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Effect of Saline Water on Soil Acidity, Alkalinity and Nutrients Leaching in Sandy Loamy Soil in Rwamagana Bella Flower Farm, Rwanda
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作者 Abel Mwubahaman Wali Umaru Garba +3 位作者 Hussein Bizimana Jean de Dieu Bazimenyera Eric Derrick Bugenimana Jean Nepomuscene Nsengiyumva 《Agricultural Sciences》 2024年第1期15-35,共21页
The necessity to saline and sodic waters is sometimes used for irrigating agricultural activities under certain circumstances, but it is important to note that the use of these waters comes with specific consideration... The necessity to saline and sodic waters is sometimes used for irrigating agricultural activities under certain circumstances, but it is important to note that the use of these waters comes with specific considerations and limitations. One way to decrease undesirable effects of sodic waters on the physical and chemical properties of soils is to apply organic and chemical amendments within the soil. This study aimed to assess the effectiveness of saline water on soil acidity, alkalinity and nutrients leaching in sandy loamy soil at Bella flower farm, in Rwamagana District, Rwanda. The water used was from the Muhazi Lake which is classified as Class I (Saline water quality). Column leaching experiments using treated soils were then conducted under saturated conditions. The soil under experimental was first analyzed for its textural classification, soil properties and is classified as sandy loamy soil. The t-test was taken at 1%, 5% and 10% levels of statistical significance compared to control soil. The results indicated that the application of saline water to soils caused an increase in some soil nutrients like increase of Phosphorus (P), Potassium (K<sup>+</sup>), Magnesium (Mg2<sup>+</sup>), Sulphur (S), CN ratio and Sodium (Na<sup>+</sup>) and decreased soil texture, physical and chemical properties and remained soil nutrients. Consequently, the intensive addition of saline water leachates to soil in PVC pipes led to decreased of soil EC through leaching and a raiser Soluble Sodium Percentage (SSP). The rate of saline water application affected the increase accumulation of SAR and Na% in the top soil layers. The study indicated that saline water is an inefficient amendment for sandy soil with saline water irrigation. The study recommends further studies with similar topic with saline water irrigation, as it accentuated the alkalinity levels. 展开更多
关键词 NUTRIENTS leaching Saline water Soil Acidity Soil Alkalinity
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Extraction of lithium from lepidolite using chlorination roasting-water leaching process 被引量:22
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作者 颜群轩 李新海 +5 位作者 王志兴 王接喜 郭华军 胡启扬 彭文杰 伍习飞 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2012年第7期1753-1759,共7页
Chlorination roasting followed by water leaching process was used to extract lithium from lepidolite.The microstructure of the lepidolite and roasted materials were characterized by X-ray diffraction(XRD).Various pa... Chlorination roasting followed by water leaching process was used to extract lithium from lepidolite.The microstructure of the lepidolite and roasted materials were characterized by X-ray diffraction(XRD).Various parameters including chlorination roasting temperature,time,type and amount of chlorinating agents were optimized.The conditional experiments indicate that the best mass ratio of lepidolite to NaCl to CaCl2 is 1:0.6:0.4 during the roasting process.The extraction of lithium reaches peak value of 92.86% at 880 °C,potassium,rubidium,and cesium 88.49%,93.60% and 93.01%,respectively.The XRD result indicates that the major phases of the product after roasting lepidolite with mixture of chlorinating agents(CaCl2 and NaCl) are SiO2,CaF2,KCl,CaSiO3,CaAl2Si2O8,NaCl and NaAlSi3O8. 展开更多
关键词 LEPIDOLITE LITHIUM chlorination roasting water leaching
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Fe extraction from high-silicon and aluminum cyanide tailings by pretreatment of water leaching before magnetic separation 被引量:11
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作者 张亚莉 李怀梅 于先进 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2013年第4期1165-1173,共9页
Pretreatment of high content of Si- and Al-containing cyanide tailings by water leaching to remove some impurities, such as the major impurities minerals of Si and A1, as well as its effect on Fe extraction in the wat... Pretreatment of high content of Si- and Al-containing cyanide tailings by water leaching to remove some impurities, such as the major impurities minerals of Si and A1, as well as its effect on Fe extraction in the water leaching process was investigated. The effects of different parameters on iron recovery were studied, and the reaction parameters were proposed as follows: sodium carbonate content of 30%, water leaching at 60 ~C for 5 min, liquid/solid ratio of 15:1, and exciting current of 2 A. Under these optimal conditions, magnetic concentrate containing 59.11% total iron and a total iron recovery rate of 76.12% was obtained. In addition, the microstructure and phase transformation of the process of water leaching were studied by X-ray powder diffraction technique (XRD), Electronic image of backscattering (BEI), X-ray fluorescence (XRF), and energy dispersive spectrometry (EDS). The results indicate that the soluble compound impurities generated in the roasting process are washed out, and the dissoluble substances enter into nonmagnetic materials by water leaching, realizing the effective separation of impurities and Fe. 展开更多
关键词 water leaching cyanide tailings grade of magnetic concentrate recovery rate of iron yield of magnetic concentrate
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Extraction of molybdenum and nickel from roasted Ni-Mo ore by hydrochloric acid leaching, sulphation roasting and water leaching 被引量:2
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作者 羡鹏飞 周升帆 +2 位作者 王明玉 王学文 陈边防 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2017年第1期220-226,共7页
To extract molybdenum and nickel from the roasted Ni-Mo ore, a process of hydrochloric acid leaching, sulphation roasting and water leaching was investigated. The results showed that this process could get a high leac... To extract molybdenum and nickel from the roasted Ni-Mo ore, a process of hydrochloric acid leaching, sulphation roasting and water leaching was investigated. The results showed that this process could get a high leaching rate of Mo and Ni. Under the optimum conditions of hydrochloric acid leaching (roasted Ni-Mo ore leached with 0.219 mL/g hydrochloric acid addition at 65 ℃ for 30 min with a L/S ratio of 3 mL/g), sulphation roasting (51.9% sulfiaric acid addition, roasting temperature 240 ℃ for 1 h), followed by leaching with the first stage hydrochloric acid leaching solution at 95 ℃ for 2 h, the leaching rates of Mo and Ni reached 95.8% and 91.3%, respectively. 展开更多
关键词 MOLYBDENUM NICKEL Ni-Mo ore hydrochloric acid leaching sulphation roasting water leaching
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Recovery of valuable metals from zinc leaching residue by sulfate roasting and water leaching 被引量:9
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作者 Guo-min JIANG Bing PENG +4 位作者 Yan-jie LIANG Li-yuan CHAI Qing-wei WANG Qing-zhu LI Ming HU 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2017年第5期1180-1187,共8页
Zinc leaching residue(ZLR),produced from traditional zinc hydrometallurgy process,is not only a hazardous waste but also a potential valuable solid.The combination of sulfate roasting and water leaching was employed t... Zinc leaching residue(ZLR),produced from traditional zinc hydrometallurgy process,is not only a hazardous waste but also a potential valuable solid.The combination of sulfate roasting and water leaching was employed to recover the valuable metals from ZLR.The ZLR was initially roasted with ferric sulfate at640°C for1h with ferric sulfate/zinc ferrite mole ratio of1.2.In this process,the valuable metals were efficiently transformed into water soluble sulfate,while iron remains as ferric oxide.Thereafter,water leaching was conducted to extract the valuable metals sulfate for recovery.The recovery rates of zinc,manganese,copper,cadmium and iron were92.4%,93.3%,99.3%,91.4%and1.1%,respectively.A leaching toxicity test for ZLR was performed after water leaching.The results indicated that the final residue was effectively detoxified and all of the heavy metal leaching concentrations were under the allowable limit. 展开更多
关键词 zinc leaching residue sulfate roasting water leaching valuable metals recovery
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Migration and distribution of saline ions in bauxite residue during water leaching 被引量:6
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作者 Xiang-feng KONG Xing-xing JIANG +4 位作者 Sheng-guo XUE Ling HUANG William HARTLEY Chuan WU Xiao-fei LI 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2018年第3期534-541,共8页
Bauxite residue,a highly saline solid waste produced from digestion of bauxite for alumina production,is hazardous to the environment and restricts vegetation establishment in bauxite residue disposal areas.A novel wa... Bauxite residue,a highly saline solid waste produced from digestion of bauxite for alumina production,is hazardous to the environment and restricts vegetation establishment in bauxite residue disposal areas.A novel water leaching process proposed here was used to investigate the dynamic migration and vertical distribution of saline ions in bauxite residue.The results show that water leaching significantly reduced the salinity of bauxite residue,leaching both saline cations Na+,K+,Ca2+and anions CO32-,SO42-,HCO3-.Na+and K+migrated from 40-50 to 20-30 cm of the column,presenting a high migration capacity.The migration capacity of Ca2+was lower and accumulated at 30-40 cm of the column.CO32-initially distributed at 20-30 cm of the column,subsequently transported to 30-40 cm of the column,and finally returned to 20-30 cm of the column along with evaporation.SO42-was originally distributed at 40-50 cm,but finally migrated to 20-30 cm of the column.Nevertheless,HCO3-remained at the bottom of the column,and its migratory was less affected by evaporation. 展开更多
关键词 bauxite residue SALINITY ion migration column stimulation water leaching
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Extraction of metals from complex sulfide nickel concentrates by low-temperature chlorination roasting and water leaching 被引量:7
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作者 Cong Xu Hong-wei Cheng +4 位作者 Guang-shi Li Chang-yuan Lu Xiong-gang Lu Xing-li Zou Qian Xu 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CAS CSCD 2017年第4期377-385,共9页
The recovery of valuable metals from complex sulfide concentrates was investigated via chlorination roasting followed by water leaching. A reaction process is proposed on the basis of previous studies and the results ... The recovery of valuable metals from complex sulfide concentrates was investigated via chlorination roasting followed by water leaching. A reaction process is proposed on the basis of previous studies and the results of our preliminary experiments. During the process, various process parameters were studied, including the roasting temperature, the addition of NH4Cl, the roasting time, the leaching time, and the liquid-to-solid ratio. The roasted products and leach residues were characterized by X-ray diffraction and vibrational spectroscopy. Under the optimum condition, 95% of Ni, 98% of Cu, and 88% of Co were recovered. In addition, the removal of iron was studied in the water leaching stage. The results demonstrate that this process provides an effective approach for extracting multiple metals from complex concentrates or ores. © 2017, University of Science and Technology Beijing and Springer-Verlag Berlin Heidelberg. 展开更多
关键词 CALCINATION Chemicals removal (water treatment) CHLORINATION leaching Metal recovery Nickel Rare earths Sulfur compounds Temperature X ray diffraction
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Chromium leaching mechanism of coal mine water—a modeling study based on Xuzhou-Datun coal mine district 被引量:5
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作者 SHAN Yao QIN Yong, WANG Wenfeng School of Resource and Earth Science, China University of Mining & Technology, Xuzhou 221116, China 《Mining Science and Technology》 EI CAS 2010年第1期97-102,共6页
In order to investigate chromium contamination of coal mine water, to analyze chromium leaching mechanism and to evaluate environment pollution potential of coal mine water, we perform site investigations, physical an... In order to investigate chromium contamination of coal mine water, to analyze chromium leaching mechanism and to evaluate environment pollution potential of coal mine water, we perform site investigations, physical and computer modeling in the Xuzhou-Datun coal mine district. The result of our test samples shows that chromium concentration was 9 μg/L in roof leachate and 3 μg/L in coal leachate. The host rock has a higher pollution potential than that of coal seams. Leaching experiments and XRD test results indicate that chromium is released from the process of transforming illite to kaolinite. The pH, pe and temperature of coal mine water affect the chromium leaching behavior. Modeling results suggest that the adsorption of adsorbents controls chromium concentration in coal mine water. The chromium adsorption ratio is quite low in both an acid and in an alkaline environment. Therefore, coal mine water has a high pollution potential. Under other conditions, chromium adsorption is stronger in a neutral water environment, so that chromium concentrations may be very low. 展开更多
关键词 CHROMIUM coal mine water leaching
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Investigation of the Leaching Behavior of Mortar Pipe Lining in Drinking Water 被引量:1
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作者 高岳毅 张亚梅 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS 2010年第5期893-896,共4页
The leaching behavior of three types of mortars was investigated using a self-design device which could simulate the field conditions of pipe lining. The results by ICP and ESEM measurement show that the developed sla... The leaching behavior of three types of mortars was investigated using a self-design device which could simulate the field conditions of pipe lining. The results by ICP and ESEM measurement show that the developed slag cement mortar is suitable for the lining of cast iron pipe that is used for delivering drinking water. 展开更多
关键词 leaching pipe lining drinking water slag cement
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Chlorination roasting-coupled water leaching process for potash recovery from waste mica scrap using dry marble sludge powder and sodium chloride 被引量:2
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作者 Sandeep Kumar Jena Jogeshwar Sahu +2 位作者 Geetikamayee Padhy Swagatika Mohanty Ajit Dash 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CAS CSCD 2020年第9期1203-1215,共13页
The present paper reports the effective utilization of marble sludge powder(MSP)for the recovery of potash values from waste mica scrap using chlorination roasting-water leaching method.Characterization studies indica... The present paper reports the effective utilization of marble sludge powder(MSP)for the recovery of potash values from waste mica scrap using chlorination roasting-water leaching method.Characterization studies indicated the presence of dolomite as the major mineral phase in MSP,whereas muscovite and quartz were observed in the mica sample.The acid leaching studies suggest a maximum of 22%potash recovery under conditions:4 M H2SO4 acid,particle size of^100μm,stirring speed of 600 r/min,leaching temperature of 75℃,and leaching time of 90 min.The chlorination roasting-water leaching process was adopted to achieve the lowest level of 80%-90%potash recovery.The optimum conditions for the recovery of^93%potash from mica(~8.6wt%K2O)requires 900℃ roasting temperature,30 min roasting time,and 1:1:0.75 mass ratio of mica:MSP:NaCl.The roasting temperature and amount of NaCl are found to be the most important factors for the recovery process.The reaction mechanism suggests the formation of different mineral phases,including sylvite(KCl),wollastonite,kyanite,and enstatite,during roasting,which were confirmed by X-ray diffraction(XRD)analyses and scanning electron microscopy(SEM)morphologies.The MSP-blended NaCl additive is more effective for potash recovery compared with the other reported commercial roasting additives. 展开更多
关键词 potash recovery mica scrap marble sludge powder chlorination roasting water leaching
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Maximizing Irrigation Water Productivity by Optimizing Leaching Fraction 被引量:1
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作者 Isam Mohammed Abdulhameed 《Journal of Agricultural Science and Technology(A)》 2017年第2期73-80,共8页
The importance of maximizing irrigation water productivity is increasing as the water resources still decreasing and deteriorating due to environmental interactions. An optimal irrigation water depth (including leach... The importance of maximizing irrigation water productivity is increasing as the water resources still decreasing and deteriorating due to environmental interactions. An optimal irrigation water depth (including leaching water depth) was estimated in order to maximize water unit volume productivity by using the optimal leaching fraction (LF), which is calculated by the new proposed model--unit yield ratio (UYR%) and irrigation depth ratio (IDP). A computer program was constructed to apply this model for several crops irrigated by two water resources--river and well. The water salinity of river was 1.1 dS/m and the well salinity was 3.85 dS/m. The results showed that there is an optimal leaching requirement (LR) value for each crop irrigated by any water resource. The maximum UYR% of the alfalfa irrigated by saline well water was 58.45% with the optimal LF = 0.4, while the maximum UYR% of the bean irrigated by river water was 78.58% with the optimal LR = 0.2. The optimal LF is saving water by increasing the productivity of irrigation water unit volume, especially when using saline irrigation water, for example, an increase of IDP for alfalfa by only 20%, followed by an increase of UYR% about 47.5% (from 12% to 57%) by increasing LF from 0.1 to 0.3. 展开更多
关键词 leaching fraction crop productivity saline irrigation water.
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Recovery of vanadium and tungsten from waste selective catalytic reduction catalysts by K_(2)CO_(3) roasting and water leaching followed by CaCl_(2) precipitation 被引量:1
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作者 Xianghui Liu Qiaowen Yang 《International Journal of Coal Science & Technology》 EI CAS CSCD 2021年第4期727-736,共10页
Waste selective catalytic reduction(SCR)catalysts are potential environmental hazards.In this study,the recovery of vanadium and tungsten from waste SCR catalysts by K_(2)CO_(3)roasting and water leaching was investig... Waste selective catalytic reduction(SCR)catalysts are potential environmental hazards.In this study,the recovery of vanadium and tungsten from waste SCR catalysts by K_(2)CO_(3)roasting and water leaching was investigated.The roasting and leaching conditions were optimized:the leaching efficiencies of vanadium and tungsten were 91.19%and 85.36%,respectively,when 18 equivalents of K_(2)CO_(3)were added to perform the roasting at 900℃ for 2 h,followed by leaching at 90°C for 1 h.Notably,in the described conditions,the leaching rate of silicon was only 28.55%.Titanates,including K_(2)Ti_(6)O_(13)and KTi8017,were also produced.Si removal was achieved in 85%efficiency adjusting the pH to 9.5,and the Si impurity thus isolated was composed of amorphous Si.Tungsten and vanadium were precipitated using CaCl_(2).At pH 10 and following the addition of 0.10 mol of H_(2)O_(2)and 16 equivalents of CaCl_(2),the precipitating efficiencies of tungsten and vanadium were 96.89%and 99.65%,respectively.The overall yield of tungsten and vanadium was 82.71%and 90.87%,respectively. 展开更多
关键词 RECOVERY Waste SCR catalyst K_(2)CO_(3)roasting water leaching CaCl_(2)precipitation
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Recovery of titanium from undissolved residue(tionite) in titanium oxide industry via NaOH hydrothermal conversion and H_2SO_4 leaching 被引量:3
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作者 孟凡成 薛天艳 +2 位作者 刘亚辉 张国之 齐涛 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2016年第6期1696-1705,共10页
To recover titanium from tionite, a new process consisting of NaOH hydrothermal conversion, water washing, and H2SO4 leaching for TiO2 preparation was developed. The experimental results show that under the optimum ... To recover titanium from tionite, a new process consisting of NaOH hydrothermal conversion, water washing, and H2SO4 leaching for TiO2 preparation was developed. The experimental results show that under the optimum hydrothermal conversion conditions, i.e., 50% NaOH (mass fraction) solution, NaOH/tionite mass ratio of 4:1, reaction temperature of 240 ℃reaction time of 1 h and oxygen partial pressure of 0.25 MPa, the titanium was mainly converted into Na2TiO3, and the conversion was 97.2%. The unwanted product Na2TiSiO5 remained stable in water washing, and its formation was prevented by improving NaOH concentration. In water washing process, about 97.6% of Na+ could be recycled by washing the hydrothermal product. The NaOH solutions could be reused after concentration. 96.7% of titanium in the washed product was easily leached in H2SO4 solution at low temperatures, forming titanyl sulfate solution to further prepare TiO2. 展开更多
关键词 tionite titanium recovery NaOH hydrothermal conversion water washing H2SO4 leaching
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Nitrate Leaching in an Irrigated Wheat-Maize Rotation Field in the North China Plain 被引量:28
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作者 ZHANGYu-Ming HUChun-Sheng +2 位作者 ZHANGJia-Bao CHENDe-Li LIXiao-Xin 《Pedosphere》 SCIE CAS CSCD 2005年第2期196-203,共8页
Soil water deep drainage and nitrate (NO-3) leaching losses below the root zone were investigated in a 1 ha wheat-maize rotation field under traditional agricultural management that local farmers generally follow in t... Soil water deep drainage and nitrate (NO-3) leaching losses below the root zone were investigated in a 1 ha wheat-maize rotation field under traditional agricultural management that local farmers generally follow in the North China Plain, using the soil water balance method and NO3-N concentration in suction samples. Water drainage, and NO3-N distribution and leaching losses exhibited pronounced spatial and temporal variability. Soil water deep drainage and NO3-N leaching loss mostly occurred during the sum… 展开更多
关键词 deep drainage nitrate leaching soil water
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Leaching behaviors of calcium and magnesium in ion-adsorption rare earth tailings with magnesium sulfate 被引量:9
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作者 Bo FAN Long-sheng ZHAO +4 位作者 Zong-yu FENG De-peng LIU Wei-Qiang YIN Zhi-qi LONG Xiao-wei HUANG 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2021年第1期288-296,共9页
The leaching behaviors of calcium and magnesium in the rare earth tailings leached with magnesium sulfate using deionized water,CaCl2 solution and lime water were investigated.Experimental data indicated that magnesiu... The leaching behaviors of calcium and magnesium in the rare earth tailings leached with magnesium sulfate using deionized water,CaCl2 solution and lime water were investigated.Experimental data indicated that magnesium in the tailings was easy to be leached out since most of the magnesium was in the form of water-soluble phase.Most of calcium in the lime water was electrostatically adsorbed on the clay mineral of the tailings,and the water-soluble magnesium was also gradually converted into exchangeable phase because of back-adsorption of Mg2+on the clay mineral with increasing the pH values.When the liquid-to-solid ratio was 0.80,the contents of readily-available magnesium and calcium were 104.4−207.6 and 201.7−1426.3 mg/kg,respectively,which could meet the requirements for plants.These results suggest a promising route for the environmental remediation of ion-adsorption rare earth ore after in-situ leaching. 展开更多
关键词 ion-adsorption rare earth ore magnesium sulfate environmental remediation leaching behaviors lime water
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Zinc extraction from zinc oxidized ore using(NH4)2SO4 roasting−leaching process 被引量:3
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作者 Xiao-yi Shen Hong-mei Shao +3 位作者 Ji-wen Ding Yan Liu Hui-min Gu Yu-chun Zhai 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CAS CSCD 2020年第11期1471-1481,共11页
An improved method of(NH4)2SO4 roasting followed by water leaching to utilize zinc oxidized ores was studied.The operating parameters were obtained by investigating the effects of the molar ratio of(NH4)2SO4 to zinc,r... An improved method of(NH4)2SO4 roasting followed by water leaching to utilize zinc oxidized ores was studied.The operating parameters were obtained by investigating the effects of the molar ratio of(NH4)2SO4 to zinc,roasting temperature,and holding time on zinc extraction.The roasting process followed the chemical reaction control mechanism with the apparent activation energy value of 41.74 kJ·mol^−1.The transformation of mineral phases in roasting was identified by X-ray diffraction analysis combined with thermogravimetry–differential thermal analysis curves.The water leaching conditions,including the leaching temperature,leaching time,stirring velocity,and liquid-to-solid ratio,were discussed,and the leaching kinetics was studied.The reaction rate was obtained under outer diffusion without product layer control;the values of the apparent activation energy for two stages were 4.12 and 8.19 kJ·mol^−1.The maximum zinc extraction ratio reached 96%while the efficiency of iron extraction was approximately 32%under appropriate conditions.This work offers an effective method for the comprehensive use of zinc oxidized ores. 展开更多
关键词 zinc oxidized ore ammonium sulfate roasting water leaching KINETICS MECHANISM extraction ratio
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COD_(Cr) leaching rules of municipal solid waste in Songtao Reservoir,Hainan Province,China
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作者 陈大勇 王里奥 《Journal of Central South University》 SCIE EI CAS 2009年第S1期379-383,共5页
By the means of static leaching experiment and dynamic leaching experiment,CODCr leaching rules of dumped MSW(Municipal Solid Waste) in Songtao Reservoir,Hainan Province,China,were studied. And according to academic e... By the means of static leaching experiment and dynamic leaching experiment,CODCr leaching rules of dumped MSW(Municipal Solid Waste) in Songtao Reservoir,Hainan Province,China,were studied. And according to academic experience and fitted results of experiment data,the models of CODCr leaching rules in the leaching condition were deduced. The static leaching experiment indicates that,both in water-changing section and no-water-changing section,the ratio of liquid to solid has a remarkable influence on CODCr leaching concentration. The exponential model could be established to approximately describe CODCr leaching rules and the curve fits well. The dynamic leaching experiment indicates that,leaching rules of MSW can be approximately described by power model,which can well fit the leaching experiment data. By the contrast of the static leaching experiment and dynamic leaching experiment,the differences of CODCr leaching rules between the two experiments are significant. By the exponential model,the average static leaching rate of CODCr is calculated as 882.24 mg/(kg·d) for water-changing section and 320.39 mg/(kg·d) for no-water-changing section; by the power model,the average dynamic leaching rate of CODCr is 208.77 mg/(kg·d). 展开更多
关键词 MUNICIPAL solid waste CODCR leaching RULES water quality model
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Leaching Phenomena of Antifouling Agents from Ships' Hull Paints
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作者 Ryuji Kojima Toshiaki Shibata Koichi Ueda 《Journal of Shipping and Ocean Engineering》 2016年第5期269-278,共10页
The effects ofpH, dissolved ion content and relative water velocity on the release rate of an antifouling agent, cuprous oxide, from ships' hull paint have been investigated by rotating cylinder tests. Additionally, ... The effects ofpH, dissolved ion content and relative water velocity on the release rate of an antifouling agent, cuprous oxide, from ships' hull paint have been investigated by rotating cylinder tests. Additionally, test paint panels were attached to a vessel and recovered after a certain period of voyage for the validation of the laboratory tests. In the initial period, the release rates are influenced by pH, dissolved ion content and water velocity, but once after a certain period of test, those effects become less significant. These phenomena can be explained when the paint film is fresh, the rate is controlled by chemical reaction, the surface and/or diffusion layer in the water phase governs the rate. After the antifouling substance in the paint film leached out from the near-surface region, a diffused layer (leached layer), that has little antifouling agent remained, is formed at the surface of the coating, and the diffusion in that layer can be a rate-determining process. The development of the leached layer is affected by a balance between the leaching rate of the antifouling ingredient and paint resin determined by the chemical properties and speed of the water. Thus, the leaching rates of antifouling agents are affected by the history of the paint in the water. 展开更多
关键词 Antifouling agent leaching rate cuprous oxide rotating cylinder substituted ocean water phosphate buffer solution.
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A LEACH-Head Expected Frequency Appraisal Algorithm for Water-Environment Monitoring Networks
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作者 Chenmin Li Guoping Tan +2 位作者 Jingyu Wu Zhen Zhang Lizhong Xu 《International Journal of Communications, Network and System Sciences》 2011年第9期562-567,共6页
Water-environment monitoring network (WMN) is a wireless sensor network based real-time system, which collects, transmits, analyzes and processes water-environment parameters in large area. Both cluster selection mech... Water-environment monitoring network (WMN) is a wireless sensor network based real-time system, which collects, transmits, analyzes and processes water-environment parameters in large area. Both cluster selection mechanisms and energy saving strategies play an important role on designing network routing protocols for the WMN. Since those existing routing algorithms can not be used directly in the WMN, we thus propose an improved version of LEACH, a LEACH-Head Expected Frequency Appraisal (LEACH-HEFA) algorithm, for the WMN in this paper. Simulation results show that the LEACH-HEFA can balance the energy consumption of nodes, rationalize the clustering process and prolong the network lifetime significantly in the WMN. It indicates that the LEACH-HEFA is suitable to the WMN. 展开更多
关键词 WSN leach Protocol Cluster-Head Selection water-Environment Monitoring
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硫酸亚铁焙烧-水浸工艺分离黑铜泥中铜和砷
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作者 贺山明 李威 +3 位作者 张佳敏 王龙倩 刘庆生 彭如振 《有色金属(冶炼部分)》 CAS 北大核心 2024年第7期33-37,84,共6页
采用硫酸亚铁焙烧-水浸工艺实现黑铜泥中铜、砷一步分离。考察了铁砷摩尔比(Fe/As)、焙烧温度、焙烧时间、水浸初始pH等对试验效果的影响。较优工艺条件为:焙烧温度400℃、Fe/As=0.3、焙烧时间120 min、水浸温度80℃、水浸时间60 min、... 采用硫酸亚铁焙烧-水浸工艺实现黑铜泥中铜、砷一步分离。考察了铁砷摩尔比(Fe/As)、焙烧温度、焙烧时间、水浸初始pH等对试验效果的影响。较优工艺条件为:焙烧温度400℃、Fe/As=0.3、焙烧时间120 min、水浸温度80℃、水浸时间60 min、水浸液固比7 mL/g、水浸初始pH=4.5,沉砷率高达99%以上,铜浸出率高达96%以上。经XRD分析,沉砷渣主要成分为臭葱石和氧化铁,实现了砷的安全固化处置。 展开更多
关键词 黑铜泥 铜砷分离 臭葱石 焙烧 水浸
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