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硝酸尾气主要由以下成分组成:少量NOx、93%的N2、3%~5%的O2、惰性气体和硝酸蒸汽。我公司原采用酸碱滴定法测定硝酸尾气中的NOx含量,即用过量氢氧化钠溶液吸收尾气中的NOx,然后用硫酸标准溶液返滴剩余氢氧化钠,由此计算出尾气中的NOx含量。但此法存在很大的弊端:一是将尾气中的硝酸蒸汽当作NOx一起分析,造成分析结果偏高;二是分析误差较大;三是用真空瓶采样,受负压、采样温度、采样装置气密性等因素影响,再现性较差。经过试验后,认为采用盐酸萘乙二胺分光光度法检测硝酸尾气中的NOx含量较好。此法操作简便、干扰少、灵敏度较高,精度和准确度都较高,是目前较理想的检测硝酸尾气中NOx含量的方法。 相似文献
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通过对色谱柱和流动相洗脱条件的优化,建立了一种检测硝酸羟胺水溶液含量的离子色谱法。在3 mmol/L甲基磺酸等度洗脱条件下,样品经IonPac CS12A阳离子交换柱分离,采用抑制型电导检测器进行检测。在40~200 mg/L质量浓度范围内,盐酸羟胺离子色谱峰面积与其质量浓度呈良好的线性关系(相关系数R2=0.999 1)。根据盐酸羟胺标准曲线计算得出硝酸羟胺质量浓度,结果表明,硝酸羟胺检出限为6.32 mg/L,该方法在30~101 mg/L加标量下的回收率大于97%,其性能指标可满足硝酸羟胺水溶液的含量分析。 相似文献
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本文通过比较稀硝酸中低含量亚硝酸的测定方法,总结了高锰酸钾滴定法、滴定高锰酸钾法、盐酸萘乙二胺分光光度法在实践应用中的优劣,并针对各种方法提出了优化建议。高锰酸钾滴定法测定亚硝酸含量不适合亚硝酸质量分数低于0.01%的情况,滴定高锰酸钾操作危险性大,不适合亚硝酸含量低于10 mg/kg的情况,分光光度法可以利用测定完硝酸含量的中性溶液,通过移取不同体积试样溶液来测定硝酸中低含量的亚硝酸,适合质量分数低于0.01%的亚硝酸的测定,具有一定的推广意义。 相似文献
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通过电化学方法,利用银电极对氯离子的选择性,采取电位滴定法测定氢氧化钠中氯化钠的含量,与分光光度法进行的检测结果进行比较,并进行了回收试验。结果表明,电位滴定法与分光光度法检测结果有较好的符合性,检测结果偏差及标准差满足测试要求,回收试验结果满足定量分析的要求。该方法操作简单、准确度高、对环境污染小,可准确测定氢氧化钠中氯化钠的含量。 相似文献
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硝酸羟胺中微量硝酸铵的测定,国外采用蒸馏比色法。文中提出直接比色法测定,即在硫酸介质中加热硝酸羟胺,再用纳氏试剂光度法测定。直接比色法的标准差为0。014%,变异系数为7。8%。 相似文献
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硝酸钍滴定法因为其简单快速而成为氟化工生产中氟含量测定的的重要方法。为了提高硝酸钍法测定排渣中氟含量的准确度,减少试验带来的误差,以X射线荧光光谱法为对照,对实验过程中的样品称样量、溶样及酸度调节等各个因素进行了试验研究,以期优化实验操作步骤。结果表明:样品研磨均匀,样品中盐酸处理干净并采用广范试纸调节酸度后按操作规程进行检测,与对照相比,不同分析者的结果异常,当用pH计调节滴定液的酸度为3.2左右时检测,该方法与X射线荧光光谱法结果吻合较好,检测结果准确可靠,可以用于测定排渣中氟的含量。 相似文献
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硝酸生产过程中80%硝酸分析常采用酸碱滴定分析法,该方法虽然准确度高,误差较小,但同时也存在耗时较长,操作繁琐等特点。通过用密度分析法测定80%硝酸含量,再用酸碱滴定分析法测定80%硝酸含量,将测定结果进行比较,两种方法的精密度无显著性差异,测定80%硝酸含量无系统误差。密度分析法在操作上更简便、快速,是另一种较理想的分析方法。 相似文献
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O. W. J. S. Rutten A. Van Sandwijk G. Van Weert 《Journal of Applied Electrochemistry》1999,29(1):87-92
Cathodic regeneration of nitrous acid by electrochemical reduction of nitrates could yield a catholyte which is useful in the processing of manganiferous ores. The purpose of the present investigations was to study the cathodic reaction in an electrolytic cell with an acidic nitrate electrolyte. Electrochemical reduction of nitrate has been investigated in the ranges 0.45–2.70m H+, 0.0–0.1m HNO2, 0.5–2.0m NO3– and 20–80°C at several cathode materials. Potentiodynamic scanning experiments with a platinized titanium cathode showed limiting current densities of 0–300Am–2 at cathode potentials of +950–+700mV vs SHE. At cathode potentials less than +700mV vs SHE, cathodic reduction of nitrous acid to nitric oxide took place. A linear relation between the nitrous acid concentration and the limiting current density was found in this experimental range. Nitrous acid can be produced by cathodic reduction of nitric acid in a membrane cell. However, the maximum concentration of nitrous acid that can be produced is limited by two reactions; decay of nitrous acid to nitric acid and nitric oxide and cathodic reduction of nitrous acid to nitric oxide. 相似文献
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造粒硝铵装置改产硝酸铵钙 总被引:8,自引:0,他引:8
介绍硝酸铵钙的物化性能,采用硝酸铵与石灰石混和法生产硝酸铵钙的工艺流程,以及技术经济指标,硝酸铵钙用作肥料能增加养分种类,改善土壤品质,并具有适应性广等特点。是硝铵生产厂家一条很好的改产途径。 相似文献
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B. N. Kondrikov V. É. Annikov V. Yu. Egorshev L. T. De Luca 《Combustion, Explosion, and Shock Waves》2000,36(1):135-145
Burning of solid crystalline hydroxylammonium nitrate (HAN) and its water solutions is studied in a constant-pressure bomb
within the pressure range from 0.1 to 36 MPa. Abnormally high pressure exponents are found to be typical of combustion of
the crystalline substance, its ≈9-mole/liter water solution, and a solution containing ethanolamine nitrate as a fuel: for
pressures below ≈10 MPa, the burning rate is proportional to the 1.5–2.6 power of pressure. Crystalline HAN retains this tendency
up to ≈20 MPa, whereas the solutions burning in the turbulent regime show a sharp decrease in the pressure exponent if the
pressure exceeds 10 MPa. In some instances, as was found in previous works, the burning rate even decreases with increasing
pressure. Special features of turbulent burning are explained. A model is proposed to describe the steady-state burning of
solid HAN. Kinetic parameters of the leading reaction are derived.
Translated fromFizika Goreniya i Vzryva, Vol. 36, No. 1, pp. 149–160, January–February, 2000.
This work was partly supported by the Russian Foundation for Fundamental Research (Grant Nos. 98-32164 and 98-32167). 相似文献
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研究了硝酸脲制备过程中可控因素的影响以及固体硝酸脲的晶体形状、吸湿性、水溶液的酸性、X射线衍射图、核磁共振图、红外图谱。实验表明硝酸脲制备过程中的主要影响因素为:尿素与硝酸的比例、硝酸的浓度、反应温度及反应时间等。其中最佳工艺条件是:n(尿素):n(硝酸)=1:1,硝酸浓度为5.5mol/L,反应温度为20℃,反应时间为20min;显微镜下观测其晶体呈现棱柱状;吸湿性比较弱:水溶液的酸性较同等浓度的硝酸弱而比柠檬酸强;X射线衍射图表明生成物与可能生成的其它物质的X射线衍射图完全不同;核磁共振及红外图谱证明生成的产物为比较纯的硝酸脲。 相似文献
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V. P. Danilov V. T. Orlova S. K. Myasnikov E. A. Frolova D. F. Kondakov M. K. Rustabbekov A. L. Taran 《Theoretical Foundations of Chemical Engineering》2008,42(5):579-582
We have studied the dependence of the of conversion of calcium nitrate into potassium nitrate on various factors, including the reaction temperature, the ratio of initial reactants [KCl and Ca(NO3)2], and the reaction time. Optimum conditions for the conversion of KCl and Ca(NO3)2 into KNO3 and a mixed salt composition comprising 55–56 wt % CaCl2, 17–18 wt % KNO3, and 24–25 wt % Ca(NO3)2 are determined. The salt mixture forms a low-temperature (?33 to ?35°C) eutectic with ice and can be used as an antiglazing reagent 相似文献