The kinetic behavior of leaching copper from low grade copper oxide ore was investigated. The effects of leaching temperature, H2SO4 concentration, particle size of crude ore and agitation rate on the leaching efficie...The kinetic behavior of leaching copper from low grade copper oxide ore was investigated. The effects of leaching temperature, H2SO4 concentration, particle size of crude ore and agitation rate on the leaching efficiency of copper were also evaluated. And the kinetic equations of the leaching process were obtained. The results show that the leaching process can be described with a reaction model of shrinking core. The reaction can be divided into three stages. The first stage is the dissolution of free copper oxide and copper oxide wrapped by hematite-limonite ore. At this stage, the leaching efficiency is very fast （leaching efficiency is larger than 60%）. The second stage is the leaching of diffiuent copper oxides, whose apparent activation energy is 43.26 kJ/mol. During this process, the chemical reaction is the control step, and the reaction order of H2SO4 is 0.433 84. The third stage is the leaching of copper oxide wrapped by hematite-limonite and silicate ore with apparent activation energy of 16.08 kJ/mol, which belongs to the mixed control.展开更多
The effectiveness of CO2 microsize bubbles for removal of Ca2＋ ions in the leaching water discharged from the final landfill site was evaluated using imitation water. For the important parameter in the Ca2＋ ion remo...The effectiveness of CO2 microsize bubbles for removal of Ca2＋ ions in the leaching water discharged from the final landfill site was evaluated using imitation water. For the important parameter in the Ca2＋ ion removal, it was found that the treatment in alkaline region above pH = 10 was optimum. The possibility of using CO2 microbubbles was examined by substitution of chemical Na2CO3, which is used in large quantifies today. In addition, the excellence of CO2 microbubbles was demonstrated by comparing with CO2 millimeter size bubbles. @ 2015 The Chemical Industry and Engineering Society of China, and Chemical Industry Press. All rights reserved.展开更多
基金Project(2005BA639C) supported by the National Science and Technology Development of China
文摘The kinetic behavior of leaching copper from low grade copper oxide ore was investigated. The effects of leaching temperature, H2SO4 concentration, particle size of crude ore and agitation rate on the leaching efficiency of copper were also evaluated. And the kinetic equations of the leaching process were obtained. The results show that the leaching process can be described with a reaction model of shrinking core. The reaction can be divided into three stages. The first stage is the dissolution of free copper oxide and copper oxide wrapped by hematite-limonite ore. At this stage, the leaching efficiency is very fast （leaching efficiency is larger than 60%）. The second stage is the leaching of diffiuent copper oxides, whose apparent activation energy is 43.26 kJ/mol. During this process, the chemical reaction is the control step, and the reaction order of H2SO4 is 0.433 84. The third stage is the leaching of copper oxide wrapped by hematite-limonite and silicate ore with apparent activation energy of 16.08 kJ/mol, which belongs to the mixed control.
基金Supported by the National Natural Science Funds for Distinguished Young Scholars(21425625)the National Science Foundation for Excellent Young Scholars(21422607)
文摘The effectiveness of CO2 microsize bubbles for removal of Ca2＋ ions in the leaching water discharged from the final landfill site was evaluated using imitation water. For the important parameter in the Ca2＋ ion removal, it was found that the treatment in alkaline region above pH = 10 was optimum. The possibility of using CO2 microbubbles was examined by substitution of chemical Na2CO3, which is used in large quantifies today. In addition, the excellence of CO2 microbubbles was demonstrated by comparing with CO2 millimeter size bubbles. @ 2015 The Chemical Industry and Engineering Society of China, and Chemical Industry Press. All rights reserved.
