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Lin H.,University of Science and Technology Beijing | Lin H.,Key Laboratory of the Ministry of Education of China for High Efficient Mining and Safety of Metal Mines | Wang Y.-N.,University of Science and Technology Beijing | Wang Y.-N.,Key Laboratory of the Ministry of Education of China for High Efficient Mining and Safety of Metal Mines | And 3 more authors.
Meitan Xuebao/Journal of the China Coal Society | Year: 2012

In order to eliminate hidden danger caused by H2S in the coal mine, Fenton reagent was used to treat H2S in the mine water. In this study, the effects of H2O2 dosage, FeSO4·7H2O dosage, pH, reaction time, rotation speed, reaction temperature on the treatment efficiency were researched. In addition, the study investigated the kinetics of removing hydrogen sulfide using Fenton reagent. The results show that the optimum dosage of Fenton reagent is 0.67 g/L FeSO4·7H2O+0.67 mL/L H2O2, the suitable pH is 6-10, the optimum flow disturbance intensity is 160 r/min of bed rotation speed, and 25 °C for 10 min. Under optimal conditions, when the initial concentration of hydrogen sulfide is 140 mg/L, the removal rate of hydrogen sulfide can reach 93.14% and the concentration of residual hydrogen sulfide in water is only 2.381 mg/L. The process of the removing reaction of H2S by Fenton reagent can be described to be the quasi-second order kinetics.


Cao Y.-Y.,University of Science and Technology Beijing | Cao Y.-Y.,Key Laboratory of the Ministry of Education of China for High Efficient Mining and Safety of Metal Mines | Sun T.-C.,University of Science and Technology Beijing | Sun T.-C.,Key Laboratory of the Ministry of Education of China for High Efficient Mining and Safety of Metal Mines | And 6 more authors.
Cailiao Rechuli Xuebao/Transactions of Materials and Heat Treatment | Year: 2015

Reduction behavior of high-phosphorus oolitic hematite was evaluated by performing a series of deep reduction tests followed by magnetic separation using coal slime as reductant. The effects of different coal slime, the mineral composition of coal slime ash and the roasting temperature on the iron reduction of deep reduction process were investigated. The results show that the main compositions of coal slime ash are quartz, gypsum and silicate minerals. The optimum iron grade of 91.35% with recovery of 81.13% and phosphorus content of the direct reduced iron (DRI) of 0.076% is obtained using Tianjin (T) coal slime as reductant at dosage of 20%. With the analysis of XRD and SEM-EDS, when the Tianjin and Hongshan (H) coal slime is used as reductant, the iron bearing minerals in raw ore are reduced to metallic iron during deep reduction. The quartz existed in coal slime ash accelerates the reduction of fluorapatite to phosphorus, which significantly increases the P content in DRI and negatively impacts the dephosphorization of DRI. ©, 2015, Editorial Office of Transactions of Materials and Heat Treatment. All right reserved.


Dong Y.,Key Laboratory of the Ministry of Education of China for High Efficient Mining and Safety of Metal Mines | Dong Y.,University of Science and Technology Beijing | Lin H.,Key Laboratory of the Ministry of Education of China for High Efficient Mining and Safety of Metal Mines | Lin H.,University of Science and Technology Beijing
Minerals Engineering | Year: 2012

This paper investigates the effects of five flotation reagents (ethyl xanthate, isopropyl xanthate, butyl xanthate, isoamyl xanthate and butylaminel) on the bioleaching capability of Acidthiobacillus ferrooxidans. It is shown that these five flotation reagents can all depress the copper extraction of At.f 6 bacteria. According to the impacts from weak to strong, the inhibition effects of these five reagents on At.f 6 bacteria are in the following order: butyl xanthate, isopropyl xanthate, isoamyl xanthate, ethyl xanthate, and butylamine. The analysis of SEM-EDS indicates that the surfaces of mineral particles are corroded by different degrees and that the weight proportion and atomic number proportion of Cu decrease, but the weight proportion and atomic number proportion of Fe and S increase; the degrees of change are in the same order with the inhibition effects of these five reagents on bioleaching capability of At.f 6 bacteria. © 2012 Elsevier B.V. All rights reserved.


Mo X.-L.,University of Science and Technology Beijing | Mo X.-L.,Key Laboratory of the Ministry of Education of China for High Efficient Mining and Safety of Metal Mines | Lin H.,University of Science and Technology Beijing | Lin H.,Key Laboratory of the Ministry of Education of China for High Efficient Mining and Safety of Metal Mines | And 6 more authors.
Beijing Keji Daxue Xuebao/Journal of University of Science and Technology Beijing | Year: 2012

Chalcopyrite-pyrite bioleaching tests were performed with shaking flasks by Acidithiobacillus ferrooxidans. The research focused on the effects of basic salt mediums, pyrite-to-chalcopyrite mass ratio and mineral size distribution. It is found that chalcopyrite bioleaching can be promoted by pyrite. The leaching rate of copper in the iron-free 9K medium in pyrite-chalcopyrite bioleaching is 1.68 times as large as that in the 9K medium. The leaching of copper is better using a wide size range of minerals and the leaching rate of copper is related to the mass ratio of pyrite to chalcopyrite. When the mass ratio is 2:2, the highest leaching rate of copper is obtained to be 45.58%. The content of pyrite is of the essence in affecting the leaching rate level of copper. At a mass ratio of pyrite to chalcopyrite no more than 5:2 the oxidation of Acidithiobacillus ferrooxidans plays an important role in the bioleaching, but when the mass ratio is 10:2 the galvanic effect between the two sulphide minerals mainly influences the bioleaching. X-ray diffraction analyses of leaching residues indicate that the generation of jarosite in the iron-free 9K medium is less than that in the 9K medium, FeSO 4 in the 9K medium can be replaced by pyrite, the galvanic effect forms with chalcopyrite, and therefore the bioleaching efficiency of copper is increased.


Wang H.,University of Science and Technology Beijing | Wang H.,Key Laboratory of the Ministry of Education of China for High Efficient Mining and Safety of Metal Mines | Lin H.,University of Science and Technology Beijing | Lin H.,Key Laboratory of the Ministry of Education of China for High Efficient Mining and Safety of Metal Mines | And 6 more authors.
Petroleum Exploration and Development | Year: 2012

To investigate the ability of exogenous bacteria to degrade brown coal, methanogens were enriched from anaerobic sludge and domesticated using brown coal as carbon source. After domestication, the lag time of initial gas production is shortened from 12 to 6 days and the CH4 production increased by 29.2% in 30 days. The generated biogas is composed of CH4 and a little CO2, no heavy hydrocarbons are detected. Experiments on gas production influencing factors demonstrate that the best initial pH for the culture medium is 7.0 and the maximum gas production is 1.9 times and 2.4 times higher than that at pH 6.4 and pH 7.4, respectively. The particle size of coal is one of factors influencing the gas production: the general trend is the smaller the particle size, the bigger the gas production, but the variation of gas production is not significant with decreasing particle size. Gas produced by the culture medium accounts for around 50% of the total gas production and it is likely caused by the addition of L-cysteine (0.5 g/L) and yeast extract (1 g/L) to the medium. © 2012 Research Institute of Petroleum Exploration & Development, PetroChina.


Dong Y.,University of Science and Technology Beijing | Dong Y.,Key Laboratory of the Ministry of Education of China for High Efficient Mining and Safety of Metal Mines | Lin H.,University of Science and Technology Beijing | Lin H.,Key Laboratory of the Ministry of Education of China for High Efficient Mining and Safety of Metal Mines
Nature Environment and Pollution Technology | Year: 2015

This paper is aimed to investigate the oxidation ability of the bacteria (Thiobacillus thioparus, Z-2) and the biological oxidation mechanism and oxidation kinetics on the reduced inorganic sulphuric compounds in sodium-process desulphurization wastewater. Results showed that the Z-2 bacteria have high oxidation activity in the high-salt environment after acclimation, and the oxidation percentage of reduced inorganic sulphuric compounds reached 95% and the chemical oxygen demand (COD) reduced from 18000mg/L to 2000 mg/L in the high-salt environment. This showed that the Z-2 bacteria have strong salt resistance and high oxidation activity. In addition, ion chromatography analysis confirmed that Z-2 bacteria were beneficial for the oxidation of reduced sulphur. A biological oxidation model was constructed by measuring the enzyme activity of the oxidation process. The results indicated that direct and indirect oxidation processes were both involved in biological oxidation. The kinetic parameters of Vmax (21.38 μM/min) and Km (79.04 μM) were obtained through biological oxidation kinetic experiments.


Dong Y.,University of Science and Technology Beijing | Dong Y.,Key Laboratory of the Ministry of Education of China for High Efficient Mining and Safety of Metal Mines | Lin H.,University of Science and Technology Beijing | Lin H.,Key Laboratory of the Ministry of Education of China for High Efficient Mining and Safety of Metal Mines | And 8 more authors.
Minerals Engineering | Year: 2011

This paper studies the effects of ultraviolet irradiation on the mutation of bacteria (i.e.; Acidithiobacillus ferrooxidans LD-1) and on the bioleaching system for low-grade copper tailings. It is shown that ultraviolet irradiation can lead to an obvious LD-1 mutation, can improve bio-activity and bioleaching capability. The mutant LD-1 bacteria, after ultraviolet irradiation for 30 min, had the best oxidation activity, the oxidation rate of ferrous ion (Fe 2+) in mutant bacteria culturing medium can reach 100% after 24 h (18 h less than that of the original bacteria under the same leaching conditions). After 30 days, copper extraction with mutant bacteria is increased by about 17%, compared with original bacteria, and by 70% compared to chemical leaching. These results show that the effects of mutant bacteria after ultraviolet irradiation are better than those of the original bacteria and much better than those of chemical leaching. The improved bioleaching rate of the mutant bacteria is attributed to the faster propagation rate and capabilities for stronger sulfuric acid generation. This study shows that mutant bacteria from ultraviolet irradiation have great potential for improving copper recovery from low-grade copper tailings. © 2010 Elsevier Inc. All rights reserved.

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