GB/T 38216.8-2026Steel slag - Determination of phosphorus content (English PDF)

1 Scope

This document describes a method for determining the phosphorus content in steel slag using the bismuth-phosphorus-molybdenum blue spectrophotometric method.

This document applies to the determination of phosphorus content in steel slag, with a determination range (mass fraction) of 0.005% to 2.00%.

2 Normative references

The contents of the following documents, through normative references within the text, constitute essential provisions of this document. Dated citations are listed below.

For references to documents, only the version corresponding to that date applies to this document; for undated references, the latest version (including all amendments) applies.

This document.

GB/T 2007.2 General Rules for Sampling and Sample Preparation of Bulk Mineral Products - Manual Sample Preparation Method

GB/T 6379.1 Accuracy (Correctness and Precision) of Measurement Methods and Results - Part 1.General Principles and Definitions

GB/T 6379.2 Accuracy (correctness and precision) of measurement methods and results - Part 2.Determining the repeatability of standard measurement methods

Basic methods of sex and representation

GB/T 6682 Specifications and test methods for water used in analytical laboratories

GB/T 7729 General Rules for Chemical Analysis of Metallurgical Products - Spectrophotometric Method

GB/T 8170 Rules for rounding off numerical values and the representation and determination of limiting values

GB/T 12807 Graduated Pipettes for Laboratory Glassware

GB/T 12808 Laboratory Glassware - Single-mark Pipettes

3 Terms and Definitions

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

4 Principles

The sample is decomposed with hydrochloric acid, nitric acid, and hydrofluoric acid. Perchloric acid fumes and removes fluorine and silicon. In sulfuric acid medium, phosphorus forms complexes with bismuth and ammonium molybdate.

The substance was then reduced to molybdenum blue with ascorbic acid. Its absorbance was measured at a wavelength of 710 nm.

5 Reagents

Unless otherwise specified, only approved analytical grade reagents and water conforming to Grade III or higher as specified in GB/T 6682 shall be used in the analysis.

It is water of comparable purity.