从铜铅锌复杂多金属精矿中两段加压浸出锌铜铁试验研究

Study on Two-stages Pressure Leaching of Zn,Cu and Fe From Cu-Pb-Zn Complex Polymetallic Ore

针对某地铜铅锌复杂多金属精矿,研究了采用两段加压浸出法浸出锌、铜、铁。试验结果表明:以H2SO4初始质量浓度105g/L、Fe质量浓度约15g/L、Zn质量浓度约55g/L的溶液为浸出剂,在温度120℃、浸出时间2h、液固体积质量比4mL/g、总压力1.9MPa、搅拌转速600r/min、添加剂加入量为矿石质量的0.3%条件下进行一次浸出,锌浸出率为72%左右,铜基本不被浸出,溶液中铁去除率为95%;对一次浸出渣,在硫酸初始质量浓度140g/L、液固体积质量比4mL/g、总压力1.9MPa、搅拌转速600r/min、温度160℃、浸出时间3h、添加剂加入量为一次浸出渣质量的0.3%的条件下进行二次浸出,锌、铜、铁浸出率分别为85.91%,77.76%和58.84%;二次浸出液配制浸出剂用于一次浸出。一次浸出液中,H2SO4及Fe质量浓度较低,便于后续工序净化除杂、获得符合锌电积要求的净化液。

The experimental sample is a Cu-Pb-Zn complex polymetallic ore. Leaching of Zn,Cu and Fe from the ore by a two-stages pressure leaching process was researched. Using the solution in which H2SO4 initial concentration is 105 g/L, Fe concentration is 15 g/L, Zn concentration is 55 g/L as leaching agent, the first-stage leaching was conducted under the conditions of leching temperature of 120 ℃ ,leaching time of 2 h,the ratio between liquid and solid of 4 mL/g,total pressure of 1.9 MPa, stirring speed of 600 r/min,additive usage of 0.3% ,the leaching rate of Zn was about 72% ,while Cu wasn＇t leached,the removal rate of Fe was 95%. The second-stage leaching of the first-stage leachingresidue was conducted under the conditions of H2804 initial concentration of 140 g/L, the ratio between liquid and solid of 4 mL/g,total pressure of 1.9 MPa,stirring speed of 600 r/min,leaching temperature of 160 ℃, leaching time of 3 h, additive usage of 0.3%, leaching rate of Zn, Cu and Fe were 85. 91%, 77. 76% and 58. 84% , respectively. The second-stage leaching solution was used to prepare the leaching agent for the first-stage leaching. The first-stage leaching solution with lower concentation of H2 SO4 and Fe is easy to be purified in subsequent,the purified solution meets with the requirement of zinc electrodepositing.