Preparation system and preparation method of dilute nitric acid

Abstract

The invention discloses a preparation system and a preparation method of dilute nitric acid. The preparation system of the dilute nitric acid is used for preparing fuming nitric acid into NO gas and dilute nitric acid. The preparation system comprises a fuming nitric acid storage tank and a reactor with a spray head at the upper part, wherein a liquor inlet end at the lower end of the reactor is communicated with the fuming nitric acid storage tank; the output end of the reactor is divided into two paths, wherein one path is connected with a NO gas preparation device and the other path is connected with a dilute nitric acid preparation device; the NO gas preparation device comprises a condenser communicated with the top of the reactor, a separator used for separating out NO gas and a NO storage tank, wherein the inlet of the separator is connected to the condenser; a gas outlet tube of the separator is connected to the NO storage tank by a compressor; a liquor outlet tube of the separator is connected to the upper part of the reactor. The preparation method of the dilute nitric acid can change the conventional route of preparing the fuming nitric acid into concentrated nitric acid at first and then preparing the concentrated nitric acid into dilute nitric acid and can be used for directly preparing fuming nitric acid into dilute nitric acid with concentration being lower than 68%, and moreover the produced NO gas can be collected; thus, the social needs can be met.

Description

Technical field [0001] The invention relates to the technical field of the utilization of fuming nitric acid, in particular to a device and process method for washing fuming nitric acid with water or dilute nitric acid, thereby producing NO gas and preparing dilute nitric acid. Background technique [0002] With the development of society, dilute nitric acid is currently used in various industries, but different industries have different requirements for nitric acid concentration. The neutralization method requires 37-43% nitric acid as a raw material, while the pressurized method produces ammonium nitrate. Nitric acid with a concentration of 60% is required as a raw material. The IT industry needs nitric acid with a concentration of 68%. The iron and steel cleaning industry needs nitric acid with a concentration of 30-40%. In addition, NO gas is produced when dilute nitric acid is prepared. The NO gas molecule is small and has a simple structure. It is a gas at room temperature ...

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Problems solved by technology

[0004] The purpose of the invention of this application is to solve the technical problems that fuming nitric acid is not fully utilized at present, it takes time and effort to produce dilute nitric acid by using fuming nitric acid, and NO gas is not well collected and utilized, and to provide a method that can be directly prepared by using fuming nitric acid A dilute nitric acid production system with a concentration below 68% and the collection of NO gas generated to meet social needs

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