CEN/TR 14539:2021
(Main)Straight ammonium nitrate fertilizers - Comparative study on the determination of porosity (oil retention)
Straight ammonium nitrate fertilizers - Comparative study on the determination of porosity (oil retention)
This document gives the results of inter-laboratory testing to compare the accuracy and convenience of the official EC method for porosity measurement (given in Annex B) with two non-standardized alternative methods (given in Annexes C and D) already used in some participating laboratories.
Three products, with a porosity between 1 % and 7 %, have been used in the inter-laboratory trials.
Reine Ammoniumnitratdünger - Bestimmung der Porosität (Ölretention)
Engrais simples à base de nitrate d’ammonium - Étude comparative pour la détermination de la porosité (rétention d'huile)
Le présent document fournit les résultats de l’essai interlaboratoires servant à comparer la précision et la praticité de la méthode CE officielle pour la mesure de la porosité (décrite dans l’Annexe B) avec deux méthodes alternatives non normalisées (décrites dans les Annexes C et D) déjà utilisées par certains laboratoires participants.
Trois produits, ayant une porosité comprise entre 1 % et 7 %, ont été utilisés pour les essais interlaboratoires.
Čista gnojila iz amonijevega nitrata - Primerjalna študija o določanju poroznosti (zadrževanje olja)
General Information
Relations
Standards Content (Sample)
SLOVENSKI STANDARD
01-november-2021
Nadomešča:
SIST-TR CR 14539:2003
Čista gnojila iz amonijevega nitrata - Primerjalna študija o določanju poroznosti
(zadrževanje olja)
Straight ammonium nitrate fertilizers - Comparative study on the determination of
porosity (oil retention)
Reine Ammoniumnitratdünger - Bestimmung der Porosität (Ölretention)
Engrais simples à base de nitrate d'ammonium - Etude comparative de méthodes de
détermination de la porosité (rétention fuel)
Ta slovenski standard je istoveten z: CEN/TR 14539:2021
ICS:
65.080 Gnojila Fertilizers
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
CEN/TR 14539
TECHNICAL REPORT
RAPPORT TECHNIQUE
June 2021
TECHNISCHER BERICHT
ICS 65.080 Supersedes CR 14539:2002
English Version
Straight ammonium nitrate fertilizers - Comparative study
on the determination of porosity (oil retention)
Engrais simples à base de nitrate d'ammonium - Etude Reine Ammoniumnitratdünger - Bestimmung der
comparative de méthodes de détermination de la Porosität (Ölretention)
porosité (rétention fuel)
This Technical Report was approved by CEN on 23 May 2021. It has been drawn up by the Technical Committee CEN/TC 260.
CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,
Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway,
Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and
United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION
EUROPÄISCHES KOMITEE FÜR NORMUNG
CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2021 CEN All rights of exploitation in any form and by any means reserved Ref. No. CEN/TR 14539:2021 E
worldwide for CEN national Members.
Contents Page
European foreword . 3
Introduction . 4
1 Scope . 5
2 Normative references . 5
3 Terms and definitions . 5
4 Test procedure . 5
4.1 Methods for measuring porosity . 5
4.2 Products . 5
4.2.1 Test samples: straight ammonium nitrate . 5
4.2.2 Gas oils . 6
4.3 Ring test procedure . 6
5 Results and statistical interpretation . 6
5.1 General. 6
5.2 Mean value . 6
5.3 Repeatability . 7
5.4 Reproducibility . 7
5.5 Interpretation of the results . 7
6 Conclusions . 7
Annex A (informative) Characteristics of and limits for straight ammonium nitrate fertilizers
of high nitrogen content as given in EC Directive 80/876/EEC . 8
Annex B (informative) Determination of oil retention — EC method as given in EC Directive
87/94/EEC . 9
Annex C (informative) Centrifuge method — Non-standardized alternative method . 12
Annex D (informative) Roller drum method — Non-standardized alternative method . 15
Bibliography . 18
European foreword
This document (CEN/TR 14539:2021) has been prepared by Technical Committee CEN/TC 260
“Fertilizers and liming materials”, the secretariat of which is held by DIN.
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CEN shall not be held responsible for identifying any or all such patent rights.
This document supersedes CR 14539:2002.
Significant changes between this document and CR 14539:2002 are as follows:
a) updated Normative references and Bibliography;
b) adaption to current principles and rules for structure and drafting.
This document is published for information only and does not have the status of a European Standard.
The Annexes A to D are informative.
Introduction
Straight ammonium nitrate fertilizers of high nitrogen content (> 28 %), following Directive
80/876/EEC [1] and Directive 87/94/EEC [2], are subject to the particular regulatory requirement of a
maximum porosity limit of 4 %. The currently used official EC method is demanding with respect to time
and skilled laboratory manpower.
Therefore, this document presents a comparison of non-standardized alternative methods for measuring
porosity with the official one, through ring testing.
In parallel, oil retention can also be determined using ISO 5313 [4].
1 Scope
This document gives the results of inter-laboratory testing to compare the accuracy and convenience of
the official EC method for porosity measurement (given in Annex B) with two non-standardized
alternative methods (given in Annexes C and D) already used in some participating laboratories.
Three products, with a porosity between 1 % and 7 %, have been used in the inter-laboratory trials.
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.
EN 1235, Solid fertilizers - Test sieving (ISO 8397)
3 Terms and definitions
No terms and definitions are listed in this document.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https://www.iso.org/obp
— IEC Electropedia: available at https://www.electropedia.org/
4 Test procedure
4.1 Methods for measuring porosity
All the methods tested for measurement of ammonium nitrate porosity are based on immersion of the
test sample in gas oil, removing the excess oil, and finally determining the absorbed amount of oil through
weighing. The methods differ in the way of removing the excess oil.
Table 1 — Methods for measuring porosity
Method Removal of oil Protocol
a
Method 1: EC Method [2] Hand-rubbing between sheets of filter paper see Annex B
Method 2: Centrifuge method Draining and centrifuging see Annex C
Method 3: Roller drum method Draining and roller drum with filter thimble see Annex D
a
This method is based on ISO 5313 [4], with some minor but significant differences.
WARNING — Appropriate safety rules and procedures should be followed while handling samples and
residues of Ammonium nitrate impregnated with gas oil.
4.2 Products
4.2.1 Test samples: straight ammonium nitrate
Three different ammonium nitrate samples have been provided to all the participants. Two samples were
fertilizer ammonium nitrates of the 33,5 % N type, the third was a special ammonium nitrate, with a
higher porosity well over 4 %.
4.2.2 Gas oils
All gas oils used in the ring test conformed to the requirements of Directive 87/94/EEC, Annex II [2]. In
order to improve the accuracy of the ring test, one specific gas oil, distributed centrally in this ring test,
has been used as a reference by all participants, parallel to oils from local origin.
4.3 Ring test procedure
This ring test has been performed by 17 participating laboratories, private ones as well as official ones.
Three ammonium nitrate samples have been tested by three different methods, using a reference gas oil,
and oils of local origin.
In order to avoid the influence of thermal cycling under different circumstances, test samples were
prepared centrally without further thermal cycling by the participating laboratories.
The participating laboratories were requested to perform at least two independent replicates of each
sample, according to each method.
Test results, observations and remarks have been reported on the appropriate sheets.
5 Results and statistical interpretation
5.1 General
Statistical calculations have been run on all the results, according to ISO 5725-2 [5] and ISO 3534-1 [3].
Repeatability and reproducibility have been evaluated for each sample coupled with each method.
Evaluations of the mean result have been carried out through variance analysis.
5.2 Mean value
Mean values for a given method have been evaluated, incorporating the influence of different gas oils and
the intra-laboratory variance.
See Table 2.
Table 2 — Mean values
Sample number
Method according to
Table 1
1 2 3
Method 1 2,20 6,22 1,42
Method 2 2,22 6,10 1,51
Method 3 1,89 6,28 1,42
5.3 Repeatability
Table 3 gives the general evaluation of standard deviation with respect to repeatability for each couple
method/sample after checking the equality of variances using Bartlett’s test.
Table 3 — Repeatability
Sample number
Method according to
Table 1
1 2 3
Method 1 0,17 0,20 0,07
Method 2 0,12 0,15 0,06
Method 3 0,10 0,17 0,05
5.4 Reproducibility
Table 4 gives the general evaluation of standard deviation with respect to reproducibility for each couple
method/sample after checking the equality of variances using Bartlett’s test.
Table 4 — Reproducibility
Sample number
Method according to
Table 1
1 2 3
Method 1 0,64 0,73 0,14
Method 2 0,75 0,64 0,28
Method 3 0,47 0,66 0,11
5.5 Interpretation of the results
When the typology of mean results is examined, the statistical proof of the existence of two groups
corresponding to the gas oil type can only be obtained in the case of the couple sample 1/method 1.
The comparison of the mean values obtained by the three methods in all cases, studied by variance
analysis of intra-laboratory means for each test shows that the methods are equivalent.
6 Conclusions
Based upon the above mentioned statistical tests, no significant difference between the methods can be
found; hence the accuracy of the different methods is equivalent.
From a practical point of view, the tested non-standardized alternative methods are more user-friendly
and more convenient than the official EC method.
It could not be shown that there is a statistical difference between results obtained with the different gas
oils conforming to the requirements of Directive 87/94/EEC, Annex II [2].
Annex A
(informative)
Characteristics of and limits for straight ammonium nitrate fertilizers of
high nitrogen content as given in EC Directive 80/876/EEC
A.1 Porosity (oil retention)
The oil retention of the fertilizer, which shall first have undergone two thermal cycles of a temperature
ranging from 25 °C to 50 °C, shall not exceed 4 % by mass.
A.2 Combustible ingredients
The mass fraction of combustible material in per cent measured as carbon shall not exceed 0,2 % for
fertilizers having a nitrogen content of at least 31,5 % (mass fraction) and shall not exceed 0,4 % for
fertilizers having a nitrogen content of at least 28 % but less than 31,5 % (mass fraction).
A.3 pH
A solution of 10 g of fertilizer in 100 ml of water shall have a pH value of at least 4,5.
A.4 Particle size analysis
Not more than a mass fraction of 5 % of the fertilizer shall pass through a 1-mm mesh sieve and not more
than a mass fraction of 3 % shall pass through a 0,5-mm mesh sieve.
A.5 Chlorine
The maximum chlorine content is set at 0,02 % (mass fraction).
A.6 Heavy metals
Heavy metals should not be added deliberately, and any traces which are incidental to the production
process should not exceed the limit fixed by the Committee.
The mass fraction of copper shall not be higher than 10 mg/kg.
No limits are specified for other heavy metals.
SIST-TP CEN/TR 145
...
SLOVENSKI STANDARD
01-november-2021
Nadomešča:
SIST-TR CR 14539:2003
Čista amonnitratna gnojila - Primerjalna študija o določanju poroznosti
(zadrževanje olja)
Straight ammonium nitrate fertilizers - Comparative study on the determination of
porosity (oil retention)
Reine Ammoniumnitratdünger - Bestimmung der Porosität (Ölretention)
Engrais simples à base de nitrate d'ammonium - Etude comparative de méthodes de
détermination de la porosité (rétention fuel)
Ta slovenski standard je istoveten z: CEN/TR 14539:2021
ICS:
65.080 Gnojila Fertilizers
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
CEN/TR 14539
TECHNICAL REPORT
RAPPORT TECHNIQUE
June 2021
TECHNISCHER BERICHT
ICS 65.080 Supersedes CR 14539:2002
English Version
Straight ammonium nitrate fertilizers - Comparative study
on the determination of porosity (oil retention)
Engrais simples à base de nitrate d'ammonium - Etude Reine Ammoniumnitratdünger - Bestimmung der
comparative de méthodes de détermination de la Porosität (Ölretention)
porosité (rétention fuel)
This Technical Report was approved by CEN on 23 May 2021. It has been drawn up by the Technical Committee CEN/TC 260.
CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,
Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway,
Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and
United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION
EUROPÄISCHES KOMITEE FÜR NORMUNG
CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2021 CEN All rights of exploitation in any form and by any means reserved Ref. No. CEN/TR 14539:2021 E
worldwide for CEN national Members.
Contents Page
European foreword . 3
Introduction . 4
1 Scope . 5
2 Normative references . 5
3 Terms and definitions . 5
4 Test procedure . 5
4.1 Methods for measuring porosity . 5
4.2 Products . 5
4.2.1 Test samples: straight ammonium nitrate . 5
4.2.2 Gas oils . 6
4.3 Ring test procedure . 6
5 Results and statistical interpretation . 6
5.1 General. 6
5.2 Mean value . 6
5.3 Repeatability . 7
5.4 Reproducibility . 7
5.5 Interpretation of the results . 7
6 Conclusions . 7
Annex A (informative) Characteristics of and limits for straight ammonium nitrate fertilizers
of high nitrogen content as given in EC Directive 80/876/EEC . 8
Annex B (informative) Determination of oil retention — EC method as given in EC Directive
87/94/EEC . 9
Annex C (informative) Centrifuge method — Non-standardized alternative method . 12
Annex D (informative) Roller drum method — Non-standardized alternative method . 15
Bibliography . 18
European foreword
This document (CEN/TR 14539:2021) has been prepared by Technical Committee CEN/TC 260
“Fertilizers and liming materials”, the secretariat of which is held by DIN.
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CEN shall not be held responsible for identifying any or all such patent rights.
This document supersedes CR 14539:2002.
Significant changes between this document and CR 14539:2002 are as follows:
a) updated Normative references and Bibliography;
b) adaption to current principles and rules for structure and drafting.
This document is published for information only and does not have the status of a European Standard.
The Annexes A to D are informative.
Introduction
Straight ammonium nitrate fertilizers of high nitrogen content (> 28 %), following Directive
80/876/EEC [1] and Directive 87/94/EEC [2], are subject to the particular regulatory requirement of a
maximum porosity limit of 4 %. The currently used official EC method is demanding with respect to time
and skilled laboratory manpower.
Therefore, this document presents a comparison of non-standardized alternative methods for measuring
porosity with the official one, through ring testing.
In parallel, oil retention can also be determined using ISO 5313 [4].
1 Scope
This document gives the results of inter-laboratory testing to compare the accuracy and convenience of
the official EC method for porosity measurement (given in Annex B) with two non-standardized
alternative methods (given in Annexes C and D) already used in some participating laboratories.
Three products, with a porosity between 1 % and 7 %, have been used in the inter-laboratory trials.
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.
EN 1235, Solid fertilizers - Test sieving (ISO 8397)
3 Terms and definitions
No terms and definitions are listed in this document.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https://www.iso.org/obp
— IEC Electropedia: available at https://www.electropedia.org/
4 Test procedure
4.1 Methods for measuring porosity
All the methods tested for measurement of ammonium nitrate porosity are based on immersion of the
test sample in gas oil, removing the excess oil, and finally determining the absorbed amount of oil through
weighing. The methods differ in the way of removing the excess oil.
Table 1 — Methods for measuring porosity
Method Removal of oil Protocol
a
Method 1: EC Method [2] Hand-rubbing between sheets of filter paper see Annex B
Method 2: Centrifuge method Draining and centrifuging see Annex C
Method 3: Roller drum method Draining and roller drum with filter thimble see Annex D
a
This method is based on ISO 5313 [4], with some minor but significant differences.
WARNING — Appropriate safety rules and procedures should be followed while handling samples and
residues of Ammonium nitrate impregnated with gas oil.
4.2 Products
4.2.1 Test samples: straight ammonium nitrate
Three different ammonium nitrate samples have been provided to all the participants. Two samples were
fertilizer ammonium nitrates of the 33,5 % N type, the third was a special ammonium nitrate, with a
higher porosity well over 4 %.
4.2.2 Gas oils
All gas oils used in the ring test conformed to the requirements of Directive 87/94/EEC, Annex II [2]. In
order to improve the accuracy of the ring test, one specific gas oil, distributed centrally in this ring test,
has been used as a reference by all participants, parallel to oils from local origin.
4.3 Ring test procedure
This ring test has been performed by 17 participating laboratories, private ones as well as official ones.
Three ammonium nitrate samples have been tested by three different methods, using a reference gas oil,
and oils of local origin.
In order to avoid the influence of thermal cycling under different circumstances, test samples were
prepared centrally without further thermal cycling by the participating laboratories.
The participating laboratories were requested to perform at least two independent replicates of each
sample, according to each method.
Test results, observations and remarks have been reported on the appropriate sheets.
5 Results and statistical interpretation
5.1 General
Statistical calculations have been run on all the results, according to ISO 5725-2 [5] and ISO 3534-1 [3].
Repeatability and reproducibility have been evaluated for each sample coupled with each method.
Evaluations of the mean result have been carried out through variance analysis.
5.2 Mean value
Mean values for a given method have been evaluated, incorporating the influence of different gas oils and
the intra-laboratory variance.
See Table 2.
Table 2 — Mean values
Sample number
Method according to
Table 1
1 2 3
Method 1 2,20 6,22 1,42
Method 2 2,22 6,10 1,51
Method 3 1,89 6,28 1,42
5.3 Repeatability
Table 3 gives the general evaluation of standard deviation with respect to repeatability for each couple
method/sample after checking the equality of variances using Bartlett’s test.
Table 3 — Repeatability
Sample number
Method according to
Table 1
1 2 3
Method 1 0,17 0,20 0,07
Method 2 0,12 0,15 0,06
Method 3 0,10 0,17 0,05
5.4 Reproducibility
Table 4 gives the general evaluation of standard deviation with respect to reproducibility for each couple
method/sample after checking the equality of variances using Bartlett’s test.
Table 4 — Reproducibility
Sample number
Method according to
Table 1
1 2 3
Method 1 0,64 0,73 0,14
Method 2 0,75 0,64 0,28
Method 3 0,47 0,66 0,11
5.5 Interpretation of the results
When the typology of mean results is examined, the statistical proof of the existence of two groups
corresponding to the gas oil type can only be obtained in the case of the couple sample 1/method 1.
The comparison of the mean values obtained by the three methods in all cases, studied by variance
analysis of intra-laboratory means for each test shows that the methods are equivalent.
6 Conclusions
Based upon the above mentioned statistical tests, no significant difference between the methods can be
found; hence the accuracy of the different methods is equivalent.
From a practical point of view, the tested non-standardized alternative methods are more user-friendly
and more convenient than the official EC method.
It could not be shown that there is a statistical difference between results obtained with the different gas
oils conforming to the requirements of Directive 87/94/EEC, Annex II [2].
Annex A
(informative)
Characteristics of and limits for straight ammonium nitrate fertilizers of
high nitrogen content as given in EC Directive 80/876/EEC
A.1 Porosity (oil retention)
The oil retention of the fertilizer, which shall first have undergone two thermal cycles of a temperature
ranging from 25 °C to 50 °C, shall not exceed 4 % by mass.
A.2 Combustible ingredients
The mass fraction of combustible material in per cent measured as carbon shall not exceed 0,2 % for
fertilizers having a nitrogen content of at least 31,5 % (mass fraction) and shall not exceed 0,4 % for
fertilizers having a nitrogen content of at least 28 % but less than 31,5 % (mass fraction).
A.3 pH
A solution of 10 g of fertilizer in 100 ml of water shall have a pH value of at least 4,5.
A.4 Particle size analysis
Not more than a mass fraction of 5 % of the fertilizer shall pass through a 1-mm mesh sieve and not more
than a mass fraction of 3 % shall pass through a 0,5-mm mesh sieve.
A.5 Chlorine
The maximum chlorine content is set at 0,02 % (mass fraction).
A.6 Heavy metals
Heavy metals should not be added deliberately, and any traces which are incidental to the production
process should not exceed the limit fixed by the Committee.
The mass fraction of copper shall not be higher than 10 mg/kg.
No limits are specified for other heavy metals.
CE
...
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