ISO 22682:2017

INTERNATIONAL ISO
STANDARD 22682
First edition
2017-08
Iron ores — Determination of trace
elements — Plasma spectrometric
method
Minerais de fer — Détermination d’éléments traces — Méthode par
spectrométrie avec plasma
Reference number
©
ISO 2017
© ISO 2017, Published in Switzerland
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ii © ISO 2017 – All rights reserved

Contents Page
Foreword .iv
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 2
4 Principle . 2
5 Reagents . 2
6 Apparatus . 4
7 Sampling and samples . 4
7.1 Laboratory sample . 4
7.2 Preparation of predried test samples . 5
8 Procedure. 5
8.1 Number of determinations . 5
8.2 Test portion . 5
8.3 Blank test and check test . 5
8.4 Determination . 5
8.4.1 Decomposition of the test portion . 5
8.4.2 Adjustment of spectrometer . 6
9 Calculation of results . 7
9.1 Calibration graph . 7
9.2 Correction of spectral interference . 8
9.3 Standardization of calibration graph (drift correction) . 9
9.4 General treatment of results .10
9.4.1 Repeatability and permissible tolerances .10
9.4.2 Determination of analytical result .10
9.4.3 Check for trueness .11
9.4.4 Calculation of final result .12
9.5 Oxide factors .12
10 Test report .12
Annex A (informative) Suggested calibration solutions .14
Annex B (normative) Plasma spectrometer performance tests .15
Annex C (normative) Flowchart of the procedure for the acceptance of analytical values of
test samples .18
Annex D (informative) Derivation of repeatability and permissible tolerance formulae .19
Annex E (informative) Precision data obtained by international analytical trials .20
Bibliography .25
Foreword
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This document was prepared by Technical Committee ISO/TC 102, Iron ore and direct reduced iron,
Subcommittee SC 2, Chemical analysis.
iv © ISO 2017 – All rights reserved

INTERNATIONAL STANDARD ISO 22682:2017(E)
Iron ores — Determination of trace elements — Plasma
spectrometric method
CAUTION — This document may involve hazardous operations and equipment. This document
does not purport to address all of the safety issues associated with its use. It is the responsibility
of the user of this document to establish appropriate safety and health practices and determine
the applicability of regulatory limitations prior to its use.
1 Scope
This document specifies a method for the determination of phosphorus, vanadium, titanium, copper,
nickel, chromium, barium and cobalt in iron ores, by inductively coupled plasma atomic emission
spectrometry (ICP-AES).
This method is applicable to the concentration ranges (mass fraction) given in Table 1, in natural iron
ores, iron ore concentrates and agglomerates, including sinter products.
Table 1 — Concentration ranges
Concentration range for Concentration range for
Element referee purpose non-referee purpose
% (mass fraction) % (mass fraction)
P 0,000 2 to 0,150 0,000 2 to 0,150
V 0,003 0 to 0,024 0,003 0 to 0,024
Ti 0,015 0 to 0,120 0,015 0 to 0,120
Cu 0,0014 to 0,250 0,001 4 to 0,250
Ni 0,005 0 to 0,090 0,005 0 to 0,090
Cr 0,004 0 to 0,015
Ba 0,002 8 to 0,035
Co 0,002 0 to 0,100
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements 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.
ISO 648, Laboratory glassware — Single-volume pipettes
ISO 1042, Laboratory glassware — One-mark volumetric flasks
ISO 2596, Iron ores — Determination of hygroscopic moisture in analytical samples — Gravimetric, Karl
Fischer and mass-loss methods
ISO 3082, Iron ores — sampling and sample preparation procedures
ISO 3696, Water for analytical laboratory use — Specification and test methods
ISO 7764, Iron ores — Preparation of predried test samples for chemical analysis
ISO 11323, Iron ore and direct reduced iron — Vocabulary
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 11323 apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— IEC Electropedia: available at http:// www .electropedia .org/
— ISO Online browsing platform: available at https:// www .iso .org/ obp
4 Principle
The test portion is decomposed with L-ascorbic acid, hydrofluoric acid, concentrated hydrochloric acid,
concentrated nitric acid and then evaporated to dryness. The dry mass is dissolved in hydrochloric acid
(1 + 1) and the solution is made up to 100 ml.
The solution is diluted to volume and measured on an ICP spectrometer. Final results are read from a
calibration graph prepared using standard calibration solutions.
5 Reagents
During the analysis, use only highly pure reagents of recognized analytical grade and only water that
complies with grade 2 of ISO 3696.
5.1 High-purity iron, metal, of minimum purity grade 99,99 % (mass fraction).
5.2 Hydrochloric acid, ρ 1,16 g/ml to 1,19 g/ml, diluted 1 + 1.
5.3 Nitric acid, ρ 1,38 g/ml to 1,4 g/ml
5.4 Hydrofluoric acid, ρ 1,13 g/ml to ρ 1,16 g/ml.
5.5 Sulfuric acid, p.a. grade.
5.6 L-ascorbic acid, C H O .
6 8 6
5.7 Stock solutions.
Stock solutions shall be prepared by convenient handling moisture-free high-purity salts, dried until a
constant mass and cooled in a desiccator. High-purity metals of minimum purity grade of 99,9 % (mass
fraction) can also be used to prepare vanadium, titanium, copper, nickel and chromium stock solutions.
Stock solutions may also be prepared by independent laboratories or reagent suppliers.
5.7.1 Phosphorus, 1 000 μg/ml.
Dissolve 4,393 6 g of potassium dihydrogen orthophosphate (KH PO ) in about 200 ml of water in a
2 4
1 000 ml one-mark volumetric flask. When the dissolution is complete, dilute to volume with water
and mix.
5.7.2 Vanadium, 1 000 μg/ml.
Dissolve 1,000 0 g of high-purity vanadium metal or 2,296 3 g of ammonium metavanadate (NH VO ) in
4 3
20 ml of nitric acid (5.3) in a covered tall-form beaker with heating. When dissolution is complete, cool
and transfer to a 1 000 ml one mark-volumetric flask, dilute to volume with water and mix.
2 © ISO 2017 – All rights reserved

5.7.3 Titanium, 1 000 μg/ml.
Dissolve 1,000 0 g of high-purity titanium metal in 100 ml of hydrochloric acid (5.2) in a covered tall-
form beaker with heating or 4,135 1 g of high-purity ammonium hexafluorotitanate [(NH ) TiF ] in
4 2 6
warm distilled water containing drops of hydrofluoridic acid (5.4) in a covered tall-form PTFE beaker.
When dissolution is complete, cool and transfer to a 1 000 ml one-mark volumetric flask,
...