SIST EN ISO 20565-2:2009

SLOVENSKI STANDARD
01-marec-2009
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Chemical analysis of chrome-bearing refractory products and chrome-bearing raw
materials (alternative to the X-ray fluorescence method) - Part 2: Wet chemical analysis
(ISO 20565-2:2008)
Chemische Analyse von chromhaltigen feuerfesten Erzeugnissen und chromhaltigen
Rohstoffen (Alternative zum Röntgenfluoreszenzverfahren) - Teil 2: Nasschemische
Verfahren (ISO 20565-2:2008)
Analyse chimique des produits réfractaires contenant du chrome et des matériaux bruts
contenant du chrome (méthode alternative a la méthode par fluorescence de rayons X) -
Partie 2: Méthodes d'analyse chimique par voie humide (ISO 20565-2:2008)
Ta slovenski standard je istoveten z: EN ISO 20565-2:2008
ICS:
71.040.40 Kemijska analiza Chemical analysis
81.080 Ognjevzdržni materiali Refractories
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EUROPEAN STANDARD
EN ISO 20565-2
NORME EUROPÉENNE
EUROPÄISCHE NORM
December 2008
ICS 81.080
English Version
Chemical analysis of chrome-bearing refractory products and
chrome-bearing raw materials (alternative to the X-ray
fluorescence method) - Part 2: Wet chemical analysis (ISO
20565-2:2008)
Analyse chimique des produits réfractaires contenant du Chemische Analyse von chromhaltigen feuerfesten
chrome et des matières premières contenant du chrome Erzeugnissen und chromhaltigen Rohstoffen (Alternative
(méthode alternative à la méthode par fluorescence de zum Röntgenfluoreszenzverfahren) - Teil 2:
rayons X) - Partie 2: Méthodes d'analyse chimique par voie Nasschemische Verfahren (ISO 20565-2:2008)
humide (ISO 20565-2:2008)
This European Standard was approved by CEN on 8 November 2008.
CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European
Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such national
standards may be obtained on application to the CEN Management Centre or to any CEN member.
This European Standard exists in three official versions (English, French, German). A version in any other language made by translation
under the responsibility of a CEN member into its own language and notified to the CEN Management Centre has the same status as the
official versions.
CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Cyprus, Czech Republic, Denmark, Estonia, Finland,
France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal,
Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION
EUROPÄISCHES KOMITEE FÜR NORMUNG
Management Centre: rue de Stassart, 36  B-1050 Brussels
© 2008 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 20565-2:2008: E
worldwide for CEN national Members.

Contents Page
Foreword .3

Foreword
This document (EN ISO 20565-2:2008) has been prepared by Technical Committee ISO/TC 33 "Refractories"
in collaboration with Technical Committee CEN/TC 187 “Refractory products and materials” the secretariat of
which is held by BSI.
This European Standard shall be given the status of a national standard, either by publication of an identical
text or by endorsement, at the latest by June 2009, and conflicting national standards shall be withdrawn at
the latest by June 2009.
Attention is drawn to the possibility that some of the elements of this document may be the subject of patent
rights. CEN [and/or CENELEC] shall not be held responsible for identifying any or all such patent rights.
According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following
countries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Cyprus, Czech
Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia,
Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain,
Sweden, Switzerland and the United Kingdom.
Endorsement notice
The text of ISO 20565-2:2008 has been approved by CEN as a EN ISO 20565-2:2008 without any
modification.
INTERNATIONAL ISO
STANDARD 20565-2
First edition
2008-12-01
Chemical analysis of chrome-bearing
refractory products and chrome-bearing
raw materials (alternative to the X-ray
fluorescence method) —
Part 2:
Wet chemical analysis
Analyse chimique des produits réfractaires contenant du chrome et des
matières premières contenant du chrome (méthode alternative à la
méthode par fluorescence de rayons X) —
Partie 2: Méthodes d'analyse chimique par voie humide

Reference number
ISO 20565-2:2008(E)
©
ISO 2008
ISO 20565-2:2008(E)
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ii © ISO 2008 – All rights reserved

ISO 20565-2:2008(E)
Contents Page
Foreword. iv
1 Scope .1
2 Normative references .2
3 Determination of silicon(IV) oxide.2
4 Determination of aluminium oxide.5
5 Determination of total iron as iron(III) oxide .8
6 Determination of titanium(IV) oxide.11
7 Determination of manganese(II) oxide .13
8 Determination of calcium oxide .14
9 Determination of magnesium oxide.15
10 Determination of sodium oxide by flame photometry .18
11 Determination of potassium oxide by flame spectrophotometry .20
12 Determination of chromium(III) oxide.21
13 Determination of zirconium oxide by xylenol orange absorption spectroscopy.24
14 Determination of phosphorus(V) oxide by molybdenum blue method.25
15 Test report .27

ISO 20565-2:2008(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 20565-2 was prepared by Technical Committee ISO/TC 33, Refractories, in collaboration with Technical
Committee CEN/TC 187, Refractory products and materials.
ISO 20565 consists of the following parts, under the general title Chemical analysis of chrome-bearing
refractory products and chrome-bearing raw materials (alternative to the X-ray fluorescence method):
⎯ Part 1: Apparatus, reagents, dissolution and determination of gravimetric silica
⎯ Part 2: Wet chemical analysis
⎯ Part 3: Flame atomic absorption spectrometry (FAAS) and inductively coupled plasma atomic emission
spectrometry (ICP-AES)
iv © ISO 2008 – All rights reserved

INTERNATIONAL STANDARD ISO 20565-2:2008(E)

Chemical analysis of chrome-bearing refractory products and
chrome-bearing raw materials (alternative to the X-ray
fluorescence method) —
Part 2:
Wet chemical analysis
1 Scope
This part of ISO 20565 specifies traditional (“wet process”) methods for the chemical analysis of chrome-
bearing refractory products and raw materials.
It is applicable to components within the ranges of determination given in Table 1.
Table 1 — Range of determination (% by mass)
Component Range
SiO
0,5 to 10
Al O
2 to 30
2 3
Fe O
0,5 to 25
2 3
TiO
0,01 to 1
MnO 0,01 to 1
CaO 0,01 to 3
MgO 15 to 85
Na O
0,01 to 1
K O
0,01 to 1
Cr O
2 to 60
2 3
ZrO
0,01 to 0,5
P O
0,01 to 5
2 5
LOI
−0,5 to 5
NOTE These values are after the loss on ignition (LOI) has been
taken into account.
ISO 20565-2:2008(E)
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 20565-1:2008, Chemical analysis of chrome-bearing refractory products and chrome-bearing raw
materials (alternative to the X-ray fluorescence method) — Part 1: Apparatus, reagents, dissolution and
determination of gravimetric silica
ISO 26845:2008, Chemical analysis of refractories — General requirements for wet chemical analysis, atomic
absorption spectrometry (AAS) and inductively compled plasma atomic emission spectromety (ICP-AES)
methods
3 Determination of silicon(IV) oxide
3.1 General
Determine the silicon(IV) oxide content using one of the following methods.
a) Combined use of the dehydration or the coagulation and molybdenum blue methods
This method is applied to samples consisting of more than 4 % by mass of silicon(IV) oxide.
b) Molybdenum blue method
This method is applied to samples consisting of less than 10 % by mass of silicon(IV) oxide.
3.2 Combined use of the coagulation and molybdenum blue methods
3.2.1 Principle
An aliquot portion of the stock solution (S1) (see ISO 20565-1), after pH adjustment, is treated with
ammonium molybdate and the silicomolybdate is reduced to yield molybdenum blue, the absorbance of which
is measured.
The sum of this residual silicon(IV) oxide in solution plus the mass of silicon(IV) oxide determined in
ISO 20565-1:2008, 9.2.2.3.3, gives the total silicon(IV) oxide content.
3.2.2 Procedure
This determination should be commenced with little delay after the stock solution (S1) is prepared, as
prolonged standing may allow polymerization of silica to occur leading to low results.
Transfer 10 ml of stock solution (S1) (see ISO 20565-1) to a 100 ml plastic beaker, add 2 ml of hydrofluoric
acid (1+9) and mix with a plastic rod. Allow to stand for 10 min and add 50 ml of boric acid solution. Add 2 ml
of ammonium molybdate solution while mixing at a temperature of 25 °C and allow to stand for 10 min. Add
5 ml of L (+)-tartaric acid solution while stirring and, after 1 min, add 2 ml of L (+)-ascorbic acid solution.
Transfer the solution to a 100 ml volumetric flask, dilute to the mark with water, mix and allow to stand for
60 min.
Measure the absorbance of the solution in a 10 mm cell at a wavelength of 650 nm against water as a
reference.
2 © ISO 2008 – All rights reserved

ISO 20565-2:2008(E)
3.2.3 Plotting calibration graph
Transfer 0 ml, 2 ml, 4 ml, 6 ml, 8 ml and 10 ml aliquot portions of diluted standard silicon(IV) oxide solution
(0 mg to 0,4 mg as silicon(IV) oxide) to separate 100 ml plastic beakers and add to each 10 ml of blank
solution (B1) (see ISO 20565-1). Treat these solutions and measure the absorbance as given in 3.2.2, and
plot the absorbances against the amounts of silicon(IV) oxide. Prepare the calibration graph by adjusting the
curve so that it passes through the point of origin.
3.2.4 Blank test
Using blank solution (B1), carry out the procedure given in 3.2.2.
3.2.5 Calculation
Calculate the mass fraction of silicon(IV) oxide, w , expressed as a percentage, using Equation (1) with
SiO
the absorbances obtained in 3.2.2 and 3.2.4 and the calibration in 3.2.3.
mm−+m−m×
()()
12 s b
w=×100 (1)
SiO
m
where
m is the mass from ISO 20565-1, in grams (g);
m is the mass from ISO 20565-1, in grams (g);
m is the mass of silicon(IV) oxide in the aliquot portion of stock solution (S1) as applicable, in grams (g);
s
m is the mass of silicon(IV) oxide in the aliquot portion of blank solution (B1) as applicable, in grams (g);
b
m is the mass of the test portion from ISO 20565-1, in grams (g).
3.3 Molybdenum blue method
3.3.1 Principle
An aliquot portion of the stock solution (S′1) (see ISO 20565-1), after pH adjustment, is treated with
ammonium molybdate and the silicomolybdate is reduced to yield molybdenum blue, the absorbance of which
is measured.
3.3.2 Procedure
Transfer precisely an aliquot portion of stock solution (S′1) (to two 100 ml plastic beakers and add to each an
aliquot portion of blank solution obtained from 3.3.3. Add to each beaker 2 ml of hydrofluoric acid (1+9), mix
with a plastic rod and allow to stand for 10 min. Add 50 ml of boric acid solution, dilute to 80 ml with water.
Add 5 ml of ammonium molybdate solution while mixing at a temperature of 25 °C and allow to stand for
10 min. Add 5 ml of L (+)-tartaric acid solution while stirring and, after 1 min, add 10 ml of L (+)-ascorbic acid
solution. Transfer each solution to a 200 ml volumetric flask, dilute to the mark with water and mix. Allow to
stand for 60 min and measure the absorbance of the solutions in a 10 mm cell at a wavelength of 650 nm
against water as a reference. Take the mean of the two measurements.
NOTE Aliquot volumes of stock solution and blank solution (B′1) are shown in Table 2, corresponding to the content
of silicon(IV) oxide in the sample.
ISO 20565-2:2008(E)
When the difference of the two absorbance measurements is greater than 0,005, repeat the procedure in
3.3.2. When measurements of the same sample with around 1,0 absorbance are repeated, it is necessary for
the spectrophotometer to show the differences within 0,002.
Table 2 — Aliquot volumes of stock and blank solutions
Mass fraction Aliquot portion Aliquot portion
of silicon(IV) oxide
of stock solution (S′1) of blank solution (B′1)
%
ml ml
< 2 20 0
2 to 4 10 10
4 to 10 5 15
3.3.3 Blank test
Using the blank solution (B′1) (see ISO 20565-1), follow the procedure given in 3.3.2. The volume of the
aliquot portion of blank solution is the same as that for the corresponding stock solution.
3.3.4 Plotting of calibration graph
Transfer 0 ml, 5 ml, 10 ml, 15 ml, 20 ml and 25 ml aliquot portions of diluted standard silicon(IV) oxide solution
[0 mg to 1 mg as silicon(IV) oxide] to separate 100 ml plastic beakers and add to each 20 ml of blank solution
(B′1) (see ISO 20565-1). Treat these solutions and measure the absorbance in accordance with the
procedure for addition of hydrofluoric acid (1+9) in 3.3.2. Plot the absorbance against the amounts of
silicon(IV) oxide and prepare the calibration graph by adjusting the curve so that it passes through the point of
origin.
3.3.5 Calculation
Calculate the mass fraction of silicon(IV) oxide, w , expressed as a percentage, using Equation (2) with
SiO
the amount of silicon(IV) oxide derived from the absorbance measurements obtained in 3.3.2 and 3.3.3 and
the calibration in 3.3.4.
mm− 250
sb
w=××100 (2)
SiO
mV
where
m is the mass of silicon(IV) oxide in the aliquot portion of stock solution (S′1), in grams (g);
s
m is the mass of silicon(IV) oxide in the aliquot portion of blank solution (B′1), in grams (g);
b
V is the aliquot volume of stock solution (S′1), in millilitres (ml);
m is the mass of the test portion, in grams (g).
4 © ISO 2008 – All rights reserved

ISO 20565-2:2008(E)
4 Determination of aluminium oxide
4.1 General
Determine the aluminium oxide content using one of the following methods:
a) cation-exchange separation — CyDTA-zinc back-titrimetric method (see 4.2);
b) cupferron extraction separation — CyDTA-zinc back-titrimetric method (see 4.3).
4.2 Cation-exchange separation — (1,2-Cyclohexylenenitrilo)tetraacetic acid zinc [CyDTA-
zinc] back-titrimetric method
4.2.1 Principle
An aliquot portion of stock solution (SE-a) is transferred. Excess CyDTA solution is added to it. A chelate
compound of aluminium CyDTA is formed by adjusting the pH with ammonia solution. The pH is further
adjusted by the addition of hexamethylenetetramine. The amount of remaining CyDTA is determined by back-
titration with zinc standard volumetric solution using xylenol orange as an indicator. The content of aluminium
oxide is calculated by adjusting the content of titanium(IV) oxide.
4.2.2 Procedure
4.2.2.1 Transfer precisely an aliquot portion of stock solution (SE-a) (see ISO 20565-1 and the following
paragraph) to a 300 ml beaker. Add an amount of 0,01 mol/l CyDTA solution, in accordance with Table 4, and
dilute to 100 ml with water. Add 1 g of hexamethylenetetramine and a drop of methyl orange solution as an
indicator. Drop in ammonia water (1+1) and ammonia solution (1+9) of up to pH 3 until it indicates a slightly
orange colour (see the paragraph directly below Table 3). Allow to stand for 5 min.
In Table 3, the aliquot volume of stock solution (SE-a) is shown. It depends on the volume of the aliquot
portion of stock solution (S5) used in ISO 20565-1.
Table 3 — Aliquot volume of stock solution (SE-a)
Aliquot volume of stock solution (S5) Aliquot volume of stock solution (SE-a)
ml ml
100 40
50 80
If ammonia solution is added to excess, add hydrochloric acid (1+1) until the colour is changed to red, then
adjust in the same manner.
NOTE The volume of 0,01 mol/l of CyDTA solution added depends on the mass fraction of aluminium oxide as
shown in Table 4.
ISO 20565-2:2008(E)
Table 4 — Aliquot volume of 0,01 mol/l CyDTA solution
Mass fraction of aluminium oxide Volume of 0,01 mol/l CyDTA solution
% ml
< 5 10
5 to 10 20
10 to 15 30
15 to 20 40
20 to 30 50
4.2.2.2 Add 5 g of hexamethylenetetramine of pH 5,5 to 5,8, add 4 or 5 drops of xylenol orange solution
as an indicator and titrate with 0,01 mol/l zinc standard volumetric solution. Titrate while mixing gently and
when the colour changes from yellow to the first appearance of a permanent reddish colour, consider this as
the end point.
4.2.3 Blank test
Using the blank solution (BE-a) (see ISO 20565-1), follow the procedure given in 4.2.2. The volumes of the
aliquot portion of blank solution (BE-a) and 0,01 mol/l CyDTA solution are the same as those for the
corresponding stock solution (SE-a).
4.2.4 Calculation
Calculate the mass fraction of aluminium oxide, w , expressed as a percentage, using Equation (3).
Al O
(VV−×) F× 0,000 509 8 100 250
ww=×××100−× 0,638 (3)
Al O TiO
23 2
m 40 100
where
V is the volume of 0,01 mol/l zinc standard volumetric solution in 4.2.3, in millilitres (ml);
V is the volume of 0,01 mol/l zinc standard volumetric solution in 4.2.2.2, in millilitres (ml);
F is the factor of 0,01 mol/l zinc standard volumetric solution;
m is the mass of the test portion (see ISO 20565-1), in grams (g);
w is the mass fraction of titanium(IV) oxide determined in 6.2.5 or 6.3.5, expressed as a percentage.
TiO
4.3 Cupferron extraction separation — (1,2-Cyclohexylenenitrilo)tetraacetic acid zinc
[CyDTA-zinc] back-titrimetric method
4.3.1 Principle
An aliquot portion of the stock solution (S6) (see ISO 20565-1) is cleaned up using first diethyldicarbonate and
then cupferron in a separating funnel. To the resulting solution an excess of CyDTA is added, then back-
titrated with a standard zinc solution.
6 © ISO 2008 – All rights reserved

ISO 20565-2:2008(E)
4.3.2 Procedure
4.3.2.1 Transfer 100 ml of the stock solution (S6) to the 500 ml separating funnel. Add the ammonia solution
drop by drop until the solution is faintly alkaline to bromophenol blue. Re-acidify with dilute hydrochloric acid
(1+3) and add an extra 4 ml. Add 20 ml of chloroform and 10 ml of sodium diethyldithiocarbamate solution.
Stopper the funnel and shake vigorously. Release the pressure in the funnel by carefully removing the stopper
and rinse the stopper and neck of the funnel with water. Allow the layers to separate and withdraw the
chloroform layer.
If an emulsion has formed, it will be necessary to add a few drops of hydrochloric acid and reshake.
Add 10 ml portions of chloroform and 5 ml portions of the sodium diethyldithiocarbamate and repeat the
extraction until a coloured precipitate (brown or pink) is no longer formed. Wash the aqueous phase with 20 ml
of chloroform to remove iron and manganese.
4.3.2.2 Add 25 ml of the hydrochloric acid, concentrated, 36 % by mass, followed by 2 ml to 3 ml of cupferron
solution and 20 ml of chloroform. Stopper the funnel and shake vigorously. Remove the stopper and rinse the
stopper and neck of the funnel with water. Allow the layers to separate and withdraw the chloroform layer.
Repeat the extraction with three 10 ml portions of chloroform to remove traces of cupferron and sodium
diethyldithiocarbamate. Run the aqueous phase from the separating funnel to a 1 l conical flask. Add a few
drops of bromophenol blue indicator, followed by the ammonia solution until the solution is just alkaline. Re-
acidify quickly with the concentrated hydrochloric acid, add an extra 5 to 6 drops and cool the flask in running
water.
4.3.2.3 Ensure that the solution is cold. Add CyDTA standard solution (0,05 M approximately) to produce an
excess of a few millilitres over the expected amount (1 ml = 1,275 % Al O ). Add ammonium acetate buffer
2 3
solution until the indicator turns blue, followed by an extra 15 ml. Add a volume of ethanol equal to the total
volume of the solution, then add 20 ml of the hydroxyammonium chloride solution and 1 ml to 2 ml of the
dithizone indicator. Titrate with zinc standard solution (0,05 M) from green to the first appearance of a
permanent pink colour.
NOTE The end point is often improved by the addition of a little naphthol green solution to eliminate any early
formation of pink colour that might have formed in the solution on the addition of the indicator.
4.3.3 Calculation
Calculate the mass fraction of aluminium oxide, w , expressed as a percentage, using Equation (4).
Al O
(VF×−V×F )× 0,001 019 6 250
11 2 2
w=××100 (4)
Al O
m 100
where
V is the volume of the 0,05 mol/l CyDTA standard solution in 4.3.2.3, in millilitres (ml);
F is the factor of the 0,05 mol/l CyDTA standard solution;
V is the volume of 0,05 mol/l zinc standard solution used in the back-titration in 4.3.2.3,
in millilitres (ml);
F is the factor of 0,05 mol/l zinc standard solution;
m is the mass of the test portion (see ISO 20565-1), in grams (g).
ISO 20565-2:2008(E)
5 Determination of total iron as iron(III) oxide
5.1 General
Determine the iron(III) oxide content using one of the following methods.
a) 1,10-Phenanthroline absorption method using stock solution (S6) or (S′6) (see ISO 20565-1)
This method is applied to samples consisting of less than 15 % by mass of iron(III) oxide (see 5.2).
b) 1,10-Phenanthroline absorption method using stock solution (SE-b) (see ISO 20565-1)
This method is applied to samples consisting of less than 15 % by mass of iron(III) oxide (see 5.3).
c) CyDTA-Zinc back-titrimetric method
This method is applied to samples consisting of 10 % by mass or more of iron(III) oxide (see 5.4).
5.2 1,10-Phenanthroline absorption method using stock solution (S6) or (S′6)
5.2.1 Principle
An aliquot portion of the stock solution (S6) (see ISO 20565-1) is reduced with hydroxylamine chloride to
iron(II) oxide, coloured with 1,10 ortho-phenanthroline and its absorbance measured at 510 nm.
5.2.2 Procedure
5.2.2.1 Dilute 25,0 ml of the stock solution (S6) (see ISO 20565-1) with water to 500 ml in a volumetric flask
and mix. Transfer 25 ml of this diluted solution to a 100 ml volumetric flask and add 2 ml of the
hydroxyammonium chloride solution followed by 5 ml of the phenanthroline solution. Add the ammonium
acetate solution until a pink colour forms, then add an extra 2 ml. Allow to stand for 15 min, dilute the solution
with water to 100 ml and mix. Use a spectrophotometer to measure the optical density of the solution against
water in 10 mm cells at 510 nm.
NOTE The use of a filter-type absorptiometer is not appropriate to this test.
5.2.2.2 Add ammonium acetate solution to stabilize the colour. Ensure that the colour is stable from 15 min to
75 min. Determine the iron(II) oxide content of the solution by reference to a calibration graph.
NOTE The dilution of the “stock” solution quoted will cover the range from 0 % to 20 % Fe O by mass. For iron
2 3
mass fractions considerably below 20 % Fe O , a decreased dilution of the “stock” solution needs to be made. The aliquot
2 3
portion of the solution should not be diluted once the colour has developed.
5.2.3 Blank test
Using blank solution (B6) (see ISO 20565-1), carry out the procedure given in 5.2.2. The volume of the aliquot
portion of blank solution is the same as those for the corresponding stock solution.
5.2.4 Plotting of calibration graph
Transfer a range from 0 ml to 15,0 ml aliquot portions of the diluted iron(III) oxide standard solution [0 mg to
0,6 mg as iron(III) oxide] to separate 250 ml volumetric flasks. Treat these solutions in accordance with 5.2.2.1
and measure the absorbance against the reference solution. Plot the relation between the absorbance and the
mass of iron(III) oxide. Prepare the calibration graph by adjusting the curve so that it passes through the point
of origin.
8 © ISO 2008 – All rights reserved

ISO 20565-2:2008(E)
5.2.5 Calculation
Calculate the mass fraction of iron(III) oxide, w , expressed as a percentage, using Equation (5), using
Fe O
the amount of iron(III) oxide which is derived from the absorbance obtained in 5.2.2.2 and 5.2.3 and the
calibration in 5.2.4.
mm−
100 500
sb
w =×× (5)
Fe O
m 25 25
where
m is the mass of iron(III) oxide in the aliquot portion of stock solution (S6), in grams (g);
s
m is the mass of iron(III) oxide in the aliquot portion of blank solution (B6), in grams (g);
b
m is the mass of the test portion (see ISO 20565-1), in grams (g).
5.3 1,10-Phenanthroline absorption method using stock solution (SE-b)
5.3.1 Principle
Stock solution (SE-b) (see ISO 20565-1) is transferred and the iron is reduced with L (+)-ascorbic acid.
1,10-Phenanthroline chloride is added and the pH is adjusted by adding ammonium acetate when the colour
of iron develops. The absorbance is measured.
5.3.2 Procedure
5.3.2.1 Transfer precisely an appropriate aliquot portion obtained by the procedure used for stock
solution (SE-b) (see ISO 20565-1) to two 250 ml volumetric flasks, respectively. Add 5 ml of L (+)-ascorbic
acid solution to each while shaking. Add 25 ml of 1,10-phenanthroline chloride solution and 10 ml of
ammonium acetate solution. Dilute to the mark with water and allow to stand for 30 min.
In Table 5, an aliquot volume of stock solution (SE-b) is shown. It depends on the volume of the aliquot portion
(see ISO 20565-1:2008, Table 2) and the mass fraction of iron(III) oxide in the sample.
Table 5 — Aliquot volume of stock solution (SE-b)
Mass fraction Aliquot volume of stock solution (SE-b) taken in ISO 20565-1
of iron(III) oxide
100 ml 50 ml
%
20 40
< 8
> 8 10 20
5.3.2.2 Transfer a portion of the solution obtained in 5.3.2.1 to two absorption cells. Measure the
absorbance of each solution at the wavelength of 510 nm against water, and calculate the mean of the
measured values.
5.3.3 Blank test
Using blank solution (BE-b) (see ISO 20565-1), carry out the procedure in accordance with 5.3.2. The volume
of the aliquot portion of blank solution is the same as that for the corresponding stock solution.
ISO 20565-2:2008(E)
5.3.4 Plotting of calibration graph
Transfer a range of 0 ml to 40,0 ml aliquot portions of the diluted iron(III) oxide standard solution [0 mg to
1,6 mg as iron(III) oxide] to several 250 ml volumetric flasks. Treat these solutions in accordance with 5.3.2.1
and measure the absorbance against the reference solution. Plot the relation between the absorbance and
mass of iron(III) oxide. Prepare the calibration graph by adjusting the curve so that it passes through the point
of origin.
5.3.5 Calculation
Calculate the mass fraction of iron(III) oxide, w , expressed as a percentage, using Equation (6), using
Fe O
the amount of iron(III) oxide which is derived from the absorbance obtained in 5.3.2.2 and 5.3.3 and the
calibration in 5.3.4.
mm−
250 100
sb
w =×××100 (6)
Fe O
mV V
where
m is the mass of iron(III) oxide in the aliquot portion of stock solution (SE-b), in grams (g);
s
m is the mass of iron(III) oxide in the aliquot portion of blank solution (BE-b), in grams (g);
b
V is the volume of the aliquot portion taken for stock solution (SE-b), in millilitres (ml);
V is the volume of aliquot portion taken for stock solution (SE-b), in grams (g);
m is the mass of the test portion described in ISO 20565-1, in grams (g).
5.4 (1,2-Cyclohexylenenitrilo)tetraacetic acid-zinc [CyDTA*-zinc] back-titrimetric method
5.4.1 Principle
An appropriate amount of CyDTA solution is added to an aliquot portion of stock solution (SE-b). A chelate
compound of iron CyDTA is formed by adjusting the pH with ammonia water. The pH is further adjusted by
addition of hexamethylenetetramine. The amount of remaining CyDTA is determined by back-titration with zinc
standard volumetric solution using xylenol orange as an indicator.
5.4.2 Procedure
5.4.2.1 Transfer precisely an appropriate volume of stock solution (SE-b) (see ISO 20565-1) to a 300 ml
beaker, add a precisely known amount of 0,01 mol/l of CyDTA solution and dilute to 100 ml with water.
In the case of 100 ml of the aliquot portion (in ISO 20565-1), use 50 ml of stock solution (SE-b).
In the case of 50 ml of the aliquot portion (in ISO 20565-1), use the entire stock solution (SE-b).
5.4.2.2 Use a volume of 0,01 mol/l of CyDTA solution, added depending on the content percentages of
iron(III) oxide, as shown in Table 6.
5.4.2.3 Carry out titration in accordance with 4.2.2.2 and add 2 g of hexamethylenetetramine.
10 © ISO 2008 – All rights reserved

ISO 20565-2:2008(E)
Table 6 — Volume of 0,01 mol/l CyDTA solution
Mass fraction of iron(III) oxide Volume of 0,01 mol/l CyDTA solution
% ml
10 to 15 20
15 to 20 30
20 to 25 40
5.4.3 Blank test
Treat the blank solution (BE-b) (see ISO 20565-1) and carry out the procedure in accordance with 5.3.3. Use
the same volumes of the aliquot portion of blank solution (BE-b) and 0,01 mol/l CyDTA solution as those for
the corresponding stock solution (SE-b).
5.4.4 Calculation
Calculate the mass fraction of iron(III) oxide, w , expressed as a percentage, using Equation (7).
Fe O
(VV−×) F× 0,000 798 5
100 250
w=×××100 (7)
Fe O
m 50 100
where
V is the volume of 0,01 mol/l zinc standard volumetric solution in 5.4.3, in millilitres (ml);
V is the volume of 0,01 mol/l zinc standard volumetric solution in 5.4.2, in millilitres (ml);
F is the factor of 0,01 mol/l zinc standard volumetric solution;
m is the mass of the test portion (see ISO 20565-1), in grams (g).
6 Determination of titanium(IV) oxide
6.1 General
The titanium(IV) oxide determination method is carried out using one of the following two methods:
a) diantipyrylmethane (DAM) method (see 6.2);
b) hydrogen peroxide method (see 6.3).
6.2 Diantipyrylmethane (DAM) method
6.2.1 Principle
Stock solution (S1) or (S′1) (see ISO 20565-1) is transferred. After the adjustment of hydrochloric acidity, iron
is reduced with the addition of L (+)-ascorbic acid. The titanium is coloured by the DAM and the absorbance is
measured.
ISO 20565-2:2008(E)
6.2.2 Procedure
6.2.2.1 Transfer precisely 20 ml of stock solution (S1) (see ISO 20565-1) or (S′1) (see ISO 20565-1) to a
50 ml volumetric flask. Add 5 ml of hydrochloric acid (1+1) and 5 ml of L (+)-ascorbic acid and allow to stand
for 1 min. Add 15 ml of DAM solution, shake the flask, dilute to the mark with water and allow to stand for
90 min.
6.2.2.2 Transfer precisely 20 ml of stock solution (S1) or (S′1) to a 50 ml volumetric flask. Add 5 ml of
hydrochloric acid (1+1) and 5 ml of L (+)-ascorbic acid and dilute to the mark with water.
6.2.2.3 Measure the absorbance of the solution obtained in 6.2.2.1 or 6.2.2.2 in a 10 mm cell at the
wavelength of 390 nm against water. Obtain the absorbance difference of the solutions obtained in 6.2.2.1
and 6.2.2.2.
6.2.3 Blank test
Using blank solution (B1) (see ISO 20565-1) or (B′1) (see ISO 20565-1), carry out the procedure described in
6.2.2. Use blank test solution (B1) corresponding to stock solution (S1) and blank test solution (B′1)
corresponding to stock solution (S′1).
6.2.4 Plotting of calibration graph
Transfer 0 ml, 5 ml, 15 ml and 20 ml aliquot portions of diluted titanium(IV) oxide standard solution
(0,01 mg/ml) [0 mg to 0,2 mg as titanium(IV) oxide] to separate 50 ml volumetric flasks and treat these
solutions as in 6.2.2.1. Plot the relation between the absorbance and the amount of titanium(IV) oxide.
Prepare the calibration graph by adjusting the curve so that it passes through the point of origin.
6.2.5 Calculation
Calculate the mass fraction of titanium(IV) oxide, w , expressed as a percentage, using Equation (8) with
TiO
the amount of titanium(IV) oxide derived from the absorbance obtained in 6.2.2.2 and 6.2.3 and the calibration
in 6.2.4.
mm− 250
sb
w 10=××0 (8)
TiO
m 20
where
m is the mass of titanium(IV) oxide in the aliquot portion of stock solution (S1) or (S′1), in grams (g);
s
m is the mass of titanium(IV) oxide in the aliquot portion of blank solution (B1) or (B′1), in grams (g);

b
m is the mass of the test portion used to prepare solution (S1 or S'1) in ISO 20565-1, in grams (g).
6.3 Hydrogen peroxide method
6.3.1 Principle
An aliquot portion is bleached with phosphoric acid, coloured with hydrogen peroxide and its absorbance
measured at 398 nm
6.3.2 Procedure
6.3.2.1 Transfer 20 ml of the stock solution (S6) (see ISO 20565-1) to each of the two 50 ml volumetric
flasks A and B. To each flask, add 10 ml of dilute phosphoric acid (2+3) and, to flask A only, add 10 ml of the
hydrogen peroxide solution.
12 © ISO 2008 – All rights reserved

ISO 20565-2:2008(E)
6.3.2.2 Dilute the solution in each flask with water to 50 ml and shake well. Measure A against B in
40 mm cells at 398 nm, or by using a colour filter or filter of similar band-pass in a suitable instrument. Ensure
that the colour is stable from 5 min until 24 h after the addition of the hydrogen peroxide solution. Determine
the titanium content of the solution by reference to a calibration graph.
6.3.3 Blank test
Using blank solution (B6) (see ISO 20565-1), carry out the procedure described in 6.3.2.
6.3.4 Plotting of calibration graph
Transfer 0 ml, 5 ml, 15 ml and 20 ml aliquot portions of diluted titanium(IV) oxide standard solution (0,2 mg/ml)
[0 mg to 4 mg as titanium(IV) oxide] to separate 50 ml volumetric flasks. To each flask, add 10 ml of dilute
phosphoric acid (2+3) and 10 ml of the hydrogen peroxide solution. Dilute the solution in each flask with water
to 50 ml and shake well. Plot the relation between the absorbance and the amount of titanium(IV) oxide.
Prepare the calibration graph by adjusting the curve so that it passes through the point of origin.
6.3.5 Calculation
Calculate the mass fraction of titanium(IV) oxide, w , expressed as a percentage, using Equation (9) with
TiO
the amount of titanium(IV) oxide derived from the absorbance obtained in 6.3.2.2 and 6.3.3 and the calibration
in 6.3.4.
mm− 500
sb
w 100=×× (9)
TiO
m 20
where
m is the mass of titanium(IV) oxide in the aliquot portion of stock solution (S6), in grams (g);
s
m is the mass of titanium(IV) oxide in the aliquot portion of blank solution (B6), in grams (g);

b
m is the mass of the test portion (see ISO 20565-1), in grams (g).
7 Determination of manganese(II) oxide
7.1 Principle
An aliquot portion of the stock solution (S6) prepared for titanium(IV) oxide is treated with sulfuric and nitric
acid to destroy the resin, coloured by oxidation to permanganate with potassium periodate and its absorbance
measured at 524 nm.
7.2 Procedure
7.2.1 Transfer 50 ml of the stock solution (S6), (see ISO 20565-1) to a 250 ml beaker. Add 10 ml of dilute
sulfuric acid (1+1), 10 ml of dilute nitric acid (1+1) and heat on a water bath until evaporated to destroy traces
of resin. Allow to cool, add 20 ml of nitric acid, concentrated, 70 % by mass, 10 ml of dilute phosphoric acid
(1+9) and 50 ml of water. Boil to dissolve the salts and to remove nitrous fumes, filtering if necessary. Add
0,5 g of potassium periodate, boil until the colour develops and then boil for a further 2 min. Transfer to a
steam bath for 10 min. Allow to cool and transfer to a 100 ml volumetric flask. Dilute the solution with water to
100 ml and mix.
7.2.2 Measure the absorbance of the solution against water in 40 mm cells at 524 nm, or by using a colour
filter or filter of similar band-pass in a suitable instrument. Determine the manganese oxide content of the
solution by reference to a calibration graph.
ISO 20565-2:2008(E)
7.3 Blank test
Using blank solution (B6) (see ISO 20565-1), carry out the procedure described in 7.2.
7.4 Plotting of calibration graph
Transfer 0 ml (as reference), 5 ml, 10 ml, 15 ml, 20 ml and 25 ml aliquot portions of the diluted manganese(II)
oxide standard solution (MnO 0,04 mg/ml) [0 mg to 1,00 mg as manganese(II) oxide] to 250 ml beakers. Treat
each of these as in 7.2.1. Then measure the absorbance against the reference solution. Plot the relation
between the absorbance and the mass of manganese(II) oxide. Prepare the calibration graph by adjusting the
curve so that it passes through the point of origin.
7.5 Calculation
Calculate the mass fraction of manganese(II) oxide, w , expressed as a percentage, using Equation (10)
MnO
with the amount of manganese(II) oxide that is derived from the absorbance in 7.2.1 and 7.3, and the
calibration in 7.4.
mm− 500
sb
w=××100 (10)
MnO
m 50
where
m is the mass of manganese(II) oxide in the aliquot portion of stock solution (S6), in grams (g);
s
m is the mass of manganese(II) oxide in the aliquot portion of blank solution (B6), in grams (g);
b
m is the mass of the test portion (see ISO 20565-1), in grams (g).
8 Determination of calcium oxide
8.1 Principle
Excess EGTA [ethylene glycol-O,O′-bis(2-aminoethyl)-N,N,N′,N′-tetraacetic acid] is added to an aliquot
portion of the stock solution (S6). The MgO is precipitated out with potassium hydroxide solution and a
precipitating agent. After making up to volume, an aliquot portion is back-titrated with calcium oxide standard
solution.
8.2 Procedure
Transfer 100 ml of the stock solution (S6) to a 250 ml separating funnel. Add 5 ml of dilute triethanolamine
(1+1), 5,0 ml of EGTA standard solution (approximately 0,05 mol/l) and dilute with water to 150 ml. Add the
potassium hydroxide solution until no further precipitation takes place, then add 10 ml in excess, followed by
10 ml of the Magflok solution (
...