Test method of precious metal alloys—Determination of palladium content for palladium and silver alloys—Butanedione dioxime gravimetry
1 Scope
This part specifies the determination method of palladium content for palladium and silver alloys.
This part is applicable to the determination of palladium content in PdIr, PdAgCu, PdAgCuAuPtZn and AgPd alloys, with determination range (mass fraction) of 4%–92%.
2 Normative references
The following standards contain provisions which, through reference in this text, constitute provisions of this part. For dated references, subsequent amendments to (excluding correction to), or revisions of, any of these publications do not apply. However, parties to agreements based on this part are encouraged to investigate the possibility of applying the most recent editions of the standards indicated below. For undated references, the latest edition of the normative document applies.
YS/T 371 Method for chemical analysis of precious metals alloys—General rules and regulations
3 Method summary
Decompose the palladium-iridium and palladium-silver-copper-gold-platinum-zinc alloy test portions by mixed acid of hydrochloric acid and nitric acid; decompose the palladium-silver-copper and silver-palladium alloy test portions by nitric acid. Reduced and separate the gold by sodium nitrite, and precipitate and separate the silver by silver chloride. In dilute hydrochloric acid medium, precipitate the palladium with butanedione dioxime, and determine the mass fraction of palladium by gravimetry.
4 Reagents and materials
Unless otherwise specified, all reagents and apparatus shall meet the requirements of YS/T 371.
4.1 Sodium chloride.
4.2 Hydrochloric acid (ρ 1.19 g/mL).
4.3 Nitric acid (ρ 1.42 g/ mL).
4.4 Acetic acid (ρ 1.05 g/mL).
4.5 Ammonia (ρ 0.90 g/mL).
4.6 Hydrochloric acid (1 + 1).
4.7 Hydrochloric acid (1 + 9).
4.8 Hydrochloric acid (2 + 98).
4.9 Mixed acid of hydrochloric acid and nitric acid: 3 unit volume of hydrochloric acid (4.2) is mixed with 1 unit volume of nitric acid (4.3). It shall be freshly prepared before use.
Foreword i
1 Scope
2 Normative references
3 Method summary
4 Reagents and materials
5 Specimen
6 Analysis procedure
7 Expression of analysis result
8 Tolerance
