GB/T 4702.1-2016Chromium metal - Determination of chromium content - The ammonium ferrous sulfate titrimetric method (English PDF)

1 Scope

This part of GB/T 4702 specifies the determination of chromium content in metallic chromium by ammonium ferrous sulfate titration.

This part is applicable to the determination of chromium content in metallic chromium (vanadium <= 0.20%), determination range (mass fraction). >=97.00%.

2 normative reference documents

The following documents are indispensable for the application of this document. For dated references, only the dated edition applies to this article

Pieces. For undated references, the latest edition (including all modifications) applies to this document.

GB/T 4010 Ferroalloy chemical analysis of the sample to take and preparation

GB/T 6682 Analytical laboratory water specifications and test methods

GB/T 12805 Laboratory glass instrumentation burette

3 principle

The sample was dissolved with dilute sulfuric acid. In the appropriate sulfuric acid acidity, silver nitrate as a catalyst, with ammonium persulfate trivalent chromium oxidation to hexavalent,

With N-phenyl anthranilic acid as an indicator, titration with ammonium titanate standard titration solution, measured chromium content.

4 reagents and materials

Unless otherwise stated, only the confirmed analytical reagent is used in the analysis, and the water used is distilled or deionized or substantially pure water,

Shall comply with the provisions of GB/T 6682 three or more water.