GB/T 3654.8-2023Ferroniobium—Determination of titanium content—Chromotropic acid photometric method and diantipyrylmethane photometric method (English PDF)

Foreword

This document complies with the provisions of GB/T 1.1-2020 "Standardization Work Guidelines Part 1: Structure and Drafting Rules of Standardization Documents" Drafting.

This document is Part 8 of GB/T 3654. GB/T 3654 has released the following parts.

---Chemical analysis method of ferroniobium to determine the amount of niobium and tantalum by paper chromatographic separation gravimetric method;

---Determination of ferroniobium copper content by new cuproline-chloroform extraction photometric method;

---Gravimetric method for determination of ferroniobium silicon content;

---Chemical analysis method of ferroniobium to determine carbon content by combustion gravimetric method;

---Chemical analysis method of ferroniobium Determination of phosphorus content by molybdenum blue photometry;

---Determination of niobium iron sulfur content by combustion iodine content, methine blue photometry and infrared absorption method;

---Determination of niobium iron titanium content by color-changing acid photometry and diantipyrine methane photometry;

---Chemical analysis method of ferroniobium. Determination of tungsten content by thiocyanate photometry.

This document replaces GB/T 3654.8-2008 "Determination of niobium iron and titanium content by chromophoric acid photometric method". In comparison with GB/T 3654.8-2008, in addition to structural adjustments and editorial changes, the main technical changes are as follows:

a) Changed the "Instruments and Equipment" of the chromotropic acid photometry (see 4.3, Chapter 5 of the 2008 edition);

b) The "number of measurements" of the chromotropic acid photometric method has been increased (see 4.5.1);

c) The sample dissolution method of the chromotropic acid photometry method has been changed (see 4.5.4.1, 7.3.1 of the 2008 version);

d) The amount of chromogenic solution added for the color-changing acid photometric method has been changed (see 4.5.4.5, 7.3.5 of the 2008 edition);

e) Changed the "Calculation and Presentation of Analytical Results" of the chromotropic acid photometric method (see 4.6, Chapter 8 of the 2008 edition);

f) Changed the "precision" of the chromotropic acid photometry (see 4.7, Chapter 9 of the 2008 edition);

g) Added "diantipyrine methane photometry" (see Chapter 5);

h) Added "Flowchart of Sample Analysis Results Acceptance Procedure" (see Appendix A).

Introduction

Since there are many detection elements involved in the ferroniobium detection process, the applicable scope and application methods of the elements are different. To ensure niobium For the convenience and accuracy of iron detection standards, we have established a national standard system to support the detection of ferroniobium based on the analysis methods of different elements of ferroniobium.

The GB/T 3654 series of analytical methods for ferroniobium is the basic standard for ferroniobium testing in my country and consists of the following 8 parts.

---Chemical analysis method of ferroniobium. Determine the amount of niobium and tantalum by paper chromatographic separation gravimetric method. The purpose is to measure the niobium and tantalum content in ferroniobium Quantity, using paper chromatography gravimetric method.

---Determination of ferroniobium copper content by new cuproline-chloroform extraction photometric method. The purpose is to measure the copper content in ferroniobium, using New cuproline-chloroform extraction photometric method.

---Gravimetric method for determination of ferroniobium silicon content. The purpose is to measure the silicon content in ferroniobium, using the gravimetric method.

---Chemical analysis method of ferroniobium. Determination of carbon content by combustion gravimetric method. The purpose is to measure the carbon content in ferroniobium, using the combustion gravimetric method.

---Chemical analysis method of ferroniobium. Determination of phosphorus content by molybdenum blue photometry. The purpose is to measure the phosphorus content in ferroniobium, using the molybdenum blue photometric method.

---Determination of niobium iron sulfur content by combustion iodine method, methine blue photometry and infrared absorption method. The purpose is to measure the The sulfur content was determined by combustion iodine content, methylene blue photometry and infrared absorption method.

---Determination of niobium iron and titanium content by color-changing acid photometry and diantipyrine methane photometry. The purpose is to measure the titanium content in ferroniobium Quantification, using color-changing acid photometry and diantipyrine methane photometry.

---Chemical analysis method of ferroniobium. Determination of tungsten content by thiocyanate photometry. The purpose is to measure the tungsten content in ferroniobium, using thiocyanate Halophotometry.

Warning---Personnel using this document should have regular laboratory work experience. This document does not address all possible security issues question. Users are responsible for taking appropriate safety and health measures and ensuring compliance with the conditions stipulated in relevant national regulations.

1 Scope

This document specifies the determination of titanium content in ferroniobium using the photochromic acid photometric method and the diantipyrine methane photometric method.

This document is applicable to the determination of titanium content in ferroniobium. The determination range (mass fraction) is: 0.010%~2.50%.

2 Normative reference documents

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

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

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

GB/T 6379.2 Accuracy of measurement methods and results (correctness and precision) Part 2: Determination of repeatability of standard measurement methods Basic methods of sex and reproducibility

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

GB/T 7729 General rules for chemical analysis of metallurgical products by spectrophotometry

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

GB/T 12806 Laboratory glassware single-marked volumetric flasks

GB/T 12807 Graduated pipettes for laboratory glass instruments

GB/T 12808 Single-marked pipette for laboratory glass instruments

3 Terms and definitions

There are no terms or definitions to be defined in this document.

4 Method 1: Color-changing acid photometry