Method for preparing super-pure nitric acid

A technology of ultra-pure nitric acid and nitric acid, which is applied in the direction of nitric acid, nitrogen oxides/oxo acids, etc., can solve the problems of unstable product quality, large fluctuations in purity, high cost, etc., to overcome unstable product quality, improve purity, The effect of stable quality

Inactive Publication Date: 2010-10-27
SHANGAI HUAYI MICROELECTRONICS MATERIAL +1
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0004] The technical problem to be solved by the present invention is to provide a preparation method of ultra-pure nitric acid to overcome the disadvantages of high energy consumption, high cost, unstable product quality and large fluctuations in purity in the prior art

Method used

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  • Method for preparing super-pure nitric acid
  • Method for preparing super-pure nitric acid
  • Method for preparing super-pure nitric acid

Examples

Experimental program
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Effect test

Embodiment 1

[0021] (1) Preparation of composite film of dibenzo-18-crown-6 and solid support: mix bis-benzo-18-crown-6 and kaolin (the main components are silicon dioxide, aluminum oxide and water) by mass Mix at a ratio of 1:3, grind to a uniform size of 200-300 mesh, form a billet, dry at low temperature, and sinter at a high temperature of 800-900°C to prepare dibenzo-18-crown-6 and a solid phase carrier with a pore size of 0.1 μm composite film.

[0022] (2) 71.0wt% industrial-grade nitric acid passes through a membrane filter composed of 0.1 μm diphenyl-18-crown-6 and solid-phase carrier composite membrane at room temperature and a pressure of 0.5 MPa, and the filtrate obtained by filtering is carried out at 120° C. One-stage rectification, two-stage series rectification at 130°C, respectively collect heavy waste acid and light waste acid (recovered for comprehensive utilization), and the condensed liquid is subjected to two-stage filtration through a membrane filter to obtain super ...

Embodiment 2

[0024] (1) Preparation of composite membrane of dibenzo-18-crown-6 and solid support: mix bis-benzo-18-crown-6 with silica gel, molecular sieve or kaolin (the main components are silicon dioxide, aluminum oxide and Water) is mixed according to the mass ratio of 1:6, ground into 200-300 mesh fine powder, then mixed evenly with the binder (polyvinyl alcohol), formed into a billet, dried at low temperature, at 800-900°C The composite membrane of dibenzo-18-crown-6 and solid phase support with a pore size of 0.15 μm was prepared by sintering.

[0025] (2) 70.7wt% industrial-grade nitric acid passes through a membrane filter composed of 0.15 μm diphenyl-18-crown-6 and solid-phase carrier composite membrane at room temperature and a pressure of 0.25 MPa, and the filtrate obtained by filtering is carried out at 45° C. One-stage rectification, two-stage series rectification at 55°C, while heavy waste acid and light waste acid are collected (recycled for comprehensive utilization), and...

Embodiment 3

[0027] (1) Preparation of composite film of dibenzo-18-crown-6 and solid support: mix bis-benzo-18-crown-6 and kaolin (the main components are silicon dioxide, aluminum oxide and water) by mass Mix at a ratio of 1:10, grind into 200-300 mesh fine powder, then mix evenly with a binder (polyvinyl alcohol), form a billet, dry at low temperature, and sinter at a high temperature of 800-900°C to obtain the pore size It is a composite film of 0.2μm dibenzo-18-crown-6 and solid support.

[0028] (2) 70.5wt% industrial-grade nitric acid passes through a membrane filter composed of 0.2 μm diphenyl-18-crown-6 and solid-phase carrier at room temperature and a pressure of 0.1 MPa, and the filtrate obtained by filtering is subjected to a first-stage process at 50° C. Rectification, two-stage series rectification at 60°C, while collecting heavy waste acid and light waste acid (recycled for comprehensive utilization), the condensed liquid is subjected to secondary filtration through a membra...

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Abstract

The invention discloses a method for preparing super-pure nitric acid. The method comprises the following steps: taking industrial nitric acid as a raw material; performing first stage filtration by a membrane filter consisting of dibenzo-18-crown-6 and solid-phase carrier composite membrane; performing second stage serial continuous rectification on the filtrate; collecting heavy waste acid and light waste acid respectively; and performing second stage filtration with the membrane filter to obtain the super-pure nitric acid serving as the target product. Upon analysis and detection, the content of each metal ion impurity is less than 1ppb, the dust particles bigger than 0.5microns are less than 5/ml and the SEMI C8 standard is met. By performing the second stage filtration with the membrane filter consisting of the dibenzo-18-crown-6 and the solid-phase carrier composite membrane, the method overcomes the disadvantage of instable quality of the product in an existing method; the method effectively improves the purity of the super-pure nitric acid product by using the second stage serial continuous rectification technology; and the super-pure nitric acid product obtained by the method has stable quality and high purity and is suitable for scale continuous production.

Description

technical field [0001] The present invention relates to a kind of preparation method of ultrapure nitric acid, particularly relate to a kind of preparation method of ultrapure nitric acid that reaches the grade 8-SEMI C8 standard (SEMI C8 standard) of the chemical material part formulated by the International Semiconductor Equipment and Materials Organization. Background technique [0002] Ultra-pure nitric acid, also known as electronic-grade ultra-clean high-purity nitric acid, is one of the most important varieties of microelectronic chemical reagents. It is widely used in the production of semiconductor components, cleaning and corrosion in the assembly and processing of VLSI. With the rapid development of the electronics industry, the requirements for the purity of nitric acid are getting higher and higher, from high-purity nitric acid (the content of a single cation is at the ppm level) to ultra-pure nitric acid (the content of a single cation is at the ppb level). The...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C01B21/46
Inventor 詹家荣杨光周励
Owner SHANGAI HUAYI MICROELECTRONICS MATERIAL
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