Carbonaceous gold mines are important refractory gold ores. The previous results demonstrate that the carbonaceous matter is mainly composed of elemental carbon, organic acid and hydrocarbons. The dissolved aurocyanid...Carbonaceous gold mines are important refractory gold ores. The previous results demonstrate that the carbonaceous matter is mainly composed of elemental carbon, organic acid and hydrocarbons. The dissolved aurocyanide complex is robbed by adsorption of carbonaceous matter, which is similar to activated carbon in cyanide leaching of gold. The pretreatment methods of carbonaceous gold ores were introduced, including high temperature roasting, bio-oxidation, chemical oxidation, competitive adsorption, barrier inhibition and microwave roasting. Recently, bio-oxidation was developed rapidly due to its advantages such as mild conditions, simple processes, low energy consumption and friendly environment. The known microorganisms related with bio-oxidation pretreatment mainly are chemolithotroph bacteria such as Thiobacillus ferrooxidans, Thiobacillus thiooxidans and Leptospirillum ferrooxidans. The researches on decomposing and passivating carbonaceous matter were commenced by Phanerochaete chrysosporium, Pseudomonadaceae and Streptomyces setonii. Finally, the main problems were analyzed and the application prospect of this technique was looked forward.展开更多
Froth flotation of scheelite has regained new focus since the 2010s and research regarding floatability and reagents has made great progress over the years. The main objective was and remains the selective flotation o...Froth flotation of scheelite has regained new focus since the 2010s and research regarding floatability and reagents has made great progress over the years. The main objective was and remains the selective flotation of scheelite from other calcium-bearing minerals, in particular calcite, fluorite and apatite. Due to similar properties, most attempts have limited success or only specific application(linked to a type of ore or a location). This article aims at reviewing all general physical-chemical information on froth flotation of scheelite, including electrokinetic properties, influence of p H and already existing reagents as well as ones still under examination. It appears that chelating or mixed collectors and modified versions of sodium silicate and quebracho hold great promise for scheelite flotation, while the use of said depressants and/or promoters seems inevitable.展开更多
Cosmogenic Ne isotopes are stable and are routinely used for constraining the timing of events and the rate of surface change beyond the limit that can be studied with radionuclides ^10Be, ^26Al, and ^36Cl. Cosmogenic...Cosmogenic Ne isotopes are stable and are routinely used for constraining the timing of events and the rate of surface change beyond the limit that can be studied with radionuclides ^10Be, ^26Al, and ^36Cl. Cosmogenic Ne analysis can be used in quartz and in a range of other minerals. Analysis typically requires significantly less material than do cosmogenic ^10Be and ^26Al, opening up the technique for small samples--individual pebbles in fiver sediments, for example. Analysis is easier and faster than for radionuclides, not least because Ne measurements do not require significant chemical procedures. However, the presence of other sources of Ne in minerals tends to restrict the use of cosmogenic ^21Ne to old landscapes and long exposure durations. In this review we briefly outline the background of cosmogenic Ne production in rocks and minerals at the Earth's surface, then document the key uses of the technique by highlighting some earlier studies, and finish with a short perspective on the future of the technique.展开更多
In karst regions,the spatial heterogeneity of soil mineral oxides and environmental variables is still not clear.We investigated the spatial heterogeneity of SiO2,Al2O3,Fe2O3,CaO,MgO,P2O5,K2O,and MnO contents in the s...In karst regions,the spatial heterogeneity of soil mineral oxides and environmental variables is still not clear.We investigated the spatial heterogeneity of SiO2,Al2O3,Fe2O3,CaO,MgO,P2O5,K2O,and MnO contents in the soils of slope land,plantation forest,secondary forest,and primary forest,as well as their relationships with environmental variables in a karst region of Southwest China.Geostatistics,principal component analysis(PCA),and canonical correlation analysis(CCA)were applied to analyze the field data.The results show that SiO2was the predominant mineral in the soils(45.02%–67.33%),followed by Al2O3and Fe2O3.Most soil mineral oxide components had a strong spatial dependence,except for CaO,MgO,and P2O5in the plantation forest,MgO and P2O5in the secondary forest,and CaO in the slope land.Dimensionality reduction in PCA was not appropriate due to the strong spatial heterogeneity in the ecosystems.Soil mineral oxide components,the main factors in all ecosystems,had greater influences on vegetation than those of conventional soil properties.There were close relationships between soil mineral oxide components and vegetation,topography,and conventional soil properties.Mineral oxide components affected species diversity,organic matter and nitrogen levels.展开更多
The leaves of 12 species (Acacia auriculiformis, Albizzia procera, Dalbergia sissoo, Gliricidia maculata, Leucaena leuco- cephala, Samanea saman, Azadirachta indica, Eucalyptus hybrida, Gmelina arborea, Michelia cham...The leaves of 12 species (Acacia auriculiformis, Albizzia procera, Dalbergia sissoo, Gliricidia maculata, Leucaena leuco- cephala, Samanea saman, Azadirachta indica, Eucalyptus hybrida, Gmelina arborea, Michelia champaca, Morus alba, and Tectona grandis) of Multipurpose trees and shrubs (MPTs) grown in the agroforestry arboretum were evaluated for their nutritional characteristics in terms of proximate composition, cell wall constituents, total tannins, major (Ca and P) and trace minerals (Fe, Cu, Zn, Mn and Co), in vitro dry matter and organic matter digestibility (IVDMD and IVOMD) and metabolisable energy (ME) values. There were significant (P〈0.01) variations among MPTs for all parameters studied. The average values of (92.02±0.30)%, (16.00±0.74)%, (3.05±0.13)%, (18.97±1.07)%, (54.00±1.12)% and (7.98 ± 0.30)% (DM basis) were observed for OM (organic matter), CP (crude protein), EE (ether extract), CF (crude fibre), NFE (nitrogen-free extract) and total ash, respectively. Leguminous trees had high CP compared to nonleguminous ones (18.30% vs 13.70%). The mean values for cell wall constituents viz., NDF (neutral detergent fibre), ADF (acid detergent fibre), hemi cellulose, cellulose and ADL (acid detergent lignin) were found to be (52.48±1.05)%, (31.72±0.97)%, (20.76±0.88)%, (16.97±0.70)% and (9.57±0.62)%, respectively. The total tannin contents averaged (4.22±0.32)%. The ratio of Ca to P was quite wider. The levels of Fe and Mn were adequate to rich in all the MPTs while many of the tree species possessed P, Cu, Zn and Co level below the critical limits for the animals. The average IVDMD and IVOMD values were found to be (48.96±1.30)% and (50.69±1.36)%, respectively. The ME value averaged (6.95i-0.11) MJ·kg-1 DM. The CP content had significant positive correlation with IVDMD, IVOMD and ME val- ues while NDF, ADF, ADL and total tannins showed negative correlations with these three parameters. Based on the results, Leucaena Leucocephala could be considered as good quality fodder as it had the highest level of IVDMD/IVOMD (65.20%/67.66%) and ME (7.95 MJ·kg-1 DM) while G. maculata, M. alba, A. indica, D. sissoo and S. saman were of medium type and rest of poor quality.展开更多
Zinc silicate ore was characterized mineralogically and the results showed that zinc exists mainly as hemimorphite and smithsonite in the sample.Sulfuric acid pressure leaching of zinc silicate ore was carried out to ...Zinc silicate ore was characterized mineralogically and the results showed that zinc exists mainly as hemimorphite and smithsonite in the sample.Sulfuric acid pressure leaching of zinc silicate ore was carried out to assess the effect of particle size,sulfuric acid concentration,pressure,reaction time and temperature on the extraction of zinc and the dissolution of silica.Under the optimum conditions employed,up to 99.25% of zinc extraction and 0.20% silica dissolution are obtained.The main minerals in leaching residue are quartz and small amounts of undissolved oxide minerals of iron,lead and aluminum are associated with quartz.展开更多
The capacities of two arbuscular mycorrhizal (AM) fungi, Glomusmosseae and Glomus versiforme, to mineralize added organic P werestudied in a sterilized clacareous soil. Mycorrhizal (inoculated witheither of the AM fun...The capacities of two arbuscular mycorrhizal (AM) fungi, Glomusmosseae and Glomus versiforme, to mineralize added organic P werestudied in a sterilized clacareous soil. Mycorrhizal (inoculated witheither of the AM fungi) and non-mycorrhizal red clover (Trifoliumpratense L.) plants were grown for eight weeks in pots with upperroot, central hyphal and lower soil compartments. The hyphal and soilcompartments received either organic P (as Na-phytte) or inorganic P(as KH_2PO_4) at the rate of 50 mg P kg^-1. No P was added to theroot compartments.展开更多
Transformation of mineral matter is important for coal utilization at high temperatures.This is especially true for blended coal.XRD and FTIR were employed together to study the transformation of mineral matter at hig...Transformation of mineral matter is important for coal utilization at high temperatures.This is especially true for blended coal.XRD and FTIR were employed together to study the transformation of mineral matter at high temperature in blended coals.It was found that the concentration of catalytic minerals, namely iron oxides, increases with an increasing ratio of Shenfu coal, which could improve coal gasification.The transformation characteristics of the minerals in blended coals are not exactly predictable from the blend ratio.This was proved by comparing the iron oxide content to the blending ratio.The results from FTIR are comparable with those from XRD.FTIR is an effective method for examining variation in mineral matter.展开更多
Differences of cyanide leaching between the calcine and the dust from a refractory gold concentrate were investigated by comparative method. Results showed that gold leaching efficiencies of the calcine and the dust w...Differences of cyanide leaching between the calcine and the dust from a refractory gold concentrate were investigated by comparative method. Results showed that gold leaching efficiencies of the calcine and the dust were 85.31% and 54.30%, respectively, with direct cyanidation. Contents and existing forms of arsenic and carbon were the main reasons for those differences. The maximum gold leaching efficiencies of the calcine and the dust were 87.70% and 58.60%, respectively, with cyanidation after NaOH pre-leaching. Harmful elements removal, gold loss in NaOH pre-leaching and iron oxides hindrance codetermined gold leaching efficiencies of the calcine and the dust. After H2SO4 pre-leaching, the maximum gold leaching efficiencies of the calcine and the dust achieved 94.96% and 80.40%, respectively. The effect of carbonaceous matter was the main reason for differences for leaching efficiencies of the calcine and the dust. Based on those differences, two proper gold extraction processes were put forward, and gold leaching efficiencies for the calcine and the dust achieved 94.91% and 91.90%, respectively.展开更多
Co-intensification was researched to accelerate gold leaching with regards to its electrochemical nature by using anodic intensifiers of heavy metal ions (Pb2+,Bi3+,Tl+,Hg2+ and Ag+) on the basis of hydrogen peroxide ...Co-intensification was researched to accelerate gold leaching with regards to its electrochemical nature by using anodic intensifiers of heavy metal ions (Pb2+,Bi3+,Tl+,Hg2+ and Ag+) on the basis of hydrogen peroxide assistant leaching on three different types of materials which were classified as a refractory sulphide gold concentrate,an easily leachable sulphide gold concentrate,and a low grade oxide gold ore according to their leaching characteristics.The results showed that,favorable co-intensification effects on the three materials were obtained and leaching time of gold was effectively shortened to no longer than 12 h from 16 to 24 h for hydrogen peroxide assistant leaching.For the five tested heavy metal ions,Bi3+and Tl+ presented co-intensifying effect on all the three materials,and Hg2+ caused co-intensifying effect on both refractory and easily leachable sulphide gold concentrates,and Pb2+ and Ag+ only had co-intensifying effect on the easily leachable sulphide gold concentrate.展开更多
The physicochemical properties of fly ash from two kinds of coal-fired power plants were studied. Three aspects were examined: the micro-morphology, the mineral composition and the content of heavy metals. The result...The physicochemical properties of fly ash from two kinds of coal-fired power plants were studied. Three aspects were examined: the micro-morphology, the mineral composition and the content of heavy metals. The results show that the fly ash from plants using a circulating fluidized bed are more irregular par- ticles, while the particles from the plants using a pulverized coal-fired boiler are mainly spherical in shape. Quartz and mullite are the main crystalline phases in the ash. Clearly, both the technology and the coal used by a power plant can influence the mineral composition of the ash. The mineral composition of fly ash from a circulating fiuidized bed is more complex than that from a pulverized coal-fired boiler. The quantity of elements found in the fly ash is greater than that found in the bottom ash for the same plant. Heavy metals are likely to be enriched in the fly ash. Heavy metal leachability was studied using two leaching methods. The results indicate that most of the heavy metals that leached during either batch leaching or column leaching experiments did not exceed the related maximum concentration standards. But Ni concentrations in the leachates from both batch and column tests exceed the standard. The highest excess rates in both tests were 572~ and 497~, which levels might threaten the environment.展开更多
A long term fertilization experiment was carried out in an experimental field in Lyczyn near Warsaw, Poland. Application ofmineral fertilizers, especially N fertilizers with and without farmyard manure accelerated th...A long term fertilization experiment was carried out in an experimental field in Lyczyn near Warsaw, Poland. Application ofmineral fertilizers, especially N fertilizers with and without farmyard manure accelerated the acidification process of the soil. Application of 1.6 t CaO ha -1 every four years was essential to maintenance of the soil pH KCl at 5.5~6.6 and base saturation degree above 60%. Application of 50 t farmyard manure ha -1 every 4 years, which contained 46 kg P and 240 kg K, was sufficient to maintain both the K and P fertility of the soil. Besides, it was beneficial to alleviating soil acidification. As a result of long term unbalanced fertilization, yield responses to N, P and K fertilizers increased significantly with time. The efficiency of N from farmyard manure was found to be comparable to that of N fertilizer during 1988~1991.展开更多
Mineralizable N and organic N components in different layers (0~15, 15~30,30~45, 45~60, 60~80 and 80~100 cm) of six soils with different fertilities sampled from YongshouCounty, Shaanxi Province, China, were det...Mineralizable N and organic N components in different layers (0~15, 15~30,30~45, 45~60, 60~80 and 80~100 cm) of six soils with different fertilities sampled from YongshouCounty, Shaanxi Province, China, were determined by the aerobic incubation method and the Bremnerprocedure, respectively. Correlation, multiple regression and path analyses were performed to studythe relation of mineralizable N to organic N components. Results of correlation and regressionanalyses showed that the amounts of the N mineralized were parallel to, and significantly correlatedwith, the total acid hydrolyzable N, but was not so with the acid-insoluble N. Of the hydrolyzableN, the amino acid N and the ammonia N had a highly consistent significant correlation with themineralized N, and their partial regression coefficients were significant in the regressionequations, showing their importance in contribution to the mineralizable N. The amino sugar N, onthe other hand, had a relatively high correlation with the mineralized N, but their partialregression coefficients were not significant in the regression equations. In contrast, thehydrolyzable unknown N had no such relations. Path analysis further indicated that the amino acid Nand ammonia N made great direct contributions to the mineralized N, but the contributions of theamino sugar N were very low. These strongly suggested that the mineralized N in the soils tested wasmainly from the hydrolyzable N, particularly the amino acid N and ammonia N which are the majorsources for its production.展开更多
Material dematerialization is a basic approach to reduce the pressure on the resources and environment and to realize the sustainable development. The material flow analysis and decomposition method are used to calcul...Material dematerialization is a basic approach to reduce the pressure on the resources and environment and to realize the sustainable development. The material flow analysis and decomposition method are used to calculate the direct material input (DMI) of 14 typical mining cities in Northeast China in 1995–2004 and to analyze the demateri- alization and its driving factors in the different types of mining cities oriented by coal, petroleum, metallurgy and multi-resources. The results are as follows: 1) from 1995 to 2006, the increase rates of the DMI and the material input intensity of mining cities declined following the order of multi-resources, metallurgy, coal, and petroleum cities, and the material utilizing efficiency did following the order of petroleum, coal, metallurgy, and multi-resources cities; 2) during the research period, all the kinds of mining cities were in the situation of weak sustainable development in most years; 3) the pressure on resources and environment in the multi-resources cities was the most serious; 4) the petro- leum cities showed the strong trend of sustainable development; and 5) in recent years, the driving function of eco- nomic development for material consuming has continuously strengthened and the controlling function of material utilizing efficiency for it has weakened. The key approaches to promote the development of circular economy of min- ing cities in Northeast China are put forward in the following aspects: 1) to strengthen the research and development of the technique of resources’ cycling utilization, 2) to improve the utilizing efficiency of resources, and 3) to carry out the auditing system of resources utilization.展开更多
Determination of the proximate, nutritionally valuable minerals and anti-nutrient compositions in larvae of Cirina forda (W) showed that they contained high levels of protein, (55.50%±1.20%) with ash, moisture, f...Determination of the proximate, nutritionally valuable minerals and anti-nutrient compositions in larvae of Cirina forda (W) showed that they contained high levels of protein, (55.50%±1.20%) with ash, moisture, fat, and carbohydrate levels being (10.26%±0.01%), (10.85%±0.38%), (4.68%±0.01%) and (18.70%±0.84%) respectively. Fibre was not detected. Protein solubility was higher in alkaline media than in acidic media while the isoelectric points were pH 4, 6 and 9 indicating that C. forda may be useful in food formulations involving foods like meat products. Phosphorus had the highest value of (215.54±0.21) mg/100 g while manganese had the lowest value of (1.14±0.10) mg/100 g. Copper, Co, Pb, Cr and Ni were not available. Water absorption capacity was (300%±0.15%), oil absorption capacity was (358.44%±0.21%) and foaming stability was (3%±0.00%). The results of anti-nutritional analysis revealed that oxalate and phytic acid contents were (4.11±0.05) mg/100 g and (1.02±0.00) mg/100 g respectively and that these values fell within nutritionally accepted values. Tannin was not detected in C. forda. C. forda, a rich source of animal nutrients, usable in human diets and animal feeds formulations.展开更多
Nitrogen forms of humic substances from a subalpine meadow soil, a latentic red soil and a weathered coal and the effect of acid hydrolysis on N structures of soil humic substances were studied by using 15N cross-pola...Nitrogen forms of humic substances from a subalpine meadow soil, a latentic red soil and a weathered coal and the effect of acid hydrolysis on N structures of soil humic substances were studied by using 15N cross-polarization magic angle spinning nuclear magnetic resonance (CPMAS NMR) spectroscopy. Of the detectable 15N-signal intensity in the spectra of soil humic substances 71%-79% may be attributed to amide groups, 10%-18% to aromatic/aliphatic amines and 6%~11% to indole- and pyrrole-like N. Whereas in the spectrum of the fulvic acid from weathered coal 46%, at least, of the total 15N-signal intensity might be assigned to pyrrole-like N, 14% to aromatic/aliphatic ammes, and the remaining intensities could not be assigned with certainty. Data on nonhydrolyzable residue of protein-sugar mixture and a 15N-labelled soil fulvic acid confirm the formation of nonhydrolyzable heterocyclic N during acid hydrolysis. Project (No. 39790100) supported by the National Natural Science Foundation of China.展开更多
基金Projects(51174062,51104036)supported by the National Natural Science Foundation of ChinaProject(2012BAE06B05)supported by the National Science and Technology Support Program of China during the 12th Five-Year Plan Period+1 种基金Projects(2012AA061502,2012AA061501)supported by the National High-Tech Research and Development Program of ChinaProjects(N120602006,N110302002,N110602005)supported by Fundamental Research Funds for the Central Universities of China
文摘Carbonaceous gold mines are important refractory gold ores. The previous results demonstrate that the carbonaceous matter is mainly composed of elemental carbon, organic acid and hydrocarbons. The dissolved aurocyanide complex is robbed by adsorption of carbonaceous matter, which is similar to activated carbon in cyanide leaching of gold. The pretreatment methods of carbonaceous gold ores were introduced, including high temperature roasting, bio-oxidation, chemical oxidation, competitive adsorption, barrier inhibition and microwave roasting. Recently, bio-oxidation was developed rapidly due to its advantages such as mild conditions, simple processes, low energy consumption and friendly environment. The known microorganisms related with bio-oxidation pretreatment mainly are chemolithotroph bacteria such as Thiobacillus ferrooxidans, Thiobacillus thiooxidans and Leptospirillum ferrooxidans. The researches on decomposing and passivating carbonaceous matter were commenced by Phanerochaete chrysosporium, Pseudomonadaceae and Streptomyces setonii. Finally, the main problems were analyzed and the application prospect of this technique was looked forward.
基金the financial support of the Optim Ore projectthe European Union’s Horizon 2020 research and innovation programme under grant agreement No. 642201
文摘Froth flotation of scheelite has regained new focus since the 2010s and research regarding floatability and reagents has made great progress over the years. The main objective was and remains the selective flotation of scheelite from other calcium-bearing minerals, in particular calcite, fluorite and apatite. Due to similar properties, most attempts have limited success or only specific application(linked to a type of ore or a location). This article aims at reviewing all general physical-chemical information on froth flotation of scheelite, including electrokinetic properties, influence of p H and already existing reagents as well as ones still under examination. It appears that chelating or mixed collectors and modified versions of sodium silicate and quebracho hold great promise for scheelite flotation, while the use of said depressants and/or promoters seems inevitable.
基金supported by the basic scientific research fund, Institute of Geology, China Earthquake Administration (Grant Nos. IGCEA1504 and IGCEA1417)
文摘Cosmogenic Ne isotopes are stable and are routinely used for constraining the timing of events and the rate of surface change beyond the limit that can be studied with radionuclides ^10Be, ^26Al, and ^36Cl. Cosmogenic Ne analysis can be used in quartz and in a range of other minerals. Analysis typically requires significantly less material than do cosmogenic ^10Be and ^26Al, opening up the technique for small samples--individual pebbles in fiver sediments, for example. Analysis is easier and faster than for radionuclides, not least because Ne measurements do not require significant chemical procedures. However, the presence of other sources of Ne in minerals tends to restrict the use of cosmogenic ^21Ne to old landscapes and long exposure durations. In this review we briefly outline the background of cosmogenic Ne production in rocks and minerals at the Earth's surface, then document the key uses of the technique by highlighting some earlier studies, and finish with a short perspective on the future of the technique.
基金Under the auspices of Chinese Academy Sciences Action Plan for the Development of Western China(No.KZCX2-XB3-10)Major State Basic Research Development Program of China(No.2011BAC09B02)+2 种基金Strategic Priority Research Program-Climate Change:Carbon Budget and Related Issues'of Chinese Academy of Sciences(No.XDA05070404,XDA05050205)National Natural Science Foundation of China(No.31070425,31000224,U1033004)Guangxi Provincial Program of Distinguished Expert in China
文摘In karst regions,the spatial heterogeneity of soil mineral oxides and environmental variables is still not clear.We investigated the spatial heterogeneity of SiO2,Al2O3,Fe2O3,CaO,MgO,P2O5,K2O,and MnO contents in the soils of slope land,plantation forest,secondary forest,and primary forest,as well as their relationships with environmental variables in a karst region of Southwest China.Geostatistics,principal component analysis(PCA),and canonical correlation analysis(CCA)were applied to analyze the field data.The results show that SiO2was the predominant mineral in the soils(45.02%–67.33%),followed by Al2O3and Fe2O3.Most soil mineral oxide components had a strong spatial dependence,except for CaO,MgO,and P2O5in the plantation forest,MgO and P2O5in the secondary forest,and CaO in the slope land.Dimensionality reduction in PCA was not appropriate due to the strong spatial heterogeneity in the ecosystems.Soil mineral oxide components,the main factors in all ecosystems,had greater influences on vegetation than those of conventional soil properties.There were close relationships between soil mineral oxide components and vegetation,topography,and conventional soil properties.Mineral oxide components affected species diversity,organic matter and nitrogen levels.
文摘The leaves of 12 species (Acacia auriculiformis, Albizzia procera, Dalbergia sissoo, Gliricidia maculata, Leucaena leuco- cephala, Samanea saman, Azadirachta indica, Eucalyptus hybrida, Gmelina arborea, Michelia champaca, Morus alba, and Tectona grandis) of Multipurpose trees and shrubs (MPTs) grown in the agroforestry arboretum were evaluated for their nutritional characteristics in terms of proximate composition, cell wall constituents, total tannins, major (Ca and P) and trace minerals (Fe, Cu, Zn, Mn and Co), in vitro dry matter and organic matter digestibility (IVDMD and IVOMD) and metabolisable energy (ME) values. There were significant (P〈0.01) variations among MPTs for all parameters studied. The average values of (92.02±0.30)%, (16.00±0.74)%, (3.05±0.13)%, (18.97±1.07)%, (54.00±1.12)% and (7.98 ± 0.30)% (DM basis) were observed for OM (organic matter), CP (crude protein), EE (ether extract), CF (crude fibre), NFE (nitrogen-free extract) and total ash, respectively. Leguminous trees had high CP compared to nonleguminous ones (18.30% vs 13.70%). The mean values for cell wall constituents viz., NDF (neutral detergent fibre), ADF (acid detergent fibre), hemi cellulose, cellulose and ADL (acid detergent lignin) were found to be (52.48±1.05)%, (31.72±0.97)%, (20.76±0.88)%, (16.97±0.70)% and (9.57±0.62)%, respectively. The total tannin contents averaged (4.22±0.32)%. The ratio of Ca to P was quite wider. The levels of Fe and Mn were adequate to rich in all the MPTs while many of the tree species possessed P, Cu, Zn and Co level below the critical limits for the animals. The average IVDMD and IVOMD values were found to be (48.96±1.30)% and (50.69±1.36)%, respectively. The ME value averaged (6.95i-0.11) MJ·kg-1 DM. The CP content had significant positive correlation with IVDMD, IVOMD and ME val- ues while NDF, ADF, ADL and total tannins showed negative correlations with these three parameters. Based on the results, Leucaena Leucocephala could be considered as good quality fodder as it had the highest level of IVDMD/IVOMD (65.20%/67.66%) and ME (7.95 MJ·kg-1 DM) while G. maculata, M. alba, A. indica, D. sissoo and S. saman were of medium type and rest of poor quality.
基金Project(2007CB613605) supported by the National Basic Research Program of China
文摘Zinc silicate ore was characterized mineralogically and the results showed that zinc exists mainly as hemimorphite and smithsonite in the sample.Sulfuric acid pressure leaching of zinc silicate ore was carried out to assess the effect of particle size,sulfuric acid concentration,pressure,reaction time and temperature on the extraction of zinc and the dissolution of silica.Under the optimum conditions employed,up to 99.25% of zinc extraction and 0.20% silica dissolution are obtained.The main minerals in leaching residue are quartz and small amounts of undissolved oxide minerals of iron,lead and aluminum are associated with quartz.
基金National Key Basic Research Support Foundation (NKBRSF) of China(No. G1999011807) the Joint Open Laboratory of Soil and Environment between the Institute of Soil Science of the Chinese Academy of Sciences and Hong Kong Baptist University.
文摘The capacities of two arbuscular mycorrhizal (AM) fungi, Glomusmosseae and Glomus versiforme, to mineralize added organic P werestudied in a sterilized clacareous soil. Mycorrhizal (inoculated witheither of the AM fungi) and non-mycorrhizal red clover (Trifoliumpratense L.) plants were grown for eight weeks in pots with upperroot, central hyphal and lower soil compartments. The hyphal and soilcompartments received either organic P (as Na-phytte) or inorganic P(as KH_2PO_4) at the rate of 50 mg P kg^-1. No P was added to theroot compartments.
基金Projects 2005CB217701-03 supported by the National Basic Research Program of China2005DFA60220 by the Ministry of Science and Technology of China
文摘Transformation of mineral matter is important for coal utilization at high temperatures.This is especially true for blended coal.XRD and FTIR were employed together to study the transformation of mineral matter at high temperature in blended coals.It was found that the concentration of catalytic minerals, namely iron oxides, increases with an increasing ratio of Shenfu coal, which could improve coal gasification.The transformation characteristics of the minerals in blended coals are not exactly predictable from the blend ratio.This was proved by comparing the iron oxide content to the blending ratio.The results from FTIR are comparable with those from XRD.FTIR is an effective method for examining variation in mineral matter.
基金Project(201552)supported by the Special Project on the Strategic Emerging Industries of Xinjiang Uygur Autonomous Region,ChinaProject(2017SK2254)supported by the Key Research and Development Project of Hunan Province,China。
文摘Differences of cyanide leaching between the calcine and the dust from a refractory gold concentrate were investigated by comparative method. Results showed that gold leaching efficiencies of the calcine and the dust were 85.31% and 54.30%, respectively, with direct cyanidation. Contents and existing forms of arsenic and carbon were the main reasons for those differences. The maximum gold leaching efficiencies of the calcine and the dust were 87.70% and 58.60%, respectively, with cyanidation after NaOH pre-leaching. Harmful elements removal, gold loss in NaOH pre-leaching and iron oxides hindrance codetermined gold leaching efficiencies of the calcine and the dust. After H2SO4 pre-leaching, the maximum gold leaching efficiencies of the calcine and the dust achieved 94.96% and 80.40%, respectively. The effect of carbonaceous matter was the main reason for differences for leaching efficiencies of the calcine and the dust. Based on those differences, two proper gold extraction processes were put forward, and gold leaching efficiencies for the calcine and the dust achieved 94.91% and 91.90%, respectively.
基金Project(50725416) supported by the National Natural Science Foundation for Distinguished Young Scholars of China
文摘Co-intensification was researched to accelerate gold leaching with regards to its electrochemical nature by using anodic intensifiers of heavy metal ions (Pb2+,Bi3+,Tl+,Hg2+ and Ag+) on the basis of hydrogen peroxide assistant leaching on three different types of materials which were classified as a refractory sulphide gold concentrate,an easily leachable sulphide gold concentrate,and a low grade oxide gold ore according to their leaching characteristics.The results showed that,favorable co-intensification effects on the three materials were obtained and leaching time of gold was effectively shortened to no longer than 12 h from 16 to 24 h for hydrogen peroxide assistant leaching.For the five tested heavy metal ions,Bi3+and Tl+ presented co-intensifying effect on all the three materials,and Hg2+ caused co-intensifying effect on both refractory and easily leachable sulphide gold concentrates,and Pb2+ and Ag+ only had co-intensifying effect on the easily leachable sulphide gold concentrate.
基金provided by the Europe-AsiaLink (No. CN/ASIA-LINK/010 94556)State Scholarship Fund of China Scholarship Council (No. 2010642035)
文摘The physicochemical properties of fly ash from two kinds of coal-fired power plants were studied. Three aspects were examined: the micro-morphology, the mineral composition and the content of heavy metals. The results show that the fly ash from plants using a circulating fluidized bed are more irregular par- ticles, while the particles from the plants using a pulverized coal-fired boiler are mainly spherical in shape. Quartz and mullite are the main crystalline phases in the ash. Clearly, both the technology and the coal used by a power plant can influence the mineral composition of the ash. The mineral composition of fly ash from a circulating fiuidized bed is more complex than that from a pulverized coal-fired boiler. The quantity of elements found in the fly ash is greater than that found in the bottom ash for the same plant. Heavy metals are likely to be enriched in the fly ash. Heavy metal leachability was studied using two leaching methods. The results indicate that most of the heavy metals that leached during either batch leaching or column leaching experiments did not exceed the related maximum concentration standards. But Ni concentrations in the leachates from both batch and column tests exceed the standard. The highest excess rates in both tests were 572~ and 497~, which levels might threaten the environment.
文摘A long term fertilization experiment was carried out in an experimental field in Lyczyn near Warsaw, Poland. Application ofmineral fertilizers, especially N fertilizers with and without farmyard manure accelerated the acidification process of the soil. Application of 1.6 t CaO ha -1 every four years was essential to maintenance of the soil pH KCl at 5.5~6.6 and base saturation degree above 60%. Application of 50 t farmyard manure ha -1 every 4 years, which contained 46 kg P and 240 kg K, was sufficient to maintain both the K and P fertility of the soil. Besides, it was beneficial to alleviating soil acidification. As a result of long term unbalanced fertilization, yield responses to N, P and K fertilizers increased significantly with time. The efficiency of N from farmyard manure was found to be comparable to that of N fertilizer during 1988~1991.
基金Project supported by the National Key Basic Research Support Foundation(NKBRSF)(No.G1999011707)and the National Natural Science Foundation of China(NFSC)(Nos.49890330,30230230 and 30070429).
文摘Mineralizable N and organic N components in different layers (0~15, 15~30,30~45, 45~60, 60~80 and 80~100 cm) of six soils with different fertilities sampled from YongshouCounty, Shaanxi Province, China, were determined by the aerobic incubation method and the Bremnerprocedure, respectively. Correlation, multiple regression and path analyses were performed to studythe relation of mineralizable N to organic N components. Results of correlation and regressionanalyses showed that the amounts of the N mineralized were parallel to, and significantly correlatedwith, the total acid hydrolyzable N, but was not so with the acid-insoluble N. Of the hydrolyzableN, the amino acid N and the ammonia N had a highly consistent significant correlation with themineralized N, and their partial regression coefficients were significant in the regressionequations, showing their importance in contribution to the mineralizable N. The amino sugar N, onthe other hand, had a relatively high correlation with the mineralized N, but their partialregression coefficients were not significant in the regression equations. In contrast, thehydrolyzable unknown N had no such relations. Path analysis further indicated that the amino acid Nand ammonia N made great direct contributions to the mineralized N, but the contributions of theamino sugar N were very low. These strongly suggested that the mineralized N in the soils tested wasmainly from the hydrolyzable N, particularly the amino acid N and ammonia N which are the majorsources for its production.
基金Under the auspices of Key Program of National Natural Science Foundation of China (No. 40635030)National Natu-ral Science Foundation of China (No. 40571041)
文摘Material dematerialization is a basic approach to reduce the pressure on the resources and environment and to realize the sustainable development. The material flow analysis and decomposition method are used to calculate the direct material input (DMI) of 14 typical mining cities in Northeast China in 1995–2004 and to analyze the demateri- alization and its driving factors in the different types of mining cities oriented by coal, petroleum, metallurgy and multi-resources. The results are as follows: 1) from 1995 to 2006, the increase rates of the DMI and the material input intensity of mining cities declined following the order of multi-resources, metallurgy, coal, and petroleum cities, and the material utilizing efficiency did following the order of petroleum, coal, metallurgy, and multi-resources cities; 2) during the research period, all the kinds of mining cities were in the situation of weak sustainable development in most years; 3) the pressure on resources and environment in the multi-resources cities was the most serious; 4) the petro- leum cities showed the strong trend of sustainable development; and 5) in recent years, the driving function of eco- nomic development for material consuming has continuously strengthened and the controlling function of material utilizing efficiency for it has weakened. The key approaches to promote the development of circular economy of min- ing cities in Northeast China are put forward in the following aspects: 1) to strengthen the research and development of the technique of resources’ cycling utilization, 2) to improve the utilizing efficiency of resources, and 3) to carry out the auditing system of resources utilization.
文摘Determination of the proximate, nutritionally valuable minerals and anti-nutrient compositions in larvae of Cirina forda (W) showed that they contained high levels of protein, (55.50%±1.20%) with ash, moisture, fat, and carbohydrate levels being (10.26%±0.01%), (10.85%±0.38%), (4.68%±0.01%) and (18.70%±0.84%) respectively. Fibre was not detected. Protein solubility was higher in alkaline media than in acidic media while the isoelectric points were pH 4, 6 and 9 indicating that C. forda may be useful in food formulations involving foods like meat products. Phosphorus had the highest value of (215.54±0.21) mg/100 g while manganese had the lowest value of (1.14±0.10) mg/100 g. Copper, Co, Pb, Cr and Ni were not available. Water absorption capacity was (300%±0.15%), oil absorption capacity was (358.44%±0.21%) and foaming stability was (3%±0.00%). The results of anti-nutritional analysis revealed that oxalate and phytic acid contents were (4.11±0.05) mg/100 g and (1.02±0.00) mg/100 g respectively and that these values fell within nutritionally accepted values. Tannin was not detected in C. forda. C. forda, a rich source of animal nutrients, usable in human diets and animal feeds formulations.
基金supported by the National Natural science Foundation of China.(No.39790100)
文摘Nitrogen forms of humic substances from a subalpine meadow soil, a latentic red soil and a weathered coal and the effect of acid hydrolysis on N structures of soil humic substances were studied by using 15N cross-polarization magic angle spinning nuclear magnetic resonance (CPMAS NMR) spectroscopy. Of the detectable 15N-signal intensity in the spectra of soil humic substances 71%-79% may be attributed to amide groups, 10%-18% to aromatic/aliphatic amines and 6%~11% to indole- and pyrrole-like N. Whereas in the spectrum of the fulvic acid from weathered coal 46%, at least, of the total 15N-signal intensity might be assigned to pyrrole-like N, 14% to aromatic/aliphatic ammes, and the remaining intensities could not be assigned with certainty. Data on nonhydrolyzable residue of protein-sugar mixture and a 15N-labelled soil fulvic acid confirm the formation of nonhydrolyzable heterocyclic N during acid hydrolysis. Project (No. 39790100) supported by the National Natural Science Foundation of China.