A novel hydrothermal process was developed to extract zinc from pure zinc ferrite（ZnFe2O4） nanopowder and zinc-containing electric arc furnace（EAF） dust using hexahydrated ferric chloride（FeCl3-6H2O） as a decomp...A novel hydrothermal process was developed to extract zinc from pure zinc ferrite（ZnFe2O4） nanopowder and zinc-containing electric arc furnace（EAF） dust using hexahydrated ferric chloride（FeCl3-6H2O） as a decomposing agent.The effects of solid FeCl3-6H2O to ZnFe2O4 ratio by mass（RF/Z）,hydrothermal reaction temperature,and time on zinc extraction were systematically investigated.In the results,when the hydrothermal reaction is conducted at 150℃ for 2 h with RF/Z of 15：20,the efficiency of zinc extraction from ZnFe2O4 reaches97.2%,and the concentration of ferric ions（Fe^3＋） in the leaching solution is nearly zero,indicating a high selectivity for zinc.In addition,the zinc extraction efficiency from the EAF dust reaches 94.5%in the case of the hydrothermal reaction performed at 200℃ for 10 h with the solid FeCl3-6H2O to EAF dust ratio by mass（RF/EAF dust） of 15：10.Zinc and iron separation is achieved by adjusting the pH value of the leaching solution according to the different precipitation pH values of metal hydroxides.展开更多
In order to improve the efficiency of reducing fine dust emissions from diffuse sources,the commonly used water mist can be electrostatically charged.Thus,the attraction between particles and droplets increases due to...In order to improve the efficiency of reducing fine dust emissions from diffuse sources,the commonly used water mist can be electrostatically charged.Thus,the attraction between particles and droplets increases due to electrostatic field forces.In the experimental investigations carried out,an electrostatic two-fluid nozzle was used to generate a charged spray mist according to the principle of charging by induction.In a chamber,dispersed dust was precipitated with the spray mist,while detecting the laser light attenuation.By means of comparative measurements it could be shown that faster sedimentation and separation takes place through electrostatic attraction.Parameter variations regarding the use of compressed air and water were investigated and the sedimentation time of the particle-droplet mixture in the chamber was shown.A size distribution was then calculated from the laser light attenuation,which shows that the proportion of small particles decreases with spray application.Furthermore,the influence of the polarity of droplets and solid particles on the reduction measure was determined.展开更多
基金supported by the National Basic Research Priorities Program of China (Nos. 2014CB643401 and 2013AA032003)the National Natural Science Foundation of China (No.51372019)
文摘A novel hydrothermal process was developed to extract zinc from pure zinc ferrite（ZnFe2O4） nanopowder and zinc-containing electric arc furnace（EAF） dust using hexahydrated ferric chloride（FeCl3-6H2O） as a decomposing agent.The effects of solid FeCl3-6H2O to ZnFe2O4 ratio by mass（RF/Z）,hydrothermal reaction temperature,and time on zinc extraction were systematically investigated.In the results,when the hydrothermal reaction is conducted at 150℃ for 2 h with RF/Z of 15：20,the efficiency of zinc extraction from ZnFe2O4 reaches97.2%,and the concentration of ferric ions（Fe^3＋） in the leaching solution is nearly zero,indicating a high selectivity for zinc.In addition,the zinc extraction efficiency from the EAF dust reaches 94.5%in the case of the hydrothermal reaction performed at 200℃ for 10 h with the solid FeCl3-6H2O to EAF dust ratio by mass（RF/EAF dust） of 15：10.Zinc and iron separation is achieved by adjusting the pH value of the leaching solution according to the different precipitation pH values of metal hydroxides.
文摘In order to improve the efficiency of reducing fine dust emissions from diffuse sources,the commonly used water mist can be electrostatically charged.Thus,the attraction between particles and droplets increases due to electrostatic field forces.In the experimental investigations carried out,an electrostatic two-fluid nozzle was used to generate a charged spray mist according to the principle of charging by induction.In a chamber,dispersed dust was precipitated with the spray mist,while detecting the laser light attenuation.By means of comparative measurements it could be shown that faster sedimentation and separation takes place through electrostatic attraction.Parameter variations regarding the use of compressed air and water were investigated and the sedimentation time of the particle-droplet mixture in the chamber was shown.A size distribution was then calculated from the laser light attenuation,which shows that the proportion of small particles decreases with spray application.Furthermore,the influence of the polarity of droplets and solid particles on the reduction measure was determined.
