GB/T 42516-2023Method for chemical analysis of high temperature shape memory alloys—Determination of platinum content—Thiourea complex precipitation method (English PDF)

Foreword

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

1 Scope

This document describes a method for the determination of platinum in high temperature shape memory alloys by the thiourea complex precipitation method.

This document is applicable to the determination of platinum content in high-temperature shape memory alloys, and the determination range (mass fraction) is 30.00%~70.00%.

2 Normative references

The contents of the following documents constitute the essential provisions of this document through normative references in the text. Among them, dated references For documents, only the version corresponding to the date is applicable to this document; for undated reference documents, the latest version (including all amendments) is applicable to this document.

GB/T 6682 Analytical laboratory water specifications and test methods

GB/T 8170 Numerical rounding off rules and expression and determination of limit values

GB/T 17433 Basic Terms for Chemical Analysis of Metallurgical Products

3 Terms and Definitions

The terms and definitions defined in GB/T 17433 apply to this document.

4 Principles

The sample was dissolved in a mixed acid of hydrochloric acid and nitric acid. Add thiourea and platinum ions into the sulfuric acid medium to form a complex, and continue heating until sulfuration occurs. matter precipitation. The precipitate was filtered, burned to constant weight in a high-temperature furnace at 900°C, and the mass fraction of platinum was calculated.

5 Reagents

Unless otherwise stated, only reagents confirmed to be of analytical grade were used in the analysis.

5.1 Water, in line with GB/T 6682 tertiary water regulations.

5.2 Hydrochloric acid-nitric acid mixed acid. mix 3 volumes of hydrochloric acid (rho=1.19mg/L) and 1 volume of nitric acid (rho=1.42mg/L), and make up immediately.

5.3 Sulfuric acid solution (1 1). add 1 volume of sulfuric acid (rho=1.84mg/L) into 1 volume of water while stirring, and mix well.

5.4 Sulfuric acid solution (5 95). Add 5 volumes of sulfuric acid (rho=1.84mg/L) into 95 volumes of water while stirring, and mix well.

5.5 Thiourea solution (100g/L). Weigh 100g of thiourea and dissolve it in 1000mL of water, and mix well.

6 Instruments and equipment

6.1 Crucible. Porcelain crucible, platinum crucible or quartz crucible, the volume is not less than 30mL.