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Effect of pyrite content on chalcopyrite flotation under different regrinding conditions

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International Journal of Minerals,Metallurgy and Materials 2025年第1期32卷 49-57页

作者： Zejun Wang Qing Shi Guofan Zhang Yuxuan Zhu Binbin Li school of Minerals Processing and Bioengineering Central South UniversityChangsha 410083China Key Laboratory of Hunan Province for Clean and Efficient Utilization of Strategic Calcium-containing Mineral resources Central South UniversityChangsha 410083China

This study aimed to investigate the effect of varying pyrite(Py)content on copper(Cu)in the presence of different regrinding conditions,which were altered using different types of grinding media:iron,ceramic balls,and their mixture,followed by flotation in the cleaner *** flotation performance of rough Cu concentrate can be improved by changing the regrinding conditions based on the Py *** electron microscopy,X-ray spectrometry,ethylenediaminetetraacetic acid disodium salt extraction,and X-ray photoelectron spectroscopy studies illustrated that when the Py content was high,the use of iron media in regrinding promoted the generation of hydrophilic Fe OOH on the surface of Py and improved the Cu *** ceramic medium with a low Py content prevented excessive Fe OOH from covering the surface of chalcopyrite(Cpy).Electrochemical studies further showed that the galvanic corrosion current of Cpy-Py increased with the addition of Py and became stronger with the participation of iron media.

关键词： chalcopyrite regrinding media pyrite galvanic corrosion flotation

Accumulation and bioavailability of heavy metals in a soil-wheat/maize system with long-term sewage sludge amendments

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Journal of Integrative Agriculture 2018年第8期17卷 1861-1870页

作者： YANG Guo-hang ZHU Guang-yun LI He-lian HAN Xue-mei LI Ju-mei MA Yi-bing school of resources and Environment University of Jinan Institute of Agricultural resources and Regional planning Chinese Academy of Agricultural Sciences

A long-term field experiment was carried out with a wheat-maize rotation system to investigate the accumulation and bioavailability of heavy metals in a calcareous soil at different rates of sewage sludge amendment. There are significant linear correlations between the contents of Hg, Zn, Cu, Pb, and Cd in soil and sewage sludge amendment rates. By increasing 1 ton of applied sludge per hectare per year in soil, the contents of Hg, Zn, Cu, Pb, and Cd in soil increased by 6.20, 619, 92.9, 49.2, and 0.500 μg kg–1, respectively. For Hg, sewage sludge could be safely applied to the soil for 18 years at an application rate of 7.5 t ha–1 before content exceeded the soil environmental quality standards in China(1 mg kg–1). The safe application period for Zn is 51 years and is even longer for other heavy metals(112 years for Cu, 224 years for Cd, and 902 years for Pb) at an application rate of 7.5 t ha–1 sewage sludge. The contents of Zn and Ni in wheat grains and Zn, Cu, and Cr in maize grains increased linearly with increasing sewage sludge amendment rates. The contents of Zn, Cr, and Ni in wheat straws and Zn, Cu, and As in maize straws were positively correlated with sewage sludge amendment rates, while the content of Cu in wheat straws and Cr in maize straws showed the opposite trend. The bioconcentration factors of the heavy metals in wheat and maize grains were found to be in the order of Zn>Cu>Cd>Hg>Cr=Ni>Pb>As. Furthermore, the bioconcentration factors of heavy metals in wheat were greater than those in maize, indicating that wheat is more sensitive than maize as an indicator plant. These results will be helpful in developing the critical loads for sewage sludge amendment in calcareous soils.

关键词： sewage sludge agricultural use heavy metals calcareous soil bioconcentration factors

Study on Headland-Bay Sandy Coast Stability in South China Coasts

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China Ocean Engineering 2011年第1期25卷 1-13页

作者：于吉涛陈子燊 Department of Water resources and Environment Geography and Planning SchoolSun Yat-sen University

Headland-bay beach equilibrium planform has been a crucial problem abroad to long-term sandy beach evolution and stabilization, extensively applied to forecast long-term coastal erosion evolvement and the influences of coastal engineering as well as long-term coastal management and protection. However, little concern focuses on this in China. The parabolic relationship is the most widely used empirical relationship for determining the static equilibrium shape of headland-bay beaches. This paper utilizes the relation to predict and classify 31 headland-bay beaches and concludes that these bays cannot achieve the ultimate static equilibrium planform in South China. The empirical bay equation can morphologically estimate beach stabilization state, but it is just a referential predictable means and is difficult to evaluate headland-bay shoreline movements in years and decades. By using Digital Shoreline Analysis System suggested by USGS, the rates of shoreline recession and accretion of these different headland-bay beaches are quantitatively calculated from 1990 to 2000. The conclusions of this paper include that （a） most of these 31 bays maintain relatively stable and the rates of erosion and accretion are relatively large with the impact of man-made constructions on estuarine within these bays from 1990 to 2000; （b） two bays, Haimen Bay and Hailingshan Bay, originally in the quasi-static equilibrium planform determined by the parabolic bay shape equation, have been unstable by the influence of coastal engineering; and （c） these 31 bays have different recession and accretion characters occuning in some bays and some segments. On the one hand, some bays totally exhibit accretion, but some bays show erosion on the whole. Shanwei Bay, Houmen Bay, Pinghai Bay and Yazhou Bay have the similar planforms, characterized by less accretion on the sheltering segment and bigger accretion on the transitional and tangential segments. On the other hand, different segments of some bays

关键词： Headland-bay beaches parabolic bay shape equation digital shoreline analysis system end point rate

Role of iron ore in enhancing gasification of iron coke:Structural evolution,influence mechanism and kinetic analysis

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International Journal of Minerals,Metallurgy and Materials 2025年第1期32卷 58-69页

作者： Jie Wang Wei Wang Xuheng Chen Junfang Bao Qiuyue Hao Heng Zheng Runsheng Xu school of Chemistry and Materials Science Hubei Engineering UniversityXiaogan 432000China Key Laboratory for Ferrous Metallurgy and resources Utilization of Ministry of Education Wuhan University of Science and TechnologyWuhan 430081China Institue of Ironmaking Technology Baosteel Central Research InstituteShanghai 201999China State Key Laboratory of Advanced Metallurgy University of Science and Technology BeijingBeijing 100083China

The utilization of iron coke provides a green pathway for low-carbon *** uncover the influence mechanism of iron ore on the behavior and kinetics of iron coke gasification,the effect of iron ore on the microstructure of iron coke was ***,a comparative study of the gasification reactions between iron coke and coke was conducted through non-isothermal thermogravimetric *** findings indicate that compared to coke,iron coke exhibits an augmentation in micropores and specific surface area,and the micropores further extend and *** provides more adsorption sites for CO_(2) molecules during the gasification process,resulting in a reduction in the initial gasification temperature of iron *** the heating rate in non-isothermal gasification can enhance the reactivity of iron *** metallic iron reduced from iron ore is embedded in the carbon matrix,reducing the orderliness of the carbon structure,which is primarily responsible for the heightened reactivity of the carbon *** kinetic study indicates that the random pore model can effectively represent the gasification process of iron coke due to its rich pore ***,as the proportion of iron ore increases,the activation energy for the carbon gasification gradually decreases,from 246.2 kJ/mol for coke to 192.5 kJ/mol for iron coke 15wt%.

关键词： low-carbon ironmaking iron coke gasification structural evolution kinetic model

Analysis of Microbial Molecular Ecology Techniques in Constructed Rapid Infiltration System

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Journal of Earth Science 2011年第5期22卷 669-676页

作者：姜昕马鸣超李俊鲁安怀钟佐燊 school of Earth and Space Sciences Peking University Institute of Agricultural resources and Regional planning Chinese Academy of Agriculture Sciences school of Water resources and Environment China University of Geosciences

The microbial molecular ecology techniques, which were developed on the basis of molecular, were applied in studying the bacteria in Constructed Rapid Infiltration （CRI） system. These techniques are very efficient in better describing the bacterial diversity, microbial community distribution, and relations between microbial group structure and nitrogen contamination through the analysis of microbial nucleic acid sequence fragment in CRI. The results further revealed the removal mechanism of contamination, which is essential for the improvement of wastewater treatment in CRI.

关键词： microbial molecular ecology techniques Constructed Rapid Infiltration (CRI) bacterial diversity microbial community distribution.

Highly mass activity electrocatalysts with ultralow Pt loading on carbon black for hydrogen evolution reaction

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International Journal of Minerals,Metallurgy and Materials 2025年第1期32卷 182-190页

作者： Shaorou Ke Yajing Zhao Xin Min Yanghong Li Ruiyu Mi Yangai Liu Xiaowen Wu Minghao Fang Zhaohui Huang Engineering Research Center of Ministry of Education for Geological Carbon Storage and Low Carbon Utilization of resources Beijing Key Laboratory of Materials Utilization of Nonmetallic Minerals and Solid WastersNational Laboratory of Mineral MaterialsSchool of Materials Science and TechnologyChina University of Geosciences(Beijing)Beijing 100083China

Pt-based nanocatalysts offer excellent prospects for various ***,the low loading of Pt with excellent performance for efficient and stable nanocatalysts still presents a considerable *** this study,nanocatalysts with ultralow Pt content,excellent performance,and carbon black as support were prepared through in-situ ***~2-nm particles uniformly and stably dispersed on carbon black because of the strong s-p-d orbital hybridizations between carbon black and Pt,which suppressed the agglomeration of Pt *** unique structure is beneficial for the hydrogen evolution *** catalysts exhibited remarkable catalytic activity for hydrogen evolution reaction,exhibiting a potential of 100 mV at 100 mA·cm^(-2),which is comparable to those of commercial Pt/C *** activity(1.61 A/mg)was four times that of a commercial Pt/C catalyst(0.37 A/mg).The ultralow Pt loading(6.84wt%)paves the way for the development of next-generation electrocatalysts.

关键词： hydrogen evolution reaction ultralow platinum in-situ synthesis ultrasound

Linking a farmer crop selection model(FCS) with an agronomic model(EPIC) to simulate cropping pattern in Northeast China

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Journal of Integrative Agriculture 2016年第10期15卷 2417-2425页

作者： HE Ying-bin CAI Wei-min Institute of Agricultural resources and Regional planning Chinese Academy of Agricultural Sciences Management school Tianjin Polytechnic University

In this paper, authors established a farmer crop selection model（FCS） for the three provinces of Liaoning, Jilin and Heilongjiang of the Northeast China. With linking to the environmental policy integrated climate model（EPIC）, the simulated results of FCS model for maize, rice and soybean were spatialized with 1 km×1 km grids to obtain cropping pattern. The reference map of spatial distribution for the three staple crops acquired by remote sensing imageries was applied to validate the simulated cropping pattern. The results showed that（1） the total simulation accuracy for the study area was 78.62%, which proved simulation method was applicable and feasible;（2） simulation accuracy for Jilin Province was the highest among the three provinces with a rate of 82.45% since its simple cropping system and not complex topography;（3） simulation accuracy for maize was the best among the three staple crops with a ratio of 81.14% because the study area is very suitable for maize growth. We hope this study could provide the reference for cropping pattern forecasting and decision-making.

关键词： cropping pattern staple crops EPIC model FCS model simulation

Driving Mechanism of Cultivated Land Transition in Yantai Proper,Shandong Province,China

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Chinese Geographical Science 2015年第3期25卷 337-349页

作者： QIN Weishan ZHANG Yifeng LI Guangdong Institute of Geographic Sciences and Natural resources Research Chinese Academy of Sciences Geography and planning school of Ludong University

Cultivated land transition and its driving mechanism are the hotspots among studies on land use change. In this study, we constructed a framework to study the driving mechanism of cultivated land transition from the quantitative perspective. Based on the vector data of land use in 1990, 2000 and 2009 of Yantai Proper, Shandong Province China, 11 explanatory variables were chosen from two aspects: the elevation, slope, cost distance to major water area and cost distance to minor water area, which presented physical factors; cost distance to district center, cost distance to town center, cost distance to city expansion center, cost distance to major roads, cost distance to city roads, cost distance to county roads and cost distance to rural roads, which presented the socio-economic factors. Combined with spatial analysis tools and Logistic regression analysis model, we construct Logistic regression analyses with four objectives that were urban construction land, rural residential land, orchard and other lands. The results show that, cost distance to district center, cost distance to town center, cost distance to city expansion center and cost distance to city roads are the significant explanatory variables for the transition of cultivated land into urban construction land. The main explained factors on the transition of cultivated land into rural residential land are slope, cost distance to town center, cost distance to county roads and cost distance to rural roads. Slope, cost distance to minor water area, cost distance to town center, cost distance to county roads and cost distance to rural roads are the significant explanatory variables for the transition of cultivated land into orchard land. Elevation, slope, cost distance to major water area and cost distance to minor water area are the main explanatory variables on the transition of cultivated land into other land uses.

关键词： cultivated land use transition driving mechanism Yantai Proper China

Analysis of temporal changes in land cover and landscape metrics of a managed forest in the west Black Sea region of northern Turkey: 1970–2010

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Journal of Forestry Research 2018年第1期29卷 139-150页

作者： Hayati Zengin Ahmet Salih Degermenci Pete Bettinger Department of Forest Management and planning Faculty of Forestry Duzce University Warnell school of Forestry and Natural resources University of Georgia

Forest structure changes continuously by natural and anthropogenic effects. Because the level of goods and services provided by forest ecosystems are related to this structure, some attributes have to be controlled while they are being managed. In this paper we describe the long-term temporal changes in land area and landscape metrics related to different land uses of a managed forest in Turkey. The study was carried out for the Daday Forest planning Unit located in the west Black Sea region of northern Turkey. The total area is 16,813 ha and besides wood production, it is managed for erosion control, public health, aesthetics, and recreation. Stand type maps that were constructed in 1970,1989, 1999, and 2010 were used in this analysis. Transition matrixes that illustrate area changes among cover types and temporal changes on some landscape metrics were obtained using Geographic Information Systems. Stands were separated into small patches, and thus the number of patches increased nearly two-fold between 1970 and 2010. The total forest edge increased and through the associated fragmentation, the amount of core forest area decreased at the landscape scale. Landscape metrics were applied to digitized versions of historical maps to assess how forest area changed. Human use of the land has changed, forest management practices have evolved, and these along with natural forest growth have contributed to interesting changes in landscape character.

关键词： Landscape metrics Land cover change Temporal change Turkey