我国铁矿资源形势及其安全供应战略构架设想   总被引：5，自引：1，他引：4       下载免费PDF全文

陈甲斌 《地质找矿论丛》2004,19(1):5-7

通过对我国铁矿资源的形势分析,得知其安全供应问题已经处于高度紧张状态,为此必定会导致它的对外依存度不断升级,而对外依存度的升级又影响到经济的安全运行.针对这些问题,为了保障我国铁矿资源的供应安全而促进经济建设的健康发展,就我国铁矿资源安全供应战略构架问题提出了一些战略要点.  相似文献   

The Spatial Variation and Factors Controlling the Concentration of Total Dissolved Iron in Rivers,Sanjiang Plain     

LiXia Wang  BaiXing Yan  XiaoFeng Pan  Hui Zhu 《洁净——土壤、空气、水》2012,40(7):712-717

The rivers across Sanjiang Plain are an important path in transferring total dissolved iron (TDFe) into Okhotsk Sea. Distribution of TDFe in main rivers (Amur River, Ussuri River, and Songhua River) and marshy rivers (Yalv River, Bielahong River, and Naoli River) of Sanjiang Plain from 2005 to 2008 was investigated. TDFe concentrations ranged from 0.05 to 6.40 mg L^?1 (mean 0.76 mg L^?1) and the TDFe species are in the following order: Colloidal iron > ionic iron > complexed iron. Compared with the main rivers, the marshy rivers showed higher TDFe concentration and dissolved organic carbon concentration (DOC), and lower pH value. TDFe concentrations were influenced by several factors, whereas, the concentration of DOC, , and showed remarkable correlation through Spearman correlation coefficient analysis. The rivers mostly showed high TDFe concentration on May and October when the farm activities frequently occur. After 50 years' cultivation of wetlands, the free iron (Fe²⁺ and Fe³⁺) showed distinct decrease from 195 to 88.2t in Naoli River. Land use change had decreased TDFe output in rivers of Sanjiang Plain because of the changed concentration and component of DOC, which had higher affinity and selectivity with iron.  相似文献   

Designing Iron‐Amended Biosand Filters for Decentralized Safe Drinking Water Provision     

Chicgoua Noubactep  Emile Temgoua  Mohammad A. Rahman 《洁净——土壤、空气、水》2012,40(8):798-807

There are ongoing efforts to render conventional biosand filters (BSF) more efficient for safe drinking water provision. One promising option is to amend BSF with a reactive layer containing metallic iron (Fe⁰). The present communication presents some conceptual options for efficient Fe⁰‐amended BSF in its fourth generation. It is shown that a second fine‐sand layer should be placed downwards from the Fe⁰‐reactive layer to capture dissolved iron. This second fine‐sand layer could advantageously contain adsorbing materials (e.g. activated carbons, wooden charcoals). An approach for sizing the Fe⁰‐reactive layer is suggested based on 3 kg Fe⁰ per filter. Working with the same Fe⁰ load will ease comparison of results with different materials and the scaling up of household BSF to large scale community slow sand filters (SSF).  相似文献   

Dry deposition and particle-size distribution of phosphorus in the marine atmosphere over the northeastern coast of Taiwan     

Hung-Yu Chen  Chin-Chang Hung  Tien-Hsi Fang  Gwo-Ching Gong 《Continental Shelf Research》2008

This study is the first to measure the particulate phosphorus, including total inorganic phosphorus (TIP) and organic phosphorus (OP), in size-fractionated atmospheric particles. The results indicate that continental and marine sources are the key controls on the particle-size distribution of phosphorus species. For continental and local anthropogenic sources, both TIP and OP are associated with fine-mode aerosols during the winter and spring, and both are also associated with coarse particles during the summer and autumn. The coarse/fine ratios are low during periods with a non-oceanic source but high at other times, probably because of the biological growing season in the surface waters of the study area. The calculated annual fluxes based on estimates of dual-mode particles are 532±185, 435±172, and 96.8±48.8 μmol m⁻² yr⁻¹ for TP, TIP, and OP, respectively. Based on previously published solubility data for particulate phosphorus (34%), we calculated an annual flux of 180±63 μmol m⁻² yr⁻¹ for readily soluble particulate phosphorus.  相似文献   

Short-term temporal variations in iron concentration and speciation in a canal during a summer algal bloom     

Takashi Nagai  Akio Imai  Kazuo Matsushige  Kunihiko Yokoi  Takehiko Fukushima 《Aquatic Sciences - Research Across Boundaries》2008,70(4):388-396

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The Horto-Baratinha itabirite-hosted iron ore: A basal fragment of the Espinhaço basin in the eastern São Francisco Craton     

《Journal of South American Earth Sciences》2019

The Horto-Baratinha (HBD) iron ore deposit is located at the eastern border of São Francisco Craton, comprising BIF-hosted high-grade bodies (>60 wt.% Fe) associated with polydeformed quartz-mica-schists, amphibole-schist of Statherian maximum deposition age, enclosed by Statherian granitoids of the Borrachudos Suite and Neoarchean gneiss. All the sequence is crosscut by undeformed dikes and sills of pegmatitic bodies probably formed during Late Ediacaran-Cambrian. The metasedimentary sequence is stratigraphically correlatable with the Orosirian-Statherian Serra da Serpentina and Serra de São José Groups that comprise the basal units of the Espinhaço Supergroup and was intensively segmented into distinct tectonic blocks. The sedimentary/diagenetic bedding of the metamorphosed BIF (itabirite) is generally transposed by an axial planar schistosity. The lamellar hematite from itabirite is the oldest iron oxide generation, which was formed during the syn-deformational stage, parallel-oriented to the rock foliation. The (keno)magnetite grains from itabirite, iron ore and pegmatite bodies developed as idioblasts that grew over the foliation formed during late and post-deformational stages. Magnetite oxidizes subsequently to martite and granular hematite. Coarse lamellar hematite crystals randomly oriented in the border of the pegmatitic bodies also formed during the post-deformational stage due to hydrothermal reaction with itabirite. The country rocks have undergone at least three stages of deformation developed during the syn-collisional and late-collisional (Ediacaran to early-Cambrian) phases of the Brasiliano Orogeny: stage 1 with the development of a pervasive foliation (S₁), parallel to axial plane to tight folds and transposition of all sedimentary structures; stage 2 with folding of S₁; stage 3 with refolding of S₁. Both fold systems interfere with each other making up a dome and basin refolding shape. During the late-collisional (Ediacaran to early-Cambrian) and post-collisional/gravitational collapse (Cambrian) the sequence was intruded by anatectic pegmatitic bodies, which are part of the Eastern Brazilian Pegmatite Province, one of the most significant pegmatitic regions worldwide. The fluid related with these intrusions could be related with the Si leaching, crystallization of magnetite and granular hematite, and consequent formation of high-grade iron bodies.  相似文献   

FeSO4稳定铬污染土的铬赋存形态及浸出特性研究     

张亭亭  李江山  薛强  王平  熊欢  梁仕华 《岩土力学》2019,40(12):4652-4658

采用硫酸亚铁（FeSO4）对Cr(VI)污染土进行稳定化处理。研究了Fe(II)/Cr(VI)摩尔比和养护龄期对污染土稳定过程中的铬赋存形态及浸出特性的影响规律。结果表明：随着Fe(II)/Cr(VI)摩尔比和养护龄期的增加,Cr(VI)和总Cr的浸出浓度降低,稳定土中Cr(VI)的含量降低,当摩尔比为3时,Cr(VI)和总Cr的浸出浓度均低于我国《危险废弃物鉴别标准 浸出毒性鉴别》（GB/T50853―2007）的限值;当摩尔比为10时,稳定土中Cr(VI)的含量低于我国《土壤环境质量标准》（GB15618―2008）中工业和商业用地的限值（30 mg/kg）;当摩尔比为20时,低于居住用地限值（5 mg/kg）。形态提取试验结果表明：FeSO4改变稳定土中铬的赋存形态,可促使铬从弱酸态向可还原态和可氧化态转化,而对残渣态的铬影响不大。Cr(VI)的浸出浓度与稳定土中的Cr(VI)含量均存在指数函数关系,且浸出试验不能全面、客观地评价铬污染土稳定效果。  相似文献   

Iron-stimulated growth and microcystin production of Microcystis novacekii UAM 250     

Hongli Li  Tom Murphy  Jay Guo  Tanya Parr  Czesia Nalewajko 《Limnologica》2009,39(3):255-259

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Color-change processes of a plinian pumice and experimental constraints of color-change kinetics in air of an obsidian   总被引：1，自引：0，他引：1  

Mihoko Moriizumi  Satoru Nakashima  Satoshi Okumura  Yuta Yamanoi 《Bulletin of Volcanology》2009,71(1):1-13

Colors of plinian pumices were measured by spectrocolorimetry, and their quantitative color parameters in the L*a*b* color space were determined. A series of heating experiments of obsidian was conducted to simulate the color-change processes of rhyolitic glasses. In these experiments, following three stages of color-change processes were observed. Stage I showed a rapid b* (yellowishness) increase associated with fast dehydration controlled by water diffusivity (D _water). In stage II, a* (reddishness) increase was accompanied by Fe²⁺ decrease. Both a* increase and Fe²⁺ decrease can be simulated by a diffusion model. Obtained diffusivity D _oxidation were about two orders of magnitude smaller than D _water . The a*-value increase after the oxidation in stage III appeared to be quasi-linear with time, indicating the zeroth order reaction corresponding to the formation of hematite-like structures in rhyolitic glasses. The diffusion-limited a* increase model in stage II was applied to a natural plinian pumice fall unit to evaluate time periods of color-change processes through oxidation by air of fragmented rhyolitic materials.  相似文献   

Extending Service Life of Household Water Filters by Mixing Metallic Iron with Sand     

Chicgoua Noubactep  Sabine Caré  Fulbert Togue‐Kamga  Angelika Schöner  Paul Woafo 《洁净——土壤、空气、水》2010,38(10):951-959

The use of metallic iron filters (Fe⁰ filters) has been discussed as a promising low‐cost option for safe drinking water production at household level. Filter clogging due to the volumetric expansive nature of iron corrosion has been identified as the major problem of Fe⁰ filters. Mixing Fe⁰ and sand (yielding Fe⁰/sand filters) has been proposed as a tool to extent filter service life. However, no systematic discussion rationalizing Fe⁰/sand mixtures is yet available. This communication theoretically discussed suitable Fe⁰/sand proportions for efficient filters. Results suggested that Fe⁰/sand filters should not contain more that 50 vol% Fe⁰ (25 wt% when Fe⁰ is mixed with quartz). The actual Fe⁰ percentage in a filter will depend on its intrinsic reactivity.  相似文献