摘要
Abstract
The effects of sulfuric acid concentration of electrolyte, cell voltage and fluidizing liquid flow rate on electrolytic process of dilute copper sulfate solution with concentration of about 1 g×L-1 were investigated in a semi-spouted bed electrode with a draft tube in which the annulus section is 46 mm´15.5 mm, the spouted section is 10 mm´15.5 mm, and the copper particles of 0.45 mm diameter were used as the cathode particles. The results show that a spouted fluidized bed electrode with a draft tube can effectively eliminate channels and dead zone, and prevent particle agglomeration. Increasing the sulfuric acid concentration of electrolyte could improve the conductivity of solution and accelerate the copper deposition rate, but if the sulfuric acid concentration is too high, it would cause serious hydrogen evolution and reduce the current efficiency and copper deposition rate. Although increasing the cell voltage could increase the initial deposition rate of copper ions, but due to the hydrogen evolution occurs earlier and faster, the copper recovery ratio and current efficiency would decrease. With the increase of fluidizing liquid flow rate, the expansion ratio of annulus area increases, the effective area of the cathode decreases and the resistance of particle phase increases, so the copper deposition rate and current efficiency decrease. The optimal process conditions are:sulfuric acid concentration 0.6 mol×L-1, cell voltage 2.5V and fluidizing liquid flow rate 135 L×h-1, when the dilute copper sulfate solution is electrolyzed for 100 minutes under above conditions, the copper recovery ratio is greater than 99%, the average current efficiency is greater than 36%; when electrolyzed for 140 minutes, the copper recovery ratio could reach 99.98%, and the concentration of copper ions could be reduced to 0.25 ppm.关键词
导向管喷动流化床电极/电流效率/沉积速率/回收率Key words
spouted fluidized bed electrode with a draft tube/current efficiency/deposition rate/recovery ratio分类
化学化工
