YB/T 4725-2018 Steel slag - Determination of metallic iron - Ferric trichloride-potassium dichromate titration
Warning: Users of this standard shall have practical work experience in standardized laboratories. This standard does not purport to address all of the safety problems, if any, associated with its use. It is the responsibility of the user to establish appropriate safety and health measures and to ensure compliance with any national regulatory conditions.
1 Scope
This standard specifies the measurement range, principle, apparatus, reagents, sample preparation, analysis steps, result calculation, test report for the determination of metallic iron in steel slag by ferric trichloride-potassium dichromate titration
This standard is applicable to the determination of metallic iron in steel slag, with the determination range (mass fraction) from 0.10% to 10.00%.
2 Normative references
The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
GB/T 2007.2 General rules for the sampling and sample preparation of minerals in bulk - Sample preparation by manual method
GB/T 6003.1 Test sieves of metal wire cloth
GB/T 6379.1 Accuracy (trueness and precision) of measurement methods and results - Part 1: General principles and definitions
GB/T 6379.2 Accuracy (trueness and precision) of measurement methods and results - Part 2: Basic method for the determination of repeatability and reproducibility of a standard measurement method
GB/T 6682 Water for analytical laboratory use - Specification and test methods
GB/T 8170 Rules of rounding off for numerical values & expression and judgement of limiting values
GB/T 12805 Laboratory glassware - Burettes
GB/T 12806 Laboratory glassware - One-mark volumetric flasks
GB/T 12807 Laboratory glassware - Graduated pipettes
GB/T 12808 Laboratory glassware - One mark pipettes
YB/T 804 Terminology for iron and steel slag & treatment and utilization
3 Principle
The sample is dissolved with ferric trichloride, and the metallic iron is oxidized to ferrous chloride. After filtration, the filtrate is acidified with sulfur-phosphorus mixed acid, and then titrated with potassium dichromate standard titration solution using sodium diphenylamine sulfonate as an indicator.
4 Terms and definitions
For the purposes of this document, the terms and definitions given in YB/T 804 apply.
5 Reagents
Unless otherwise specified, the reagents used are analytical grade reagents; the test water meets the requirements of Grade III water in GB/T 6682.
5.1 Phosphoric acid (ρ 1.69 g/mL).
5.2 Sulfuric acid 1+2.
Foreword i
1 Scope
2 Normative references
3 Principle
4 Terms and definitions
5 Reagents
6 Apparatus
7 Sample preparation
8 Analytical steps
9 Results calculation
10 Test report
Annex A (Normative) Flow chart of test sample analytical value acceptance procedure
(Start with independent replicate results)
