共查询到19条相似文献,搜索用时 375 毫秒
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在浸没循环撞击流反应器中,以NiCl2、NH4HCO3为原料,采用液-液相反应沉淀法制备了纳米NiO,并对产品进行了X射线衍射(XRD)和电子透射显微镜(TEM)表征。探讨了反应物浓度、反应温度、反应时间及原料配比对收率的影响,初步确定制备纳米NiO较适宜的工艺条件为:NiCl2的摩尔浓度0.20mol·L-1,反应温度是50℃,反应时间为90min,NH4HCO3与NiCl2的摩尔比为2.0,此条件下收率为90.14%。XRD和TEM表征表明产品成分为NiO,平均粒径40nm。 相似文献
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纳米氧化镍制备及表征 总被引:1,自引:0,他引:1
以六水硝酸镍和氨水为原料,采用配位均匀沉淀法制备了纳米氧化镍。探讨了制备条件对氧化镍前驱体产率和纳米氧化镍平均粒径的影响,得出最佳工艺条件:镍离子浓度为0.8 mol/L,反应物配比[n(氨水)/n(硝酸镍)]为3∶1,沉淀反应温度为80 ℃,反应时间为90 min,焙烧温度为400 ℃,焙烧时间为1 h。同时,利用X射线衍射(XRD)和透射电镜(TEM)等分析方法对产品组成和形貌进行了表征,结果显示,实验制得的氧化镍纳米晶属标准面心立方晶系结构,晶粒呈球形,平均粒径约为12 nm。 相似文献
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撞击流反应-沉淀法制备纳米碳酸锶 总被引:1,自引:0,他引:1
在浸没循环撞击流反应器中,以硝酸锶和碳酸氢铵为原料,通过反应-沉淀法制得高纯纳米碳酸锶产品.通过正交设计实验,研究了Sr(NO3)2浓度和温度、加料速度、反应时间等因素对产品收率的影响,并初步确定出制备纳米碳酸锶的最优工艺条件为:Sr(NO3)2浓度1.4 mol/L,Sr(NO3)2温度 85 ℃,加料速度 20 mL/min,反应时间 60 min,该条件下产品收率可达 93.5 %.制得的碳酸锶产品经XRD表征,结晶效果较好,纯度较高;经TEM表征,其形貌为球形或接近球形,在最优工艺条件下制取的产品平均粒径为 25 nm. 相似文献
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在浸没循环撞击流反应器中,以纯碱与硝酸锌反应-沉淀制得前驱体,经煅烧后得到纳米氧化锌产品。通过正交设计实验研究了Zn(NO3)2浓度、反应温度、反应时间、Na2CO3与Zn(NO3)2摩尔比等因素对产品收率的影响。初步确定了制备纳米氧化锌的最优工艺条件:Zn(NO3)2浓度1.5 mol/L,反应温度60℃,反应时间1 h,Na2CO3与Zn(NO3)2摩尔比1.3∶1;该条件下锌收率可达94%。制得的氧化锌产品经XRD表征,其纯度较高;经TEM表征,其形貌为球形或接近球形;在最优工艺条件下制取的产品平均粒径为20 nm。建立了相关工艺条件与产品收率的数学关系式。 相似文献
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在浸没循环撞击流反应器中,以六水合氯化镁和氢氧化钾为原料,通过直接沉淀法制备出纳米氧化镁,并对其进行了XRD和TEM表征.探讨了反应物浓度、反应温度、原料配比、加料时间及螺旋桨转速等因素对收率的影响,并初步确定出在SCISR中制备纳米氧化镁较适宜的工艺条件. 相似文献
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Nickel oxide was prepared by anodic deposition in a basic solution comprising nickel chloride, ammonium chloride and ammonia.
The influence of ammonia was investigated using galvanostatic reduction techniques and cyclic voltammetry (CV). It was found
that the oxidization peak potentials shift positively with decreasing ammonia concentration, while the oxidization peak currents
firstly increase with decreasing ammonia concentration and then decrease when the ammonia concentration is lower than 1.67 mol L−1. This is mainly attributed to the fact that the equilibrium concentration of Ni(OH)2(aq) varies with the ammonia concentration. A potential plateau at about 0.75 V was observed in galvanostatic reduction curves
for nickel oxide, and the length of the potential plateau in solution with 1.67 mol L−1 ammonia concentration was longer than that in the other solutions, which agreed well with the CV results. 相似文献
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通过化学合成方法得到分散均匀的氧化亚铜方块,在此基础上以其作为硬模板采用模板技术,以六水合二氯化镍为金属源,通过“协同刻蚀”的方法获得氢氧化镍空心壳材料,并进一步热处理得到氧化镍空心壳材料。经过透射电子显微镜(TEM),并结合广角X射线衍射等手段,证实所得材料为空心氧化镍材料。通过在旁热式气敏元件表面简单涂抹的办法制得气敏器件,并对其正丁醇气敏性能进行了测定。研究结果表明,该种材料在250 ℃下对正丁醇具有较好的敏感性,这表明该种材料是一种非常有前途的功能材料,有望获得广泛应用。 相似文献
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Andreev A. A. D’yachenko A. N. Kraidenko R. I. 《Theoretical Foundations of Chemical Engineering》2011,45(4):521-525
A method for processing nickel ores with ammonium chloride is considered. The results of thermodynamic calculations for the
reactions of the oxide components of nickel ore with ammonium chloride are given. Thermogravimetric and kinetic investigations
were performed. The technological sequence of the separation of oxidized nickel ores into individual oxides was developed. 相似文献
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用混酸浸取铁红废渣生产复合离子聚铁 ,并回收渣中镍、铜。实验结果表明 :聚铁产品质量稳定 ,镍、铜回收率高达 99%以上。 相似文献
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连续电镀锌镍合金的研究 总被引:4,自引:0,他引:4
提出了一种高氯化铵弱酸型镀液体系连续电镀锌镍合金工艺,研究了m(Ni^2 )/[m(Ni^2 ) m(Zn^2 )]、氯化铵浓度,电流密度、温度、PH值对镀层镍含量的影响,推导出连续镀的镀速计算公式,采用此工艺可获得外观良好、镍含量在13%-15%的锌镍合金镀层。 相似文献
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Effect of Ni content on the corrosion behavior of Cu-Ni alloys in neutral chloride solutions 总被引:1,自引:0,他引:1
The effect of systematic increase of Ni content on the electrochemical behavior of the Cu-Ni alloys in neutral chloride solutions was investigated. The pitting corrosion behavior of Cu-Ni alloys with different Ni contents, namely, 5, 10, 30 and 65 mass% Ni, in a stagnant 0.6 mol dm−3 NaCl solution of pH 7.0 was studied. The effect of chloride ion concentration on the electrochemical behavior of these alloys was also investigated. The results show that the increase in nickel content decreases the corrosion rate of the alloys in the neutral chloride solution. The increase of chloride concentration up to 0.3 mol dm−3 increases the corrosion rate. At higher concentrations ([Cl−] > 0.3 mol dm−3) the corrosion rate decreases due to the hydrolysis of Cu(I) chloride to form the passive Cu(I) oxide film. The breakdown potential depends on the chloride ion concentration and the nickel content of the alloy. For these investigations conventional electrochemical techniques and electrochemical impedance spectroscopy (EIS) were used. The impedance measurements have shown that the increase of the Ni content and the immersion time of the alloys in the chloride solution increase the corrosion resistance of the alloys. The experimental impedance data were fitted to theoretical values according to a proposed equivalent circuit model. 相似文献
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硫酸盐电铸镍内应力的影响因素 总被引:1,自引:0,他引:1
研究了NiSO4·6H2O质量浓度、NiCl2·6H2O质量浓度、温度和阴极电流密度等工艺参数对硫酸盐电铸镍层内应力的影响。通过铜箔阴极弯曲法半定量地测定了镍铸层的内应力,采用扫描电镜和X射线衍射表征了镀层在不同应力状态下的表面形貌和微观结构。结果表明,当NiSO4·6H2O质量浓度为100~150g/L时,其变化对内应力影响较大;镀液中氯离子浓度的增加会增大镀层内应力;低温和大电流密度条件下获得的镀层具有大的拉应力,高温小电流则有利于降低镀层的拉应力。 相似文献
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In this work the effect of boric acid on the nickel transport properties through an IONICS 67-HMR-412 cation-exchange membrane was evaluated by means of chronopotentiometry. Nickel chloride solutions with and without boric acid were investigated. The obtained results showed that the addition of boric acid to a nickel chloride solution does not affect the limiting current density value nor the nickel transport number through the membrane. The obtained results also revealed that, under very high current densities, the secondary transfer phenomenon associated to water splitting occurs when nickel chloride solutions are employed, and a bipolar membrane structure is formed, resulting from a Ni(OH)2 precipitation on the membrane surface. The addition of boric acid to the nickel chloride solution can minimize or avoid this phenomenon depending on the boric acid concentration in the solution. 相似文献