SIST ISO 692:1996

Pulps -- Determination of alkali solubility

Specifies a method for the determination of the solubility of pulp in cold sodium hydroxide solutions of various and fixed concentrations, being mainly intended for the investigation of bleached pulps. It may, however, also be used with unbleached pulps.

Pâtes -- Détermination de la solubilité dans les solutions d'hydroxyde de sodium

La présente Norme internationale spécifie une méthode de détermination de la solubilité des pâtes dans les solutions d'hydroxyde de sodium froides à concentrations différentes et déterminées. Les concentrations de solution d'hydroxyde de sodium le plus souvent utilisées sont 18 et 10 % (m/m). Cette méthode s'applique principalement aux pâtes blanchies, mais peut cependant être également utilisée avec les pâtes écrues, par exemple, au cours des différents stades de fabrication de pâtes blanchies.

Vlaknine - Določanje topnosti v alkalijah

General Information

• Status: Published
• Publication Date: 31-Mar-1996
• ICS: 85.040 - Pulps
• Technical Committee: VPK - Pulp, paper, board and products
• Current Stage: 6060 - National Implementation/Publication (Adopted Project)
• Start Date: 01-Apr-1996
• Due Date: 01-Apr-1996
• Completion Date: 01-Apr-1996
• Ref Project: ISO 692:1982 - Pulps — Determination of alkali solubility

Standards Content (Sample)

692
International Standard
INTERNATIONAL ORGANIZATION FOR STANDARDIZATlON.ME~YHAPOfiHAfi OPrAHM3AlUlR ilO CTAH~APTbl3AL&WlWIRGANlSATlON INTERNATIONALE DE NORMALISATION
Pulps - Determination of alkali solubility
- Dbtermina tion de la solubilitk dans les solutions d’h ydroxyde de sodium
P&es
Second edition - 1982-11-B
Ref. No. IS0 692-1982 (E)
UDC 676.014.362
Descriptors : paper pulps, chemical analysis, solubility, sodium hydroxide, volumetric analysis.
Price based on 4 pages

---------------------- Page: 1 ----------------------
Foreword
IS0 (the international Organization for Standardization) is a worldwide federation of
national standards institutes (IS0 member bodies). The work of developing Inter-
national Standards is carried out through IS0 technical committees. Every member
body interested in a subject for which a technical committee has been set up has the
right to be represented on that committee. International organizations, governmental
and non-governmental, in liaison with’lS0, also take part in the work.
Draft International Standards adopted by the technical committees are circulated to
the member bodies for approval before their acceptance as International Standards by
the IS0 Council.
International Standard IS0 692 was developed by Technical Committee ISO/TC 6,
Paper, board and pulps.
This second edition was submitted directly to the IS0 Council, in accordance with
clause 6.11.2 of part 1 of the Directives for the technical work of ISO. It cancels and
replaces the first edition (i.e. IS0 692-19741, which had been approved by the member
bodies of the following countries :
Australia Germany, F. R. Romania
Belgium
India South Africa, Rep. of
Brazil Iran Spain
Canada Ireland Sweden
Chile A Israel Switzerland
Colombia Italy Turkey
Czechoslovakia United Kingdom
Japan
Denmark New Zealand USA
Egypt, Arab Rep. of Norway Yugoslavia
Finland Poland
France Portugal
The member body of the following country had expressed disapproval of the docu-
men t on tech nical grounds :
Netherlands
International Organization for Standardization, 1982
0
Printed in Switzerland

---------------------- Page: 2 ----------------------
INTERNATIONAL STANDARD IS0 692-1982 (E)
Pulps - Determination of alkali solubility
0 Introduction 4 Principle
The object of both this International Standard and IS0 699, Treatment of the pulp with sodium hydroxide solution and ox-
Pulps - Determination of alkali resistance, is to permit the idation of the dissolved organic matter with potassium
study of the behaviour of pulps in the presence of alkali solu-
dichromate. Titration of the excess potassium dichromate and
tions, but their fields of application are different : while this In- calculation of the amount of cellulose equivalent to the
ternational Standard describes the volumetric determination of potassium dichromate consumed.
the alkali-soluble constituents of the pulp and is applied
preferably to the control of bleached pulps, IS0 699 describes
the gravimetric determination of the alkali-insoluble consti-
5 Reagents
tuents of the pulp and applies to all categories of pulps.
Use only reagents of recognized analytical grade and only
distilled water or water of equivalent purity.
1 Scope and field of application
5.1 Sodium hydroxide, solution of known concentration,
containing less than 1 g of sodium carbonate per litre (see the
This International Standard specifies a method for the deter-
note), for example :
mination of the solubility of pulp in cold sodium hydroxide solu-
tions of various and fixed concentrations. The sodium hydrox-
-
5,39 + 0,03 mol/l solution, containing 18,0 & 0,l g
most frequently used are 18 and
ide concentrations
of sodium hydroxide loog of solution
Per
10 % (m/m).
1,197 2 g/ml), equivalent to 215,5 _+ 1,0 g of
(e20 =
sodium hydroxide per litre;
The method is mainly intended for the investigation of
bleached pulps, but may, however, also be used with
-
2,77 + 0,03 mol/l solution, containing 10,O + 0,l g
unbleached pulps, for example in the different stages of
of sodium hydroxide loog of solution
manufacture of bleached pulp. Per
1,108 9 g/ml), equivalent to 110,9 + 1 ,o g of
&I =
sodium hydroxide per Iitre.
2 Reference
NOTE - The sodium hydroxide solution may be conveniently
prepared as follows :
Determination of dry matter content.
IS0 638, Pulps -
Dissolve a quantity of solid sodium hydroxide in an equal mass of water
and allow the suspended sodium carbonate to settle. Decant the super-
natant liquid and dilute with carbon dioxide-free water to the ap-
3 Definitions
propriate concentration. Check by titration with standard acid solution.
3.1 S-value : Alkali solubili,ty; the soluble fraction expressed
5.2 Sulphuric acid, concentrated, not less than 94 % (IV Y)
as a percentage by mass of the oven-dry pulp.
(ezo = 1,84 g/ml).
3.2 &a, SIO or S, : S-values in which the indices 18, 10 or c
NOTE - If the concentration of the sulphuric acid is less than
refer to the chosen concentration, in grams of sodium hydrox-
94 % (Vl V), the temperature will not reach the 125 to 130 OC required
ide per 100 g of solution. during the oxidation.
1

---------------------- Page: 3 ----------------------
IS0 692-1982 (E)
5.3 Potassium dichromate, about 0,067 mol/l solution in 6.4 Suction flasks, for the crucibles or funnels.
2,7 mol/l sulphuric acid solution : 20 g of potassium
(K2Cr207) and 150 ml of sulphuric acid
dichromate
6.5 Balance, accurate to 1 mg.
= 1,84 g/ml) per litre of solution.
(@ZO
6.6 Reaction vessel, of capacity 200 ml and tall in shape.
5.4 Ammonium iron(H) sulphate, approximately 0,l mol/l
solution (concentration known to an accuracy of
Dimensions in millimetres
t 0,000 2 mol/l) : 40 to 41 g of ammonium iron sulphate
hexahydrate [(NH,)2S04FeS0,.6H20] and 10 ml of sulphuric
acid (eZo = 1,84 g/ml) per litre of solution.
This solution is not stable and its concentration shall be
checked every day.
In order to restore the original concentration of the am-
NOTE -
monium iron sulphate solution, a reducing agent can be placed be-
tween the supply bottle and the burette.
Prepare the reducing agent as follows :
I ir
Wash metallic cadmium (which passes a sieve of aperture size 1,4 to
2,0 mm, complying with the requirements’ of IS0 565) with water to
remove fine.particles. Treat the metal for about 5 min with a 2 % solu-
tion of mercury( II) nitrate IHg(NO$z. Hz01 or mercury( II) chloride
(HgCl2) containing 5 ml of concentrated nitric acid per litre, and then
wash the amalgamated metal.
Stainless steel
The ammonium iron( II) sulphate solution may standardized against
potassium dichromate as a primary standard.
The concentration of the ammonium iron sulphate solution will stay
constant if 5 g of aluminium shavings, of purity greater than 99,99 %,
are added to 10 i of solution.
5.5 Phosphoric acid, 85 % (V/ v) (e20 = 1,70 g/ml).
5.6 Ferroin indicator solution : 15 g of 1, lo-phenanthroline
monohydrate (C12HsN2’ H20), or 16 g of 1, lo-phenanthroline
hydrochloride (C,2H,N2DHCI.H20), and 7 g of iron sulphate
(FeSOdm7H20) per litre of solution, or
5.7 Sodium diphenylaminosulphonate indicator solu-
Figure
tion : dissolve 0,l g of sodium diphenylaminosulphonate
(C12HIoNS03Na) in water and dilute to 100 ml.
7 Preparation of the test sample
If the pulp is in sheet form, tear into pieces of size approxi-
mately 5 mm x 5 mm. If it is in slush form, remove the water
6 Apparatus
by suction, press between blotters and dry at a maximum
temperature of 60 OC. Before weighing, condition the sample
Ordinary laboratory apparatus, and
for not less than 20 min in the atmosphere near the balance.
6.1 Stirring equipment, with a propeller-type agitator made
of stainless steel or other corrosion-resistant material. The
8 Procedure
angle of the blades shall be adjusted so that air is not intro-
duced into the pulp suspension during stirring.
8.1 Test portion
NOTE - Suitable equipment is shown in the figure. A satisfactory
motor is one of 15 W, operating at a rotational frequency between
Weigh, to the nearest 0,005 g, the equivalent amount of ap-
about 28 and 24 s - 1.
proximately 1,5 g of oven-dry putp. Then immediately weigh
two test portions for the determination of the dry matter con-
6.2 Constant temperature bath, capable of maintaining a tent in accordance with IS0 638.
temperature o
...

SLOVENSKI STANDARD
SIST ISO 692:1996
01-april-1996
9ODNQLQH'RORþDQMHWRSQRVWLYDONDOLMDK
Pulps -- Determination of alkali solubility
Pâtes -- Détermination de la solubilité dans les solutions d'hydroxyde de sodium
Ta slovenski standard je istoveten z: ISO 692:1982
ICS:
85.040 Vlaknine Pulps
SIST ISO 692:1996 en
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

---------------------- Page: 1 ----------------------

SIST ISO 692:1996

---------------------- Page: 2 ----------------------

SIST ISO 692:1996
692
International Standard
INTERNATIONAL ORGANIZATION FOR STANDARDIZATlON.ME~YHAPOfiHAfi OPrAHM3AlUlR ilO CTAH~APTbl3AL&WlWIRGANlSATlON INTERNATIONALE DE NORMALISATION
Pulps - Determination of alkali solubility
- Dbtermina tion de la solubilitk dans les solutions d’h ydroxyde de sodium
P&es
Second edition - 1982-11-B
Ref. No. IS0 692-1982 (E)
UDC 676.014.362
Descriptors : paper pulps, chemical analysis, solubility, sodium hydroxide, volumetric analysis.
Price based on 4 pages

---------------------- Page: 3 ----------------------

SIST ISO 692:1996
Foreword
IS0 (the international Organization for Standardization) is a worldwide federation of
national standards institutes (IS0 member bodies). The work of developing Inter-
national Standards is carried out through IS0 technical committees. Every member
body interested in a subject for which a technical committee has been set up has the
right to be represented on that committee. International organizations, governmental
and non-governmental, in liaison with’lS0, also take part in the work.
Draft International Standards adopted by the technical committees are circulated to
the member bodies for approval before their acceptance as International Standards by
the IS0 Council.
International Standard IS0 692 was developed by Technical Committee ISO/TC 6,
Paper, board and pulps.
This second edition was submitted directly to the IS0 Council, in accordance with
clause 6.11.2 of part 1 of the Directives for the technical work of ISO. It cancels and
replaces the first edition (i.e. IS0 692-19741, which had been approved by the member
bodies of the following countries :
Australia Germany, F. R. Romania
Belgium
India South Africa, Rep. of
Brazil Iran Spain
Canada Ireland Sweden
Chile A Israel Switzerland
Colombia Italy Turkey
Czechoslovakia United Kingdom
Japan
Denmark New Zealand USA
Egypt, Arab Rep. of Norway Yugoslavia
Finland Poland
France Portugal
The member body of the following country had expressed disapproval of the docu-
men t on tech nical grounds :
Netherlands
International Organization for Standardization, 1982
0
Printed in Switzerland

---------------------- Page: 4 ----------------------

SIST ISO 692:1996
INTERNATIONAL STANDARD IS0 692-1982 (E)
Pulps - Determination of alkali solubility
0 Introduction 4 Principle
The object of both this International Standard and IS0 699, Treatment of the pulp with sodium hydroxide solution and ox-
Pulps - Determination of alkali resistance, is to permit the idation of the dissolved organic matter with potassium
study of the behaviour of pulps in the presence of alkali solu-
dichromate. Titration of the excess potassium dichromate and
tions, but their fields of application are different : while this In- calculation of the amount of cellulose equivalent to the
ternational Standard describes the volumetric determination of potassium dichromate consumed.
the alkali-soluble constituents of the pulp and is applied
preferably to the control of bleached pulps, IS0 699 describes
the gravimetric determination of the alkali-insoluble consti-
5 Reagents
tuents of the pulp and applies to all categories of pulps.
Use only reagents of recognized analytical grade and only
distilled water or water of equivalent purity.
1 Scope and field of application
5.1 Sodium hydroxide, solution of known concentration,
containing less than 1 g of sodium carbonate per litre (see the
This International Standard specifies a method for the deter-
note), for example :
mination of the solubility of pulp in cold sodium hydroxide solu-
tions of various and fixed concentrations. The sodium hydrox-
-
5,39 + 0,03 mol/l solution, containing 18,0 & 0,l g
most frequently used are 18 and
ide concentrations
of sodium hydroxide loog of solution
Per
10 % (m/m).
1,197 2 g/ml), equivalent to 215,5 _+ 1,0 g of
(e20 =
sodium hydroxide per litre;
The method is mainly intended for the investigation of
bleached pulps, but may, however, also be used with
-
2,77 + 0,03 mol/l solution, containing 10,O + 0,l g
unbleached pulps, for example in the different stages of
of sodium hydroxide loog of solution
manufacture of bleached pulp. Per
1,108 9 g/ml), equivalent to 110,9 + 1 ,o g of
&I =
sodium hydroxide per Iitre.
2 Reference
NOTE - The sodium hydroxide solution may be conveniently
prepared as follows :
Determination of dry matter content.
IS0 638, Pulps -
Dissolve a quantity of solid sodium hydroxide in an equal mass of water
and allow the suspended sodium carbonate to settle. Decant the super-
natant liquid and dilute with carbon dioxide-free water to the ap-
3 Definitions
propriate concentration. Check by titration with standard acid solution.
3.1 S-value : Alkali solubili,ty; the soluble fraction expressed
5.2 Sulphuric acid, concentrated, not less than 94 % (IV Y)
as a percentage by mass of the oven-dry pulp.
(ezo = 1,84 g/ml).
3.2 &a, SIO or S, : S-values in which the indices 18, 10 or c
NOTE - If the concentration of the sulphuric acid is less than
refer to the chosen concentration, in grams of sodium hydrox-
94 % (Vl V), the temperature will not reach the 125 to 130 OC required
ide per 100 g of solution. during the oxidation.
1

---------------------- Page: 5 ----------------------

SIST ISO 692:1996
IS0 692-1982 (E)
5.3 Potassium dichromate, about 0,067 mol/l solution in 6.4 Suction flasks, for the crucibles or funnels.
2,7 mol/l sulphuric acid solution : 20 g of potassium
(K2Cr207) and 150 ml of sulphuric acid
dichromate
6.5 Balance, accurate to 1 mg.
= 1,84 g/ml) per litre of solution.
(@ZO
6.6 Reaction vessel, of capacity 200 ml and tall in shape.
5.4 Ammonium iron(H) sulphate, approximately 0,l mol/l
solution (concentration known to an accuracy of
Dimensions in millimetres
t 0,000 2 mol/l) : 40 to 41 g of ammonium iron sulphate
hexahydrate [(NH,)2S04FeS0,.6H20] and 10 ml of sulphuric
acid (eZo = 1,84 g/ml) per litre of solution.
This solution is not stable and its concentration shall be
checked every day.
In order to restore the original concentration of the am-
NOTE -
monium iron sulphate solution, a reducing agent can be placed be-
tween the supply bottle and the burette.
Prepare the reducing agent as follows :
I ir
Wash metallic cadmium (which passes a sieve of aperture size 1,4 to
2,0 mm, complying with the requirements’ of IS0 565) with water to
remove fine.particles. Treat the metal for about 5 min with a 2 % solu-
tion of mercury( II) nitrate IHg(NO$z. Hz01 or mercury( II) chloride
(HgCl2) containing 5 ml of concentrated nitric acid per litre, and then
wash the amalgamated metal.
Stainless steel
The ammonium iron( II) sulphate solution may standardized against
potassium dichromate as a primary standard.
The concentration of the ammonium iron sulphate solution will stay
constant if 5 g of aluminium shavings, of purity greater than 99,99 %,
are added to 10 i of solution.
5.5 Phosphoric acid, 85 % (V/ v) (e20 = 1,70 g/ml).
5.6 Ferroin indicator solution : 15 g of 1, lo-phenanthroline
monohydrate (C12HsN2’ H20), or 16 g of 1, lo-phenanthroline
hydrochloride (C,2H,N2DHCI.H20), and 7 g of iron sulphate
(FeSOdm7H20) per litre of solution, or
5.7 Sodium diphenylaminosulphonate indicator solu-
Figure
tion : dissolve 0,l g of sodium diphenylaminosulphonate
(C12HIoNS03Na) in water and dilute to 100 ml.
7 Preparation of the test sample
If the pulp is in sheet form, tear into pieces of size approxi-
mately 5 mm x 5 mm. If it is in slush form, remove the water
6 Apparatus
by suction, press between blotters and dry at a maximum
temperature of 60 OC. Before weighing, condition the sample
Ordinary laboratory apparatus, and
for not less than 20 min in the atmosphere near the balance.
6.1 Stirring equipment, with a propeller-type agitator made
of stainless steel or other corrosion-resistant material. The
8 Procedure
angle of the blades shall be adjusted so that air is not intro-
duced into the pulp suspension during stirring.
8.1 Test portion
NOTE - Suitable equipment is shown in the figure. A
...

Norme internationale
INTERNATIONAL ORGANIZATION FOR STANDARDIZATlON.ME~YHAPO~HAR OPI-AHM3AL&lR fl0 CTAH~APTbl3A~MM.ORGANlSATlON INTERNATIONALE DE NORMALISATION
Determination de la solubilit6 dans les solutions
P&es -
d’hydroxyde de sodium
Pulps - Determination of alkali solubility
Deuxihme bdition - 1982-11-15
CDU 676.014.362 Rbf. no : IS0 692-1982 (F)
Descripteurs : p5te ti papier, analyse chimique, solubilit6, hydroxyde de sodium, analyse volum6trique.
Prix base sur 4 pages

---------------------- Page: 1 ----------------------
Avant-propos
L’ISO (Organisation internationale de normalisation) est une federation mondiale
d’organismes nationaux de normalisation (comites membres de I’ISO). L’elaboration
des Normes internationales est confide aux comites techniques de I’ISO. Chaque
comite membre interesse par une etude a le droit de faire partie du comite technique
correspondant. Les organisations internationales, gouvernementales et non gouverne-
mentales, en liaison avec I’ISO, participent egalement aux travaux.
Les projets de Normes internationales adopt& par les comites techniques sont soumis
aux comites membres pour approbation, avant leur acceptation comme Normes inter-
nationales par le Conseil de I’ISO.
La Norme internationale IS0 692 a ete elaboree par Ie comite technique ISCVTC 6,
Papiers, cartons et piites.
Cette deuxieme edition fut soumise directement au Conseil de I’ISO, conformement au
paragraphe 6.11.2 de la partie 1 des Directives pour les travaux techniques de l’lS0.
Elle annule et remplace la premiere edition US0 692-19741, qui avait ete approuvee par
les comites membres des pays suivants :
Afrique du Sud, Rep. d’ Finlande Portugal
Allemagne, R. F. France Roumanie
Australie lnde Royaume-Uni
Belgique Iran Suede
Bresil lrlande Suisse
Canada Israel Tchecoslovaquie
Chili ltalie Turquie
Colombie Japon USA
Danemark Norvege Yougoslavie
Egyptel Rep. arabe d’ Nouvelle-Zelande
Pologne
Espagne
Le comite membre du pays suivant I’avait desapprouvee pour des raisons techniques :
Pays- Bas
Organisation internationale de normalisation, 1982
Imprime en Suisse

---------------------- Page: 2 ----------------------
IS0 6924982 (F)
NORME INTERNATIONALE
PStes - Determination de la solubilit6 dans les solutions
d’hydroxyde de sodium
0 Introduction 4 Principe
Traitement de la pate par une solution d’hydroxyde de sodium
La presente Norme internationale et I’ISO 699, PStes - Deter-
mina tion de la r&is tance aux solutions d’h ydrox yde de sodium, et oxydation des matieres organiques dissoutes par le dichro-
ont toutes deux pour objet de permettre I’etude du comporte- mate de potassium. Titrage de I’exces de dichromate de potas-
sium et calcul de I’equivalent en cellulose du dichromate de
ment des pates en presence de solutions d’hydroxyde de
potassium consomme.
sodium, mais leurs domaines d’application sont differents :
tandis que la presente Norme internationale, qui decrit le
dosage volumetrique des constituants de la pate solubles dans
les solutions d’hydroxyde de sodium, est applicable de prefe-
rence au controle des pates blanchies, I’ISO 699, qui decrit la
5 Rkactifs
determination gravimetrique des constituants de la pate insolu-
bles dans les solutions d’hydroxyde de sodium, concerne tou-
N’utiliser que des reactifs de qualite analytique reconnue et seu-
tes les categories de pates.
lement de I’eau distillee ou de I’eau de purete equivalente.
1 Objet et domaine d’application
5.1 Hydroxyde de sodium, solution de concentration con-
nue contenant moins de I g de carbonate de sodium par litre
La presente Norme internationale specific une methode de
(voir la note), par exemple :
determination de la solubilite des pates dans les solutions
d’hydroxyde de sodium froides a concentrations differentes et -
solution 5,39 + 0,03 mol/l, contenant 18,O + 0,I g
determinees. Les concentrations de solution d’hydroxyde de
d’hydroxyde de sodium pour 100 g de solution
sodium le plus souvent utilisees sont 18 et 10 % (m/m).
= 1,197 2 g/ml), soit 215,5 + 1,0 g d’hydroxyde de
I@20
sodium par litre;
Cette methode s’applique principalement aux pates blanchies,
mais peut cependant etre egalement utilisee avec les pates
- solution 277 t 0,03 mol/l, contenant IO,0 + 0,I g
&rues, par exemple, au tours des differents stades de fabrica-
d’hydroxyde de sodium pour 100 g de solution
tion de pates blanchies.
1,108 9 g/ml), soit I IO,9 + I,0 g d’hydroxyde de
k20 =
sodium par litre.
2 Mfhrence
NOTE - La solution d’hydroxyde de sodium peut etre preparee com-
modement comme suit :
IS0 638, PStes - Dhtermina tion de la teneur en mat&es
Dissoudre une certaine quantite d’hydroxyde de sodium solide dans
skhes.
une masse egale d’eau et laisser deposer le carbonate de sodium en
suspension. Decanter le liquide surnageant, puis diluer a la concentra-
tion voulue avec de I’eau exempte de gaz carbonique. Contriiler la con-
3 Dhfinitions
centration avec une solution titree d’acide.
3.1 valeur S : Solubilite dans les solutions d’hydroxyde de
sodium; pourcentage en masse de pate s&he a I’etuve, dis-
5.2 Acide sulfurique, concentre a au moins 94 % (V/v)
soute dans une solution d’hydroxyde de sodium.
I ,84 g/ml).
I@20 =
3.2 S,*, slo ou SC : Valeurs S, ou les indices 18, IO ou c
NOTE - Si la concentration de I’acide sulfurique est inferieure 8 94 %
correspondent a la concentration choisie, en grammes ( V/ V), la temperature n’atteindra pas la valeur voulue de 125 a 130 OC
au tours de I’oxydation.
d’hydroxyde de sodium pour 100 g de solution.

---------------------- Page: 3 ----------------------
IS0 692-1982 (F)
6.4 Fioles a vide, pour les creusets ou entonnoirs.
5.3 Dichromate de potassium, solution a environ
0,067 mol/l dans I’acide sulfurique a 27 mol/l : 20 g de dichro-
mate de potassium (K2Cr207) par litre et 150 ml d’acide sulfuri-
6.5 Balance, precise a 1 mg.
que concentre (QzO = 1,84 g/ml) par litre de solution.
6.6 Vase a rBaction, de forme haute, de 200 ml de capacite.
5.4 Sulfate d’ammonium-fer(ll), solution a 0,l mol/l envi-
ron (concentration connue a + 0,000 2 mol/l pres) : 40 a
Dimensions en millimetres
41 g au litre de sulfate d’ammonium-fer(II) hexahydrate
[ FeS04( NH412S04*6H201 et 10 ml d’acide sulfurique
(ezO = 1,84 g/ml) par litre de solution.
Cette solution n’est pas stable et sa concentration doit etre veri-
free chaque jour.
NOTE - Pour retablir la concentration initiale de la solution de sulfate
d’ammonium-fer(ll), on peut placer un reducteur entre le flacon d’ali-
mentation et la burette.
Preparer le reducteur comme suit :
Prendre du cadmium metallique passe au tamis de I,4 a 20 mm
d’ouverture de maille conforme aux exigehces de l’lSO565. Eliminer
les particules fines par lavage a I’eau. Traiter le metal durant 5 min envi-
ron par une solution a 2 % de nitrate de mercure( II) [Hg(NO&. Hz01
ou de chlorure de mercure(ll) (HgCl$, contenant 5 ml d’acide nitrique
concentre par litre, puis laver le metal amalgam&
Acier inoxydable
On peut titrer la solution de sulfate d’ammonium-fer(II) avec du dichro-
mate de potassium (etalon primaire).
Le titre de la solution de sulfate d’ammonium-fer(ll) reste constant si
I’on ajoute 5 g de copeaux d’aluminium de purete superieure a 99,99 %
a 10 I de solution.
5.5 Acide phosphorique, 85 % ( vl v) (ezO = 1,70 g/ml).
5.6 Ferroi’ne, solution a 15 g de monohydrate de
phenanthroline-1 , lO( C12H8N2’ H,O), ou 16 g de chlorhydrate de
A-A
phenanthroline 1,lO (C12H8N2~HCI.H20) et 7 g de sulfate de
fer(ll) (FeS04.7H20) par litre de solution, ou
5.7 Diphenylamine sulfonate de sodium : Dissoudre 0, I g
Figure
de diphenylamine sulfonate de sodium (C12H10NS03Na) dans
I’eau et diluer a 100 ml.
7 Preparation de I’bchantillon pour essai
Si la pate est en feuilles, la d&hirer en morceaux de
6 Appareillage
5 mm x 5 mm environ. Si elle est liquide, eliminer I’eau par
essorage, presser entre deux buvards et s&her a 60 OC maxi-
Appareillage courant de laboratoire et
mum. Avant de peser, conditionner I’echantillon durant 20 min
au moins dans I’atmosphere entourant la balance.
6.1 Agitateur B hQlice, en acier inoxydable ou autre mate-
riau resistant a la corrosion. L’inclinaison des pales doit etre
reglee de maniere a ne pas introduire d’air dans la suspension
8 Mode opbratoire
de pate pendant I’agitation.
NOTE - La figure ci-apres represente un appareillage approprie. On
8.1 Prise d’essai
peut employer un moteur de 15 W fonctionnant a une frequence de
rotation entre 28 et 24 s - 1 environ.
Peser, a 0,005 g pres, une quantite de pate correspondant a
1,5 g environ de pate s&he a I’etuve. Peser immediatement
6.2 Bain 6 temperature constante, permettant de mainte- apt-es deux prises d’essai en vue de la determination de la
teneur en mat&es seches suivant I’ISO 638.
nir une temperature de 20 + 0,2 OC.
6.3 Creusets ou entonnoirs filtrants, de 50 ml de capacite, 8.2 Dbtermination
en matiere resistant a I’hydroxyde de
...