镍是一种近银白色、硬且延展性并具的金属元素，它具有很好的可塑性、耐腐蚀性和磁性等性能，主要被应用于钢铁、高温合金、电镀及电池等领域。镍是高温合金的主要元素，高端领域高温合金中镍含量一般大于60%，到2020年，我国高温合金需求约为4万吨，对应市场空间90.5亿元，而目前我国高温合金实际产量2万吨左右，高温合金未来7年的需求复合增长率有望超过20%。镍主要来源于硫化镍矿与红土镍矿，随着硫化镍矿资源逐渐减少，氧化镍矿使用量逐渐增加。硫化镍矿中杂质元素种类多达20几种，其中Pb，As，Sb，Sn都是比较难除去的杂质元素，高性能的高温合金对杂质元素的控制非常严格，相比之下元素组成比较简单的红土镍矿更适合制备高温合金用高纯镍。因此，开发由红土镍矿制备高纯镍的新方法显得尤为重要。本文以作者所在课题组研发的红土镍矿常压盐酸浸出新工艺得到的初步除杂浸出液为原料，开展了溶液的深度净化除杂、高纯镍电沉积、高纯硫酸镍溶液及高纯金属镍中杂质元素的分析方法筛选及建立等相关研究工作。主要结论如下：（1）建立了电感耦合等离子体原子发射光谱（ICP-AES）分析高纯镍溶液和高纯金属镍中杂质元素的方法，实现了ICP-AES对高纯镍溶液和高纯镍中痕量杂质元素的准确测定。通过实验确定了最优仪器参数：射频功率为1350W，雾化器流速为0.5L/min，观测距离为15mm，蠕动泵泵速为1.0mL/min。应用基体匹配、标准加入和多谱线拟合（MSF）三种校正方法分别测定了加标高纯镍溶液，当加标浓度为0.10，0.20mg/L，镍浓度5g/L时，三种方法均得到很好的回收率，线性相关系数均大于0.9996，回收率95.0~102%，RSD在2.09~4.63%之间，其中MSF法的线性范围最广（0.02~0.5mg/L），检出限最低（0.002mg/L）；当加标浓度为0.02，0.06mg/L，镍浓度15g/L时，实验结果表明只有MSF法能够得到准确的结果，其线性相关系数为0.9999，线性范围0.02~0.1mg/L，检出限为0.002mg/L，回收率为95.0~105%，RSD在3.92~4.60%之间。采用MSF法测试实际样品，分析结果与辉光放电质谱（GD-MS）法基本一致，进一步验证了方法的准确性和精密性。新方法不仅抗干扰能力强，操作简便，经济实用，且精密度高，检出限低，测量下限（0.0001%）和范围均优于国标原子吸收光谱法（0.001%），对高纯样品中痕量杂质元素的测定提供了重要的方法手段。（2）通过采用溶剂萃取方法对初步除杂浸出溶液进行深度净化除杂研究，镍钴比高于5000，得到了可制备99.99%金属镍的高纯镍溶液。其中有机相的最佳组成为：10%Cyanex272，5%TBP，85%磺化煤油。最佳萃取条件为：皂化率60%；初始pH为3.5；萃取后水相pH控制在5.10~5.70；最佳相比为1.5:1（O/A）；混合震荡时间为5min。通过萃取等温线及McCabe-Thiele图计算理论萃取级数，当相比为1:1（O/A）时，理论萃取级数为4级，当相比为1.5:1（O/A），理论萃取级数为3级，后通过分别模拟3、4级逆流萃取，其结果与理论级数相符。有机相反萃采用稀硫酸溶液，最佳反萃条件为：硫酸浓度，50g/L；相比：2:1（O/A）。（3）通过对高纯镍溶液的电沉积过程进行研究，制备出了99.99%的高纯金属镍。实验考察了硼酸浓度、pH、镍离子浓度、电流密度、极矩、电解时间、电解温度、钠离子浓度以及镁离子浓度对电解槽电压、阴极电流效率及能耗的影响。实验表明当硼酸浓度为3g/L，初始pH为3，镍离子浓度为60g/L，电流密度为200A/m2，极矩30mm，电解时间1.5h，电解温度40℃，钠离子浓度小于20g/L时，镁离子浓度小于1.5g/L时，槽电压可低至2.82V，电流效率达到95.7%，能耗低至2690kW·h/t，在该条件下得到的电解镍，表面光滑平整，经过检测符合国标GB/T 6516牌号Ni9999的要求。 ;Nickel is a nearly silver-white, hard and ductile metal element. It has good plasticity, corrosion resistance and magnetic properties. It is mainly used in steel, superalloy, electroplating and battery fields. Nickel is the main element of superalloys. The nickel content in high-end superalloys is generally more than 60%. By 2020, the demand for superalloys in China will be about 40,000 tons, corresponding to a market space of 9.05 billion yuan. At present, the actual output of superalloys in China is about 20,000 tons. The composite growth rate of superalloy demand in the next seven years is expected to exceed 20%.Nickel mainly comes from nickel sulfide ore and laterite nickel ore. With the decrease of nickel sulfide ore resources, the use of laterite nickel ore increases gradually. There are more than 20 kinds of impurity elements in nickel sulfide ores. Among them, Pb, As, Sb and Sn are difficult to remove. As high-performance superalloys control impurity elements very strictly, laterite nickel ores with simple element composition are more suitable for preparing high-purity nickel for superalloys. Therefore, it is particularly important to develop a new method for preparing high purity nickel from laterite nickel ore.In this paper, the preliminary impurity removal leaching solution from laterite nickel ore by hydrochloric acid leaching under atmospheric pressure developed by the author's research group was used as raw material to carry out the related research work, such as deep purifying the solution, high purity nickel electrodepositing, analysis method screening and establishing for annlysis impurity elements in high purity nickel metal and high purity nickel sulfate solution. The main conclusions are as follows:(1) An inductively coupled plasma atomic emission spectrometry (ICP-AES) method for the analysis of impurity elements in high purity nickel solution and high purity nickel metal was established. The accurate determination of trace impurity elements in high purity nickel solution and high purity nickel metal by ICP-AES was realized. The optimum parameters of the instrument are determined by experiments: the RF power is 1350W, the flow rate of the atomizer is 0.5L/min, the observation distance is 15mm, and the pump speed of the peristaltic pump is 1.0mL/min. Matrix matching, standard addition and MSF correction methods were used to determine the high purity nickel solution. When the standard concentration was 0.10, 0.20 mg/L and nickel concentration was 5 g/L, the three methods all obtained good recovery rates. The linear correlation coefficient was greater than 0.9996, the recovery rate was 95.0-102%, RSD was between 2.09-4.63%. Then The MSF method has the widest linear range (0.02-0.5 mg/L) and the lowest detection limit (0.002 mg/L). When the standard concentration is 0.02, 0.06 mg/L and nickel concentration is 15 g/L, the results show that only MSF method can get accurate results. Its linear correlation coefficient is 0.9999, linear range is 0.02-0.1 mg/L, detection limit is 0.002 mg/L, recovery is 95.0-105%, RSD is between 3.92-4.60%. The result of analysis were basically consistent with that of glow discharge mass spectrometry (GD-MS) when the actual samples were tested by MSF method, which further verified the accuracy and accuracy of the method. The new method not only has strong anti-interference ability, simple operation, economy and practicability, but also has high precision, low detection limit, lower detection limit (0.0001%) and scope better than the national standard atomic absorption spectrometry (0.001%). It provides an important methodological means for the determination of trace impurity elements in high purity samples.(2) A high purity nickel solution (Nickel-cobalt ratio higher than 5000) for electrodepositing 99.99% nickel metal was prepared by deep purifying of the initial impurity removal leaching solution by solvent extraction. The optimum composition of organic phase is 10% Cyanex 272, 5% TBP and 85% sulfonated kerosene. The optimum extraction conditions were as follows: saponification rate 60%, initial pH 3.5, water phase pH 5.10-5.70, optimum ratio 1.5:1 (O/A), mixing oscillation time 5 min. The theoretical extraction stage was calculated by the extraction isotherms and McCabe-Thiele diagram. When the ratio was 1:1 (O/A), the theoretical extraction stage was 4, when the ratio was 1.5:1 (O/A), and the theoretical extraction stage was 3. Then the theoretical extraction stage was respectively simulated by 3 and 4 counter-current extraction. The results were consistent with the theoretical series. Dilute sulfuric acid solution was used for the reverse extraction of organic phase, and the optimum conditions of reverse extraction were sulfuric acid concentration 50g/L, and 2:1 (O/A) ratio.(3) The electrodeposition process of high purity nickel solution was studied, and 99.99% of high purity nickel metal was prepared. The effects of boric acid concentration, pH, nickel ion concentration, current density, polar moment, electrolysis time, electrolysis temperature, sodium ion concentration and magnesium ion concentration on cell voltage, cathode current efficiency and energy consumption were investigated. Experiments show that when boric acid concentration was 3 g/L, initial pH was 3, nickel ion concentration was 60 g/L, current density was 200 A/m2, polar moment was 30 mm, electrolysis time was 1.5 h, electrolysis temperature was 40 C, sodium ion concentration was less than 20 g/L, magnesium ion concentration was less than 1.5 g/L, cell voltage was low to 2.82V, current efficiency was 95.7%, energy consumption was low to 2.690 kw·h/t. Under these conditions, nickel electrolysis obtained with smooth surface and the test result show that it met the requirements of brand Ni9999 in national standard GB/T 6516.