GB/T 6730.48-2021Iron ores—Determination of bismuth content— Dithiodiantipyryl methane spectrophotometric 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 of Standardization Documents" drafted.

This document is Part 48 of GB/T 6730. See Appendix A for the published part of GB/T 6730.

This document replaces GB/T 6730.48-1986 "Methods for Chemical Analysis of Iron Ore Dithiodiantipyridine Methane Spectrophotometric Determination of Bismuth". Compared with GB/T 6730.48-1986, except for structural adjustment and editorial changes, the main technical changes are as follows:

a) Added the chapter "Normative References" (see Chapter 2);

b) Changed the sample decomposition method (see 8.4.1 and 8.4.2, 4.5.1 and 4.5.2 of the 1986 edition);

c) Changed the color development acidity control method (see 8.4.4.1, 4.5.4.1 of the 1986 edition);

d) the selection of the reference in the measurement has been changed (see 8.4.4.1 and 8.4.4.2, 4.5.4.1 and 4.5.4.2 of the 1986 edition);

e) The calculation of the analysis results has been changed (see Chapter 9, Chapter 5 of the 1986 edition).

Introduction

Iron ore is the main raw material of the iron and steel industry. In the standard system of the iron and steel field, the standard system for the determination of chemical composition of iron ore is the It plays an important role in ensuring the quality of iron ore products. This series of method standards serves the production of iron ore production, trade and application, and provide technical support for the high-quality development of my country's iron and steel industry.

GB/T 6730 is a series of standards for the determination of chemical composition of iron ore, which respectively stipulates moisture, total iron, metallic iron, Ferrous, silicon, aluminum, calcium, magnesium, sulfur, phosphorus, manganese, titanium, total rare earth, barium, chromium, vanadium, tin, copper, cobalt, nickel, zinc, niobium, bismuth, potassium, sodium, carbon, lead, arsenic, cadmium, Methods for the determination of chemical components such as mercury, fluorine, chlorine, loss on ignition, and combined water.

In 1986, GB/T 6730 issued 51 national standards for the determination of chemical composition of iron ore for the first time.

According to the development of technology and the actual needs of production, after years of continuous formulation and revision work, a relatively complete standard system has been formed at present. The GB/T 6730 constituent documents are detailed in Appendix A.

GB/T 6730.48 describes the spectrophotometric method for the determination of bismuth content in iron ore by dithiodiantipyridine methane. After this revision Consistent with international standards.

Caution - Persons using this document should have practical experience in formal laboratory work. This document does not address all possible security issues question. 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 a method for the spectrophotometric determination of bismuth content by dithiodiantipyridinemethane.

This document applies to the determination of iron ore, iron concentrate and lump ore, including the determination of bismuth content in sintered products, the determination range (mass fraction): 0.0020%~0.200%.

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 6682 Analysis Laboratory Water Specifications and Test Methods

GB/T 6730.1 Preparation of pre-dried samples for iron ore analysis

GB/T 7729 General Principles of Spectrophotometry for Chemical Analysis of Metallurgical Products

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

GB/T 10322.1 Iron ore sampling and sample preparation method

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 is dissolved with hydrochloric acid, hydrofluoric acid and nitric acid, the sulfuric acid emits smoke, and the residue is melted with potassium pyrosulfate. In 0.5mol/L nitric acid medium, the Manganese dioxide was used as a carrier to precipitate bismuth, and the filtered precipitate was dissolved in hydrochloric acid-hydrogen peroxide solution, heated and concentrated. At a pH of 2 to 3 in the hydrochloric acid medium, bismuth and dithiodiantipyridine methane form a red complex, and the absorbance is measured at the wavelength of 525nm with a spectrophotometer to calculate the bismuth content.

5 Reagents

Unless otherwise specified, only use approved analytical reagents and distilled water of grade 3 or higher in accordance with GB/T 6682 or water of comparable purity.