Search

The average grade of iron ore is low in China, and it is significant for the effective utilization of iron ore to obtain grades. In the paper, the high-precision model was constructed based on the spectrum of hematite and the multiple hidden layers extreme learning machine with random values and dense connection, which took the output of all previous layers as the input of each hidden layer. It has achieved high precision during the detection of the total iron content for hematite, which meets the requirements for the construction and development of new green and intelligent mines. [ABSTRACT FROM AUTHOR]

The Naxiguole Banded Iron Formation (BIF), located in the Eastern Kunlun Orogenic Belt, Northwest China, is hosted by the Jinshuikou Group and has a Fe of 75 Mt at a grade of 15–28.83 wt.% Fe. In this paper, we use integrated petrological, geochemical, and geochronological data to limit the age and origin of the Naxiguole BIF. Country rocks mainly comprise marble, felsic paragneiss, plagioclase amphibolite schist, and biotite plagioclase gneiss. The features of sedimentary structure (blastopsammitic texture and blastobedding structure) and trace elements (e.g. La, Ni, Zr) from the country rock indicate that their protoliths are sedimentary rock. The 141 detrital zircons from the Jinshuikou Group yield a minimum age of 908 Ma, which can be considered the upper limit for the Naxiguole BIF. According to the age (602 Ma) of the mafic rocks intruding into the Jinshuikou Group, it is reasonable to assume that the formation age of BIF can be limited at 908–602 Ma (i.e. Neoproterozoic). The high contents of Al2O3 + TiO2 (3–6 wt.%), ΣREE (36–135 ppm) for BIF samples suggest that terrestrial clastic material contributed to BIF formation. The BIF samples show seawater-like features, such as depletion in LREEs, positive Y anomaly and high Y/Ho ratios (30.7–57.5, average = 42.5), implying that the Naxiguole BIF precipitated from seawater. The positive Eu/Eu*PAAS anomalies (average 1.52) suggest the influence of high-T hydrothermal fluids. Based on positive Eu anomalies and high terrestrial clastic components and no obvious Ce anomalies, the Naxiguole BIF was formed in an anoxic or suboxic sedimentary basin within active continental island arc, and is similar to Superior-type BIFs worldwide. [ABSTRACT FROM AUTHOR]

Since the Circular Economy Promotion Law of People's Republic of China came into force in 2009, the concept of circular economy (CE) has gained a rising attention from governments and researchers. Policy makers, companies and researchers have started to establish different sets of principles and strategies for adoption. This paper introduces the CE within China's economy background and reviews the drivers to adopt and facilitate its CE. It integrates several current CE practices in China and conducts an analysis on the recycling rate from the government official reports that show China has made some progress in recycling industrial tangible waste and major renewable resources such as iron and steel with remaining challenges and barriers. Further analysis suggests that China requires a more systematic approach to promote CE by individuals, organizations and the nation. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Natural Fibers is the property of Taylor & Francis Ltd and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The article presents comments of the author on a paper on the iron and steel industry by Kuei-Sheng Chang. He has adopted a useful approach in analyzing the locational pattern in terms of major nuclei associated with secondary centers in the various regions in China. Based on my current research, however, I fear that the picture of Communist China's iron and steel industry that emerges in this paper is one exaggerated achievement and it is likely to mislead some readers who have not followed recent developments.

Groundwater exploitation along a river bank can not only induce the river water infiltrating but also affect the biogeochemical reactions in the riverbank infiltration zone. Due to the differences in water chemistry in river water and groundwater, there are obvious physical, chemical and biological gradients in the riverbank infiltration zone, resulting in a series of strong and complex biogeochemical processes. In this study, Huangjia groundwater source area along the Liao River is selected as the case study area. To explore the REDOX environment in the infiltration zone induced by groundwater exploitation, and to deduce the major geochemical reactions of release arsenic and iron in aquifer to groundwater under different REDOX environment during bank infiltration. A number of highlighted conclusions has been obtained through this study: arsenic and iron in the sediments are mainly released to groundwater through desorption and reductive dissolution of iron minerals. The content of exchangeable and iron-manganese oxides bound state changes significantly. Co-evolution characteristics of As and Fe release processes are strongly correlated with the variation of REDOX environment, the oxidation of organic matter bound iron minerals under weak oxidizing condition also played an important role in promoting the release of As and Fe. [ABSTRACT FROM AUTHOR]

Trace elements play an important role in maintaining the normal metabolic and immune function. The onset of recurrent respiratory tract infection (RRI) is associated with the immune function, genetic factors and nutritional status. However, the association between the levels of trace elements and RRI remains inconclusive. We aimed to investigate the alterations of hair levels of zinc (Zn), copper (Cu) and iron (Fe) in Chinese children with RRI by performing a meta-analysis. A predefined electronic databases search was performed to identify eligible studies for the analysis of hair Zn, Cu or Fe levels in Chinese children with RRI. Thirteen studies were included. RRI patients displayed significantly lower levels of hair Zn (13 studies, random effects SMD: − 1.215, 95% CI: − 1.704 to − 0.725, p < 0.0001), Cu (11 studies, random effects SMD: − 0.384, 95% CI: − 0.717 to − 0.052, p = 0.023) and Fe (12 studies, random effects SMD: − 0.569, 95% CI: − 0.827 to − 0.312, p < 0.0001) compared with controls. No evidence of publication bias was observed. Sensitivity analysis did not change the results significantly. In conclusion, the deficiency of Zn, Cu and Fe may be contributing factors for the susceptibility of RRI in Chinese children. However, more studies in different ethnicities should be performed in the future. [ABSTRACT FROM AUTHOR]

The article presents a response of the author on comments made by scholar Theodore Shabad on his paper on the iron and steel industry in China. The study of any important aspect of the industrial geography of Communist China involves difficulties and pitfalls seldom encountered in other endeavors. I fully understand what Shabad means by the frustrating process he himself is now engaged in. Aware of limitations of individual effort, from the outset I choose only a limited objective to offer a locational analysis of the major nuclei in the emerging pattern and their effect upon the development of secondary centers in the various regions of China.

Heavy metals (Cd, Ni, Cu, Pb, and Zn) and total sulfur (TS) in both surficial sediments and adjacent floodplain topsoils of the Lean River catchment are investigated to comprehend the effects of flooding on heavy metals in soils, the evolution of the quality of sediments, and transfer of sediment metals. The results show that concentrations of metals except for Ni in soils are significantly correlated with those in sediments. At most upstream or downstream locations, sediment metal concentrations are found comparable to those in soils (sed/soil≈1). For Cu at locations close to the Dexing Copper Mine (DCM), flooding brought Cu-poor clays into the floodplain soil system and this leads to sed/soil<1, while at locations adjacent to the Yinshan Lead-zinc Mine (YLM), suspended solids containing high concentrations of iron and magnesium oxide absorb large quantities of dissolved Cd, Pb, and Zn and deposit on the floodplain during flooding (sed/soil>1). In spite of an elevated Cu production of the DCM, a significant decrease in sediment Cu concentrations is found as compared to those 10 years ago. The decrease may be due to the elevated Cu ore utilizing efficiency and the use of a new modern tailing pool. At the location closest to the Yinshan Lead-zinc Mine (YLM), Pb and Zn concentrations increased in recent sediments. In the Lean River, metal contamination in sediments cannot reach the location 60 km downstream of their sources in 2005. [ABSTRACT FROM AUTHOR]

SHRIMP U-Pb zircon dating of a granite in the Mengku iron district, Altay, Xinjiang, yielded an age of 400 ± 6 Ma (MSDW = 1.3), which is similar to the age (SHRIMP U-Pb zircon age 404 ± 8 Ma) of granite north of orebody No. 1 in the Mengku iron deposit. This indicates that the two plutons are of Early Devonian age. These plutons intruded the Kangbutiebao Formation, thereby constraining the age of the Kangbutiebao Formation to >404 Ma. The Mengku granite and granite north of the No. 1 orebody are characterised by high silica (SiO2 = 72.29-78.63%), Na enrichment (Na2O = 4.12-7.98%), elevated Th, La, Ce, Nd and LREE, depleted Nb, Ta, P and Ti, as well as moderate negative Eu anomalies (δEu = 0.38-0.65). The granites belong to the low-K (tholeiitic) series with Na2O/K2O = 6.36-196.25 and are metaluminous and slightly peraluminous with alumina oversaturation indices of 0.97-1.09. Sr-Nd isotopic analyses [εNd(t) = 1.04-2.17] indicate that the sources of the Mengku pluton are predominantly mantle-derived, contaminated with small amounts of crustal components. Chemical, isotopic and structural characteristics indicate that granites in the Mengku district originated in a continental-arc setting associated with plate subduction. [ABSTRACT FROM AUTHOR]

In vitro solubility of calcium, iron and zinc in relation to phytic acid (PA) levels in 30 commercial rice-based foods from China was studied. Solubility of minerals and molar ratios of PA to minerals varied with degrees of processing. In primary products, [PA]/[Ca] values were less than 5 and [PA]/[Fe] and [PA]/[Zn] similarly ranged between 5 and 74, with most values between 20 and 30. [PA]/[mineral] molar ratios in intensively processed products were lower. Solubility of calcium ranged from 0% to 87%, with the lowest in brown rice (12%) and the highest in infant foods (50%). Iron solubility in two-thirds of samples was lower than 30%, and that of zinc narrowly ranged from 6% to 30%. Solubility of minerals was not significantly affected by [PA]/[mineral]. At present, neither primary nor intensively processed rice-based products are good dietary sources of minerals. Improvements should be attempted by dephytinization, mineral fortification or, preferably, combination of both. [ABSTRACT FROM AUTHOR]