This hydrometallurgical method consists of oxidation leaching, sulfide impurities removing, and sulfur dioxide reduction. The crude tellurium powder was treated by H2Oa oxidation for 2.0 h at pH 2.5 when adding 50 ml ...This hydrometallurgical method consists of oxidation leaching, sulfide impurities removing, and sulfur dioxide reduction. The crude tellurium powder was treated by H2Oa oxidation for 2.0 h at pH 2.5 when adding 50 ml H2O2 （30 %） per 100 g raw material, a tellurium recover rate around 91% is achieved. The tellurium leaching ratio can reach 98.9 % under 3.75 mol.L-1 NaOH concentration in liquid-solid ratio of 5：1 at 80 ℃ for 1.5 h. The overall separation of tellurium and other heavy metals is optimum at sulfide dosages of about 1.1 times of the theoretical values. The removal rates of Ag, Ni, Pb, and Cu from the solution are greater than 99.8 %, and As and Se removal rates are 98.6 % and 97.2 %, respectively. Over 99.5 % tellurium can be recovered by SOu reaction when the operation is conducted at 85 ℃ in 6 mol.L-1 HC1 solution. The tellurium powder with size of 〈5 μm and purity of 〉99.999 % is obtained.展开更多
To compare the cytotoxicity on HeLa cells induced by nanosized and microsized tellurium powders, HeLa cells were exposed to different concentrations of tellurium powders （0, 50, 100, 150 and 200 μg/mL） for 12 h. In...To compare the cytotoxicity on HeLa cells induced by nanosized and microsized tellurium powders, HeLa cells were exposed to different concentrations of tellurium powders （0, 50, 100, 150 and 200 μg/mL） for 12 h. In this study, detection of a series of biomarkers, including reactive oxygen species （ROS）, glutathione （GSH）, 8-hydroxy-2＇- deoxyguanosine （8-OHdG）, in addition to DNA and protein crosslink （DPC） and MTT assay, were conducted to evaluate the cytotoxicity. It is indicated that compared with the control group, there was no significant difference in the induced cytotoxicity at concentrations lower than 50 μg/mL for both nanosized and microsized tellurium powders. While there appears a significant difference in the induced cytotoxicity for nanosized tellurium powders when the concentration is higher than 100 μg/mL as well as for microsized tellurium powders when the concentration is higher than 200 μg/mL. Moreover, it is found that the cytotoxicity induced on HeLa cells exhibits a certain dose-effect relationship with the concentration of tellurium powders. A conclusion has been reached that the toxicity on HeLa cells can be induced by both nanosized and microsized tellurium powders, and the toxicity of the nanosized tellurium powders is significantly greater than the microsized one.展开更多
基金financially supported by the Science and Technology Department of Guangdong Province(No.2011B0508000033)
文摘This hydrometallurgical method consists of oxidation leaching, sulfide impurities removing, and sulfur dioxide reduction. The crude tellurium powder was treated by H2Oa oxidation for 2.0 h at pH 2.5 when adding 50 ml H2O2 （30 %） per 100 g raw material, a tellurium recover rate around 91% is achieved. The tellurium leaching ratio can reach 98.9 % under 3.75 mol.L-1 NaOH concentration in liquid-solid ratio of 5：1 at 80 ℃ for 1.5 h. The overall separation of tellurium and other heavy metals is optimum at sulfide dosages of about 1.1 times of the theoretical values. The removal rates of Ag, Ni, Pb, and Cu from the solution are greater than 99.8 %, and As and Se removal rates are 98.6 % and 97.2 %, respectively. Over 99.5 % tellurium can be recovered by SOu reaction when the operation is conducted at 85 ℃ in 6 mol.L-1 HC1 solution. The tellurium powder with size of 〈5 μm and purity of 〉99.999 % is obtained.
文摘To compare the cytotoxicity on HeLa cells induced by nanosized and microsized tellurium powders, HeLa cells were exposed to different concentrations of tellurium powders （0, 50, 100, 150 and 200 μg/mL） for 12 h. In this study, detection of a series of biomarkers, including reactive oxygen species （ROS）, glutathione （GSH）, 8-hydroxy-2＇- deoxyguanosine （8-OHdG）, in addition to DNA and protein crosslink （DPC） and MTT assay, were conducted to evaluate the cytotoxicity. It is indicated that compared with the control group, there was no significant difference in the induced cytotoxicity at concentrations lower than 50 μg/mL for both nanosized and microsized tellurium powders. While there appears a significant difference in the induced cytotoxicity for nanosized tellurium powders when the concentration is higher than 100 μg/mL as well as for microsized tellurium powders when the concentration is higher than 200 μg/mL. Moreover, it is found that the cytotoxicity induced on HeLa cells exhibits a certain dose-effect relationship with the concentration of tellurium powders. A conclusion has been reached that the toxicity on HeLa cells can be induced by both nanosized and microsized tellurium powders, and the toxicity of the nanosized tellurium powders is significantly greater than the microsized one.
