GB/T 6730.51-2023Iron ores—Determination of carbon content in carbonate—The caustic asbestos absorption gravimetric 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.

This document is part 51 of GB/T 6730, see Appendix A for the published parts of GB/T 6730.

This document replaces GB/T 6730.51-1986 "Methods for Chemical Analysis of Iron Ore - Determination of Carbon in Carbonate by Caustic Soda Asbestos Absorption Gravimetric Method" Compared with GB/T 6730.51-1986, except for structural adjustment and editorial changes, the main technical changes are as follows:

a) Change the measurement range to 0.10%~10.00% (see Chapter 1, paragraph 1 of the text of the 1986 edition);

b) Added normative references GB/T 6682 (see Chapter 5), GB/T 10322.1 (see Chapter 7) and GB/T 8170 (see 9.2.3), delete GB/T 1467-1978 (see paragraph 2 of the text of the 1986 edition);

c) The chapter "Principle" has been added, and the content of the original chapter "Summary of Methods" has been changed and included (see Chapter 4, Chapter 1 of the 1986 edition chapter);

d) Soda lime and silver vanadate are added to the reagents (see 5.1 and 5.5);

e) The reaction and measurement part of the negative pressure gas supply measurement device has been changed, and the position of the two-way piston has been adjusted (see 6.1, No. 3 of the 1986 edition chapter);

f) A positive pressure gas supply measurement device is added to the instruments and equipment (see 6.2);

g) Changed the regulations on the number of determinations (see 8.1, 5.1 of the 1986 edition);

h) Added the method of air tightness inspection in positive pressure and negative pressure gas supply devices (see 8.3);

i) Changed the weighing amount and conversion result of the sample in the calibration test (see 8.5, 5.4 of the 1986 edition);

j) The expression of the measurement process has been changed, and the measurement of the positive pressure gas supply device has been added (see 8.6, 5.5 of the 1986 edition);

k) Added the determination of the hygroscopic water content in the sample (see 8.7);

l) Add the deduction of blank value in the calculation formula of carbon content in carbonate (see 9.1, 6.1 of the 1986 edition);

m) Changed the determination and presentation of analysis results (see 9.2.2, 6.2 of the 1986 edition);

n) The chapter "Test Report" has been added (see Chapter 10).

Introduction

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

GB/T 6730 includes a series of standards for the determination of the chemical composition of iron ore, respectively specifying the moisture content, total iron, and metal content of iron ore products.

Iron, ferrous, silicon, aluminum, calcium, magnesium, sulfur, phosphorus, manganese, titanium, total rare earths, barium, chromium, vanadium, tin, copper, cobalt, nickel, zinc, niobium, bismuth, potassium, sodium, carbon, lead, arsenic, Determination methods for chemical components such as cadmium, 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.

Based on the development of technology and the actual needs of production, after years of continuous revision work, a relatively complete standard system has been formed. Except already issued In addition to the part published (see Appendix A), the following parts are also planned to be released.

--- Part 84. Determination of Total Rare Earth Inductively Coupled Plasma Atomic Emission Spectrometry;

--- Part 85. Preparation and determination of certified standard samples for chemical analysis;

--- Part 86. Determination of radionuclides Inductively coupled plasma mass spectrometry;

--- Part 87. Determination of total iron and other multi-element content Wavelength dispersive X-ray fluorescence spectrometry (cobalt internal standard method).

Determination of carbon content in iron ore carbonate Caustic soda asbestos absorption gravimetric method Caution. Personnel using this document should have practical experience in formal laboratory work. This document does not address all possible security issues.

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

1 Scope

This document describes a method for the determination of carbon content in carbonates using the caustic soda asbestos absorption gravimetric method.

This document is applicable to the determination of carbon content in carbonates in iron ore, iron concentrate, sinter and pellets. The determination range (mass fraction) is 0.10%~10.00%.

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 6730.1 Preparation of pre-dried samples for iron ore analysis

GB/T 6730.3 Determination of hygroscopic water in iron ore analysis samples by gravimetric method, Karl Fischer method and mass loss method

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

GB/T 10322.1 Iron ore sampling and sample preparation methods

3 Terms and Definitions

This document does not have terms and definitions that need to be defined.

4 Principles

Samples are decomposed with phosphoric acid to remove carbon dioxide dry air (negative pressure supply) or compressed gas without carbon dioxide (positive pressure supply)

As a carrier gas, absorb the generated carbon dioxide with caustic soda asbestos, and calculate the carbon content in the carbonate in the iron ore according to its increased mass.

5 Reagents

In the analysis, unless otherwise specified, only the approved reagents of analytical grade and distilled water of grade 3 or above in accordance with the provisions of GB/T 6682 or other Water of comparable purity.

5.1 Soda lime, particle size 2.5mm~5.0mm, irregular cylindrical particles.

5.2 Caustic soda asbestos, particle size 0.60mm~0.85mm.

5.3 Anhydrous calcium chloride, particle size 2.0mm~5.0mm.

5.4 Anhydrous magnesium perchlorate (or phosphorus pentoxide), particle size 0.85mm~2.00mm, dry in an oven at 180°C for 2 hours, then quickly transfer to dry Cool in a desiccator for later use. The used magnesium perchlorate can be reused after drying.