provide a valuable ref-erence for understanding the relationship between the curative mechanism, pharmacology characteristics and their geological condition for the two traditional Chinese medicines investigated. 相似文献
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Caili Xu Chengbin Zhong Renliang Lyu Yaoyang Ruan Zhenyue Zhang Ru′an Chi 《中国稀土学报(英文版)》2019,37(3):334-338
Mineral liberation analyser (MLA) was applied to quantitatively analyze the rare earth ore from Weishan in Shandong. Mineralogy parameters, such as mineral composition, occurrence states of rare earth elements (REEs) and valuable elements, mineral embedded grain size distribution, mineral association and liberation, are obtained. Results show that the contents of REEs and other valuable elements mainly contained in the ore were La 1.02 wt%, Ce 4.29 wt%, Pr 0.34 wt%, Nd 0.84 wt%, Sr 3.4 wt% and Ba 26.53 wt%, respectively. The REEs mainly occur in bastnaesite and carbocernaite in the form of independent mineral and the contents of bastnaesite and carbocernaite in the ore were 5.96 wt% and 12.30 wt%, respectively. 67.34% of strontium occurs in carbocernaite and the rest occurs in celestobarite and strontianite mineral. 92.71% of barium occurs in barite. Liberation of main rare-earth minerals such as bastnaesite and carbocernaite is more than 80% when the grinding fineness is 78.42% passing 74 μm. The research results could be employed to provide detailed basic theoretical data for further improvement of the beneficiation process flow and the processing index of rare earth ore, the recycling of other valuable minerals and the comprehensive utilization of tailings. 相似文献
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Fractionations of rare earth elements (REEs) and the forming mechanisms in plants were studied using Triticum aestivum as plant material with application of exogenous REEs and hydroponic culture. REEs were significantly fractionated in different parts of Triticum aestivum. M-type tetrad effect could be observed in both root and shoot of Triticum aestivum, which might result from the different abilities of REEs to form phosphate precipitation. Middle REEs (MREEs), light REEs (LREEs) and heavy REEs (HREEs) were enriched in root, stem and leaf of Triticum aestivum, respectively. REE speciation calculations using VMINTEQ program show REEs in simulated xylem solution mainly exist as REE-EDTA- and RE3 , but only HREEs are enriched in REE-EDTA-, while LREEs are enriched in the other REE species. It is suggested that the fractionation between LREEs and HREEs might be caused by the uptake of REE-EDTA- in Triticum aestivum leaves, but might result from the uptake of the other REE species in their stems. 相似文献
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LI 《中国稀土学报(英文版)》2010,28(6):957-964
The accumulation of rare earth elements(REEs)in soil has occurred due to the pollution caused by the exploitation of rare earth resources and the wide rare earth fertilizers in agriculture.The accumulation of REEs has a toxic effect on the soil macrofauna community.12study samples were collected near a mine tailings dam with a large amount of REEs by distance gradient sample method.The total concentration of REEs was analyzed and the results were compared with that of the sample from a control site.The effects of the amount of REEs in the soil on the soil macrofauna community were also analyzed.The results showed that the accumulation of REEs in soil was significant in the study area and its concentration was strongly correlated with the distance from the pollution source.One-way ANOVA analysis indicated the significant differences in soil macrofauna communities among the different sites.The ordination obtained through the redundancy analysis demonstrated that the concentration of REEs and the total nitrogen,total potassium and pH,had affected the soil macrofauna community.A small amount of REEs in the soil can promote the diversity of soil macrofauna,but a large amount of REEs can reduce its diversity.The insect groups of Carabidae and Dermaptera were comparatively sensitive to the concentration of REEs in soil,and could be used as an indicator of soil pollution of REEs.However,the Formicidae and Stibaropus formosanus exhibited a high tolerance to REEs in soil.We believe that it is very important for the soil environment protection to strictly control the application of the rare earth fertilizers in agriculture in China. 相似文献
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Vertisol developed on argillaceous rocks has its special pedogenic processes and properties, and formed some secondary no,Jules. In study area, contents of rare earth elements (REE) are significantly different in different sedimentary rocks due to varied contents of clay fraction and clay mineral composition, etc. Under the dry and hot climate, REEs were less differentiated than their parent sedimentary rocks. However, REEs in secondary nodules formed in pedogenic process display their specific behaviors. They are more concentrated in iron concretions, the content of heavy REEs increases relatively, and positive Ce-anomaly appeares. But, negative Ceanomaly was found in calcium concretions, while normal Cecontent in parent recks and vertisol. 相似文献
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To get features of rare earth elements(REEs)fractionation,106 surface sediment samples from eastern South China Sea were determined for REEs combined with major and trace elements by ICP-MS.The distribution pattern of REEs,strong correlation between REEs and Al,North American shale composite(NASC)normalization all suggest a dominant crustal source for REEs in the research area.However, distinct fractionation among REEs was observed in surface sediment from area with water depth over 2000 m,confirmed by the strong positive correlation among light rare earth elements(LREEs)and among heavy rare earth elements(HREEs)but weaker relationship between LREEs and HREEs.Eluviation by Cl – might be a key role on the fractionation of REEs,comparing with factors such as grain size,co-precipitation with Fe and Mn hydroxide,calcareous and siliceous biogenic precipitation.The fractionation among REEs could be used as index to illustrate the sedimentary environment in reverse. 相似文献
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New rare earth (RE) materials including RE phosphate as base fertilizer, bioactive RE micro-fertilizer and RE entire plant nutrition agent as topdressing fertilizer are treated on Hongti grope.The result showes that the plant leaves become thicker, the color is dark green, the plant disease index is lower, and the sugar content significantly increases. 相似文献
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《中国稀土学报(英文版)》2016,(5)
A novel process was proposed to strengthen the decomposition of the mixed rare earth concentrate by utilizing the microwave radiation.Mineralogical information on the mechanisms by which microwave heating improved the leaching behavior of rare earth elements(REEs),and an interpretation of the interrelationship between mineralogy,decomposition process,and leaching process were provided in this study.The influences of the temperature,time of microwave heating and contents of NaO H(mass ratio of NaO H to mixed rare earth concentrate)on the decomposition of mixed rare earth concentrate were investigated.The results revealed that the temperature was the main factor affecting the decomposition process.The recovery of REEs by hydrochloric acid leaching reached 93.28% under the microwave heating conditions:140 oC,30 min and 35.35% NaO H.The BET specific surface area and SEM analysis indicated that the particles of mixed rare earth concentrate were non-hole,while the particles presented a porous structure after heating the concentrate by microwave radiation.For the microwave treated sample after water leaching,the BET specific surface area was 11.04 m~2/g,which was higher than the corresponding values(6.94 m~2/g)for the mixed rare earth concentrate.This result could be attributed to the phase changes of bastnaesite and monazite,and a number of cracks induced by thermal stress.The increase of BET specific surface area resulted in an increase of the recovery of REEs by promoting interaction within the system of acid leaching. 相似文献