GB/T 15072.3-2025Methods for chemical analysis of precious metal alloys — Part 3: Determination of platinum content (English PDF)

Foreword

This document complies with the provisions of GB/T 1.1-2020 "Standardization Work Guidelines Part 1: Structure and Drafting Rules of Standardization Documents". Drafting.

This document is Part 3 of GB/T 15072 "Chemical Analysis Methods for Noble Metal Alloys". GB/T 15072 has been published as follows. part.

— Part 1: Determination of Gold Content;

— Part 2: Determination of Silver Content;

— Part 3: Determination of Platinum Content;

— Part 4: Determination of Palladium Content;

— Part 6: Determination of Iridium Content;

— Part 7: Determination of Chromium and Iron Contents in Gold Alloys by Inductively Coupled Plasma Atomic Emission Spectrometry;

— Part 8: Determination of Copper Content in Gold, Palladium, and Silver Alloys. Thiourea Precipitation EDTA Complexometric Back Titration;

— Part 9: Determination of Indium Content in Gold Alloys by EDTA Complexometric Back Titration;

— Part 10.Determination of Nickel Content in Gold Alloys by EDTA Complexometric Back Titration;

— Part 11.Determination of Gadolinium and Beryllium Contents in Gold Alloys by Inductively Coupled Plasma Atomic Emission Spectrometry;

— Part 12.Determination of Vanadium Content in Silver Alloys by Hydrogen Peroxide Spectrophotometry;

— Part 13.Determination of Tin, Cerium and Lanthanum Contents in Silver Alloys by Inductively Coupled Plasma Atomic Emission Spectrometry;

— Part 14.Determination of Aluminum and Nickel Contents in Silver Alloys by Inductively Coupled Plasma Atomic Emission Spectrometry;

— Part 15.Determination of Nickel, Zinc and Manganese Contents in Gold, Silver and Palladium Alloys by Inductively Coupled Plasma Atomic Emission Spectrometry;

— Part 16.Determination of Copper and Manganese Contents in Gold Alloys by Inductively Coupled Plasma Atomic Emission Spectrometry;

— Part 17.Determination of Tungsten Content in Platinum Alloys by Tungsten Trioxide Gravimetric Method;

— Part 18.Determination of Zirconium and Gallium Contents in Gold Alloys by Inductively Coupled Plasma Atomic Emission Spectrometry;

— Part 19.Determination of Vanadium and Magnesium Contents in Silver Alloys by Inductively Coupled Plasma Atomic Emission Spectrometry;

— Part 20.Determination of Rhodium Content This document replaces GB/T 15072.3-2008 "Chemical Analysis Methods for Precious Metal Alloys. Determination of Platinum Content in Gold, Platinum and Palladium Alloys (High Manganese)".

Compared with GB/T 15072.3-2008, the main technical changes in "Potassium Acid Current Titration Method" are as follows, except for structural adjustments and editorial modifications.

a) The use of sulfuric acid has been removed (see 4.12.2 and 7.3.2 in the 2008 edition);

b) The conditions for treating the test solution, such as aeration, have been changed (see 5.4, 5.5, and 8.4; 4.10, 4.12, and 7.3.2 in the 2008 edition);

c) The description of the platinum standard solution as "1 mL contains 2.3 mg platinum" is changed to "1 mL contains 1 mg platinum" (see 5.6, 4.11 of the 2008 edition);

d) The detection equipment was changed from "ordinary polarograph" to "automatic potentiometric titrator" (see 6.2, 5.1 of the 2008 edition);

e) The sample handling method has been changed, replacing "sample" with "test specimen" (see Chapter 7, Chapter 6 of the 2008 edition);

f) The requirements for "sample quantity and its accuracy" have been changed (see 8.1, 7.1 in the 2008 edition);

g) The requirement for "allowable difference" has been removed (see Chapter 9 of the 2008 edition);

h) Added “reproducibility” and “repeatability” (see 10.1 and 10.2).

Please note that some content in this document may involve patents. The issuing organization of this document assumes no responsibility for identifying patents.

This document was proposed by the China Nonferrous Metals Industry Association.

This document is under the jurisdiction of the National Technical Committee on Standardization of Nonferrous Metals (SAC/TC243).

This document was drafted by: Guizhou Research Institute of Testing Technology (Yunnan) Co., Ltd., Nonferrous Metals Technology and Economic Research Institute Co., Ltd., and Jiangxi Province.

Junxin Precious Metals Technology Materials Co., Ltd., Guizhou Research Resources (Yimen) Co., Ltd., Beikuang Testing Technology Co., Ltd., and Lifu (Jiangmen) Environmental Protection Technology Co., Ltd.

Bao Technology Co., Ltd., Jinchuan Group Co., Ltd., Shenzhen Zhongjin Lingnan Nonferrous Metals Co., Ltd. Danxia Smelter Yunnan Precious Metals New Materials Holding Group Co., Ltd., Zhongbao Zhengxin Gold and Silver Jewelry Testing Co., Ltd., and Yunnan Gold Mining Group Precious Metals Testing Co., Ltd., Guangdong Academy of Sciences Industrial Analysis and Testing Center, and National Standard (Beijing) Inspection and Certification Co., Ltd.

The main drafters of this document are: Liang Jie, Yang Meiying, Zhao Wenhu, Xiang Lei, Yu Fengshan, Zhang Tianqi, Du Hao, Xie Zhuosen, Xu Yanyan, and Liu Zhenjiang.

Chen Xiaoke, Li Xiaoyao, Li Na, Sun Qi, Hou Yulian, Chen Neng, Luo Xian, Liu Huimin, Chen Xinggang, Fang Yuan, Feng Yanbo, Tian Jia, Lin Peipei, Jin Yaqiu Zhao Zhenhao, Yang Fan, Luo Xiong, Li Li, Li Qiuying, Zhu Wuxun, Ai Shuhan.

This document was first published in 1994 and revised for the first time in 2008; this is the second revision.

Introduction

Precious metal alloys are alloy materials composed of one or more precious metals (such as gold, silver, platinum, palladium, etc.) and other metallic or non-metallic elements.

These alloys not only retain the excellent properties of precious metals, such as corrosion resistance, electrical conductivity, and ductility, but can also be modified by adding other metals.

Modifying or enhancing certain physical, chemical, or mechanical properties of an alloy. This makes precious metal alloys advantageous in improving material utility and reducing costs.

It is of great significance and has wide applications in the automotive industry, electronic communications, new energy, petrochemicals, weaponry, aerospace, and other fields. GB/T 15072 The aim is to establish a set of standardized methods for chemical composition analysis to meet the needs of the production and trade of precious metal alloy products. GB/T 15072 is proposed. It consists of 20 parts.

— Part 1: Determination of Gold Content. The aim is to establish potentiometric titration and fire assay methods for determining the gold content in precious metal alloys. Methods of measurement.

— Part 2: Determination of Silver Content. The aim is to establish potentiometric titration and fire assay methods for determining the silver content in precious metal alloys. Methods of measurement.

— Part 3: Determination of Platinum Content. The aim is to establish a potentiometric titration method for determining the platinum content in noble metal alloys.

— Part 4: Determination of Palladium Content. The aim is to establish gravimetric and titration methods for determining palladium content in noble metal alloys.

— Part 6: Determination of Iridium Content. The aim is to establish a potentiometric titration method for determining the iridium content in noble metal alloys.

— Part 7: Platinum, Palladium, Rhodium, Iridium, Ruthenium, Cobalt, Chromium, Iron, Nickel, Zinc, Copper, Manganese, Gadolinium, Yttrium, Tin, Cerium, Lanthanum, Aluminum, Vanadium, Magnesium, Gallium, Beryllium, Antimony Determination of zirconium, molybdenum, and titanium content. The aim is to establish an inductively coupled plasma atomic emission spectrometry (ICP-AES) method for determining the content of zirconium, molybdenum, and titanium in noble metal alloys.

Methods for determining elemental content.

— Part 8: Determination of Copper Content. The aim is to establish a titration method for determining the copper content in noble metal alloys.

— Part 9: Determination of Indium and Zirconium Content. The aim is to establish a titration method for determining the indium and zirconium content in noble metal alloys.

— Part 10.Determination of Nickel Content. The aim is to establish methods for determining the nickel content in noble metal alloys using titration and gravimetric methods.

— Part 12.Determination of Vanadium, Rhenium, Gadolinium, and Yttrium Content by Spectrophotometry. The aim is to establish a spectrophotometric method for the determination of precious metal content.

Methods for determining the content of vanadium, rhenium, gadolinium, and yttrium in gold.

— Part 17.Determination of Tungsten Content. The aim is to establish a gravimetric method for determining the tungsten content in noble metal alloys.

— Part 20.Determination of Rhodium Content. The aim is to establish spectrophotometric and gravimetric methods for determining the rhodium content in noble metal alloys. method.

— Part 21.Determination of Ruthenium Content. The aim is to establish a spectrophotometric method for determining the ruthenium content in noble metal alloys.

— Part 22.Determination of Manganese Content. The aim is to establish a titration method for determining the manganese content in noble metal alloys.

— Part 23.Determination of Cobalt Content. The aim is to establish a titration method for determining the cobalt content in noble metal alloys.

— Part 24.Determination of Tin Content. The aim is to establish a titration method for determining the tin content in noble metal alloys.

— Part 25.Determination of Copper, Manganese, Antimony, and Nickel Content by Flame Atomic Absorption Spectrometry. The aim is to establish a flame atomic absorption spectrometry method.

A method for determining the content of copper, manganese, antimony and nickel in precious metal alloys by spectroscopic method.

— Part 26.Determination of Oxygen, Nitrogen, and Hydrogen Content. The aim is to establish an inert gas melting-infrared absorption/thermal conductivity method for the determination of oxygen, nitrogen, and hydrogen content.

Nitrogen and hydrogen content.

— Part 27.Determination of Carbon Content. The aim is to establish a high-frequency infrared detection method for determining carbon content.

— Part 28.Determination of Trace Element Content. The aim is to establish an inductively coupled plasma atomic emission spectrometry (ICP-AES) method for the determination of precious metals.

Methods for determining the content of trace elements in alloys.

The 2008 edition of GB/T 15072.3 has been in effect for over ten years, but its scope of application does not cover some current products. Therefore, it is indeed necessary to revise this standard.

The document was revised to ensure it adapts to industry changes and market demands.

This document further improves the applicability of the standard, fully covering the requirements of existing product standards and meeting market demands.

Improving the quality of precious metal alloy products is of great significance for promoting their production, trade, and expanding application demand.

Chemical Analysis Methods for Noble Metal Alloys Part 3: Determination of Platinum Content Warning---Personnel using this document should have practical experience working in a formal laboratory. This document does not address all possible safety issues.

Users are responsible for taking appropriate safety and health measures and ensuring compliance with relevant national regulations.

1 Scope

This document describes a method for determining the platinum content in noble metal alloys using potassium permanganate potentiometric titration.

This document applies to the determination of platinum content in precious metal alloys. Determination range (mass fraction). 5.00%~95.00%.

2 Normative references

GB/T 8170

3 Terms and Definitions

This document does not contain any terms or definitions that need to be defined.

4 Principles

The sample was placed in a polytetrafluoroethylene digestion vessel, and hydrochloric acid and hydrogen peroxide were added. It was then heated in an oven to dissolve. The solution was then dissolved using nitrous chloride in a dilute hydrochloric acid solution.

Copper reduces platinum(IV) to platinum(II), which is then titrated with a standard potassium permanganate solution. The endpoint is indicated by potentiometric method to determine the platinum content.

5 Reagents and Materials

Unless otherwise specified, only reagents confirmed to be of analytical grade and distilled or deionized water or water of equivalent purity shall be used in the analysis.

5.1 Hydrochloric acid (rho=1.19g/mL).

5.2 Hydrogen peroxide (rho=1.10g/mL).

5.3 Saturated sodium chloride solution.

5.4 Cuprous chloride solution (40 g/L). Weigh 4.0 g of cuprous chloride, place it in a 100 mL volumetric flask, add 40 mL of hydrochloric acid (5.1) and water.

Dilute to the mark and mix well. Prepare fresh before use.

5.5 The potassium permanganate standard titration solution {c[1/5(KMnO4)]=0.0044mol/L} is prepared and standardized according to the following steps.

a) Preparation. Weigh 0.7g of potassium permanganate, place it in a 5L beaker, add 4L of water, heat and boil for 1.5 hours, then let stand overnight.

Filter the solution using a No. 3 glass frit funnel. Dilute the filtrate with water to 5L, mix well, and store in a brown bottle in the dark.

b) Standardization. Standardization is performed in parallel with the determination of the sample. Transfer 10.00 mL of platinum standard solution (5.6) to a 150 mL beaker, add...

0.5 mL of saturated sodium chloride solution (5.3) is evaporated at low temperature until it becomes a wet salt. Then, 3 mL of hydrochloric acid (5.1) and 3 mL of water are added, and the solution is evaporated at low temperature until it becomes a wet salt.