Dissolution mechanism and solubility of hemimorphite in NH3-(NH4)2SO4-H2O system at 298.15 K简

The dissolution mechanism of hemimorphite in NH3-（NH4）2SO4-H2O system at 298.15 K was investigated by X-ray powder diffraction （XRD）, scanning electron microscopy （SEM）, Fourier transform infrared spectroscopy （FTIR） and X-ray photoelectron spectroscopy （XPS） analysis. The results show that hemimorphite is soluble in NH3-（NH4）2SO4-H2O system and its residue exists in the form of an amorphous SiO2 layer on the hemimorphite surface. The XPS data also indicate that the Si 2p3/2 and O ls spectra of the hemimorphite are broadened and shift to higher binding energies and their binding energies are closer to silica with an increase of total ammonia and time. Solubility of hemimorphite in NH3-（NH4）2SO4-H2O system was measured by means of isothermal solution method at 298.15 K based on the study of the dissolution mechanism of hemimorphite. The results show that the solubility of zinc in solution increases firstly and then decreases with the increase of cr（NH3） （total ammonia concentration） at different NH3/NH4^＋ ratios. The solubility of silicon in solution decreases from 0.0334 mol/kg in ct（NH3）-4.1245 mol/kg NH3-（NH4）2SO4-H2O solution to 0.0046 mol/kg in cT（NH3）=7.6035 mol/kg NH3-（NH4）2SO4-H2O solution.     

某型中频接收机故障分析

某型导弹在进行地面测试中,发生无法准备好的故障,分析认为是中频接收机故障,具体表现为中频接收机Y路输出信号幅度减小、消耗电流增大。该文描述了中频接收机的故障定位过程,结合产品的电路原理对故障发生的机理进行了详细分析,并通过模拟故障复现试验和产品的装配结构分析,验证了故障定位的准确性和机理分析的正确性,最后通过在工艺上增加控制措施的方法使故障得以彻底解决。     

CuO/活性炭(AC)复合材料的制备与表征及吸附性能

制备了CuO/活性炭(AC)复合材料,并研究了它对废水中Mo(Ⅵ)的吸附性能。利用X射线衍射仪、傅里叶红外光谱分析仪、带能谱仪的扫描电子显微镜和透射电子显微镜对CuO/AC结构进行了表征,结果表明,复合材料颗粒平均粒径25～31 nm。考察了pH值、温度和Mo(Ⅵ)初始浓度等因素对CuO/AC吸附性能的影响,并研究了其吸附热力学和动力学规律,结果表明,在pH＝6、温度50 ℃时,CuO/AC的饱和吸附量为391.60 mg/g; CuO/AC复合材料对Mo(Ⅵ)的吸附过程符合Langmuir方程和准二级动力学模型,吸附过程为自发吸热过程。     

过硫酸盐氧化碱浸低品位铜精矿提取钼

以过硫酸钠为氧化剂, 在碳酸钠溶液中从低品位铜精矿中提取钼。运用单因素实验法, 探讨了搅拌速度、过硫酸钠和碳酸钠初始浓度、浸出时间、温度和液固比等因素对氧化碱浸提取钼的影响。结果表明,铜精矿氧化碱浸提取钼的优化条件为: 搅拌速度500 r/min, 浸出温度50 ℃, 碳酸钠初始浓度2.5 mol/L, 过硫酸钠初始浓度0.7 mol/L, 液固比10 mL/g, 浸出时间4.0 h, 在此条件下钼浸出率达97.10%。     

氧化碱浸体系下次级铜精矿中钼和硅的浸出行为

以过硫酸钠(Na2S2O8)为氧化剂,研究了次级铜精矿中钼和硅的碱浸行为。探讨了搅拌速度、Na2S2O8和氢氧化钠(NaOH)的初始浓度、浸出时间、温度和液固比(L/S)等因素对次级铜精矿中钼和硅浸出行为的影响。结果表明：次级铜精矿的氧化碱浸较佳条件为：搅拌速度500 r?min-1,温度50 ℃,NaOH初始浓度2.0 mol?L-1,Na2S2O8初始浓度0.5 mol?L-1,液固比10/1 mL?g-1,浸出时间3.0 h。此条件下次级铜精矿中钼浸出率达96.85%,硅浸出率为28.87%,实现了高选择性分离铜和钼,铝和锌基本脱除,硅和硫部分脱除,获得了合格铜精矿