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公开(公告)号：US4018873A
公开(公告)日：1977-04-19
申请号：US639194
申请日：1975-12-09
CPC分类号： C01B21/26
摘要： Nitric acid having a concentration of at least 98 wt.% is prepared by recovering in liquid state nitrogen peroxide from a gaseous flow containing the same, by absorption in nitric acid, heating of the resulting solution and liquefaction of the gaseous peroxide evolved, followed by a first chemical absorption of a fraction of the liquid peroxide with nitric acid at 70-80% and air and distillation of the resulting concentrated nitric acid. The gaseous products discharged from said first absorption and comprising unreacted peroxide and air are contacted with nitric acid and water in a second chemical absorption stage, thereby to produce the nitric acid used in the first absorption. The remaining fraction of liquid peroxide is delivered to the distillation column, discharged at the top thereof and recycled to the liquefaction stage, while nitric acid is extracted at the bottom of the distillation column and recycled to the second absorption stage.
摘要翻译： 具有至少98重量％浓度的硝酸是通过在含氮氧化物的气态流中在液态氮中回收，通过在硝酸中吸收，加热所得溶液和液化所产生的气态过氧化物，然后制备的 用硝酸70-80％的一部分液体过氧化物进行第一次化学吸收并蒸馏所得浓硝酸。 从第一次吸收排出的含有未反应的过氧化物和空气的气体产物在第二化学吸收阶段与硝酸和水接触，从而产生在第一次吸收中使用的硝酸。 液体过氧化物的剩余部分被输送到蒸馏塔，在其顶部排出并再循环到液化阶段，同时在蒸馏塔的底部提取硝酸并再循环到第二吸收阶段。
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公开(公告)号：US4031187A
公开(公告)日：1977-06-21
申请号：US641613
申请日：1975-12-17
CPC分类号： C01B21/26
摘要： Nitric acid having a concentration of at least 98% by weight is obtained from a gaseous stream resulting from catalytic oxidation of ammonia and containing nitrogen oxide and steam, by flowing said stream in an oxidation and condensation column in countercurrent with a stream of nitric acid at 40-60 wt.%, recovering nitrogen peroxide at the top of the column, liquefying said peroxide, bringing it into contact with aqueous nitric acid, oxygen and air in a chemical absorption stage, and distilling the resulting superazeotropic nitric acid. A part of the nitric acid discharged from the oxidation column is directly recycled and the remainder is recycled after distillation to give azeotropic acid and remove water, a part of the latter being used for the chemical absorption.
摘要翻译： 浓度为至少98重量％的硝酸是由氨的催化氧化产生的含有氮氧化物和蒸汽的气流，通过在氧化和冷凝塔中与硝酸流逆流地流动， 40-60重量％，回收塔顶部的过氧化氮，使所述过氧化物液化，使其在化学吸收阶段与硝酸，氧气和空气中的硝酸接触，并蒸馏生成的超声波硝酸。 从氧化塔排出的硝酸的一部分被直接再循环，其余部分在蒸馏后再循环，得到共沸酸，除去水，后者的一部分用于化学吸收。
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公开(公告)号：US4018872A
公开(公告)日：1977-04-19
申请号：US639192
申请日：1975-12-09
CPC分类号： C01B21/26
摘要： Nitric acid having a concentration of at least 98 wt.% is produced from nitrogen peroxide by absorbing the latter in superazeotropic nitric acid, distilling the resulting solution so as to recover nitric acid at a concentration of at least 98 wt.% and nitrogen peroxide, liquefying the latter and reacting it in a first stage with aqueous nitric acid (70-80% wt.%) and air and delivering the resulting superazeotropic nitric acid, together with the solution, to the distillation column. Nitrogen peroxide and oxygen unreacted in the first stage are contacted with nitric acid at 68-75 wt.% in a second stage, thus to produce said aqueous nitric acid fed to the second stage. The said nitric acid at 68-75 wt.% and the superazeotropic acid used for the absorption are extracted from the bottom part of the distillation column.
摘要翻译： 浓度至少为98重量％的硝酸通过在超氧阴离子硝酸中吸收后者，由氮氧化物产生，蒸馏所得溶液以回收浓度至少为98重量％的硝酸和过氧化氢， 液化后者并在第一阶段使其与硝酸水溶液（70-80重量％）和空气反应，并将所得的超声波硝酸与溶液一起输送到蒸馏塔。 第一阶段中未反应的过氧化氢和氧气在第二阶段与68-75重量％的硝酸接触，从而产生供给第二阶段的硝酸水溶液。 所述硝酸为68-75重量％，用于吸收的超级酸性酸从蒸馏塔的底部提取。
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公开(公告)号：USD308581S
公开(公告)日：1990-06-12
申请号：US75875
申请日：1987-07-21
申请人： Giorgio Macchi
设计人： Giorgio Macchi
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