The oxidative dissolution of metalliferous black shale in sulfuric acid solution using sodium persulfate as an oxidant was investigated. The effects of leaching factors including leaching temperature, leaching time, s...The oxidative dissolution of metalliferous black shale in sulfuric acid solution using sodium persulfate as an oxidant was investigated. The effects of leaching factors including leaching temperature, leaching time, stirring speed, initial concentration of sodium persulfate and sulfuric acid and particle size on the leaching rate were studied as well. The leaching kinetics of molybdenum, nickel and iron from metalliferous black shale shows that the leaching rate is controlled by a chemical reaction through a layer on the unreacted shrinking core. The leaching process follows the kinetics model 1-(1-a)^1/3=kt with apparent activation energies of 34.50, 43.14 and 71.79 kJ/mol for Mo, Ni and Fe, respectively. The reaction orders in sodium persulfate are 0.80, 1.01 and 0.75 for molybdenum, nickel and iron, respectively, while in sulfuric acid, these orders are 0.45, 0.75 and 0.50 for molybdenum, nickel and iron, respectively. In addition, the reaction mechanism for the dissolution of the metalliferous black shale was discussed.展开更多
We tested the utility of chemical marking techniques in the juvenile black rockfish Sebastes schlegelii. Juveniles (30-40 mm total length) were immersed in a range of tetracycline hydrochloride (TC) solutions at c...We tested the utility of chemical marking techniques in the juvenile black rockfish Sebastes schlegelii. Juveniles (30-40 mm total length) were immersed in a range of tetracycline hydrochloride (TC) solutions at concentrations ranging from 300 to 500 mg/L, and alizarin complexone (ALC) solutions at concentrations ranging from 200 to 400 mg/L in filtered sea water (salinity of 30) for 24 h, respectively. Otoliths (sagittae, asteriscus), scales, fin rays (dorsal, pectoral, ventral, anal, and caudal fin rays), and fin spines (dorsal, ventral, and anal fin spines) were sampled and used to detect fluorescent marks after a 60-day growth experiment. With the exception of 300 mg/L TC, acceptable marks were produced in the otoliths and fin spines by all concentrations of TC and ALC. In particular, we observed clearly visible marks in the sagittae, asteriscus, and fin spines under normal light at concentrations of200~00 mg/L, 250-400 mg/L, and 250-400 mg/L ALC, respectively. Scales and fin rays had acceptable marks at much higher concentrations (_〉350 mg/L TC, 〉250 mg/L ALC for scales and _〉350 mg/L TC, 〉300 mg/L ALC for fin rays). The best mark quality (i.e., acceptable marks were observed in all sampled structures after immersion marking) were obtained following immersion in TC at between 350-500 rag/L, and ALC between 300-400 mg/L. In addition, there was no significant difference in survival and growth of TC and ALC marked fish compared to their controls up to 60 days post-marking (P〉0.05).展开更多
The recovery of nickel from molybdenum leach residue by the process of segregation roasting-sulfuric acid leaching-solvent extraction was investigated. The residue was characterized by microscopic investigations, usin...The recovery of nickel from molybdenum leach residue by the process of segregation roasting-sulfuric acid leaching-solvent extraction was investigated. The residue was characterized by microscopic investigations, using X-ray fluorescence spectrometry (XRF) and X-ray diffractometry (XRD) techniques and the residue after segregation roasting was characterized by chemical phase analysis method. A series of experiments were conducted to examine the mass ratio of activated carbon (AC) to the residue, segregation roasting time and temperature, sulfuric acid concentration, liquid-to-solid ratio, leaching time, leaching temperature, addition amount of 30% H2O2, stirring speed (a constant) on the leaching efficiency of nickel. A maximum nickel leaching efficiency of 90.5% is achieved with the mass ratio of AC to the residue of 1:2.5, segregation roasting time of 2 h, segregation roasting temperature of 850 ℃, sulfuric acid concentration of 4.5 mol/L, liquid-to-solid ratio of 6:1, leaching time of 5 h, leaching temperature of 80 ℃, addition of 30% H202 of 0.6 mL for 1 g dry residue. Under these optimized conditions, the average leaching efficiency of nickel is 89.3%. The nickel extraction efficiency in the examined conditions is about 99.6%, and the nickel stripping efficiency in the examined conditions is about 99.2%.展开更多
Black rockfish Sebastes schlegelii juveniles (30-40 mm total length) were immersed in a range of calcein (CAL) solutions at concentrations ranging from 50 to 250 mg/L and alizarin red S (ARS) solutions at concen...Black rockfish Sebastes schlegelii juveniles (30-40 mm total length) were immersed in a range of calcein (CAL) solutions at concentrations ranging from 50 to 250 mg/L and alizarin red S (ARS) solutions at concentrations ranging from 100 to 500 mg/L in filtered seawater (salinity 30) for 24 h. Fluorescent marks were detected in otoliths (sagittae, asteriscus), scales, fin rays (dorsal, pectoral, ventral, anal, and caudal fin rays), and fin spines (dorsal, ventral, and anal fin spines) after a 60-d growth experiment. With the exception of 50-100 rng/L CAL, acceptable marks were produced in the otoliths and fin spines by all concentrations of CAL and ARS. In particular, marks were clearly visible under normal light in the sagittae, asteriscus, and fin spines offish immersed in 200 500 mg/L, 300-500 rag/L, and 200-500 mg/LARS, respectively. Scales and fin rays had acceptable marks at much higher concentrations (≥50 mg/L CAL, ≥300 mg/L ARS for scales and ≥50 mg/L CAL,≥200 mg/L ARS for fin rays). The mark quality was highest (i.e., acceptable marks were observed in all sampled structures after immersion marking) in fish immersed in 150-250 mg/L CAL or 300-500 mg/LARS. In addition, there was no significant difference in survival and growth of marked fish compared with controls 60 d post-marking (P〉0.05).展开更多
A new hydrometallurgical route for separation and recovery of Cu from Cu-As-bearing copper electrorefining black slime was developed. The proposed process comprised oxidation acid leaching of Cu-As-bearing slime and s...A new hydrometallurgical route for separation and recovery of Cu from Cu-As-bearing copper electrorefining black slime was developed. The proposed process comprised oxidation acid leaching of Cu-As-bearing slime and selective sulfide precipitation of Cu from the leachate. The effects of various process parameters on the leaching and precipitation of Cu and As were investigated. At the first stage, Cu extraction of 95.2% and As extraction of 97.6% were obtained at 80 ℃ after 4 h with initial H2 SO4 concentration of 1.0 mol/L and liquid-to-solid ratio of 10 mL/g. In addition, the leaching kinetics of Cu and As was successfully reproduced by the Avrami model, and the apparent activation energies were found to be 33.6 and 35.1 kJ/mol for the Cu and As leaching reaction, respectively, suggesting a combination of chemical reaction and diffusion control. During the selective sulfide precipitation, about 99.4% Cu was recovered as CuS, while only 0.1% As was precipitated under the optimal conditions using sulfide-to-copper ratio of 2.4:1, time of 1.5 h and temperature of 25 ℃.展开更多
The results of investigation of micromineralogy of disseminated-sulphide gold ore deposits of the Yana-Kolyma belt; the investigation was conducted via electron microscopy using a QEMSCAN (Quantitative Evaluation of ...The results of investigation of micromineralogy of disseminated-sulphide gold ore deposits of the Yana-Kolyma belt; the investigation was conducted via electron microscopy using a QEMSCAN (Quantitative Evaluation of Minerals by Scanning Electron Microscopy) hardware and software instrument equipped with a Quantax quantitative analysis system. The following micro-mineral phases have been detected: native gold and silver, selenides of Au and Ag (naumanite and fishesserite (?), hessite, sulfoarsenides of Ni and Co (gersdorffite, cobaltite, rammelsbergite), molibdenite and platinum group minerals. Our findings in disseminated sulfide ores selenides of Au and Ag, and molybdenite, together with the findings of platinum group minerals and Ni and Co, emphasize the "black shale" specifics character of these types of deposits.展开更多
基金Project(15A151)supported by the Key Research Projects of Education Department of Hunan Province,ChinaProject(2015JJ2115)supported by the Natural Science Fund Council of Hunan Province,China+1 种基金Project(JSU071308)supported by the Construct Program of the Key Discipline in Hunan Province,ChinaProject(APSTIRT02)supported by the Aid Program for Science and Technology Innovative Research Team in Higher Educational Institutions of Hunan Province,China
文摘The oxidative dissolution of metalliferous black shale in sulfuric acid solution using sodium persulfate as an oxidant was investigated. The effects of leaching factors including leaching temperature, leaching time, stirring speed, initial concentration of sodium persulfate and sulfuric acid and particle size on the leaching rate were studied as well. The leaching kinetics of molybdenum, nickel and iron from metalliferous black shale shows that the leaching rate is controlled by a chemical reaction through a layer on the unreacted shrinking core. The leaching process follows the kinetics model 1-(1-a)^1/3=kt with apparent activation energies of 34.50, 43.14 and 71.79 kJ/mol for Mo, Ni and Fe, respectively. The reaction orders in sodium persulfate are 0.80, 1.01 and 0.75 for molybdenum, nickel and iron, respectively, while in sulfuric acid, these orders are 0.45, 0.75 and 0.50 for molybdenum, nickel and iron, respectively. In addition, the reaction mechanism for the dissolution of the metalliferous black shale was discussed.
基金Supported by the Special Fund for Agro-Scientific Research in the Public Interest(No.201003068)the National Natural Science Foundation of China(Nos.31172447,41176117)
文摘We tested the utility of chemical marking techniques in the juvenile black rockfish Sebastes schlegelii. Juveniles (30-40 mm total length) were immersed in a range of tetracycline hydrochloride (TC) solutions at concentrations ranging from 300 to 500 mg/L, and alizarin complexone (ALC) solutions at concentrations ranging from 200 to 400 mg/L in filtered sea water (salinity of 30) for 24 h, respectively. Otoliths (sagittae, asteriscus), scales, fin rays (dorsal, pectoral, ventral, anal, and caudal fin rays), and fin spines (dorsal, ventral, and anal fin spines) were sampled and used to detect fluorescent marks after a 60-day growth experiment. With the exception of 300 mg/L TC, acceptable marks were produced in the otoliths and fin spines by all concentrations of TC and ALC. In particular, we observed clearly visible marks in the sagittae, asteriscus, and fin spines under normal light at concentrations of200~00 mg/L, 250-400 mg/L, and 250-400 mg/L ALC, respectively. Scales and fin rays had acceptable marks at much higher concentrations (_〉350 mg/L TC, 〉250 mg/L ALC for scales and _〉350 mg/L TC, 〉300 mg/L ALC for fin rays). The best mark quality (i.e., acceptable marks were observed in all sampled structures after immersion marking) were obtained following immersion in TC at between 350-500 rag/L, and ALC between 300-400 mg/L. In addition, there was no significant difference in survival and growth of TC and ALC marked fish compared to their controls up to 60 days post-marking (P〉0.05).
基金Project(2007CB613604)supported by the National Basic Research Program of China
文摘The recovery of nickel from molybdenum leach residue by the process of segregation roasting-sulfuric acid leaching-solvent extraction was investigated. The residue was characterized by microscopic investigations, using X-ray fluorescence spectrometry (XRF) and X-ray diffractometry (XRD) techniques and the residue after segregation roasting was characterized by chemical phase analysis method. A series of experiments were conducted to examine the mass ratio of activated carbon (AC) to the residue, segregation roasting time and temperature, sulfuric acid concentration, liquid-to-solid ratio, leaching time, leaching temperature, addition amount of 30% H2O2, stirring speed (a constant) on the leaching efficiency of nickel. A maximum nickel leaching efficiency of 90.5% is achieved with the mass ratio of AC to the residue of 1:2.5, segregation roasting time of 2 h, segregation roasting temperature of 850 ℃, sulfuric acid concentration of 4.5 mol/L, liquid-to-solid ratio of 6:1, leaching time of 5 h, leaching temperature of 80 ℃, addition of 30% H202 of 0.6 mL for 1 g dry residue. Under these optimized conditions, the average leaching efficiency of nickel is 89.3%. The nickel extraction efficiency in the examined conditions is about 99.6%, and the nickel stripping efficiency in the examined conditions is about 99.2%.
基金Supported by the Special Fund for Agro-scientific Research in the Public Interest(No.201003068)the National Natural Science Foundation of China(Nos.31172447,41176117)
文摘Black rockfish Sebastes schlegelii juveniles (30-40 mm total length) were immersed in a range of calcein (CAL) solutions at concentrations ranging from 50 to 250 mg/L and alizarin red S (ARS) solutions at concentrations ranging from 100 to 500 mg/L in filtered seawater (salinity 30) for 24 h. Fluorescent marks were detected in otoliths (sagittae, asteriscus), scales, fin rays (dorsal, pectoral, ventral, anal, and caudal fin rays), and fin spines (dorsal, ventral, and anal fin spines) after a 60-d growth experiment. With the exception of 50-100 rng/L CAL, acceptable marks were produced in the otoliths and fin spines by all concentrations of CAL and ARS. In particular, marks were clearly visible under normal light in the sagittae, asteriscus, and fin spines offish immersed in 200 500 mg/L, 300-500 rag/L, and 200-500 mg/LARS, respectively. Scales and fin rays had acceptable marks at much higher concentrations (≥50 mg/L CAL, ≥300 mg/L ARS for scales and ≥50 mg/L CAL,≥200 mg/L ARS for fin rays). The mark quality was highest (i.e., acceptable marks were observed in all sampled structures after immersion marking) in fish immersed in 150-250 mg/L CAL or 300-500 mg/LARS. In addition, there was no significant difference in survival and growth of marked fish compared with controls 60 d post-marking (P〉0.05).
基金financial supports from the National Natural Science Foundation of China (51634010,51904354)the National Science Fund for Distinguished Young Scholars of China (51825403)+1 种基金the National Key R&D Program of China (2018YFC1900306,2019YFC1907405)Key Research and Development Program of Hunan Province,China (2019SK2291)。
文摘A new hydrometallurgical route for separation and recovery of Cu from Cu-As-bearing copper electrorefining black slime was developed. The proposed process comprised oxidation acid leaching of Cu-As-bearing slime and selective sulfide precipitation of Cu from the leachate. The effects of various process parameters on the leaching and precipitation of Cu and As were investigated. At the first stage, Cu extraction of 95.2% and As extraction of 97.6% were obtained at 80 ℃ after 4 h with initial H2 SO4 concentration of 1.0 mol/L and liquid-to-solid ratio of 10 mL/g. In addition, the leaching kinetics of Cu and As was successfully reproduced by the Avrami model, and the apparent activation energies were found to be 33.6 and 35.1 kJ/mol for the Cu and As leaching reaction, respectively, suggesting a combination of chemical reaction and diffusion control. During the selective sulfide precipitation, about 99.4% Cu was recovered as CuS, while only 0.1% As was precipitated under the optimal conditions using sulfide-to-copper ratio of 2.4:1, time of 1.5 h and temperature of 25 ℃.
文摘The results of investigation of micromineralogy of disseminated-sulphide gold ore deposits of the Yana-Kolyma belt; the investigation was conducted via electron microscopy using a QEMSCAN (Quantitative Evaluation of Minerals by Scanning Electron Microscopy) hardware and software instrument equipped with a Quantax quantitative analysis system. The following micro-mineral phases have been detected: native gold and silver, selenides of Au and Ag (naumanite and fishesserite (?), hessite, sulfoarsenides of Ni and Co (gersdorffite, cobaltite, rammelsbergite), molibdenite and platinum group minerals. Our findings in disseminated sulfide ores selenides of Au and Ag, and molybdenite, together with the findings of platinum group minerals and Ni and Co, emphasize the "black shale" specifics character of these types of deposits.