Title: Process for producing safety powder by zinc method and method for recovering sodium sulfite and common salt from waste liguor
Application Number: 89102534 Application Date: 1989.04.18
Publication Number: 1040012 Publication Date: 1990.02.28
Approval Pub. Date: Granted Pub. Date: 1992.07.22
International Classifi-cation: C01D3/04,C01D5/14
Applicant(s) Name: Laohekou City Petroleum-Chemical General Plant. Address:
Inventor(s) Name:
Attorney & Agent: MENG JINGQIAN FAN LINGFENG
Abstract:
     Sulfur dioxide is directly sent into the waste liquor while the temp. is controlled at 40-60 deg.C. When the pH value of waste liquor is equal to 5-6, original alkaline waste liquor is returned for neutralization to make its pH value to be equal to 9-10. Then, the first vaporizaiton of waste liquor is conducted for obtaining sodium sulfite and through the second vaporization of filter liquor, sodium chloride is gained. Filtered mother liquor is returned for next vaporization without exhausting sewage and secondary pollution. The gained sodium chloride is used for salting-out process without affecting the quality standard and yield rate of sodium hydrosulfite.
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