利用导向管喷动流化床电极从低浓度溶液中回收铜的研究  

Study on Copper Recovery from Low Concentration Solution with Draft Tube Spoute-Fluid Electrode

作　　者：马刚[1] 周勇[1] 朱家骅[1] 

机构地区：[1]四川大学化学工程学院,四川成都610065

出　　处：《高校化学工程学报》2014年第1期177-182,共6页Journal of Chemical Engineering of Chinese Universities

摘　　要：在环隙区截面为46 mm×15.5 mm,喷动区截面为10 mm×15.5 mm的半床形式的矩形导向管喷动流化床电极中,以直径0.45 mm的铜颗粒为阴极颗粒,考察了电解液硫酸浓度、槽电压、流化液流量等因素对浓度为1 g?L?1的稀CuSO4溶液电解过程的影响。研究结果表明,导向管喷动流化床电极可以有效地消除"沟流"和"死区",避免颗粒结块;增加硫酸浓度,可以提高溶液的电导率,加快铜离子的沉积速率,但硫酸浓度过高会导致析氢加剧,降低电流效率和铜离子沉积速率;增加槽电压虽然可以增加电解初期铜离子的沉积速率,但由于析氢更早更快,铜回收率和电流效率将下降;流化液流量增加,环隙区膨胀率增大,阴极有效面积减小,颗粒相电阻增大,铜离子沉积速率和电流效率都下降。在实验条件范围内较佳的工艺条件是:硫酸浓度0.6 mol?L?1、槽电压2.5 V、流化液流速135 L?h?1,在此条件下电解100 min,铜回收率大于99%,平均电流效率大于36%;电解140 min铜回收率可达99.98%、铜离子浓度可降到0.25 ppm。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 

分 类 号：O646.54[理学—物理化学]