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如同广泛采用的硫酸一样,盐酸和硝酸也可用来分解磷矿以生产磷酸。这两种情况,产品酸都必须从反应混合物中分离出来,但是与硫酸分解作用后的分离步骤不同,硫酸分解后只需较简单的过滤步骤即可,而后述两种方法中,磷酸的回收则是复杂的:硝酸分解后的主要副产硝酸钙和盐酸酸化后所得到的副产氯化钙都残留在溶液中。 相似文献
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《化学试剂》2021,43(10):1399-1403
对ICP-OES测定TA31钛合金中铝、铌、锆、钼、铁、硅6种元素含量的硫酸-硝酸、氢氟酸-硝酸、氢氟酸-硫酸-硝酸和盐酸-氢氟酸-硝酸4种不同酸体系样品制备方法的试剂用量、处理温度和制备时间进行了比较,并对4种样品制备方法对应的检测方法的灵敏度、检出限、精密度、准确度等性能指标进行了比较分析。结果表明,氢氟酸-硝酸体系下的试剂用量最小,盐酸-氢氟酸-硝酸体系下的试剂用量最大,此两种样品制备方法均在常温下进行,无需加热,溶解时间较短;4种样品制备方法对应检测方法的灵敏度按照硫酸-硝酸、氢氟酸-硫酸-硝酸、盐酸-氢氟酸-硝酸、氢氟酸-硝酸的顺序依次升高;检出限和定量限基本一致;铝、铌、锆、钼、铁5种元素在4种制备方法下均可得到一致的检测结果,准确度和精密度整体上良好,氢氟酸-硫酸-硝酸制备方法下精密度略差;硫酸-硝酸和氢氟酸-硫酸-硝酸制备方法下,硅测定结果的精密度和准确度较差,不适合硅含量的测定。 相似文献
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介绍了利用硫酸和硝酸从低品位硫钴矿中浸取钴。结果表明,以硫酸和硝酸的混酸为浸取剂,在90℃下,搅拌浸取,钴的浸出率可达96%以上。 相似文献
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概述我国硝酸磷肥的发展状况,介绍硝酸-硫酸(硫酸盐)法生产硝酸磷肥的工艺流程和基本原理及其特点,列出了主要工艺控制条件。用硫酸或硫酸盐与硝酸共同分解磷矿可以制得各种规格的硝酸磷肥。 相似文献
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分析当前腐植酸复肥生产中常用的酸催化氧解法和碱溶酸析法(酸法和碱法)的活化条件对风化煤腐植酸活化率的影响,探索了两种方法在复肥生产中最佳的腐植酸活化条件.研究表明,风化煤腐植酸最佳活化条件分别为:酸法采用硝酸、硫酸或二者混酸为活化剂,每克风化煤需纯酸量0.5 ~ 1.5 mL、反应时长15 ~ 30 min、反应温度80℃左右;碱法采用强碱或混碱、氨水为活化剂,每克风化煤需碱折纯量0.10~ 0.23 mL、反应时长30 ~ 60 min、反应温度50~90℃. 相似文献
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以1-金刚烷甲酸为原料、硝酸和浓硫酸为氧化剂氧化合成了3-羟基-1-金刚烷甲酸。在优化反应条件下,3-羟基-1-金刚烷甲酸最高收率可达77%。采用红外光谱、核磁共振氢谱、元素分析、熔点测定等方法对产物进行了结构鉴定,并提出了可能的反应机理。 相似文献
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Nunziata Clara Marziano Claudio Tortato Lucio Ronchin Federica Martini Claudia Bianchi 《Catalysis Letters》1999,58(2-3):81-87
Solid acids prepared by adding sulfuric acid on silica gel have been used as catalysts in the nitration of nitrobenzenes and
their properties have been tested by kinetic studies at 25°C. Nitration rates in concentrated aqueous solutions of sulfuric
acid were also analysed and the catalytic efficiencies of sulfuric acid in liquid and solid phase were compared by using kinetic
data of analogous compounds. The results show that the solid acid samples exhibit nitrating properties very similar to those
observed in concentrated aqueous solutions of sulfuric acid (range of 90 wt%). The relationship between nitration rates and
effective concentration of electrophilic species [NO
2
+
], determined by studying the protonation–dehydration equilibrium of nitric acid in strong acids (HNO3 + H+ ⇌ H2O + NO
2
+
), was tested to better understand the acidity properties of medium.
This revised version was published online in November 2006 with corrections to the Cover Date. 相似文献
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The electrochemical oxidation behavior of Ce(III) in nitric acid and sulfuric acid media with various concentrations and compositions were investigated by cyclic voltammetry (CV) and potentiostatic electrolysis. In nitric acid media, the peak potential separation for the redox reactions of the Ce(III)/Ce(IV) couple shifted to base side with the increasing concentration of nitric acid from 1 to 6 M. The kinetics of the Ce(III)/Ce(IV) couple is rapid in high concentration nitric acid. The formal potential is independent of both proton and nitrate concentrations while the standard rate constant increases with added protons but is independent of nitrate concentration. Constant-potential electrolysis also shows that a high proton concentration is electrochemically favorable for the electron transfer of the Ce(III)/Ce(IV) couple and for a high Ce(IV) yield in nitric acid media. The current efficiency was ca. 75% for the oxidation process of Ce(III) at 298 K. A Ce(IV) yield of ca. 80% was achieved for the electrolysis of 100 mM Ce(III) in 6 M HNO3 solution. In sulfuric acid media, the peak potential separation for the redox reactions of the Ce(III)/Ce(IV) couple shifted to noble side with rising concentration of sulfuric acid from 0.1 to 2 M and then shifted to base side with further increase in the concentration. A Ce(IV) yield of ca. 95% was achieved for the potentiostatic electrolysis of 100 mM Ce(III) in 3 M H2SO4 solution. 相似文献
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Thermodynamic modeling of HNO3‐H2SO4‐H2O ternary system with symmetric electrolyte NRTL model 下载免费PDF全文
Meng Wang Harnoor Kaur Chau‐Chyun Chen 《American Institute of Chemical Engineers》2017,63(7):3110-3117
The nitric acid concentration/sulfuric acid concentration (NAC/SAC) process has been widely used for concentrating dilute aqueous nitric acid and recovering spent sulfuric acid. Dilute nitric acid (65 to 80 wt %) is concentrated using sulfuric acid to bind water and break the nitric acid‐water azeotrope at approximately 68 wt % nitric acid. To support heat and mass balance calculations and process simulation for NAC/SAC processes, we develop a comprehensive thermodynamic model for nitric acid‐sulfuric acid‐water ternary system based on previously published thermodynamic models of nitric acid‐water and sulfuric acid‐water binary systems with eNRTL equation. The ternary system model correlates well the isobaric vapor‐liquid equilibrium data at one atmosphere and the water and nitric acid activities data at 273.15 K for the ternary. Contour plots of boiling points, vapor phase composition, and specific heat capacity of the ternary system, as well as a Merkel enthalpy‐concentration chart are generated for engineering use. © 2017 American Institute of Chemical Engineers AIChE J, 63: 3110–3117, 2017 相似文献
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以2-氯-6-硝基甲苯为起始原料,在硫酸介质中,五氧化二矾催化下,滴加硝酸,常压氧化生成2-氯-6-硝基苯甲酸。 相似文献
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湿法磷酸的工艺研究进展 总被引:7,自引:0,他引:7
介绍了以磷矿为生产原料的硝酸法、盐酸法、硫酸法等湿法磷酸生产工艺,并对其工艺进行了说明和比较。突出了湿法磷酸生产中的除氟问题。指出了湿法磷酸产生磷石膏废物将是制约湿法磷酸生产的主要环节。 相似文献
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磷酸是一种重要的化工原料,其用途十分广泛。使用传统硫酸法会产生大量磷石膏,磷石膏在利用方面缺乏较为完整成熟的技术,磷石膏利用率较低,容易造成环境污染,给企业带来成本压力。并且硫酸法对磷矿品位有一定要求,相比之下盐酸法具有其独特优势。盐酸法粗磷酸中主要成分是磷酸和氯化钙,氯化钙的去除技术和综合利用是影响盐酸法大规模工业应用的关键所在。介绍了萃取法、三聚氰胺法、离子交换法、液膜法去除氯化钙技术以及氯化钙废液的综合利用现状,针对盐酸法工艺存在的问题提出了建议。指出经济、高效地去除盐酸法粗磷酸中的氯化钙以及对其有效利用是盐酸法湿法磷酸工艺推广应用的关键。 相似文献