This paper deals with the recovery of ilmenite mineral from red sediments of badlands topography and suggested flowsheet with material balance.The results of these investigations reveal that the red sediment samples c...This paper deals with the recovery of ilmenite mineral from red sediments of badlands topography and suggested flowsheet with material balance.The results of these investigations reveal that the red sediment samples contain 33.2%total heavy mineral,in which ilmenite mineral concentrate is 28.71%(by weight).The ilmenite concentrate recovered from red sediment sample by physical benefciation process,which included scrubbing,desliming,gravity concentration,magnetic and electrostatic separation,contains 99.41%grade with 97.3%recovery.The ilmenite mineral concentrate recovered from red sediments is also suitable for industrial applications.The characterization studies on ilmenite reveal that the TiO2percentage is marginally increasing from 46.69%to 47.86%with increasing magnetic intensity from0.46 to 1.55 T.展开更多
In this paper an attempt is made to recover sillimanite by flotation tree analysis process and conventional flotation process from non magnetic fraction of red sediments.The experimental results of both the processes ...In this paper an attempt is made to recover sillimanite by flotation tree analysis process and conventional flotation process from non magnetic fraction of red sediments.The experimental results of both the processes are presented.The data reveal that the deslimed sample contains 33.2%(by weight) total heavy minerals and out of which the sillimanite mineral content is 3.6%(by weight).It is observed that flotation tree analysis needs 10 cells to get five output products and where as conventional flotation process needs 15 cells to recover similar grade of five output products.Thus,flotation tree analysis is not only economic process but also efficient process(to say efficient process,the tree analysis product should be higher grade).展开更多
This paper deals with the recovery of zircon minerals from beach sand and red sediments of bad land topography and flow sheets with material balance are suggested. The experimental data reveal that the total heavy min...This paper deals with the recovery of zircon minerals from beach sand and red sediments of bad land topography and flow sheets with material balance are suggested. The experimental data reveal that the total heavy mineral content of red sediment sample is 43.9% in which zircon mineral concentrate is 2.75% by weight, where as for beach-dune sand sample the THM content is 16.7% in which zircon mineral concentrate is 0.16% by weight. It is found that U and Th and REE elements contents are much higher in red sediment zircon sample than beach sand zircon. Zircon concentrates recovered from beach-dune sand and red sediments contain 98 to 98.1% zircon with 79.6 to 80% recovery respectively. These zircon minerals from both the sources are suitable for industrial applications.展开更多
Layer LJ3 of Linjiang stratigraphic section in Dongjiang River valley in the south of the Nanling Mountains is a set of red sandy sediments.Measured by thermoluminescence(TL) dating,it was found to be formed in MIS2-9...Layer LJ3 of Linjiang stratigraphic section in Dongjiang River valley in the south of the Nanling Mountains is a set of red sandy sediments.Measured by thermoluminescence(TL) dating,it was found to be formed in MIS2-9,500 ± 800 yr to 19,600 ± 1,800 yr B.P.After analy-sis of the grain sizes of the 16 samples(LJ3-100 to LJ3-85) in this layer,it was discovered that(1) The contents of each grain group in dif-ferent samples are similar.(2) The values of Md,Mz,,Sk,and Kg vary from LJ3-100 to LJ3-85 in a narrow range.(3) The segments of each sample in the accumulative curves extend parallel with similar slopes.All the three aspects reveal the Aeolian characteristics of Layer LJ3.Therefore,it is thought that Layer LJ3 consists of red sandy sediments formed in MIS2 in the south of Nanling Mountain,which reflects the arid climate at that time.展开更多
The distribution of metals (Cd, Cr, Pb, Cu, Ni and Zn) was determined in sediment cores collected from five major areas representing different anthropogenic activities along the Jordanian coast during 27 February-11 M...The distribution of metals (Cd, Cr, Pb, Cu, Ni and Zn) was determined in sediment cores collected from five major areas representing different anthropogenic activities along the Jordanian coast during 27 February-11 March 2008. Metal concentrations in these sediments were relatively low compared to reported values from polluted areas. At some of the sites metal concentrations showed fluctuations with depth in the core suggesting changes in metal loading with time. The calculated contamination factors (CFs) for the suite of metals decreased in the following order Cd > Pb > Cr > Ni >Zn > Cu. The Pollution Loading Index (PLI) calculated for the different areas were highest at Phosphate Loading Berth (0.008, 0.2607, 0.0161, 0.007, 47.9375 and 0.0296 for Cu, Pb, Ni, Zn, Cd and Cr, respectively) and lowest at Hotel Area (0.0001, 0.0075, 0.0008, 0.0006, 1.0483 and 0.0005 for Cu, Pb, Ni, Zn, Cd and Cr, respectively) with others sites between these extremes. Result of this study could be used to assess the magnitude of pollution at each site and guide rational management decisions. Moreover, the data constitutes a baseline against which future anthropogenic effects can be assessed.展开更多
Two ornithogenic sediment cores,which have a time span of 1000 years and are influenced by red-footed booby （Sula sula）,were collected from Dongdao Islands,South China Sea.The determined mercury concentrations of th...Two ornithogenic sediment cores,which have a time span of 1000 years and are influenced by red-footed booby （Sula sula）,were collected from Dongdao Islands,South China Sea.The determined mercury concentrations of the two cores show similar and substantial fluctuations during the past millennium,and the fluctuations are most likely caused by the changes in mercury level of the ocean environment and in anthropogenic Hg emission.For the past 500 years,the mercury concentration in the red-footed booby excrement has a striking association with global anthropogenic mercury emission.The mercury concentration increased rapidly after AD 1600 in corresponding to beginning of the unparalleled gold and silver mining in South Central America that left a large volume of anthropogenic mercury pollution.Since the Industrial Revolution,the mercury level has increased at a fast pace,very likely caused by modern coal combustion,chlor-alkali and oil refining industries.The comparison of mercury profiles from different places on earth suggested that anthropogenic mercury pollution after the Industrial Revolution is more severe in Northern Hemisphere than in Antarctica.展开更多
Trace elements are found in small concentrations in soil, yet plants require them for physiological functions. The runoff process leads to soil fertility loss by shifting soil particles and elements, and deposits them...Trace elements are found in small concentrations in soil, yet plants require them for physiological functions. The runoff process leads to soil fertility loss by shifting soil particles and elements, and deposits them to a different position. However, there is a lack of information about the amount of trace elements that flow in tobacco-growing red soil during the natural rainy seasons due to runoff. In this study, runoff discharge was collected from two different soil mulching conditions (straw and no straw) at 15?, in Miyi county of Sichuan province, to evaluate the characteristics of trace elements in runoff discharge. The runoff discharge was filtered to separate water (runoff) from sediment. The concentrations of the elements were analyzed in samples obtained from 9 erosive rainfall events, with 3 replications for every sample. The considered trace elements were Zinc (Zn), Copper (Cu), and Molybdenum (Mo). In addition, the total amount of each element loss per unit area (total loss) was also calculated statistically. The results revealed different concentrations and total losses for the selected trace elements. The total loss in runoff ranged from 10.82 to 194.05 mg/ha, 0.62 to 18.91 mg/ha, and 0.32 to 2.37 mg/ha for Zn, Cu, and Mo, respectively. The total loss in sediment ranged from 54.65 to 12036.34 mg/ha, 44.74 to 5285.30 mg/ha, and 1.78 to 399.82 mg/ha for Zn, Cu, and Mo, respectively. Rainfall intensity, runoff depth, and sediment yield showed distinct positive correlations with the trace elements losses. The loss reduced with the addition of straw in the experimental area. Since each trace element showed distinct characteristics in the runoff and sediment, it is crucial to assess the loss of trace elements in runoff discharge from different agronomic practices. In turn, various sustainable practices of preventing soil fertility loss will be identified.展开更多
The increase in maritime traffic means that ports have to continuously improve their efficiency. This involves reducing the inactivity caused by adverse conditions that affect its operation and maintenance which inclu...The increase in maritime traffic means that ports have to continuously improve their efficiency. This involves reducing the inactivity caused by adverse conditions that affect its operation and maintenance which includes the sedimentation rate, the shallow depth, water current regimes and tidal cycle. This study examines the hypothesis that these factors could affect Taba Heights international marina. The results showed that the harbor offered very good protection against sediment deposition (rate of sediment deposition ranging from 0.2 to 1.9 mg·cm-2·day-1) and currents (two main currents having opposite directions, the first at bearing 261 degree North with mean speed of 3.5 cm/sec., the second at bearing 85 degree North with mean speed of 4.5 cm/sec), while it had a suitable tidal range (0.3 m for neap tidal range and 0.9 m for spring tidal range). The bathymetric study of the marina area showed deeper water at the approaching channel (3.5 to 4.0 meters deep) and inside the marina (3.0 - 4.0 m) than the surrounding marine areas (0.5 to 1.5 meters). The data obtained illustrated that all the investigated factors had limited effect on the operation of Taba Hieghts international marina.展开更多
文摘This paper deals with the recovery of ilmenite mineral from red sediments of badlands topography and suggested flowsheet with material balance.The results of these investigations reveal that the red sediment samples contain 33.2%total heavy mineral,in which ilmenite mineral concentrate is 28.71%(by weight).The ilmenite concentrate recovered from red sediment sample by physical benefciation process,which included scrubbing,desliming,gravity concentration,magnetic and electrostatic separation,contains 99.41%grade with 97.3%recovery.The ilmenite mineral concentrate recovered from red sediments is also suitable for industrial applications.The characterization studies on ilmenite reveal that the TiO2percentage is marginally increasing from 46.69%to 47.86%with increasing magnetic intensity from0.46 to 1.55 T.
文摘In this paper an attempt is made to recover sillimanite by flotation tree analysis process and conventional flotation process from non magnetic fraction of red sediments.The experimental results of both the processes are presented.The data reveal that the deslimed sample contains 33.2%(by weight) total heavy minerals and out of which the sillimanite mineral content is 3.6%(by weight).It is observed that flotation tree analysis needs 10 cells to get five output products and where as conventional flotation process needs 15 cells to recover similar grade of five output products.Thus,flotation tree analysis is not only economic process but also efficient process(to say efficient process,the tree analysis product should be higher grade).
文摘This paper deals with the recovery of zircon minerals from beach sand and red sediments of bad land topography and flow sheets with material balance are suggested. The experimental data reveal that the total heavy mineral content of red sediment sample is 43.9% in which zircon mineral concentrate is 2.75% by weight, where as for beach-dune sand sample the THM content is 16.7% in which zircon mineral concentrate is 0.16% by weight. It is found that U and Th and REE elements contents are much higher in red sediment zircon sample than beach sand zircon. Zircon concentrates recovered from beach-dune sand and red sediments contain 98 to 98.1% zircon with 79.6 to 80% recovery respectively. These zircon minerals from both the sources are suitable for industrial applications.
基金funded by the National Natural Science Foundation of China (No 40471139)National Basic Research Program of China (No 2004CB 720206)the State Key Laboratory of Loess and Quaternary Geology,Institute of Earth Environment, Chinese Academy of Sci-ences Foundation (No SKLLQG0309)
文摘Layer LJ3 of Linjiang stratigraphic section in Dongjiang River valley in the south of the Nanling Mountains is a set of red sandy sediments.Measured by thermoluminescence(TL) dating,it was found to be formed in MIS2-9,500 ± 800 yr to 19,600 ± 1,800 yr B.P.After analy-sis of the grain sizes of the 16 samples(LJ3-100 to LJ3-85) in this layer,it was discovered that(1) The contents of each grain group in dif-ferent samples are similar.(2) The values of Md,Mz,,Sk,and Kg vary from LJ3-100 to LJ3-85 in a narrow range.(3) The segments of each sample in the accumulative curves extend parallel with similar slopes.All the three aspects reveal the Aeolian characteristics of Layer LJ3.Therefore,it is thought that Layer LJ3 consists of red sandy sediments formed in MIS2 in the south of Nanling Mountain,which reflects the arid climate at that time.
文摘The distribution of metals (Cd, Cr, Pb, Cu, Ni and Zn) was determined in sediment cores collected from five major areas representing different anthropogenic activities along the Jordanian coast during 27 February-11 March 2008. Metal concentrations in these sediments were relatively low compared to reported values from polluted areas. At some of the sites metal concentrations showed fluctuations with depth in the core suggesting changes in metal loading with time. The calculated contamination factors (CFs) for the suite of metals decreased in the following order Cd > Pb > Cr > Ni >Zn > Cu. The Pollution Loading Index (PLI) calculated for the different areas were highest at Phosphate Loading Berth (0.008, 0.2607, 0.0161, 0.007, 47.9375 and 0.0296 for Cu, Pb, Ni, Zn, Cd and Cr, respectively) and lowest at Hotel Area (0.0001, 0.0075, 0.0008, 0.0006, 1.0483 and 0.0005 for Cu, Pb, Ni, Zn, Cd and Cr, respectively) with others sites between these extremes. Result of this study could be used to assess the magnitude of pollution at each site and guide rational management decisions. Moreover, the data constitutes a baseline against which future anthropogenic effects can be assessed.
基金supported by the Natural Science Foundation of China (NSFC) (No.40730107)the National Basic Research Program (973) of China (No.2010CB428902)
文摘Two ornithogenic sediment cores,which have a time span of 1000 years and are influenced by red-footed booby （Sula sula）,were collected from Dongdao Islands,South China Sea.The determined mercury concentrations of the two cores show similar and substantial fluctuations during the past millennium,and the fluctuations are most likely caused by the changes in mercury level of the ocean environment and in anthropogenic Hg emission.For the past 500 years,the mercury concentration in the red-footed booby excrement has a striking association with global anthropogenic mercury emission.The mercury concentration increased rapidly after AD 1600 in corresponding to beginning of the unparalleled gold and silver mining in South Central America that left a large volume of anthropogenic mercury pollution.Since the Industrial Revolution,the mercury level has increased at a fast pace,very likely caused by modern coal combustion,chlor-alkali and oil refining industries.The comparison of mercury profiles from different places on earth suggested that anthropogenic mercury pollution after the Industrial Revolution is more severe in Northern Hemisphere than in Antarctica.
文摘Trace elements are found in small concentrations in soil, yet plants require them for physiological functions. The runoff process leads to soil fertility loss by shifting soil particles and elements, and deposits them to a different position. However, there is a lack of information about the amount of trace elements that flow in tobacco-growing red soil during the natural rainy seasons due to runoff. In this study, runoff discharge was collected from two different soil mulching conditions (straw and no straw) at 15?, in Miyi county of Sichuan province, to evaluate the characteristics of trace elements in runoff discharge. The runoff discharge was filtered to separate water (runoff) from sediment. The concentrations of the elements were analyzed in samples obtained from 9 erosive rainfall events, with 3 replications for every sample. The considered trace elements were Zinc (Zn), Copper (Cu), and Molybdenum (Mo). In addition, the total amount of each element loss per unit area (total loss) was also calculated statistically. The results revealed different concentrations and total losses for the selected trace elements. The total loss in runoff ranged from 10.82 to 194.05 mg/ha, 0.62 to 18.91 mg/ha, and 0.32 to 2.37 mg/ha for Zn, Cu, and Mo, respectively. The total loss in sediment ranged from 54.65 to 12036.34 mg/ha, 44.74 to 5285.30 mg/ha, and 1.78 to 399.82 mg/ha for Zn, Cu, and Mo, respectively. Rainfall intensity, runoff depth, and sediment yield showed distinct positive correlations with the trace elements losses. The loss reduced with the addition of straw in the experimental area. Since each trace element showed distinct characteristics in the runoff and sediment, it is crucial to assess the loss of trace elements in runoff discharge from different agronomic practices. In turn, various sustainable practices of preventing soil fertility loss will be identified.
文摘The increase in maritime traffic means that ports have to continuously improve their efficiency. This involves reducing the inactivity caused by adverse conditions that affect its operation and maintenance which includes the sedimentation rate, the shallow depth, water current regimes and tidal cycle. This study examines the hypothesis that these factors could affect Taba Heights international marina. The results showed that the harbor offered very good protection against sediment deposition (rate of sediment deposition ranging from 0.2 to 1.9 mg·cm-2·day-1) and currents (two main currents having opposite directions, the first at bearing 261 degree North with mean speed of 3.5 cm/sec., the second at bearing 85 degree North with mean speed of 4.5 cm/sec), while it had a suitable tidal range (0.3 m for neap tidal range and 0.9 m for spring tidal range). The bathymetric study of the marina area showed deeper water at the approaching channel (3.5 to 4.0 meters deep) and inside the marina (3.0 - 4.0 m) than the surrounding marine areas (0.5 to 1.5 meters). The data obtained illustrated that all the investigated factors had limited effect on the operation of Taba Hieghts international marina.
