Traditional pyrometallurgical and hydrometallurgical methods to extract bismuth from sulfide ores face problems such as high cost,low-concentration SO_(2)generation,and long process time.In this study,the cyclone tech...Traditional pyrometallurgical and hydrometallurgical methods to extract bismuth from sulfide ores face problems such as high cost,low-concentration SO_(2)generation,and long process time.In this study,the cyclone technology and slurry electrolysis method were combined.The bismuth sulfide ore was dissolved directly at the anode,while the high purity bismuth was deposited efficiently at the cathode under the advantages of the two methods.The short process and high-efficiency extraction of bismuth sulfide ore were realized,and the pollution of low-concentration SO_(2)was avoided.Then,the effects of several crucial experimental conditions(current density,reaction time,temperature,pH,liquid-solid ratio,and circulation flow rate)on the leaching efficiency and recovery efficiency of bismuth were investigated.The leaching and electrowinning mechanisms during the recovery process were also analyzed according to the research results of this paper to better understand the cyclone slurry electrolysis process.The experimental results showed that 95.19%bismuth was leached into the acid solution in the anode area under optimal conditions,and the recovery efficiency and purity of bismuth on the cathode reached 91.13%and 99.26%,respectively,which were better than those by the traditional hydrometallurgy recovery process.展开更多
Making use of basic equation of large deformation of circular membrane under the concentrated force and its boundary conditions and Hencky transformation, the problems of nonlinear boundary condition were solved. The ...Making use of basic equation of large deformation of circular membrane under the concentrated force and its boundary conditions and Hencky transformation, the problems of nonlinear boundary condition were solved. The Hencky transformation was extended and a exact solution of large deformation of circular membrane under the concentrated force has been obtained.展开更多
Successfully developed an innovative process of direct reduction of cold bound pellets from iron ore concentrate with a coal based rotary kiln, in comparison with the traditional direct reduction of fired oxide pellet...Successfully developed an innovative process of direct reduction of cold bound pellets from iron ore concentrate with a coal based rotary kiln, in comparison with the traditional direct reduction of fired oxide pellets in coal based rotary kilns , possesses such advantages as: shorter flowsheet, lower capital investment, greater economic profit, good quality of direct reduced iron. The key technologies , such as the composite binder and corresponding feasible techniques were employed in practice. A mill utilizing this process and with an annual capacity of 50 thousand ton DRI has been put into operation.展开更多
Based on physicochemical study of the reaction between scheelite and NaOH, a new decomposition process for scheelite and scheelitewolframite concentrate, i. e., mechenically activating caustic decomposition has bee...Based on physicochemical study of the reaction between scheelite and NaOH, a new decomposition process for scheelite and scheelitewolframite concentrate, i. e., mechenically activating caustic decomposition has been developed, and it has been successfu展开更多
The bacterial pre-oxidation process of arsenic-containing gold concentrates and the bacterial activity under different chloride ion concentrations were studied by using a mixture of thermophilic strains TCJ domesticat...The bacterial pre-oxidation process of arsenic-containing gold concentrates and the bacterial activity under different chloride ion concentrations were studied by using a mixture of thermophilic strains TCJ domesticated in production.The experimental result shows that with different samples and leaching systems,the adaptability and Cl- tolerance of bacteria are different,and that appropriate chloride ion concentration is conductive to bacterial oxidation,while higher chloride ion concentration will inhibit the bacterial activity and affect the pre-oxidation performance.Under the present production conditions,TCJ can adapt to the changes of water quality in the source of water and its critical chloride ion tolerance value is 2.7 g/L.展开更多
Sodium sulfide leaching of a low-grade jamesonite concentrate in the production of sodium pyroantimoniate through the air oxidation process and the influencing factors on the leaching rate of antimony were investigate...Sodium sulfide leaching of a low-grade jamesonite concentrate in the production of sodium pyroantimoniate through the air oxidation process and the influencing factors on the leaching rate of antimony were investigated. In order to decrease the consumption of sodium sulfide and increase the concentration of antimony in the leaching solution, two-stage leaching of jamesonite concentrate and combination leaching of high-grade stibnite concentrate and jamesonite concentrate were used. The experimental results show that the consumptions of sodium sulfide for the two-stage leaching process and the combination leaching process are decreased by 20% and 60% compared to those of one-stage leaching process respectively. The final concentrations of antimony in the leaching solutions of both processes are above 100g/L.展开更多
For the high sulfur refractory gold concentrate with 41.82%sulfur and 15.12 g/t gold,of which 82.11%was wrapped in sulfide,a well-controlled stirring tank leaching was carried out to improve the bio-oxidation efficien...For the high sulfur refractory gold concentrate with 41.82%sulfur and 15.12 g/t gold,of which 82.11%was wrapped in sulfide,a well-controlled stirring tank leaching was carried out to improve the bio-oxidation efficiency.Results show that bio-oxidation pretreatment can greatly improve the gold recovery rate of high-sulfur refractory gold concentrate,and at the optimum pH 1.3 in this study,compared with the process without pH control,the oxidation rate of sulfur increased from 79.31%to 83.29%,while the recovery rate of gold increased from 76.54%to 83.23%;under this condition the activity of mixed culture could be sustained and the formation of jarosite could diminish.The results also displayed that for the high sulfur refractory gold concentrate,the recovery of gold is positively correlated with the oxidation rate of sulfur,and the recovery rate of gold increases with the increase of sulfur oxidation rate within a certain range.展开更多
In order to enhance the electrogenerative leaching rate of chalcopyrite concentrate reasonably, the principle of generative process was applied to simultaneous leaching of chalcopyrite concentrate and MnO2. The result...In order to enhance the electrogenerative leaching rate of chalcopyrite concentrate reasonably, the principle of generative process was applied to simultaneous leaching of chalcopyrite concentrate and MnO2. The results show that Cu^2＋ and Mn^2＋ in addition to electrical energy could be acquired in the simultaneous electrogenerative leaching process. The leaching cell has the open circuit potential of about 1.0 V and gains quantity of electricity of about 700 C. The optimum leaching rates of Cu^2＋ and Mn^2＋ are 23.10% and 22.1%, respectively after electrogenera- tive leaching for about 10 h under the present conditions.展开更多
The leaching results of bismuth sulfide concentrate containing molybdenum and tungsten in air-H2O2-NaOH system, pressure-O2-Na2CO3 system and pressure-O2-NaOH system were investigated. The results show that the extrac...The leaching results of bismuth sulfide concentrate containing molybdenum and tungsten in air-H2O2-NaOH system, pressure-O2-Na2CO3 system and pressure-O2-NaOH system were investigated. The results show that the extraction of molybdenum, tungsten and sulfur goes up with the increase of NaOH concentration, oxygen partial pressure and reaction time. The extraction of molybdenum and tungsten also rises up with temperature, but the leaching ratio of sulfur increases initially to a peak of 98% at 150℃ and then decreases with the increase of temperature. Under the optimal conditions, the extraction of molybdenum, tungsten and sulfur is more than 95.6%, 93.8% and 96.0%, respectively, and the main phases of residue are Bi2O3 and Fe2O3. Therefore, the method of pressure leaching in alkaline solution is provided as an effective separation of molybdenum, tungsten and sulfur from bismuth and a beneficial pretreatment for consequent process.展开更多
The enrichment of Ni from a low-grade saprolitic laterite ore,which has been pre-treated by high pressure grinding roller（HPGR） to be 74% passing 0.074 mm and contains 0.92% Ni,18.47% Fe,10.61% MgO and 42.27% SiO2,w...The enrichment of Ni from a low-grade saprolitic laterite ore,which has been pre-treated by high pressure grinding roller（HPGR） to be 74% passing 0.074 mm and contains 0.92% Ni,18.47% Fe,10.61% MgO and 42.27% SiO2,was conducted by using pelletizing,rotary kiln reduction and magnetic separation process on a semi industrial scale,and the effects of reduction duration,mass ratio of coal to pellets（C/P）,the types of magnetic separator,the sections of grinding-separation and the grinding fineness on the recovery of Ni and Fe were examined.It is shown that nickel concentrate containing 3.13 % Ni and 59.20 % Fe was achieved at recoveries of 84.36 % and 71.51% for Ni and Fe,respectively under the following conditions：reducing at （1120±40） ℃ for 120 min,C/P being 1.0,wet grinding of reduced pellets up to 70%-87% passing 0.074 mm and a magnetic field intensity of 238.8 kA/m during the first section of grinding-magnetic separation,and a grinding fineness of 84%-91% passing 0.045 mm and a magnetic intensity of 39.8 kA/m during the second section of grinding-magnetic separation.The enriched Ni containing concentrate has a low content of S and P,and can be used for further processing to produce high-grade ferronickel alloy.展开更多
In order to utilize the chemical energy in hydrometallurgical process of sulfide minerals reasonably and to simplify the purifying process, the electrogenerative process was applied and a dual cell system was introduc...In order to utilize the chemical energy in hydrometallurgical process of sulfide minerals reasonably and to simplify the purifying process, the electrogenerative process was applied and a dual cell system was introduced to investigate FeCl3 leaching of nickel sulfide concentrate. Some factors influencing the electrogenerative leaching, such as electrode structure, temperature and solution concentration were studied. The results show that a certain quantity of electrical energy accompanied with the leached products can be acquired in the electrogenerative leaching process. The output current and power increase with the addition of acetylene black to the electrode. Varying the components of electrode just affects the polarization degree of anode. Increasing FeCl3 concentration results in a sharp increase in the output of the leaching cell when c（FeCl3） is less than 0.1 mol/L. The optimum value of NaCl concentration for electrogenerative leaching nickel sulfide concentrate with FeCl3 is 3.0 mol/L. Temperature influences electrogenerative leaching by affecting anodic and cathodic polarization simultaneously. The apparent activation energy is determined to be 34.63 kJ/mol in the range of 298 K to 322 K. The leaching rate of Ni2+ is 29.3% after FeCl3 electrogenerative leaching of nickel sulfide concentrate for 620 min with a filter bag electrode.展开更多
A refractory gold concentrate with 19% arsenic was treated by a mixed moderately thermophiles in an airlift bioreactor through an adaptation protocol. The moderately thermophiles could respond well to 20%(w/v) pulp de...A refractory gold concentrate with 19% arsenic was treated by a mixed moderately thermophiles in an airlift bioreactor through an adaptation protocol. The moderately thermophiles could respond well to 20%(w/v) pulp density with less than 10% loss of productivity, and resist arsenic up to 15 g/L. There were a lot of jarosite, arsenolite and sulfur, but not scorodite and ferric arsenate in the bioleached residue. Jarosite passivation and lower sulfur-oxidizing activity of the cells due to the toxicity of the high concentrations of soluble arsenic and iron ions at low p H value should mainly response for the incomplete extraction at high pulp density. The initial bacterial community did not change in nature except for new found P aeruginosa ANSC, but sulfur-oxidizing microorganisms have been dominant microorganisms after a long time of adaptation. Pseudomonas aeruginosa originating from the gold concentrate should be closely relative to the metabolism of the organic matters contained in the refractory gold concentrate.展开更多
To shorten the bioleaching cycle of arsenic-containing gold concentrate, surfactants were used to promote the interaction between bacteria and ore to increase the arsenic leaching rate. Three different kinds of surfac...To shorten the bioleaching cycle of arsenic-containing gold concentrate, surfactants were used to promote the interaction between bacteria and ore to increase the arsenic leaching rate. Three different kinds of surfactants were used to evaluate the effects of surfactants on the growth of bacteria and arsenic leaching rate of arsenic-containing gold concentrate. The mechanism underlying surfactant enhancement was also studied. Results show that when relatively low-concentration surfactants are added to the medium, no significant difference is observed in the growth and Fe2+ oxidation ability of the bacteria compared with no surfactant in the medium. However, only the anionic surfactant calcium lignosulfonate and the nonionic surfactant Tween 80 are found to improve the arsenic leaching rates. Their optimum mass concentrations are 30 and 80 mg/L, respectively. At such optimum mass concentrations, the arsenic leaching rates are approximately 13.7% and 9.1% higher than those without the addition of surfactant, respectively. Mechanism research reveals that adding the anionic surfactant calcium lignosulfonate improves the percentage of bacterial adhesion on the mineral surface and decreases the surface tension in the leaching solution.展开更多
Carboxylmethyl cellulose(CMC) has become a commercial organic binder in agglomeration of iron ore concentrates. The relative molecular mass and degree of substitution(DS) of CMC have a large impact on its binding perf...Carboxylmethyl cellulose(CMC) has become a commercial organic binder in agglomeration of iron ore concentrates. The relative molecular mass and degree of substitution(DS) of CMC have a large impact on its binding performance. The interaction mechanism between CMC and iron ore particles was analyzed through Zeta potential measurements, adsorption measurements and infrared spectra. The results show that the interaction is chemical adsorption-oriented and the CMC's adsorption performance is related to the properties of CMC as well as the type of iron oxides. CMC has a greater affinity to Fe2O3 than Fe3O4, and CMC with higher relative molecular mass shows a higher adsorption isotherm. Pelletization of practical iron ore concentrates added with CMC further illustrates that CMC with higher relative molecular mass or DS exhibits a better binding performance, which is consistent with the results of adsorption tests.展开更多
Scheelite and scheelite-wolframite mixed concentrates with different grades were decomposed by caustic soda digestion, and the effects of caustic soda（NaOH） dosage, the ratio of water to ore and the stirring rate on...Scheelite and scheelite-wolframite mixed concentrates with different grades were decomposed by caustic soda digestion, and the effects of caustic soda（NaOH） dosage, the ratio of water to ore and the stirring rate on tungsten recovery were studied. The results show that under the conditions that the ratio of water to ore is （0.8,） stirring rate is 500 r·min-1 and the heating time is 2.0 h at （160 ℃,） the recovery of tungsten reaches 98% for scheelite （w（WO3） is （65.04%）） and wolframite containing high proportion of calcium （w（WO3） is 65.58%, w（Ca） is （7.53%）,） when caustic soda dosage is 2.2 and 2.0 times of theoretical value, respectively; the recovery of tungsten can be more than 98%,98% and 96% respectively for low-grade scheelite-wolframite mixed concentrate with （55.78%,） 45.32% and 25.21% WO3, when caustic soda dosage is 2.6,3.2 and 5.5 times of theoretical value, respectively.展开更多
The study of non-axisymmetric fuel dispersal and detonation can provide reference for the prevention of industrial cloud explosion accidents and the design of fuel air explosive(FAE).The concentration and detonation f...The study of non-axisymmetric fuel dispersal and detonation can provide reference for the prevention of industrial cloud explosion accidents and the design of fuel air explosive(FAE).The concentration and detonation fields of 85 kg cylindrical and fan-shaped fuel are investigated by experiments and numerical simulations.A dynamic model of the whole process for fuel dispersal and detonation is built.The concentration distribution of fuel is used as the initial condition to calculate the detonation stage,thus solving the initial value problem of detonation field.The phase and component changes of fuel cloud at different locations are compared.The fuel cloud is divided into directions of 0°,90°,135°and 180°.The results show that the maximum cloud radius is 20.94 m in 135°and the minimum is 12.04 m in 0°.The diameter of the detonation fireball is 53.6 m,and the peak temperature is 3455 K.The highest peak overpressure is 3.44 MPa in 0°and the lowest is 2.97 MPa in 135°.The proportion of liquid phase in 0°is22.90%,and the fuel loss is 11.8% and 9% higher than that in 135°and cylindrical charge,respectively.The stable propagation distance of blast wave in 135°is 42.50% longer than 0°and 28.37% longer than cylindrical charge.展开更多
The effect of composite agglomeration process(CAP) on fluoric iron concentrates sintering was investigated.The yield and quality of the sinter are greatly improved when using CAP assisted with heat airflow and enhanci...The effect of composite agglomeration process(CAP) on fluoric iron concentrates sintering was investigated.The yield and quality of the sinter are greatly improved when using CAP assisted with heat airflow and enhancing magnesium oxide(MgO) contents.For conventional sintering of fluoric iron concentrate,due to lower viscosity of binding phase and higher fluidity of liquid phase,the sinter is formed with large thin-walled holes and the strength of the sinter is deteriorated consequently.The novel process forms composite agglomerate in which acid pellets are embedded in basic sinter.The pellets are solid with interconnecting crystals of hematite(Fe2O3) and magnetic(Fe3O4).For basic sintering,after adding MgO,the viscosity of the melting phase increases and the fluidity decreases;and calcium and aluminum silico-ferrites and magnesium ferrite are formed with perfect crystals and good sintering microstructure.展开更多
In the present paper,the fundamental research on the properties of boron-rich slag melting separated from boron-bearing iron concentrate was performed.The melting and fluidity of B2O3–MgO–SiO2–FeO slag system,cryst...In the present paper,the fundamental research on the properties of boron-rich slag melting separated from boron-bearing iron concentrate was performed.The melting and fluidity of B2O3–MgO–SiO2–FeO slag system,crystallization of separated boron-rich slag and factors on the extraction efficiency of boron-rich slag were systematically investigated.B2O3 content would heavily affect the melting and fluidity property of boron-rich slag.Generally,FeO could improve the melting and fluidity property of boron-rich slag.Boron-containing crystalline phase mainly precipitated in temperature range from 1200°C to 1100°C.Higher smelting temperature and B2O3 reduction ratio were negative for the extraction of boron.The cooling rate of 10–20°C/min was better for the crystallization of boron-containing crystalline phase.Based on the obtained experimental results,the optimum operating parameters for the development of pyrometallurgical boron and iron separation process and further boron-rich slag cooling process were proposed.展开更多
基金Projects(52104355,52074363,52374364)supported by the National Natural Science Foundation of ChinaProject(2023YFC2907904)supported by the National Key R&D Program of China。
文摘Traditional pyrometallurgical and hydrometallurgical methods to extract bismuth from sulfide ores face problems such as high cost,low-concentration SO_(2)generation,and long process time.In this study,the cyclone technology and slurry electrolysis method were combined.The bismuth sulfide ore was dissolved directly at the anode,while the high purity bismuth was deposited efficiently at the cathode under the advantages of the two methods.The short process and high-efficiency extraction of bismuth sulfide ore were realized,and the pollution of low-concentration SO_(2)was avoided.Then,the effects of several crucial experimental conditions(current density,reaction time,temperature,pH,liquid-solid ratio,and circulation flow rate)on the leaching efficiency and recovery efficiency of bismuth were investigated.The leaching and electrowinning mechanisms during the recovery process were also analyzed according to the research results of this paper to better understand the cyclone slurry electrolysis process.The experimental results showed that 95.19%bismuth was leached into the acid solution in the anode area under optimal conditions,and the recovery efficiency and purity of bismuth on the cathode reached 91.13%and 99.26%,respectively,which were better than those by the traditional hydrometallurgy recovery process.
文摘Making use of basic equation of large deformation of circular membrane under the concentrated force and its boundary conditions and Hencky transformation, the problems of nonlinear boundary condition were solved. The Hencky transformation was extended and a exact solution of large deformation of circular membrane under the concentrated force has been obtained.
基金The Key Project of the 9th Five year Plan of Ministry of Science andTechnology!(No .960 40 2 0 2A)the Foundation for Unive
文摘Successfully developed an innovative process of direct reduction of cold bound pellets from iron ore concentrate with a coal based rotary kiln, in comparison with the traditional direct reduction of fired oxide pellets in coal based rotary kilns , possesses such advantages as: shorter flowsheet, lower capital investment, greater economic profit, good quality of direct reduced iron. The key technologies , such as the composite binder and corresponding feasible techniques were employed in practice. A mill utilizing this process and with an annual capacity of 50 thousand ton DRI has been put into operation.
文摘Based on physicochemical study of the reaction between scheelite and NaOH, a new decomposition process for scheelite and scheelitewolframite concentrate, i. e., mechenically activating caustic decomposition has been developed, and it has been successfu
基金Project(2007AA060902) supported by the National High Technology Research and Development Program of ChinaProject(2010CB630905) supported by the National Basic Research Program of China
文摘The bacterial pre-oxidation process of arsenic-containing gold concentrates and the bacterial activity under different chloride ion concentrations were studied by using a mixture of thermophilic strains TCJ domesticated in production.The experimental result shows that with different samples and leaching systems,the adaptability and Cl- tolerance of bacteria are different,and that appropriate chloride ion concentration is conductive to bacterial oxidation,while higher chloride ion concentration will inhibit the bacterial activity and affect the pre-oxidation performance.Under the present production conditions,TCJ can adapt to the changes of water quality in the source of water and its critical chloride ion tolerance value is 2.7 g/L.
文摘Sodium sulfide leaching of a low-grade jamesonite concentrate in the production of sodium pyroantimoniate through the air oxidation process and the influencing factors on the leaching rate of antimony were investigated. In order to decrease the consumption of sodium sulfide and increase the concentration of antimony in the leaching solution, two-stage leaching of jamesonite concentrate and combination leaching of high-grade stibnite concentrate and jamesonite concentrate were used. The experimental results show that the consumptions of sodium sulfide for the two-stage leaching process and the combination leaching process are decreased by 20% and 60% compared to those of one-stage leaching process respectively. The final concentrations of antimony in the leaching solutions of both processes are above 100g/L.
基金Projects(51704028,51574036)supported by the National Natural Science Foundation of ChinaProject supported by Program for Key Laboratory of Biohydrometallurgy of Ministry of Education Foundation,China。
文摘For the high sulfur refractory gold concentrate with 41.82%sulfur and 15.12 g/t gold,of which 82.11%was wrapped in sulfide,a well-controlled stirring tank leaching was carried out to improve the bio-oxidation efficiency.Results show that bio-oxidation pretreatment can greatly improve the gold recovery rate of high-sulfur refractory gold concentrate,and at the optimum pH 1.3 in this study,compared with the process without pH control,the oxidation rate of sulfur increased from 79.31%to 83.29%,while the recovery rate of gold increased from 76.54%to 83.23%;under this condition the activity of mixed culture could be sustained and the formation of jarosite could diminish.The results also displayed that for the high sulfur refractory gold concentrate,the recovery of gold is positively correlated with the oxidation rate of sulfur,and the recovery rate of gold increases with the increase of sulfur oxidation rate within a certain range.
文摘In order to enhance the electrogenerative leaching rate of chalcopyrite concentrate reasonably, the principle of generative process was applied to simultaneous leaching of chalcopyrite concentrate and MnO2. The results show that Cu^2＋ and Mn^2＋ in addition to electrical energy could be acquired in the simultaneous electrogenerative leaching process. The leaching cell has the open circuit potential of about 1.0 V and gains quantity of electricity of about 700 C. The optimum leaching rates of Cu^2＋ and Mn^2＋ are 23.10% and 22.1%, respectively after electrogenera- tive leaching for about 10 h under the present conditions.
文摘The leaching results of bismuth sulfide concentrate containing molybdenum and tungsten in air-H2O2-NaOH system, pressure-O2-Na2CO3 system and pressure-O2-NaOH system were investigated. The results show that the extraction of molybdenum, tungsten and sulfur goes up with the increase of NaOH concentration, oxygen partial pressure and reaction time. The extraction of molybdenum and tungsten also rises up with temperature, but the leaching ratio of sulfur increases initially to a peak of 98% at 150℃ and then decreases with the increase of temperature. Under the optimal conditions, the extraction of molybdenum, tungsten and sulfur is more than 95.6%, 93.8% and 96.0%, respectively, and the main phases of residue are Bi2O3 and Fe2O3. Therefore, the method of pressure leaching in alkaline solution is provided as an effective separation of molybdenum, tungsten and sulfur from bismuth and a beneficial pretreatment for consequent process.
基金Project(NDRC-Hitech Office 2009-606)supported by the National Development and Reform Commission of ChinaProject(50974135)supported by the National Natural Science Foundation of China
文摘The enrichment of Ni from a low-grade saprolitic laterite ore,which has been pre-treated by high pressure grinding roller（HPGR） to be 74% passing 0.074 mm and contains 0.92% Ni,18.47% Fe,10.61% MgO and 42.27% SiO2,was conducted by using pelletizing,rotary kiln reduction and magnetic separation process on a semi industrial scale,and the effects of reduction duration,mass ratio of coal to pellets（C/P）,the types of magnetic separator,the sections of grinding-separation and the grinding fineness on the recovery of Ni and Fe were examined.It is shown that nickel concentrate containing 3.13 % Ni and 59.20 % Fe was achieved at recoveries of 84.36 % and 71.51% for Ni and Fe,respectively under the following conditions：reducing at （1120±40） ℃ for 120 min,C/P being 1.0,wet grinding of reduced pellets up to 70%-87% passing 0.074 mm and a magnetic field intensity of 238.8 kA/m during the first section of grinding-magnetic separation,and a grinding fineness of 84%-91% passing 0.045 mm and a magnetic intensity of 39.8 kA/m during the second section of grinding-magnetic separation.The enriched Ni containing concentrate has a low content of S and P,and can be used for further processing to produce high-grade ferronickel alloy.
文摘In order to utilize the chemical energy in hydrometallurgical process of sulfide minerals reasonably and to simplify the purifying process, the electrogenerative process was applied and a dual cell system was introduced to investigate FeCl3 leaching of nickel sulfide concentrate. Some factors influencing the electrogenerative leaching, such as electrode structure, temperature and solution concentration were studied. The results show that a certain quantity of electrical energy accompanied with the leached products can be acquired in the electrogenerative leaching process. The output current and power increase with the addition of acetylene black to the electrode. Varying the components of electrode just affects the polarization degree of anode. Increasing FeCl3 concentration results in a sharp increase in the output of the leaching cell when c（FeCl3） is less than 0.1 mol/L. The optimum value of NaCl concentration for electrogenerative leaching nickel sulfide concentrate with FeCl3 is 3.0 mol/L. Temperature influences electrogenerative leaching by affecting anodic and cathodic polarization simultaneously. The apparent activation energy is determined to be 34.63 kJ/mol in the range of 298 K to 322 K. The leaching rate of Ni2+ is 29.3% after FeCl3 electrogenerative leaching of nickel sulfide concentrate for 620 min with a filter bag electrode.
基金Project(2010CB630903)supported by the National Basic Research Program of ChinaProject(31200382)supported by the Chinese Science Foundation for Distinguished Group,China
文摘A refractory gold concentrate with 19% arsenic was treated by a mixed moderately thermophiles in an airlift bioreactor through an adaptation protocol. The moderately thermophiles could respond well to 20%(w/v) pulp density with less than 10% loss of productivity, and resist arsenic up to 15 g/L. There were a lot of jarosite, arsenolite and sulfur, but not scorodite and ferric arsenate in the bioleached residue. Jarosite passivation and lower sulfur-oxidizing activity of the cells due to the toxicity of the high concentrations of soluble arsenic and iron ions at low p H value should mainly response for the incomplete extraction at high pulp density. The initial bacterial community did not change in nature except for new found P aeruginosa ANSC, but sulfur-oxidizing microorganisms have been dominant microorganisms after a long time of adaptation. Pseudomonas aeruginosa originating from the gold concentrate should be closely relative to the metabolism of the organic matters contained in the refractory gold concentrate.
基金Projects(51104024,51374043)supported by National Natural Science Foundation of ChinaProject(10JJ6019)supported by Hunan Provincial Natural Science Foundation,China+1 种基金Project(10C0399)supported by Scientific Research Fund of Hunan Provincial Education Department,ChinaProject(2014SK3182)supported by Hunan Provincial Science&Technology Department,China
文摘To shorten the bioleaching cycle of arsenic-containing gold concentrate, surfactants were used to promote the interaction between bacteria and ore to increase the arsenic leaching rate. Three different kinds of surfactants were used to evaluate the effects of surfactants on the growth of bacteria and arsenic leaching rate of arsenic-containing gold concentrate. The mechanism underlying surfactant enhancement was also studied. Results show that when relatively low-concentration surfactants are added to the medium, no significant difference is observed in the growth and Fe2+ oxidation ability of the bacteria compared with no surfactant in the medium. However, only the anionic surfactant calcium lignosulfonate and the nonionic surfactant Tween 80 are found to improve the arsenic leaching rates. Their optimum mass concentrations are 30 and 80 mg/L, respectively. At such optimum mass concentrations, the arsenic leaching rates are approximately 13.7% and 9.1% higher than those without the addition of surfactant, respectively. Mechanism research reveals that adding the anionic surfactant calcium lignosulfonate improves the percentage of bacterial adhesion on the mineral surface and decreases the surface tension in the leaching solution.
基金Project(2012zzts101)supported by the Fundamental Research Funds for the Central Universities,China
文摘Carboxylmethyl cellulose(CMC) has become a commercial organic binder in agglomeration of iron ore concentrates. The relative molecular mass and degree of substitution(DS) of CMC have a large impact on its binding performance. The interaction mechanism between CMC and iron ore particles was analyzed through Zeta potential measurements, adsorption measurements and infrared spectra. The results show that the interaction is chemical adsorption-oriented and the CMC's adsorption performance is related to the properties of CMC as well as the type of iron oxides. CMC has a greater affinity to Fe2O3 than Fe3O4, and CMC with higher relative molecular mass shows a higher adsorption isotherm. Pelletization of practical iron ore concentrates added with CMC further illustrates that CMC with higher relative molecular mass or DS exhibits a better binding performance, which is consistent with the results of adsorption tests.
文摘Scheelite and scheelite-wolframite mixed concentrates with different grades were decomposed by caustic soda digestion, and the effects of caustic soda（NaOH） dosage, the ratio of water to ore and the stirring rate on tungsten recovery were studied. The results show that under the conditions that the ratio of water to ore is （0.8,） stirring rate is 500 r·min-1 and the heating time is 2.0 h at （160 ℃,） the recovery of tungsten reaches 98% for scheelite （w（WO3） is （65.04%）） and wolframite containing high proportion of calcium （w（WO3） is 65.58%, w（Ca） is （7.53%）,） when caustic soda dosage is 2.2 and 2.0 times of theoretical value, respectively; the recovery of tungsten can be more than 98%,98% and 96% respectively for low-grade scheelite-wolframite mixed concentrate with （55.78%,） 45.32% and 25.21% WO3, when caustic soda dosage is 2.6,3.2 and 5.5 times of theoretical value, respectively.
基金supported by the National Natural ScienceFoundation of China ( 20306015 ) and the Scientific ResearchFoundation for Returned Overseas Chinese Scholars , the NationalEducation Ministry of China ( [2003] 406) .
基金supported by the National Key Research and Development Program of China (Grant No.2021YFC3001204)。
文摘The study of non-axisymmetric fuel dispersal and detonation can provide reference for the prevention of industrial cloud explosion accidents and the design of fuel air explosive(FAE).The concentration and detonation fields of 85 kg cylindrical and fan-shaped fuel are investigated by experiments and numerical simulations.A dynamic model of the whole process for fuel dispersal and detonation is built.The concentration distribution of fuel is used as the initial condition to calculate the detonation stage,thus solving the initial value problem of detonation field.The phase and component changes of fuel cloud at different locations are compared.The fuel cloud is divided into directions of 0°,90°,135°and 180°.The results show that the maximum cloud radius is 20.94 m in 135°and the minimum is 12.04 m in 0°.The diameter of the detonation fireball is 53.6 m,and the peak temperature is 3455 K.The highest peak overpressure is 3.44 MPa in 0°and the lowest is 2.97 MPa in 135°.The proportion of liquid phase in 0°is22.90%,and the fuel loss is 11.8% and 9% higher than that in 135°and cylindrical charge,respectively.The stable propagation distance of blast wave in 135°is 42.50% longer than 0°and 28.37% longer than cylindrical charge.
基金Project(50725416) supported by the National Science Fund for Distinguished Young Scholars
文摘The effect of composite agglomeration process(CAP) on fluoric iron concentrates sintering was investigated.The yield and quality of the sinter are greatly improved when using CAP assisted with heat airflow and enhancing magnesium oxide(MgO) contents.For conventional sintering of fluoric iron concentrate,due to lower viscosity of binding phase and higher fluidity of liquid phase,the sinter is formed with large thin-walled holes and the strength of the sinter is deteriorated consequently.The novel process forms composite agglomerate in which acid pellets are embedded in basic sinter.The pellets are solid with interconnecting crystals of hematite(Fe2O3) and magnetic(Fe3O4).For basic sintering,after adding MgO,the viscosity of the melting phase increases and the fluidity decreases;and calcium and aluminum silico-ferrites and magnesium ferrite are formed with perfect crystals and good sintering microstructure.
基金Project(FRF-TP-16-019A1)supported by the Fundamental Research Funds for the Central Universities,ChinaProject(51274033)supported by the National Natural Science Foundation of China
文摘In the present paper,the fundamental research on the properties of boron-rich slag melting separated from boron-bearing iron concentrate was performed.The melting and fluidity of B2O3–MgO–SiO2–FeO slag system,crystallization of separated boron-rich slag and factors on the extraction efficiency of boron-rich slag were systematically investigated.B2O3 content would heavily affect the melting and fluidity property of boron-rich slag.Generally,FeO could improve the melting and fluidity property of boron-rich slag.Boron-containing crystalline phase mainly precipitated in temperature range from 1200°C to 1100°C.Higher smelting temperature and B2O3 reduction ratio were negative for the extraction of boron.The cooling rate of 10–20°C/min was better for the crystallization of boron-containing crystalline phase.Based on the obtained experimental results,the optimum operating parameters for the development of pyrometallurgical boron and iron separation process and further boron-rich slag cooling process were proposed.
