# US 8,540,960 B2 · Method for producing of ultra-clean and high-purity electronic grade reagents

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- Number: US 8,540,960 B2
- Document ID: US8540960B2
- Status: Granted
- Kind: B2
- Application number: 12/914,716
- Filed: 2010-10-28
- Published: 2011-04-28
- Granted: 2013-09-24
- Earliest claimed: 2010-09-16
- Assignees: Shanghai Chemical Reagent Research Institute
- Applicants: Jiarong Zhan; Mao Huiping; Hui Shaoliang; Shen Zheyu
- Inventors: Jiarong Zhan; Mao Huiping; Hui Shaoliang; Shen Zheyu
- Web page: https://patentgrep.com/patent/US8540960B2

## CPC

- B01D 3/00: Distillation or related exchange processes in which liquids are contacted with gaseous media, e.g. stripping ({evaporation in general, e.g. of liquids for gas phase reactions B01B1/005;} gas chromatography B01D15/08; destructive distillation C10B; preparation of alcoholic beverages by distillation C12H6/02)
- C01B 7/0706: {of hydrogen chloride}
- C01B 7/0712: {by distillation}
- C07C 29/76: by physical treatment
- B01D: SEPARATION (separating solids from solids by wet methods B03B, B03D; by pneumatic jigs or tables B03B; by other dry methods B07; magnetic or electrostatic separation of solid materials from solid materials or fluids, separation by high-voltage electric fields B03C; centrifuges, vortex apparatus B04; presses per se for squeezing-out liquid from liquid-containing material B30B9/02; treatment of water C02F, e.g. softening by ion-exchange C02F1/42; {arrangements of air intake cleaners in gas turbine plants F02C7/05} ; arrangements or mounting of filters in air-conditioning, air-humidification or ventilation F24F13/28)
- C01B: NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; {METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C}
- C07C: ACYCLIC OR CARBOCYCLIC COMPOUNDS

## Abstract

A method for producing of ultra-clean and High-purity electronic grade reagents is disclosed. The industrial grade reagents are chemically pretreated and filtered, and the colature is rectified. Heating the steam during the rectification to overheated steam, and filtering the overheated steam used the microporous membrane to remove the solid particulates. Condensing the overheated steam and the secondarily filter to remove the dust in the product. Due to the adoption of the technical scheme, the ultra-clean and High-purity isopropanol produced is in conformity with standard SEMI-C12 and the hydrochloric acid to standard SEMI-C8. And the method is applicable for the large-scale continuous production.

## Claims

### Claim 1

A method for producing ultra-clean and high-purity hydrochloric acid comprising the following steps:
step 1: adding a dearsenical agent to industrial grade hydrochloric acid at room temperature and reacting for 0.5-1.5 hours to remove arsenic; filtering the hydrochloric acid and collecting a filtrate;
step 2: atmospherically rectifying the filtrate at a temperature of 115-116° C. in a top part of a rectifying column with 0.5-1.5 meter/second gas flow rate in the column, and heating steam to 118-120° C. to produce overheated steam during the rectification; then filtering the overheated steam through a microporous membrane having 0.1 μm apertures; and
step 3: condensing the overheated steam filtered in step 2 and collecting a fraction, and filtering the fraction through a microporous membrane.

### Claim 2 (depends on 1)

The method according to claim 1, wherein the dearsenical agent is hydrazine hydrate of 40% mass concentration.

### Claim 3 (depends on 2)

The method according to claim 2, wherein the weight ratio between the hydrazine hydrate and the industrial grade hydrochloric acid is 5-8:100.

### Claim 4

A method of producing ultra-clean and high-purity isopropanol comprising the following steps:
step 1: adding a dehydrant to industrial grade isopropanol at room temperature and reacting for 0.5-1.5 hours; filtering the isopropanol and collecting a filtrate;
step 2: atmospherically rectifying the filtrate at a temperature of 82-83° C. in a top part of a rectifying column with 0.5-1.5 m/s gas flow rate in the column, and heating steam to 84-86° C. to produce overheated steam during the rectification; then filtering the overheated steam through a microporous membrane having 0.1 μm apertures; and
step 3: condensing the overheated steam filtered in step 2 and collecting a fraction, and filtering the fraction through a microporous membrane.

### Claim 5 (depends on 4)

The method according to claim 4, wherein the dehydrant is CaCl2.

### Claim 6 (depends on 5)

The method according to claim 5, wherein the weight ratio between the CaCl2 and the industrial grade isopropanol is 3-5:100.