The effects of surfactant on the solvent extraction in leachingsphalerite were investigated. It is found that sodium dodecylsulfonate is the effective surfactant in improving the zinc recoveryfrom sphalerite in the aq...The effects of surfactant on the solvent extraction in leachingsphalerite were investigated. It is found that sodium dodecylsulfonate is the effective surfactant in improving the zinc recoveryfrom sphalerite in the aqueous FeCl_3-HCl-tetrachloroethylene system.Through the measurements of surface tension and viscosity of thesphalerite Slurry modified with different surfactants, it isconcluded that sodium dodecyl sulfonate in the concentration rang Of0.05 to 0.2 g·L^-1 can improve the viscosity of sphalerite slurry inthe water, decrease the surface tension of Leaching solution, preventthe aggregation of ore particles, and give very high zinc extraction.展开更多
Hardwoods are important raw material for making pulp and paper products. Eucalyptus camaldulensis is a fast-growing hardwood species with a wide distribution in Iran and can be introduced as appropriatematerial to com...Hardwoods are important raw material for making pulp and paper products. Eucalyptus camaldulensis is a fast-growing hardwood species with a wide distribution in Iran and can be introduced as appropriatematerial to compensate the wood shortages of the natural forest. Kraft pulping was performed under different cooking conditions and, based on the relations of pulp yield and kappa number, bleachable kraft pulp at screened yield of 43.3% and kappa number of 31.3 was selected for DED （Chlorine Dioxide-Alkaline Extraction-Chlorine Dioxide） bleaching and its bleachability was studied at different kappa factor in D~ stage. The results indicated that the bleachable kraft pulp from this species has high kappa number at acceptable screened yield and to complete the delignification in the bleaching process, higher kappa factor may be needed in DED bleaching sequence. The main reduction in final kappa number and yield loss were observed at kappa factor level of 0.2 but by further increase in kappa factor up to 0.4, more development were observed in optical properties but at lower opacity.展开更多
This study aims to evaluate the presence of free chlorides by the silver nitrate colorimetric spraying method in mortars made with Portland cement CP II Z-32. In order to make an assessment beyond the qualitative anal...This study aims to evaluate the presence of free chlorides by the silver nitrate colorimetric spraying method in mortars made with Portland cement CP II Z-32. In order to make an assessment beyond the qualitative analysis, a calculation of the contaminated areas by free chlorides was performed by measuring the regions using a computer image analysis software （IMAGEJ）. The experimental part of the research involved samples of 5 cm x 10 cm of mortar and 0.1 M solution of silver nitrate in distilled water. The mortar samples were made with cement CP II Z-32 with the following concentrations of chloride incorporated into the mixing water： 0%0, 0.4%, 0.6%, 0.8%, 1.0% and 2.0%, in relation to the mass of cement, totaling 108 samples. The average of percentage results from the contaminated area of the series of samples was respectively 0%, 14.9694%, 19.7444%, 46.0239%, 62.3311% and 96.0083% in relation to the total area, concluding that the method of silver nitrate spraying is applicable and that the white color indicates the presence of chloride ions and other possible aggressive salts to the structure or the concrete.展开更多
A two-liquid-phase （TLP） soil slurry system was employed to quantify the efficiencies of autoclaving and mercuric chloride sterilization in the dissipation of polycyclic aromatic hydrocaxbons （PAHs）. The fates of ...A two-liquid-phase （TLP） soil slurry system was employed to quantify the efficiencies of autoclaving and mercuric chloride sterilization in the dissipation of polycyclic aromatic hydrocaxbons （PAHs）. The fates of 11 PAHs （naphthalene, fluorene, phenanthrene, anthracene, fluoranthene, pyrene, benzo（a）anthracene, benzo（a）pyrene, benzo（b）fluoranthene, benzo（k）fluoranthene, dibenzo（a, h）anthracene） were recorded over 113 days of incubation. No microorganisms were detected in the HgC12-sterilized soil slurries during the whole incubation period, indicating very effective sterilization. However, about 2% 36% losses of PAHs were observed in the HgCl2- sterilized slurry. In contrast to the HgCl2-sterilized soil slurry, some microorganisms survived in the autoclaved soil slurries. Moreover, significant biodegradiation of 6 PAHs （naphthalene, fluorene, phenanthrene, anthracene, fluoranthene and pyrene） was observed in the autoclaved soil slurries. This indicated that biodegradation results of PAHs in the soil slurries, calculated on basis of the autoclaved control, would be underestimated. It could be concluded that the sterilization efficiency and effectiveness of HgCl2 on soil slurry was much higher than those of autoclaving at 121 ℃ for 45 rain.展开更多
基金Supported by the National Natural Science Foundation of China (No. 29836130).
文摘The effects of surfactant on the solvent extraction in leachingsphalerite were investigated. It is found that sodium dodecylsulfonate is the effective surfactant in improving the zinc recoveryfrom sphalerite in the aqueous FeCl_3-HCl-tetrachloroethylene system.Through the measurements of surface tension and viscosity of thesphalerite Slurry modified with different surfactants, it isconcluded that sodium dodecyl sulfonate in the concentration rang Of0.05 to 0.2 g·L^-1 can improve the viscosity of sphalerite slurry inthe water, decrease the surface tension of Leaching solution, preventthe aggregation of ore particles, and give very high zinc extraction.
文摘Hardwoods are important raw material for making pulp and paper products. Eucalyptus camaldulensis is a fast-growing hardwood species with a wide distribution in Iran and can be introduced as appropriatematerial to compensate the wood shortages of the natural forest. Kraft pulping was performed under different cooking conditions and, based on the relations of pulp yield and kappa number, bleachable kraft pulp at screened yield of 43.3% and kappa number of 31.3 was selected for DED （Chlorine Dioxide-Alkaline Extraction-Chlorine Dioxide） bleaching and its bleachability was studied at different kappa factor in D~ stage. The results indicated that the bleachable kraft pulp from this species has high kappa number at acceptable screened yield and to complete the delignification in the bleaching process, higher kappa factor may be needed in DED bleaching sequence. The main reduction in final kappa number and yield loss were observed at kappa factor level of 0.2 but by further increase in kappa factor up to 0.4, more development were observed in optical properties but at lower opacity.
文摘This study aims to evaluate the presence of free chlorides by the silver nitrate colorimetric spraying method in mortars made with Portland cement CP II Z-32. In order to make an assessment beyond the qualitative analysis, a calculation of the contaminated areas by free chlorides was performed by measuring the regions using a computer image analysis software （IMAGEJ）. The experimental part of the research involved samples of 5 cm x 10 cm of mortar and 0.1 M solution of silver nitrate in distilled water. The mortar samples were made with cement CP II Z-32 with the following concentrations of chloride incorporated into the mixing water： 0%0, 0.4%, 0.6%, 0.8%, 1.0% and 2.0%, in relation to the mass of cement, totaling 108 samples. The average of percentage results from the contaminated area of the series of samples was respectively 0%, 14.9694%, 19.7444%, 46.0239%, 62.3311% and 96.0083% in relation to the total area, concluding that the method of silver nitrate spraying is applicable and that the white color indicates the presence of chloride ions and other possible aggressive salts to the structure or the concrete.
基金Supported by the National High Technology Research and Development Program (863 Program) of China (No. 2007AA061101)the National Natural Science Foundation of China (Nos. 20707028,4092106,40771104 and 40701078)
文摘A two-liquid-phase （TLP） soil slurry system was employed to quantify the efficiencies of autoclaving and mercuric chloride sterilization in the dissipation of polycyclic aromatic hydrocaxbons （PAHs）. The fates of 11 PAHs （naphthalene, fluorene, phenanthrene, anthracene, fluoranthene, pyrene, benzo（a）anthracene, benzo（a）pyrene, benzo（b）fluoranthene, benzo（k）fluoranthene, dibenzo（a, h）anthracene） were recorded over 113 days of incubation. No microorganisms were detected in the HgC12-sterilized soil slurries during the whole incubation period, indicating very effective sterilization. However, about 2% 36% losses of PAHs were observed in the HgCl2- sterilized slurry. In contrast to the HgCl2-sterilized soil slurry, some microorganisms survived in the autoclaved soil slurries. Moreover, significant biodegradiation of 6 PAHs （naphthalene, fluorene, phenanthrene, anthracene, fluoranthene and pyrene） was observed in the autoclaved soil slurries. This indicated that biodegradation results of PAHs in the soil slurries, calculated on basis of the autoclaved control, would be underestimated. It could be concluded that the sterilization efficiency and effectiveness of HgCl2 on soil slurry was much higher than those of autoclaving at 121 ℃ for 45 rain.
