Purification process of ultra-pure electronic grade nitric acid

By combining waste heat recovery preheating, reboiling distillation and staged condensation processes with clean air purging of the decolorization tower, the problems of high energy consumption, serious pollution and insufficient purity in nitric acid purification in existing technologies have been solved, realizing efficient and stable production of ultrapure electronic-grade nitric acid, which meets the purity requirements of high-end electronic materials.

CN122585965APending Publication Date: 2026-08-18SUZHOU CHANGSONG TECHNOLOGY CO LTD
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Patent Information

Application Number
CN202610936377.0
Authority / Receiving Office
CN · China
Patent Type
Applications(China)
Current Assignee / Owner
Filing Date
2026-06-26
Publication Date
2026-08-18

AI Technical Summary

Technical Problem

Existing industrial purification processes for ultrapure electronic-grade nitric acid suffer from problems such as high energy consumption, low thermal energy utilization, easy introduction of secondary pollution from metal ions, the introduction of new impurities such as organic matter and anions by ion exchange, large volume of regeneration wastewater, poor corrosion resistance of membrane separation, short lifespan, and insufficient purification precision.

Method used

A combination of processes, including waste heat recovery preheating, reboiling distillation, staged condensation, and clean air purging of the decolorization tower, combined with the recycling of substandard products and a deep condensation system for tail gas, is used to achieve efficient purification of nitric acid.

Benefits of technology

It significantly reduces steam consumption, improves nitric acid separation efficiency and purity, reduces waste acid, and achieves stable G4+ purity, meeting the requirements of semiconductor and high-end electronic material manufacturing, while reducing energy consumption and environmental protection pressure.

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Abstract

The application discloses a kind of purification processes of ultra-pure electronic grade nitric acid, it is related to electronic chemical purification technical field, comprising the following steps: S1: unloading filtration: industrial grade nitric acid raw material is pumped into raw material tank by unloading pump, normal temperature and pressure, then is transported to raw material filter by raw material delivery pump and is filtered, after removing large particles, it enters raw material buffer tank, and is stored at normal temperature and pressure;S2: waste heat preheating: the nitric acid raw material with the concentration of 70-71% is pumped into preheater by feed pump, and is preheated by waste acid as heat medium from the bottom of reboiler, after preheating, it enters rectifying column, and waste acid is cooled and enters waste acid tank.The application is coupled by "waste heat recovery preheating+reboiling rectification+staged condensation", the raw material is preheated by waste acid waste heat from the bottom of reboiler, which significantly reduces steam consumption, while staged condensation improves the separation efficiency and product purity of nitric acid, reduces NO compound emission, and overall energy consumption is reduced by 5%-10% compared with traditional process.
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