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ISO 2369:1972

Withdrawn
Withdrawn

A Withdrawn Standard is one, which is removed from sale, and its unique number can no longer be used. The Standard can be withdrawn and not replaced, or it can be withdrawn and replaced by a Standard with a different number.

Aluminium fluoride for industrial use Determination of silica content Spectrophotometric method using the reduced silicomolybdic complex
Available format(s)

Hardcopy , PDF , PDF 3 Users , PDF 5 Users , PDF 9 Users

Withdrawn date

05-29-2019

Language(s)

English, French

Published date

12-01-1972

The method can be applied provided the phosphorus pentoxide content does not exceed 0,02 % (m/m). The principle is based on alkaline fusion of a test portion by means of a mixture of sodium carbonate and boric acid. Solution of the fused mass in excess nitric acid so that the pH of the final solution is between 0,3 and 0,5 after being diluted. Formation, in a suitable aliquot portion, of the (yellow) oxidized silicomolybdic complex under clearly defined conditions of acidity, concentration of reagents, temperature and time. Selective reduction in a high acidity sulphuric acid medium and in the presence of tartaric acid. Spectrophotometric measurement at a wavelength of about 815 nm.

DocumentType
Standard
Pages
4
PublisherName
International Organization for Standardization
Status
Withdrawn

Standards Relationship
BS 4993-3:1974 Similar to
NBN T 03 439 : 1983 Identical
NFT 20 161 : 84 FD Identical

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US$73.00
Excluding Tax where applicable

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