(1. 中南大学 冶金科学与工程学院，410083 长沙；
2. 中南大学 粉末冶金国家重点实验，410083 长沙；
3. 江西省环境工程职业学院，342000 赣州)
摘 要: 提出了超富集植物的“焚烧→湿法提取与净化→电化学沉积/化学沉淀法→金属/化工产品”工艺。以镍的超富集植物Berkheya coddii为例，对该收获物进行焚烧处理后，对焚烧产物进行氨法浸出，对浸出液进行一定处理后直接进行电积镍，最终得到高纯镍板(99.999%)，该工艺既实现了对超富集植物收获物的去毒化处理，又实现了收获物中有价金属的回收。对于浸出实验，优化实验条件分别为：浸出温度60 ℃，氯化铵及氨水的摩尔比(n(NH4Cl)׃n(NH3))0.6，液固比(L/S)5׃1，浸出时间2 h；对于镍电积实验，优化实验条件为：ρ(Ni2+)浓度23 g/L，极距3.5 cm；电流密度200 A/m2，温度40 ℃。
关键字: 超富集植物；Berkheya coddii；资源化利用；浸出；电沉积
（1. School of Metallurgical Science and Engineering, Central South University, Changsha 410083, China;
2. State Key Laboratory of Powder Metallurgy, Central South University, Changsha 410083, China;
3. Environmental Engineering Vocational College, Gangzhou 342000, China）
Abstract: The leaching and electrowinning of nickel from Berkheya coddii biomass was studied according to incineration→hydro-extraction and purification→electrodeposition→Metal/product flowsheet, and ammonia-ammonium chloride solution was used as leaching agents. The research was carried out in two phases, which are a leaching study to determine nickel extraction efficiency of this leaching agent, and an electrowinning study to determine nickel electrodeposition efficiency from the filtrate. The results show that leaching temperature has the most dominant effect on the metal extraction performance, followed by mole ratio of NH4Cl to NH3, liquid-solid ratio and leaching time. Accordingly, the optimum leaching conditions are that temperature of 50 ℃, n(NH4Cl)׃n(NH3)=0.6, leaching time of 2 h and L/S=5׃1. The total nickel removal after leaching under optimum condition reaches to 97.61%. The optimum conditions of nickel electrodeposition experiments are obtained as ρ(Ni2+) of 23 g/L, polar distance of 3.5 cm, current density of 200 A/m2 and temperature of 40 ℃, and the ultimate nickel content in the as-synthesized nickel plate is more than 99.999%.
Key words: hyperaccumulator; Berkheya coddii; resource utilization; leaching; electrowinning
