(1. 湖南大学 材料科学与工程学院,长沙 410082;2. 中南大学 资源加工与生物工程学院,长沙 410083)
摘 要: 研究在酸性介质中从锰银矿中同时浸出锰和银的热力学基础与技术条件。Mn-H2O系和Ag-H2O系电位(
关键字: 锰银矿;一步法浸出;电位( ø )—pH图;过氧化氢
(1. College of Materials Science and Engineering, Hunan University, Changsha 410082, China;2. School of Resources Processing and Bioengineering, Central South University, Changsha 410083, China)
Abstract:Abstract: Thermodynamics and technologies of simultaneous leaching of manganese and silver from manganese-silver associated ore in the sulfuric solution were investigated. Thermodynamics investigations of Mn-H2O system and Ag-H2O system show that there is a predominance area in potential ( ø )—pH diagram, where Mn2+ and Ag+ coexist in solution. The conditions are: 25 ℃ and 101.325 kPa, [Mn]=1 mol/L, [Ag]=10−3 mol/L, pH<3.63, 0.621 7< ø <(1.229−0.118 2pH) and 3.63<pH<4.635, 0.621 7< ø <(1.443 4−0.177 3pH). The added hydrogen peroxide is critical to the simultaneous leaching, plays part of both the reducing agent of manganese dioxide and the oxidizing agent of native silver. The added potassium permanganate is for oxidizing the silver that is unwrapped by manganese dioxide in the ore. A recovery of 95.62% for Mn and 83.28% for Ag is attained at room temperature under the leaching conditions of 2 h leaching time, 2 g/L KMnO4, 0.8 mol/L H2O2 and 0.9 mol/L H2SO4.
Key words: manganese-silver associated ore; one-step leaching; potential ( ø )—pH diagram; hydrogen peroxide