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
The removal of phosphate from aqueous solution by Donnan dialysis with anion-exchange membrane was investigated.The results show that phosphate could be removed from aqueous solution without supplying external high pr...The removal of phosphate from aqueous solution by Donnan dialysis with anion-exchange membrane was investigated.The results show that phosphate could be removed from aqueous solution without supplying external high pressure or electrical potential.Under the conditions of influent phosphate of 2.0 mg/L,counterion(Cl-)concentration of 0.1 mol/L,stirring speed of 500 r/min and phase temperature of 298 K,the removal of phosphate achieves 70.0%.Decreasing counterion concentration has little influence on the removal of phosphate,but phosphate amount in anion-exchange membrane increases significantly.With the increase of stirring speed and phase temperature,the removal efficiency of phosphate greatly is improved.Existing forms of phosphate in aqueous solution affected transport of phosphate and only strong acidic pH of feed solution(pH=3.0)decreases the removal of phosphate.Transport of phosphate is also accompanied by change of pH value of feed solution.In consequence,it might be a promise potential process for phosphate advanced wastewater treatment,especially in the area where high salted nature water can be utilized.展开更多
A new method for production of ammonium metatungstate (AMT) directly from ammonium tungstate solution—Donnan dialysis method is advanced. Laboratory experiments are conducted by a Donnan dialysis cell with the membra...A new method for production of ammonium metatungstate (AMT) directly from ammonium tungstate solution—Donnan dialysis method is advanced. Laboratory experiments are conducted by a Donnan dialysis cell with the membrane area of 140 mm×200 mm. The result shows that the transformation rate of AMT reaches 370 g WO 3/(m 2·h), the recovery ratio of AMT by the Donnan dialysis method is nearly 100%, and the loss of tungsten is less than 0.2%. It has been proved that the Donnan dialysis method is effective for production of AMT.展开更多
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(50778065)supported by the National Natural Science Foundation of China
文摘The removal of phosphate from aqueous solution by Donnan dialysis with anion-exchange membrane was investigated.The results show that phosphate could be removed from aqueous solution without supplying external high pressure or electrical potential.Under the conditions of influent phosphate of 2.0 mg/L,counterion(Cl-)concentration of 0.1 mol/L,stirring speed of 500 r/min and phase temperature of 298 K,the removal of phosphate achieves 70.0%.Decreasing counterion concentration has little influence on the removal of phosphate,but phosphate amount in anion-exchange membrane increases significantly.With the increase of stirring speed and phase temperature,the removal efficiency of phosphate greatly is improved.Existing forms of phosphate in aqueous solution affected transport of phosphate and only strong acidic pH of feed solution(pH=3.0)decreases the removal of phosphate.Transport of phosphate is also accompanied by change of pH value of feed solution.In consequence,it might be a promise potential process for phosphate advanced wastewater treatment,especially in the area where high salted nature water can be utilized.
文摘A new method for production of ammonium metatungstate (AMT) directly from ammonium tungstate solution—Donnan dialysis method is advanced. Laboratory experiments are conducted by a Donnan dialysis cell with the membrane area of 140 mm×200 mm. The result shows that the transformation rate of AMT reaches 370 g WO 3/(m 2·h), the recovery ratio of AMT by the Donnan dialysis method is nearly 100%, and the loss of tungsten is less than 0.2%. It has been proved that the Donnan dialysis method is effective for production of AMT.
