Sulfuric acid leaching process was applied to extract nickel from roasting-dissolving residue of a spent catalyst, the effect of different parameters on nickel extraction was investigated by leaching experiments, and ...Sulfuric acid leaching process was applied to extract nickel from roasting-dissolving residue of a spent catalyst, the effect of different parameters on nickel extraction was investigated by leaching experiments, and the leaching kinetics of nickel was analyzed. The experimental results indicate that the effects of particle size and sulfuric acid concentration on the nickel extraction are remarkable; the effect of reaction temperature is mild; while the effect of stirring speed in the range of 400-1 200 r/min is negligible. Decreasing particle size or increasing sulfuric acid concentration and reaction temperature, the nickel extraction efficiency is improved. 93.5% of nickel in residue is extracted under suitable leaching conditions, including particle size （0.074-0.100） mm, sulfuric acid concentration 30% （mass fraction）, temperature 80 ~C, reaction time 180 min, mass ratio of liquid to solid 10 and stirring speed 800 r/min. The leaching kinetics analyses shows that the reaction rate of leaching process is controlled by diffusion through the product layer, and the calculated activation energy of 15.8 kJ/mol is characteristic for a diffusion controlled process.展开更多
The corrosion behavior of the acidophilic sulfur-oxidizing microorganism(ASOM)Acidithiobacillusthiooxidans(A.thiooxidans)on mortar was investigated for changes of medium and mortar,as well as for weight lossand surfac...The corrosion behavior of the acidophilic sulfur-oxidizing microorganism(ASOM)Acidithiobacillusthiooxidans(A.thiooxidans)on mortar was investigated for changes of medium and mortar,as well as for weight lossand surface morphology of mortar specimens.Weight loss analysis showed that mortar weight was reduced by(15.1±2.2)%after 56 d.Morphological surface analysis of mortar specimens showed weakly structured fibrous substances with2−100μm in size.The pH variations of the mortar surface and medium indicated that biogenic sulfuric acid had beenproduced by A.thiooxidans.The results prove that A.thiooxidans accelerated concrete corrosion and caused concretefailure.展开更多
Concentrating sulfuric acid solution by vacuum membrane distillation with flat PEFE membrane is explored. The effects of sulfuric acid concentration, temperature of the feed, the vacuum degree of the vacuum side on th...Concentrating sulfuric acid solution by vacuum membrane distillation with flat PEFE membrane is explored. The effects of sulfuric acid concentration, temperature of the feed, the vacuum degree of the vacuum side on the flux of membrane distillation and the separation efficiency of acid are investigated. The results illustrate that the flux of the membrane distillation increases with the rise of feed temperature and the vacuum degree of the vacuum side, but it decreases with the rise of the sulfuric acid concentration of the feed. The separation efficiency of acid is correlated with the flux of membrane distillation; the separation efficiency of the acid can amount to 100% in the process, when operative conditions are properly controlled. It can also been obtained from the experiment that, compared with other methods of membrane distillation, the vacuum membrane distillation can obtain greater distillation flux.展开更多
In the process of sulfuric acid production from pyrite, there is a lot of waste acid produced in fume washing with dilute acid. Acid recovery from this sort of waste sulfuric acid by diffusion dialysis is studied in t...In the process of sulfuric acid production from pyrite, there is a lot of waste acid produced in fume washing with dilute acid. Acid recovery from this sort of waste sulfuric acid by diffusion dialysis is studied in the paper. The mass transfer dialysis coefficient of sulfuric acid of the membrane AFX is measured, the effect of the flowrate of the feed and ratio of feed to water is investigated, and the two kinds of membrane (AFX and S203) are compared. The results show that diffusion dialysis process can separate the metal cation from sulfuric acid effectively, but it is difficult to separate non cation impurities as As - and F -. The contrast tests of the two membranes show that the dialysis mass transfer coefficient of the membrane AFX is larger, while capacity of the removing impurities of membrane S203 is somewhat better.展开更多
Inner Mongolian serpentine ore was subjected to sulfuric acid leaching tests,and the effects of the leaching process parameters on the leaching efficiency of different metals were investigated.The leaching efficiency ...Inner Mongolian serpentine ore was subjected to sulfuric acid leaching tests,and the effects of the leaching process parameters on the leaching efficiency of different metals were investigated.The leaching efficiency of Mg,Fe,Al,Ni,and Co reaches 93.98%,60.09%,82.08%,90.58%,and 94.06%,respectively,under the leaching conditions of 5 mol/L H_(2)SO_(4),liquid/solid ratio of 4 mL/g,and leaching temperature 100℃.Hence,the valuable metals in serpentine were effectively recovered by sulfuric acid leaching.The leaching behaviors of Mg,Fe,and a small amount of Al were analyzed using X-ray diffraction.The results show that the unreacted Mg and Fe remained as MgFe_(2)O_(4),and Al formed Al_(2)Si_(2)O_(5)(OH)_(4) in the leaching residue.The kinetics of Mg and Ni in the leaching process was studied respectively.The leaching kinetics of Mg conformed to the shrinking core model with an activation energy of 16.95 kJ/mol,which was controlled by the combination of the diffusion and chemical reaction.The leaching kinetics of Ni accorded with the Avrami equation with an activation energy of 11.57 kJ/mol,which was controlled by diffusion.In the study,the valuable metal elements were extracted from serpentine minerals with high efficiency and low cost,which possessed important practical values.展开更多
A two-step leaching method in combination of acid and ethylene diaminetetraacetic acid disodium （EDTA-Na2） was applied to extract metals such as Cd, Cu, Fe, Pb and Zn from a zinc smelting slag. The results show that...A two-step leaching method in combination of acid and ethylene diaminetetraacetic acid disodium （EDTA-Na2） was applied to extract metals such as Cd, Cu, Fe, Pb and Zn from a zinc smelting slag. The results show that the extraction rates of Cd, Cu, Fe and Zn in slag reach 88.3%, 54.1%, 69.6% and 54.7%, respectively, while the extraction rate of Pb is only 0.05% leached with 1.25 mol/L sulfuric acid under the conditions of the ratio of slag to liquid of 100 g/L, 65 ℃ and 120 r/min for 2 h. However, Pb extraction rate from 1.25 mol/L sulfuric acid leached residue reaches as high as 66.5% by using 0.1 mol/L EDTA-Na2 solution. The results indicate that two-step sequential extraction procedure combining 1.25 mol/L sulfuric acid and 0.1 mol/L EDTA-Na2 solution can extensively extract Cd, Cu, Fe, Pb and Zn from zinc smelting slag.展开更多
concentrating sulfuric acid by membrane distillation in a flat sheet direct contact membrane distillation device with a self made metal PTFE composite membrane has been studied. The effect of sulfuric acid concentrati...concentrating sulfuric acid by membrane distillation in a flat sheet direct contact membrane distillation device with a self made metal PTFE composite membrane has been studied. The effect of sulfuric acid concentration of feed, the flowrate and liquor temperature in high temperature side and low temperature side on the flux and separation efficiency is investigated. The stability of this composite membrane is also inspected. The experimental results show that the metal PTFE composite membrane can be used in membrane distillation, and its properties are very stable. It is feasible to concentrate sulfuric acid by membrane distillation with this membrane.展开更多
基金Project (50574101) supported by the National Natural Science Foundation of ChinaProject (2003UDBEA00C020) supported by the Collaborative Project of School and Province of Yunnan Province,China
文摘Sulfuric acid leaching process was applied to extract nickel from roasting-dissolving residue of a spent catalyst, the effect of different parameters on nickel extraction was investigated by leaching experiments, and the leaching kinetics of nickel was analyzed. The experimental results indicate that the effects of particle size and sulfuric acid concentration on the nickel extraction are remarkable; the effect of reaction temperature is mild; while the effect of stirring speed in the range of 400-1 200 r/min is negligible. Decreasing particle size or increasing sulfuric acid concentration and reaction temperature, the nickel extraction efficiency is improved. 93.5% of nickel in residue is extracted under suitable leaching conditions, including particle size （0.074-0.100） mm, sulfuric acid concentration 30% （mass fraction）, temperature 80 ~C, reaction time 180 min, mass ratio of liquid to solid 10 and stirring speed 800 r/min. The leaching kinetics analyses shows that the reaction rate of leaching process is controlled by diffusion through the product layer, and the calculated activation energy of 15.8 kJ/mol is characteristic for a diffusion controlled process.
基金Project(42476209)supported by the National Natural Science Foundation of ChinaProject(2023GXNSFBA026252)supported by the Youth Science Foundation of Guangxi Province,China+2 种基金Project(ZR2023MD024)supported by the Natural Science Foundation of Shandong Province,ChinaProject(JC22022104)supported by the Natural Science Foundation of Nantong,ChinaProject(2023VEA0007)supported by the Chinese Academy of Sciences President’s International Fellowship Initiative。
文摘The corrosion behavior of the acidophilic sulfur-oxidizing microorganism(ASOM)Acidithiobacillusthiooxidans(A.thiooxidans)on mortar was investigated for changes of medium and mortar,as well as for weight lossand surface morphology of mortar specimens.Weight loss analysis showed that mortar weight was reduced by(15.1±2.2)%after 56 d.Morphological surface analysis of mortar specimens showed weakly structured fibrous substances with2−100μm in size.The pH variations of the mortar surface and medium indicated that biogenic sulfuric acid had beenproduced by A.thiooxidans.The results prove that A.thiooxidans accelerated concrete corrosion and caused concretefailure.
文摘Concentrating sulfuric acid solution by vacuum membrane distillation with flat PEFE membrane is explored. The effects of sulfuric acid concentration, temperature of the feed, the vacuum degree of the vacuum side on the flux of membrane distillation and the separation efficiency of acid are investigated. The results illustrate that the flux of the membrane distillation increases with the rise of feed temperature and the vacuum degree of the vacuum side, but it decreases with the rise of the sulfuric acid concentration of the feed. The separation efficiency of acid is correlated with the flux of membrane distillation; the separation efficiency of the acid can amount to 100% in the process, when operative conditions are properly controlled. It can also been obtained from the experiment that, compared with other methods of membrane distillation, the vacuum membrane distillation can obtain greater distillation flux.
文摘In the process of sulfuric acid production from pyrite, there is a lot of waste acid produced in fume washing with dilute acid. Acid recovery from this sort of waste sulfuric acid by diffusion dialysis is studied in the paper. The mass transfer dialysis coefficient of sulfuric acid of the membrane AFX is measured, the effect of the flowrate of the feed and ratio of feed to water is investigated, and the two kinds of membrane (AFX and S203) are compared. The results show that diffusion dialysis process can separate the metal cation from sulfuric acid effectively, but it is difficult to separate non cation impurities as As - and F -. The contrast tests of the two membranes show that the dialysis mass transfer coefficient of the membrane AFX is larger, while capacity of the removing impurities of membrane S203 is somewhat better.
基金Project(51574286)supported by the National Natural Science Foundation of China。
文摘Inner Mongolian serpentine ore was subjected to sulfuric acid leaching tests,and the effects of the leaching process parameters on the leaching efficiency of different metals were investigated.The leaching efficiency of Mg,Fe,Al,Ni,and Co reaches 93.98%,60.09%,82.08%,90.58%,and 94.06%,respectively,under the leaching conditions of 5 mol/L H_(2)SO_(4),liquid/solid ratio of 4 mL/g,and leaching temperature 100℃.Hence,the valuable metals in serpentine were effectively recovered by sulfuric acid leaching.The leaching behaviors of Mg,Fe,and a small amount of Al were analyzed using X-ray diffraction.The results show that the unreacted Mg and Fe remained as MgFe_(2)O_(4),and Al formed Al_(2)Si_(2)O_(5)(OH)_(4) in the leaching residue.The kinetics of Mg and Ni in the leaching process was studied respectively.The leaching kinetics of Mg conformed to the shrinking core model with an activation energy of 16.95 kJ/mol,which was controlled by the combination of the diffusion and chemical reaction.The leaching kinetics of Ni accorded with the Avrami equation with an activation energy of 11.57 kJ/mol,which was controlled by diffusion.In the study,the valuable metal elements were extracted from serpentine minerals with high efficiency and low cost,which possessed important practical values.
基金Project(2011SK3262) supported by Science and Technology Program of Hunan Province,China
文摘A two-step leaching method in combination of acid and ethylene diaminetetraacetic acid disodium （EDTA-Na2） was applied to extract metals such as Cd, Cu, Fe, Pb and Zn from a zinc smelting slag. The results show that the extraction rates of Cd, Cu, Fe and Zn in slag reach 88.3%, 54.1%, 69.6% and 54.7%, respectively, while the extraction rate of Pb is only 0.05% leached with 1.25 mol/L sulfuric acid under the conditions of the ratio of slag to liquid of 100 g/L, 65 ℃ and 120 r/min for 2 h. However, Pb extraction rate from 1.25 mol/L sulfuric acid leached residue reaches as high as 66.5% by using 0.1 mol/L EDTA-Na2 solution. The results indicate that two-step sequential extraction procedure combining 1.25 mol/L sulfuric acid and 0.1 mol/L EDTA-Na2 solution can extensively extract Cd, Cu, Fe, Pb and Zn from zinc smelting slag.
文摘concentrating sulfuric acid by membrane distillation in a flat sheet direct contact membrane distillation device with a self made metal PTFE composite membrane has been studied. The effect of sulfuric acid concentration of feed, the flowrate and liquor temperature in high temperature side and low temperature side on the flux and separation efficiency is investigated. The stability of this composite membrane is also inspected. The experimental results show that the metal PTFE composite membrane can be used in membrane distillation, and its properties are very stable. It is feasible to concentrate sulfuric acid by membrane distillation with this membrane.
