GB/T 4333.8-2022Ferrosilicon—Determination of calcium content—Flame atomic absorption spectrometry (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 of Standardization Documents" drafted.

This document is part 8 of GB/T 4333.GB/T 4333 has published the following parts.

---Determination of ferrosilicon content by perchloric acid dehydration gravimetric method and potassium fluorosilicate volumetric method;

--- Ferrosilicon Chemical Analysis Method Bismuth Phosphorus Molybdenum Blue Photometric Determination of Phosphorus Content;

--- Ferrosilicon chemical analysis method Potassium periodate photometric method for the determination of manganese content;

--- Determination of the content of ferrosilicon and aluminum chrome azure S spectrophotometry, EDTA titration and flame atomic absorption spectrometry;

--- Determination of ferrosilicon silicon, manganese, aluminum, calcium, chromium and iron content wavelength dispersive X-ray fluorescence spectrometry (fused cast glass plate method);

--- Determination of ferrosilicon and chromium content by diphenylcarbohydrazide spectrophotometric method;

---Determination of ferrosilicon sulfur content by infrared absorption method and chromatographic separation barium sulfate gravimetric method;

--- Determination of calcium ferrosilicon content by flame atomic absorption spectrometry;

--- Determination of ferrosilicon carbon content by infrared absorption method.

This document replaces GB/T 4333.8-1988 "Chemical Analysis Method of Ferrosilicon for Determination of Calcium by Atomic Absorption Spectrometry", and GB/T 4333.8- Compared with 1988, except for structural adjustment and editorial changes, the main technical changes are as follows.

a) Hydrochloric acid is added to the dissolution of lanthanum solution (see 5.8);

b) Replace the platinum dish with a Teflon beaker (see 8.5.1, 6.6.1 of the 1988 edition);

c) Hydrochloric acid was added to the sample dissolution method (see 8.5.1);

d) In the sample dissolution method, the amount of perchloric acid was adjusted from 5mL to 3mL (see 8.5.1, 6.6.1 of the 1988 edition);

e) The drawing of the low concentration calibration curve has been changed (see 8.6.1, 6.7.1 of the 1988 edition);

f) The drawing of the high concentration calibration curve has been changed, and the fractionation step has been deleted (see 8.6.2, 6.7.2 of the 1988 edition);

g) An inter-laboratory precision co-experiment was carried out, and the "tolerance" was replaced by the statistical repeatability limit (r) and reproducibility limit (R) (see Chapter 10, Chapter 8 of the 1988 edition);

h) Added the content of the test report (see Chapter 11);

i) Added the normative appendix "Process Flow Chart for Acceptance of Test Analysis Results" (see Appendix A);

j) The calculation of the coefficient of variation of the precision index was deleted (see Appendix A of the 1988 edition).

Introduction

Since there are many detection elements involved in the detection process of ferrosilicon, the applicable scope and applicable methods of the elements are different. To ensure that the silicon The iron detection standard is convenient and accurate. For the analysis methods of different elements of ferrosilicon, we have established a national standard body to support the detection of ferrosilicon.

Tie. GB/T 4333 is the basic standard for ferrosilicon testing in my country, which consists of the following nine parts.

---Determination of ferrosilicon content by perchloric acid dehydration gravimetric method and potassium fluorosilicate volumetric method. The purpose is to measure the silicon content in ferrosilicon The amount was determined by the perchloric acid dehydration gravimetric method and the potassium fluorosilicate volumetric method.

--- Ferrosilicon chemical analysis method Bismuth phosphorus molybdenum blue light method to determine the amount of phosphorus. The purpose is to measure the phosphorus content in ferrosilicon, using bismuth phosphorus molybdenum blue light method.

--- Ferrosilicon chemical analysis method Potassium periodate photometric method to determine the amount of manganese. The purpose is to measure the manganese content in ferrosilicon using periodic acid Potassium Photometry.

--- Determination of silicon-iron-aluminum content Chromium azure S spectrophotometry, EDTA titration and flame atomic absorption spectrometry. aim at To measure the aluminum content in ferrosilicon, azure S spectrophotometry, EDTA titration and flame atomic absorption spectrometry were used.

--- Determination of ferrosilicon silicon, manganese, aluminum, calcium, chromium and iron content wavelength dispersive X-ray fluorescence spectrometry (cast glass method). target The method is to measure the content of silicon, manganese, aluminum, calcium, chromium and iron in ferrosilicon using wavelength dispersive X-ray fluorescence spectrometry (fused glass film method).

--- Determination of ferrosilicon and chromium content by diphenylcarbohydrazide spectrophotometry. The purpose is to measure the chromium content in ferrosilicon using two Phenylcarbazide spectrophotometry.

---Determination of ferrosilicon sulfur content Infrared absorption method and chromatographic separation barium sulfate gravimetric method. The purpose is to measure the sulfur content in ferrosilicon Quantity, using infrared absorption method and chromatographic separation of barium sulfate gravimetric method.

--- Determination of calcium ferrosilicon content by flame atomic absorption spectrometry. The purpose is to measure the calcium content in ferrosilicon using flame atom Absorption Spectroscopy.

--- Determination of ferrosilicon carbon content by infrared absorption method. The purpose is to measure the carbon content in ferrosilicon by infrared absorption method.

In addition, the content of the original "chemical analysis method of ferrosilicon for determination of aluminum content by flame atomic absorption spectrometry" has been merged into "the content of ferrosilicon and aluminum" Determination of Chromium Azurite S Spectrophotometry, EDTA Titration and Flame Atomic Absorption Spectrometry", this part is now obsolete.

Determination of calcium ferrosilicon content flame atomic absorption spectrometry Caution - Persons using this document should have formal laboratory work experience. This document does not address all possible security issues.

It is the user's responsibility to take appropriate safety and health measures and to ensure compliance with the conditions stipulated by relevant national regulations.

1 Scope

This document specifies the determination of calcium content in ferrosilicon by flame atomic absorption spectrometry.

This document applies to the determination of calcium content in ferrosilicon. Measurement range (mass fraction). 0.050%~2.50%.

2 Normative references

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

GB/T 4010 Collection and preparation of samples for chemical analysis of ferroalloys

GB/T 6379.1 Accuracy (correctness and precision) of measurement methods and results - Part 1: General provisions and definitions

GB/T 6379.2 Accuracy (correctness and precision) of measurement methods and results - Part 2: Determining repetition of standard measurement methods Basic Methods of Reproducibility and Reproducibility

GB/T 6682 Analysis Laboratory Water Specifications and Test Methods

GB/T 8170 Numerical Rounding Rules and Representation and Judgment of Limit Values

GB/T 12806 Laboratory glass instrument single-line volumetric flask

GB/T 12807 Laboratory glass instrument indexing pipette

GB/T 12808 Laboratory glass instrument single reticle pipette

3 Terms and Definitions

There are no terms and definitions that need to be defined in this document.

4 Principles

The sample was decomposed with nitric acid, hydrofluoric acid and hydrochloric acid, perchloric acid was smoky and evaporated to dryness, and lanthanum salt was used as the releasing agent in the hydrochloric acid medium, and the atomic absorption spectrometry was carried out.

At the wavelength of 422.7nm, the absorbance of calcium was measured by air-acetylene flame, and the content of calcium was calculated.

5 Reagents

In the analysis, unless otherwise stated, only use the approved reagents of analytical grade and above and distilled water above the second grade in accordance with the provisions of GB/T 6682 or water of comparable purity.