High phosphorous oolitic hematite ore is one of typical intractable iron ores in China, and the conventional beneficiation methods are found to be impracticable to , remove phosphorus from the ore effectively. Better ...High phosphorous oolitic hematite ore is one of typical intractable iron ores in China, and the conventional beneficiation methods are found to be impracticable to , remove phosphorus from the ore effectively. Better beneficiation index were gotten by direct reduction roasting with dephosphorization agent followed by two stages of grinding and magnetic separation. P content decreases from 0.82% in the raw ore to 0.06% in the magnetic concentrate, and the total iron grade increases from 43.65% to 90.23%, the recovery of iron can reach 87%. Mechanisms of phosphorus removal in the beneficiation of high phosphorous oolitic hematite ore by direct reduction roasting with dephosphorization agent were studied using XRD, SEM and EPMA. The results showed that about 20% of the apatite in the raw ore transferred into phosphorus and volatilized with the gas in the process of reduction roasting, while the rest 80% apatite was not involved in the reaction of generation of phosphorus, and remained as apatite in the roasted products, which was removed to tailings by grinding and magnetic separation. A small amount of phosphorus existed in the magnetic concentrate as apatite. The oolitic texture of raw ore was partly changed during roasting, resulting in the formation of nepheline in the reaction between the dephosphorization agent, SiO2 and Al2O3 in the raw ore, which greatly improved the liberation degree of minerals in the roasted products, and it was beneficial to the subsequent grinding and magnetic separation.展开更多
Reduction of nitrate by zero-valent iron is a highly exergonic reaction that has long been known to occur. Use of scrap iron filings (SIF) as the PRB (Permeable Reactive Barrier) material can be used to recycle certai...Reduction of nitrate by zero-valent iron is a highly exergonic reaction that has long been known to occur. Use of scrap iron filings (SIF) as the PRB (Permeable Reactive Barrier) material can be used to recycle certain by-products, and identify cheaper replacements for expensive conventional PRB materials, especially pure metallic iron. The feasibility of reductive denitrification of nitrate by SIF was studied by batch experiments. Operational parameters such as pH value, SIF dosage and initial concentration of nitrate were investigated. The removal efficiency of nitrate reached 80% under the conditions of pH of 2.5, nitrate initial con- centration of 45 mg/L and SIF dosage of 100 g/L within 4 h. Results indicated that nitrate removal is inversely related to pH. Low pH value condition favors for the nitrate transformation. Different from the results of others who studied nitrate reduction using iron powder, we found that there was a lag time before nitrate reduction occurs, even at low pH. Finally, the possible mechanism of nitrate reduction by Fe0 is discussed.展开更多
Optimization of factors influencing the experiments on reactions involving 8 different chelating agents and soluble Fe(III)/Fe(II) salts was carried out to yield chelated iron complexes. A combination of optimized inf...Optimization of factors influencing the experiments on reactions involving 8 different chelating agents and soluble Fe(III)/Fe(II) salts was carried out to yield chelated iron complexes. A combination of optimized influencing factors has resulted in a Fe chelating capacity of the iron-based desulfurization solution to be equal to 6.83—13.56 g/L at a redox potential of 0.185—0.3. The desulfurization performance of Fe(III)/Fe(II) chelating agents was investigated on a simulated sulfur-containing industrial gas composed of H2 S and N2 in a cross-flow rotating packed bed. Test results have revealed that the proposed iron-based desulfurization solution showed a sulfur removal efficiency of over 99% along with a Fe chelating capacity exceeding 1.35 g/L. This desulfurization technology which has practical application prospect is currently in the phase of commercial scale-up study.展开更多
The utilization of coal derived pyrite by electrolysis was studied. It is obvious that the sulfur and Fe in pyrite can be electrolyzed into Fe 3+ and SO 2- 4, and the no pollutant is drained off. In this paper, the in...The utilization of coal derived pyrite by electrolysis was studied. It is obvious that the sulfur and Fe in pyrite can be electrolyzed into Fe 3+ and SO 2- 4, and the no pollutant is drained off. In this paper, the influence of conditions, including electrolysis potential, time, temperature, the acidity of electrolysis solutions, the concentration of adding agent, the concentration of pyrite, and the rate of conversion of pyrite (Cr) was investigated. Cr increases with the rise of potential, time, temperature, acidity and the concentration of additive agent, but decreases with the rise of concentration of pyrite. At the certain conditions (at the potential of 3 0 V, temperature of 298 K, time of 12 h, the concentration of MnSO 4 of 6%, concentration of pyrite of 4%, and concentration of acid of 10%), Cr is high to 93%. In the same time, the mechanism of electrolysis of pyrite was provided. The electrolysis of pyrite is actually the recycle of Mn ion between anodic surface and pyrite. At last, the production of FeSO 4·7H 2O through electrolysis of pyrite was introduced.展开更多
In this work, the removal of thiophene from simulated oil has been studied by using the adsorption, extraction and oxidation/adsorption methods, respectively. In the adsorptive desulfurization process, different comme...In this work, the removal of thiophene from simulated oil has been studied by using the adsorption, extraction and oxidation/adsorption methods, respectively. In the adsorptive desulfurization process, different commercial adsorbents were used to eliminate thiophene at ambient pressure and mild temperature, and the results showed that carbon powder had the best adsorption ability. In the extractive desulfurization process, the best desulfurization result was obtained when DMF is used. In the oxidative/adsorptive desulfurization procedure using synthesized potassium ferrate as the oxidant and phosphomolybdic acid solution as the catalyst, thiophene was oxidized and removed from hydrocarbons in combination with active carbon adsorption, and the residual sulfur content of simulated oil could be reduced to 15.3mg/L from the original level of 200mg/L, with the desulfurization rate reaching 92.3%.展开更多
MgO/Al2O3 and Fe2O3/MgO/Al2O3 solid bases were prepared through mixing method. After sulfonated cobalt phthalocyanine （CoPcS） being supported on these solid bases, the catalytic performance of these catalysts was ev...MgO/Al2O3 and Fe2O3/MgO/Al2O3 solid bases were prepared through mixing method. After sulfonated cobalt phthalocyanine （CoPcS） being supported on these solid bases, the catalytic performance of these catalysts was evaluated by means of mercaptan oxidation reaction. The samples were characterized by X-ray diffraction （XRD）, CO2 temperature-programmed desorption （CO2-TPD）, FTIR spectroscopy, and X-ray photoelectron spectroscopy （XPS）. Investigation was focused on the effect of Fe2O3 on activity, crystal structure, basicity, and stability of the catalyst and also on the role of Fe2O3 in the mercaptan oxidation processes. Test results have shown that the Fe2O3/MgO/Al2O3- CoPcS catalyst has a higher initial activity and a much longer service life than the MgO/Al2O3-CoPcS catalyst. The increased types of basic sites coupled with an enhanced oxidation ability resulted from the addition of Fe2O3 have contributed to the improvement of the catalytic activity of the MgO/Al2O3-CoPcS catalyst.展开更多
Magnetically recyclable Au/Co/Fe core-shell nanoparticles （NPs） have been successfully synthesized via a one-step in situ procedure. Transmission electron microscope （TEM）, energy dispersive X-ray spectroscopic （...Magnetically recyclable Au/Co/Fe core-shell nanoparticles （NPs） have been successfully synthesized via a one-step in situ procedure. Transmission electron microscope （TEM）, energy dispersive X-ray spectroscopic （EDS）, and electron energy-loss spectroscopic （EELS） measurements revealed that the trimetallic Au/Co/Fe NPs have a triple-layered core-shell structure composed of a Au core, a Co-rich inter-layer, and a Fe-rich shell. The Au/Co/Fe core-shell NPs exhibit much higher catalytic activities for hydrolytic dehydrogenation of ammonia borane （NHBBH3, AB） than the monometallic （Au, Co, Fe） or bimetallic （AuCo, AuFe, CoFe） counterparts.展开更多
基金Project (51074016) support by the National Natural Science Foundation of China
文摘High phosphorous oolitic hematite ore is one of typical intractable iron ores in China, and the conventional beneficiation methods are found to be impracticable to , remove phosphorus from the ore effectively. Better beneficiation index were gotten by direct reduction roasting with dephosphorization agent followed by two stages of grinding and magnetic separation. P content decreases from 0.82% in the raw ore to 0.06% in the magnetic concentrate, and the total iron grade increases from 43.65% to 90.23%, the recovery of iron can reach 87%. Mechanisms of phosphorus removal in the beneficiation of high phosphorous oolitic hematite ore by direct reduction roasting with dephosphorization agent were studied using XRD, SEM and EPMA. The results showed that about 20% of the apatite in the raw ore transferred into phosphorus and volatilized with the gas in the process of reduction roasting, while the rest 80% apatite was not involved in the reaction of generation of phosphorus, and remained as apatite in the roasted products, which was removed to tailings by grinding and magnetic separation. A small amount of phosphorus existed in the magnetic concentrate as apatite. The oolitic texture of raw ore was partly changed during roasting, resulting in the formation of nepheline in the reaction between the dephosphorization agent, SiO2 and Al2O3 in the raw ore, which greatly improved the liberation degree of minerals in the roasted products, and it was beneficial to the subsequent grinding and magnetic separation.
基金Project (No. 20407015) supported by the National Natural Sci-ence Foundation of China
文摘Reduction of nitrate by zero-valent iron is a highly exergonic reaction that has long been known to occur. Use of scrap iron filings (SIF) as the PRB (Permeable Reactive Barrier) material can be used to recycle certain by-products, and identify cheaper replacements for expensive conventional PRB materials, especially pure metallic iron. The feasibility of reductive denitrification of nitrate by SIF was studied by batch experiments. Operational parameters such as pH value, SIF dosage and initial concentration of nitrate were investigated. The removal efficiency of nitrate reached 80% under the conditions of pH of 2.5, nitrate initial con- centration of 45 mg/L and SIF dosage of 100 g/L within 4 h. Results indicated that nitrate removal is inversely related to pH. Low pH value condition favors for the nitrate transformation. Different from the results of others who studied nitrate reduction using iron powder, we found that there was a lag time before nitrate reduction occurs, even at low pH. Finally, the possible mechanism of nitrate reduction by Fe0 is discussed.
基金financially supported by the Natural Science Fundation of China (No.21376229) the Science and Technology Development Plan of Shanxi Province,China (No.20130321035-02)
文摘Optimization of factors influencing the experiments on reactions involving 8 different chelating agents and soluble Fe(III)/Fe(II) salts was carried out to yield chelated iron complexes. A combination of optimized influencing factors has resulted in a Fe chelating capacity of the iron-based desulfurization solution to be equal to 6.83—13.56 g/L at a redox potential of 0.185—0.3. The desulfurization performance of Fe(III)/Fe(II) chelating agents was investigated on a simulated sulfur-containing industrial gas composed of H2 S and N2 in a cross-flow rotating packed bed. Test results have revealed that the proposed iron-based desulfurization solution showed a sulfur removal efficiency of over 99% along with a Fe chelating capacity exceeding 1.35 g/L. This desulfurization technology which has practical application prospect is currently in the phase of commercial scale-up study.
文摘The utilization of coal derived pyrite by electrolysis was studied. It is obvious that the sulfur and Fe in pyrite can be electrolyzed into Fe 3+ and SO 2- 4, and the no pollutant is drained off. In this paper, the influence of conditions, including electrolysis potential, time, temperature, the acidity of electrolysis solutions, the concentration of adding agent, the concentration of pyrite, and the rate of conversion of pyrite (Cr) was investigated. Cr increases with the rise of potential, time, temperature, acidity and the concentration of additive agent, but decreases with the rise of concentration of pyrite. At the certain conditions (at the potential of 3 0 V, temperature of 298 K, time of 12 h, the concentration of MnSO 4 of 6%, concentration of pyrite of 4%, and concentration of acid of 10%), Cr is high to 93%. In the same time, the mechanism of electrolysis of pyrite was provided. The electrolysis of pyrite is actually the recycle of Mn ion between anodic surface and pyrite. At last, the production of FeSO 4·7H 2O through electrolysis of pyrite was introduced.
基金financially supported by the Science and Technology Program of the Department of Education,Heilongjiang Province(11531012)
文摘In this work, the removal of thiophene from simulated oil has been studied by using the adsorption, extraction and oxidation/adsorption methods, respectively. In the adsorptive desulfurization process, different commercial adsorbents were used to eliminate thiophene at ambient pressure and mild temperature, and the results showed that carbon powder had the best adsorption ability. In the extractive desulfurization process, the best desulfurization result was obtained when DMF is used. In the oxidative/adsorptive desulfurization procedure using synthesized potassium ferrate as the oxidant and phosphomolybdic acid solution as the catalyst, thiophene was oxidized and removed from hydrocarbons in combination with active carbon adsorption, and the residual sulfur content of simulated oil could be reduced to 15.3mg/L from the original level of 200mg/L, with the desulfurization rate reaching 92.3%.
文摘MgO/Al2O3 and Fe2O3/MgO/Al2O3 solid bases were prepared through mixing method. After sulfonated cobalt phthalocyanine （CoPcS） being supported on these solid bases, the catalytic performance of these catalysts was evaluated by means of mercaptan oxidation reaction. The samples were characterized by X-ray diffraction （XRD）, CO2 temperature-programmed desorption （CO2-TPD）, FTIR spectroscopy, and X-ray photoelectron spectroscopy （XPS）. Investigation was focused on the effect of Fe2O3 on activity, crystal structure, basicity, and stability of the catalyst and also on the role of Fe2O3 in the mercaptan oxidation processes. Test results have shown that the Fe2O3/MgO/Al2O3- CoPcS catalyst has a higher initial activity and a much longer service life than the MgO/Al2O3-CoPcS catalyst. The increased types of basic sites coupled with an enhanced oxidation ability resulted from the addition of Fe2O3 have contributed to the improvement of the catalytic activity of the MgO/Al2O3-CoPcS catalyst.
文摘Magnetically recyclable Au/Co/Fe core-shell nanoparticles （NPs） have been successfully synthesized via a one-step in situ procedure. Transmission electron microscope （TEM）, energy dispersive X-ray spectroscopic （EDS）, and electron energy-loss spectroscopic （EELS） measurements revealed that the trimetallic Au/Co/Fe NPs have a triple-layered core-shell structure composed of a Au core, a Co-rich inter-layer, and a Fe-rich shell. The Au/Co/Fe core-shell NPs exhibit much higher catalytic activities for hydrolytic dehydrogenation of ammonia borane （NHBBH3, AB） than the monometallic （Au, Co, Fe） or bimetallic （AuCo, AuFe, CoFe） counterparts.
