SIST ISO 2599:2005

SLOVENSKI STANDARD
SIST ISO 2599:2005
01-november-2005
äHOH]RYHUXGH±'RORþHYDQMHIRVIRUMD±7LWULPHWULMVNDPHWRGD
Iron ores -- Determination of phosphorus content -- Titrimetric method
Minerais de fer -- Dosage du phosphore -- Méthode titrimétrique
Ta slovenski standard je istoveten z: ISO 2599:2003
ICS:
73.060.10 Železove rude Iron ores
SIST ISO 2599:2005 en
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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SIST ISO 2599:2005

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SIST ISO 2599:2005


INTERNATIONAL ISO
STANDARD 2599
Third edition
2003-02-15

Iron ores — Determination of phosphorus
content — Titrimetric method
Minerais de fer — Dosage du phosphore — Méthode titrimétrique




Reference number
ISO 2599:2003(E)
©
ISO 2003

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SIST ISO 2599:2005
ISO 2599:2003(E)
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ii © ISO 2003 — All rights reserved

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SIST ISO 2599:2005
ISO 2599:2003(E)
Contents Page
Foreword. iv
1 Scope. 1
2 Normative references . 1
3 Principle . 1
4 Reagents . 2
5 Apparatus. 3
6 Sampling and samples . 3
6.1 Laboratory sample. 3
6.2 Preparation of predried test samples . 4
7 Procedure. 4
7.1 Number of determinations . 4
7.2 Test portion . 4
7.3 Blank test and check test. 4
7.4 Determination . 5
8 Expression of results. 7
8.1 Calculation of phosphorus content . 7
8.2 General treatment of results . 7
8.3 Oxide factor . 9
9 Test report. 9
Annex A (normative) Flowsheet of the procedure for the acceptance of analytical values for test
samples. 10
Annex B (informative) Derivation of repeatability and permissible tolerance equations . 11
Annex C (informative) Precision data obtained by international analytical trials. 12

© ISO 2003 — All rights reserved iii

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SIST ISO 2599:2005
ISO 2599:2003(E)
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies
(ISO member bodies). The work of preparing International Standards is normally carried out through ISO
technical committees. Each member body interested in a subject for which a technical committee has been
established has the right to be represented on that committee. International organizations, governmental and
non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the
International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization.
International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2.
The main task of technical committees is to prepare International Standards. Draft International Standards
adopted by the technical committees are circulated to the member bodies for voting. Publication as an
International Standard requires approval by at least 75 % of the member bodies casting a vote.
Attention is drawn to the possibility that some of the elements of this document may be the subject of patent
rights. ISO shall not be held responsible for identifying any or all such patent rights.
ISO 2599 was prepared by Technical Committee ISO/TC 102, Iron ore and direct reduced iron, Subcommittee
SC 2, Chemical analysis.
This third edition cancels and replaces the second edition (ISO 2599:1983), which has been editorially revised.

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SIST ISO 2599:2005
INTERNATIONAL STANDARD ISO 2599:2003(E)

Iron ores — Determination of phosphorus content — Titrimetric
method
WARNING — This International Standard may involve hazardous materials, operations and equipment.
This International Standard does not purport to address all of the safety problems associated with its
use. It is the responsibility of the user of this International Standard to establish appropriate health
and safety practices and determine the applicability of regulatory limitations prior to use.
1 Scope
This International Standard specifies a titrimetric method for the determination of the phosphorus content of
iron ores, using hexaammonium heptamolybdate (ammonium molybdate).
1)
This method is applicable to a concentration range of 0,10 % (m/m) to 5,0 % (m/m) of phosphorus in natural
iron ores, and iron ore concentrates and agglomerates including sinter products.
This International Standard provides a quality control method for the determination of phosphorus by titration,
however, the method cannot be used for referee purposes.
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.
ISO 648:1977, Laboratory glassware — One-mark pipettes
ISO 1042:1998, Laboratory glassware — One-mark volumetric flasks
ISO 3082:2000, Iron ores — Sampling and sample preparation procedures
ISO 3696:1987, Water for analytical laboratory use — Specification and test methods
ISO 7764:1985, Iron ores — Preparation of predried test samples for chemical analysis
3 Principle
The test portion is decomposed by treatment with hydrochloric, nitric and perchloric acids. The insoluble
residue is filtered and the filtrate is reserved as the main solution.
The residue is ignited, treated with sulfuric and hydrofluoric acids to remove silicon dioxide, fused with sodium
carbonate and the melt is leached with water. The alkaline solution is filtered and the residue is discarded.

1) This method has been tested internationally on samples containing phosphorus contents ranging from 0,03 % (m/m) to
1,50 % (m/m).
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SIST ISO 2599:2005
ISO 2599:2003(E)
The filtrate from residue treatment is acidified using hydrochloric acid, iron(III) chloride is added and the
phosphorus is collected by precipitation with ammonia solution. The precipitate is dissolved in hydrochloric
acid and combined with the main solution. Hydrobromic acid is added and evaporated to fumes of perchloric
acid to expel arsenic. The salts are dissolved in water and the solution, or an aliquot, is neutralized with
ammonia solution and the acidity is adjusted using nitric acid. The solution is cooled to 20 °C and vanadium is
reduced by iron(II) sulfate. Ammonium molybdate is added to the cold solution and the yellow precipitate of
ammonium molybdophosphate is collected by filtration.
The precipitate is washed free of acid and dissolved in a slight excess of sodium hydroxide, the excess being
titrated with nitric acid.
For test portions containing more than 18 mg of titanium, a modified procedure is used (see 7.4.1.2).
4 Reagents
During the analysis, use only reagents of recognized analytical grade, and only water that conforms to grade 2
of ISO 3696:1987.
4.1 Ammonium nitrate (NH NO ).
4 3
4.2 Sodium carbonate (Na CO ), anhydrous.
2 3
4.3 Hydrochloric acid, ρ 1,16 g/ml to 1,19 g/ml
4.4 Hydrochloric acid, ρ 1,16 g/ml to 1,19 g/ml diluted 1 + 1.
4.5 Nitric acid, ρ 1,42 g/ml.
4.6 Nitric acid, ρ 1,42 g/ml diluted 1 + 50.
4.7 Nitric acid, ρ 1,42 g/ml diluted 1 + 5 000.
4.8 Sulfuric acid, ρ 1,84 g/ml.
4.9 Sulfuric acid, ρ 1,84 g/ml diluted 1 + 1.
4.10 Perchloric acid, ρ 1,54 g/ml, 60 % (m/m) solution, or ρ 1,67 g/ml, 70 % (m/m) solution.
4.11 Hydrofluoric acid, ρ 1,13 g/ml, 40 % (m/m) solution.
4.12 Hydrobromic acid, ρ 1,38 g/ml, 40 % (m/m) solution or ρ 1,48 g/ml, 47 % (m/m) solution.
4.13 Ammonia solution, ρ 0,9 g/ml.
4.14 Hydrogen peroxide, 30 % (m/m) solution, free from phosphate stabilizer.
4.15 Potassium nitrate, 10 g/l solution.
4.16 Ammonium molybdate, solution.
Dissolve 40 g of finely pulverized crystalline ammonium molybdate tetrahydrate [(NH ) Mo O ⋅4H O] in
4 6 7 24 2
300 ml of warm water and 80 ml of ammonia solution (4.13). Allow the solution to cool and add this solution in
small portions to 600 ml of nitric acid (1 + 1), while stirring. Add a few milligrams of sodium hydrogen
phosphate or ammonium hydrogen phosphate and allow to stand for at least 2 d. Filter before use.
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SIST ISO 2599:2005
ISO 2599:2003(E)
4.17 Iron(III) chloride solution, containing 3 g of Fe/l.
Dissolve 0,3 g of pure iron, with as small a content of phosphorus as possible, by treatment with hydrochloric
acid (4.3), add a few drops of nitric acid (4.5) to oxidize the iron, and boil the mixture to remove chlorine.
Allow the solution to cool and dilute with water to 100 ml.
4.18 Iron(III) sulfate solution, 100 g/l.
Dissolve 100 g of iron(II) sulfate heptahydrate (FeSO⋅7H O) in 1 l of sulfuric acid (1 + 19).
4 2
4.19 Water, free of CO .
2
Heat distilled or deionized water to boiling point in a conical flask for 5 min to expel carbon dioxide. Cool,
protecting the water in an appropriate way against any pickup of carbon dioxide.
4.20 Sodium hydroxide, standard volumetric solution, c(NaOH) = 0,2 mol/l approximately.
Dissolve 8 g of sodium hydroxide in 1 l of freshly boiled and cooled water (4.19). Standardize this solution
using either amidosulfuric acid (sulfamic acid) or potassium hydrogen phthalate.
Dry either potassium hydrogen phthalate or sulfamic acid at 105 °C for 1 h and weigh, to the nearest 0,001 g,
either approximately 1 g of potassium hydrogen phthalate or approximately 0,5 g of sulfamic acid. Dissolve
either material in 50 ml of water free of CO (4.19) and titrate with sodium hydroxide solution (4.20) using
2
phenolphthalein solution (4.22) as indicator.
4.21 Nitric acid, standard volumetric solution c(HNO ) = 0,2 mol/l approximately.
3
Dilute 13 ml of nitric acid (4.5) with water, to 1 l.
Standardize the solution as follows: accurately measure 25 ml of sodium hydroxide standard volumetric
solution (4.20) and titrate with nitric acid solution, using phenolphthalein solution (4.22) as indicator.
4.22 3,3-Bis(4-hydroxyphenyl)phthalide (phenolphthalein) solution, 0,1 g/100 ml.
Dissolve 0,10 g of powdered phenolphthalein in 90 ml of ethanol, 95 % (V/V), and dilute with water, to 100 ml.
5 Apparatus
Ordinary laboratory apparatus, including one-mark pipettes and one-mark volumetric flasks in accordance with
ISO 648 and ISO 1042.
6 Sampling and samples
6.1 Laboratory sample
For analysis, use a laboratory sample of − 100 µm particle size which has been taken and prepared in
accordance with ISO 3082. In the case of ores having significant contents of combined water or oxidizable
compounds, use a particle size of − 160 µm.
NOTE A guideline on significant contents of combined water and oxidizable compounds is incorporated in ISO 7764.
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SIST ISO 2599:2005
ISO 2599:2003(E)
6.2 Preparation of predried test samples
Thoroughly mix the laboratory sample and, taking multiple increments, extract a test sample in such a manner
that it is representative of the whole contents of the container. Dry the test sample at 105 °C ± 2 °C as
specified in ISO 7764. (This is the predried test sample.)
7 Procedure
7.1 Number of determinations
Carry out the analysis at least in duplicate in accordance with the flowsheet in Annex A, independently, on one
predried test sample.
NOTE The expression “independently” means that the second and any subsequent result is not affected by the
previous result(s). For this particular analytical method, this condition implies that the repetition of the procedure be carried
out either by the same operator at a different time or by a different operator including, in either case, appropriate
recalibration.
7.2 Test portion
Taking several increments, weigh, to the nearest 0,000 2 g, the amount of the predried test sample (6.2)
specified in Table 1.
NOTE The test portion should be taken and weighed quickly, in order to avoid reabsorption of moisture.
Table 1 — Mass of test portion
Phosphorus Mass of test Volume of aliquot Volume of ammonium
content portion portion molybdate solution (4.16)
% g ml ml
0,1 to 0,5 1,0 total 50
0,5 to 2,5 0,5 total 100
2,5 to 5,0 0,5 100/250 100

7.3 Blank test and check test
In each run, one blank test and one analysis of a certified material of the same type of ore shall be carried out
in parallel with the analysis of the ore sample(s) under the same conditions. A predried test sample of the
certified reference material shall be prepared as specified in 6.2.
NOTE The certified reference material should be of the same type as the sample to be analysed and th
...