1987L0094 — EN — 06.01.1988 — 001.001 — 1
This document is meant purely as a documentation tool and the institutions do not assume any liability for its contents
►B COMMISSIONDIRECTIVE
of8December 1986
on the approximation of the laws of the Member States relating to procedures for the control of
characteristics of, limits for andresistance to detonationofstraight ammonium nitrate fertilizers
ofhighnitrogencontent
(87/94/EEC)
(OJ L 38, 7.2.1987, p. 1)
Amended by:
Official Journal
No page date
►M1Commission Directive 88/126/EEC of 22 December 1987 L 63 12 9.3.1988
Corrected by:
►C1Corrigendum, OJ L 63, 9.3.1988, p. 16 (87/94/EEC)
▼B
COMMISSIONDIRECTIVE
of8December 1986
on the approximationof the lawsofthe Member States relating to
proceduresforthecontrolofcharacteristicsof,limitsforandresis-tancetodetonationofstraightammoniumnitratefertilizersofhigh
nitrogencontent
(87/94/EEC)
THE COMMISSION OF THE EUROPEAN COMMUNITIES,
Having regard to the Treaty establishing the European Economic
Community,
Having regard to Council Directive 80/876/EEC of 15 July 1980 on the
approximation of the laws of the Member States relating to straightammonium nitrate fertilizers of high nitrogen content(
1), and in parti-
cular Article 8 thereof,
Having regard to Council Directive 76/116/EEC of 18 December 1975
on the approximation of the laws of the Member States relating to ferti-lizers(
2), and in particular Article 9 (2) thereof,
Whereas Directive 80/876/EEC provides for characteristics of, limits
for and a test of resistance to detonation for the fertilizers in question;
whereas Article 8 thereof provides that the methods of checking,analysis and test be established in accordance with the procedure laiddown in Article 11 of Directive 76/116/EEC;
Whereas Directive 76/116/EEC provides for official control for
Community fertilizers for the purpose of checking compliance with
requirements arising under the Community provisions concerning the
quality and composition of fertilizers;
Whereas it seemed necessary, having regard to the particular nature of
straight ammonium nitrate fertilizers of high nitrogen content and tothe requirements it entails regarding public safety, health, and protec-tion of workers, to lay down additional Community rules for these
fertilizers;
Whereas for straight ammonium nitrate fertilizers, sampling and
analysis for official controls of Community fertilizers are carried outin accordance with the methods described in Commission Directive77/535/EEC(
3), as amended by Directive 79/138/EEC(4);
Whereas in accordance with the same procedure the number of the
thermal cycles to which the sample is to be submitted before beingtested for resistance to detonation is established as provided in AnnexII to Directive 80/876/EEC, and the limit value for heavy metals isestablished as provided in Annex I to the same Directive;
Whereas the method of the closed thermal cycles as described is
regarded as stimulating sufficiently the conditions to be taken into
account within the scope of application of Directive 80/876/EEC;whereas, however, this method may not necessarily simulate all condi-tions arising during bulk transport by water;
Whereas the measures provided for in this Directive are in accordance
with the opinion of the Committee on the Adaptation to Technical
Progress of the Directives for the Removal of Technical Barriers toTrade in Fertilizers,1987L0094 — EN — 06.01.1988 — 001.001 — 2
(1) OJ No L 250, 23. 9. 1980, p. 7.
(2) OJ No L 24, 30. 1. 1976, p. 21.
(3) OJ No L 213, 22. 8. 1977, p. 1.
(4) OJ No L 39, 14. 2. 1979, p. 3.
▼B
HAS ADOPTED THIS DIRECTIVE:
Article 1
1. Member States shall take the necessary measures to ensure that
the methods of checking, analysis and test for official controls ofstraight ammonium nitrate fertilizers of high nitrogen content provided
for by Directive 80/876/EEC are carried out in accordance withth e
methods described in Annexes II and III to this Directive.
2. Annex I fixes:
— the permissible heavy metals content,
— the required number of thermal cycles applicable to samples
submitted to the detonation test.
Article 2
1. Member States shall take the measures necessary to comply with
this Directive not later than ►
M130 November 1988 ◄. They shall
forthwith inform the Commission thereof.
2. Member States shall communicate to the Commission the texts of
the provisions of national law which they adopt in the field governed
by this Directive.
Article 3
This Directive is addressed to the Member States.1987L0094 — EN — 06.01.1988 — 001.001 — 3
▼B
ANNEX I
1.Limits for heavy metals according to Annex I, point 6, to Council
Directive 80/876/EEC.
1.1. The copper content shall not be higher than 10 mg/kg.1.2. No limits are specified for other heavy metals.
2.Number of thermal cycles in accordance with Annex II to Council
Directive 80/876/EEC.
The number of thermal cycles to be applied shall be five.1987L0094 — EN — 06.01.1988 — 001.001 — 4
▼B
ANNEX II
METHODSOFCHECKINGCOMPLIANCEWITHTHELIMITSSPECI-
FIEDINANNEXESIANDIITOCOUNCILDIRECTIVE80/876/EEC
METHOD 1. METHODS FOR THE APPLICATION OF THERMAL CYCLES
1.Scopeandfieldofapplication
This document defines the procedures for the application of thermal
cycles prior to the execution of the oil retention test and detonability
test in straight ammonium nitrate fertilizer of high nitrogen content.
2.Thermal cycles referred to in Annex I to Council Directive 80/876/
EEC
2.1.Field of application
This procedure is for thermal cycling prior to determining the oil reten-
tion of the fertilizer.
2.2.Principle and definition
In an Erlenmeyer flask, heat the sample from ambient temperature to
50 ºC and maintain at this temperature for a period of two hours (phase
at 50 ºC). Thereupon cool the sample until a temperature of 25 ºC is
achieved and maintain at that temperature for two hours (phase at 25 ºC).
The combination of the successive phases at 50 ºC and 25 ºC forms one
thermal cycle. After being subjected to two thermal cycles, the test
sample is held at a temperature of 20 ± 3 ºC for the determination of
the oil retention value.
2.3.Apparatus
Normal laboratory apparatus, in particular:
— water baths thermostated at 25 (± 1) and 50 (± 1) ºC respectively,
— Erlenmeyer flasks withan individual capacity of 150 ml.
2.4.Procedure
Put eachtest sample of 70 (± 5) grams into an Erlenmeyer flask wh ichis
then sealed with a stopper.
Move each flask every two hours from the 50 ºC bath to the 25 ºC bath
and vice versa.
Maintain the water in each bath at constant temperature and keep in
motion by rapid stirring to ensure the water level comes above the level
of the sample. Protect the stopper from condensation by a foam rubber
cap.
3.Thermal cycles to be used for Annex II to Council Directive 80/876/
EEC
3.1.Field of application
This procedure is for thermal cycling prior to the execution of the deton-
ability test.
3.2.Principle and definition
In a watertight box, heat the sample from ambient temperature to 50 ºC
and maintain at this temperature far a period of one hour (phase at 50 ºC).
Thereupon, cool the sample until a temperature of 25 ºC is achieved and
maintain at that temperature for one hour (phase at 25 ºC). The combina-
tion of the successive phases at 50 and 25 ºC forms one thermal cycle.
After being subjected to the required number of thermal cycles, the test
sample is held at a temperature of 20 ± 3 ºC pending the execution of
the detonability test.
3.3.Apparatus
— A water bath, thermostated in a temperature range of 20 to 51 ºC with
a minimum heating and cooling rate of 10 ºC/h, or two water baths,
one thermostated at a temperature of 20 ºC, the otherat 51 ºC. The1987L0094 — EN — 06.01.1988 — 001.001 — 5
▼C1
▼B
▼C1
▼B
▼B
water in the bath(s) is continuously stirred; the volume of the bath
should be large enough to guarantee ample circulation of the water.
— A stainless steel box, watertight all around and provided with a ther-
mocouple in the centre. The outside width of the box is 45 (± 2) mm
and the wall thickness is 1,5 mm (see Figure 1); The height and
length of the box can be chosen to suit the dimensions of the water
bath, e.g. length 600 mm, height 400 mm.
3.4.Procedure
Place a quantity of fertilizer sufficient for a single detonation into the box
and close the cover. Place the box in the water bath. Heat the water to
51 ºC and measure the temperature in the centre of the fertilizer. One
hour after the temperature at the centre has reached 50 ºC cool the water.
►C1One hour after the temperature at the centre has reached 25 ºC heat
the water to start the second cycle. In the case of two water baths,
transfer the box to the other bath after each heating/cooling period. ◄
Figure 1
METHOD 2. DETERMINATION OF OIL RETENTION
1.Scopeandfieldofapplication
This document defines the procedure for the determination of oil reten-
tion of straight ammonium nitrate fertilizers of high nitrogen content.
The method is applicable to both prilled and granular fertilizers which do
not contain oil-soluble materials.
2.Definition
Oil retention of a fertilizer: the quantity of oil retained by the fertilizer
determined under the operating conditions specified, and expressed as a
percentage by mass.
3.Principle
Total immersion of the test portion in gas oil for a specified period,
followed by the draining away of surplus oil under specified conditions.
Measurement of the increase in mass of the test portion.1987L0094 — EN — 06.01.1988 — 001.001 — 6
▼C1
▼B
▼B
4.Reagent
Gas oil
Viscosity max.: 5 mPas at 40 ºCDensity: 0,8 to 0,85 g/ml at 20 ºCSulphur content: ≤1,0 % (m/m)
Ash:≤0,1 % (m/m)
5.Apparatus
Ordinary laboratory apparatus, and:
5.1. Balance, capable of weighing to the nearest 0,01 gram.5.2. Beakers, of capacity 500 ml.5.3. Funnel, of plastic materials, preferably witha cylindrical wall at th e
upper end, diameter approximately 200 mm.
5.4. Test sieve, aperture 0,5 mm, fitting into the funnel (5.3).
Note:The size of the funnel and sieve is such as to ensure that only a
few granules lie one above another and the oil is able to drain easily.
5.5. Filter paper, rapid filtering grade, creped, soft, weight 150 g/m
2.
5.6. Absorbent tissue (laboratory grade).
6.Procedure
6.0. Two individual determinations are carried out in quick succession on
separate portions of the same test sample.
6.1. Remove particles smaller than 0,5 mm using the test sieve (5.4). Weigh
to the nearest 0,01 gram approximately 50 grams of the sample into the
beaker (5.2). Add sufficient gas oil (section 4) to cover the prills comple-
tely and stir carefully to ensure that the surfaces of all the prills are fully
wetted. Cover the beaker with a watch glass and leave to stand for one
hour at 25 (± 2) ºC.
6.2. Filter the entire contents of the beaker through the funnel (5.3) containing
the test sieve (5.4). Allow the portion retained by the sieve to remain
there for one hour so that most of the excess oil can drain away.
6.3. Lay two sheets of filter paper (5.5) (about 500 × 500 mm) on top of each
other on a smooth surface; fold the four edges of both filter papers
upwards to a widthof about 40 mm to prevent th e prills from rolling
away. Place two layers of absorbent tissue (5.6) in the centre of the filter
papers. Pour the entire contents of the sieve (5.4) over the absorbent
tissues and spread the prills evenly with a soft, flat brush. After two
minutes lift one side of the tissues to transfer the prills to the filter papers
beneath and spread them evenly over these with the brush. Lay another
sheet of filter paper, similarly with its edges turned upward, on the
sample and roll the prills between the filter papers with circular move-
ments while exerting a little pressure. Pause after every eight circular
movements to lift the opposite edges of the filter papers and return to
the centre the prills that have rolled to the periphery. Keep to the
following procedure: make four complete circular movements, first clock-
wise and then anticlockwise. Then roll the prills back to the centre as
described above. This procedure to be carried out three times (24 circular
movements, edges lifted twice). Carefully insert a new sheet of filter
paper between the bottom sheet and the one above it and allow the prills
to roll onto the new sheet by lifting the edges of the upper sheet. Cover
the prills with a new sheet of filter paper and repeat the same procedure
as described above. Immediately after rolling, pour the prills into a tared
dish and reweigh to the nearest 0,01 gram to determine the weight of the
quantity of gas oil retained.
6.4.Repeating the rolling procedure and reweighing
If the quantity of gas oil retained in the portion is found to be greater
than 2,00 grams, place the portion on a fresh set of filter papers and
repeat the rolling procedure, lifting the corners in accordance with section
6.3 (two times eight circular movements, lifting once). Then reweigh the
portion.1987L0094 — EN — 06.01.1988 — 001.001 — 7
▼B
7.Expressionofresults
7.1.Method of calculation and formula
The oil retention, from each determination (6.0) expressed as a percen-
tage by mass of the sieved test portion, is given by the equation:
Oil retention ¼m2/C0m1
m1/C2100
where:m
1is the mass, in grams, of the sieved test portion (6.1);
m2is the mass, in grams, of the test portion according to section 6.3 or
6.4 respectively as the result of the last weighing.
Take as the result the arithmetic mean of the two individual determina-
tions.
METHOD 3. DETERMINATION OF THE COMBUSTIBLE INGREDIENTS
1.Scopeandfieldofapplication
This document defines the procedure for the determination of the
combustible content of straight ammonium nitrate fertilizers of high
nitrogen content.
2.Principle
The carbon dioxide produced by inorganic fillers is removed in advance
withan acid. Th e organic compounds are oxidized by means of a
chromic acid/sulphuric acid mixture. Carbon dioxide formed is absorbed
in a barium hydroxide solution. The precipitate is dissolved in a solution
of hydrochloric acid and measured by back-titration with sodium hydro-
xide solution.
3.Reagents
3.1. Analytical-grade chromium (VI) trioxide CrO3.
3.2. Sulphuric acid, diluted. to 60 % by volume — pour 360 ml of water into
a one-litre beaker and carefully add 640 ml of sulphuric acid (density at
20 ºC = 1,83 g/ml).
3.3. Silver nitrate: 0,1 M solution;
3.4. Barium hydroxide:
weighout 15 grams of barium h ydroxide (Ba(OH)2.8H2O), and dissolve
completely in hot water. Allow to cool and transfer to a one-litre flask.
Fill up to the mark and mix. Filter through a pleated filter paper.
3.5. Hydrochloric acid: 0,1 M standard solution;3.6. Sodium hydroxide: 0,1 M standard solution;3.7. Bromophenol blue: solution of 0,4 grams per litre in water;3.8. Phenolphthalein: solution of 2 grams per litre in 60 % by volume ethanol;3.9. Soda lime: particle dimensions, about 1,0 to 1,5 mm.3.10. Demineralized water, freshly boiled to remove carbon dioxide.
4.Apparatus
4.1. Standard laboratory equipment, in particular:
— filter crucible witha plate of sintered glass and a capacity of 15 ml;
plate diameter: 20 mm; total height: 50 mm; porosity 4 (pore diameter
from 5 to 15 µm);
— 600-ml beaker.
4.2. Compressed nitrogen supply.4.3. Apparatus made up of the following parts and assembled, if possible, by
means of spherical ground joints (see Figure 2).
4.3.1. Absorption tube A about 200 mm long and 30 mm in diameter filled with
soda lime (3.9) kept in place by fibreglass plugs.
4.3.2. 500-ml reaction flask B withside arm and a round bottom.1987L0094 — EN — 06.01.1988 — 001.001 — 8
▼C1
▼B
▼B
4.3.3. Vigreux fractionating column about 150 mm long (C ′).
4.3.4. Double-surface condenser C, 200 mm long.4.3.5. Drechsel bottle D acting as a trap for any excess acid which may distill
over.
4.3.6. Ice bath E to cool the Drechsel bottle.4.3.7. Two absorption vessels F
1and F2, 32 to 35 mm in diameter, the gas
distributor of which comprises a 10 mm disc of low-porosity sintered
glass.
4.3.8. Suction pump and suction regulating device G comprising a T-shaped
glass piece inserted into the circuit, the free arm of which is connected
to the fine capillary tube by a short rubber tube fitted with a screw clamp.
Caution:The use of boiling chromic acid solution in an apparatus under reduced
pressure is a hazardous operation and requires appropriate precautions.
5.Procedure
5.1.Sample for analysis
Weighapproximately 10 grams of ammonium nitrate to th e nearest 0,001
grams.
5.2.Removal of carbonates
Place the sample for analysis in the reaction flask B. Add 100 ml of
H
2SO4(3.2). The prills dissolve in about 10 minutes at ambient tempera-
ture. Assemble the apparatus as indicated in the diagram: connect one end
of the absorption tube (A) to the nitrogen source (4.2) via a non-return
flow device containing 5 to 6 mm of mercury and the other end to the
feed tube which enters the reaction flask. Place the Vigreux fractionating
column (C ′) and the condenser (C) with cooling water supply in position.
Adjust the nitrogen to provide a moderate flow through the solution,
bring the solution to boiling point and heat for two minutes. ►C1At
the end of this time there should be no more effervescence; if efferves-
cence is seen, continue heating for 30 minutes. Allow solution to cool
for at least 20 minutes with the nitrogenflowing through it. ◄
Complete assembly of the apparatus as indicated in the diagram by
connecting the condenser tube to the Drechsel bottle (D) and the bottle
to the absorption vessels F1and F2. The nitrogen must continue to pass
through the solution during the assembly operation. Rapidly introduce
50 ml of barium hydroxide solution (3.4) into each of the absorption
vessels (F1and F2).
Bubble a stream of nitrogen through for about 10 minutes. The solution
must remain clear in the absorbers. If this does not happen, the carbonate
removal process must be repeated.
5.3.Oxidation and absorption
After withdrawing the nitrogen feed tube, rapidly introduce 20 grams of
chromium trioxide (3.1) and 6 ml of silver nitrate solution (3.3) via the
side arm of the reaction flask (B). Connect the apparatus to the suction
pump and adjust the nitrogen flow so that a steady stream of gas bubbles
passes through the sintered-glass absorbers F1and F2.
Heat the reaction flask (B) until the liquid boils and keep it boiling for
one-and-a-half hours(1). It may be necessary to adjust the suction-regu-
lating valve (G) to control the nitrogen flow since it is possible that the
barium carbonate precipitated during the test may block the sintered-glass
discs. The operation is satisfactory when the barium hydroxide solution in
the absorber F2remains clear. Otherwise repeat the test. Stop heating and
dismantle the apparatus. Wash each of the distributors both inside and
outside to remove barium hydroxide and collect the washings in the
corresponding absorber. Place the distributors one after the other in a
600-ml beaker which will subsequently be used for the determination.
Rapidly filter under vacuum firstly the contents of absorber F2and then
of absorber F1using the sintered-glass crucible. Collect the precipitate1987L0094 — EN — 06.01.1988 — 001.001 — 9
(1) A reaction time of one-and-a-half hours, is sufficient in the case of most of the organic
substances in the presence of silver nitrate catalyst.▼C1
▼B
▼B
by rinsing the absorbers with water (3.10) and wash the crucible with
50 ml of the same water. ►C1Place the crucible in the 600 ml beaker
and add about 100 ml of boiled water (3.10): Introduce 50 ml of boiled
water into each of the absorbers and pass nitrogen through the distributors
for five minutes. ◄Combine the water with that from the beaker.
Repeat the operation once to ensure that the distributors are rinsed thor-
oughly.
5.4.Measurement of the carbonates originating from organic material
Add five drops of phenolphthalein (3.8) to the contents of the beaker. The
solution becomes red in colour. ►C1Add hydrochloric acid (3.5) drop
by drop until the pink colour just disappears. Stir the solution well in
the crucible to check that the pink colour does not reappear. ◄Add
five drops of bromphenol blue and titrate with hydrochloric acid until
the solution turns yellow. Add a further 10 ml of hydrochloric acid.
Heat the solution to boiling point and continue boiling for a maximum of
one minute. Check carefully that no precipitate remains in the liquid.
Allow to cool and back titrate with the sodium hydroxide solution (3.6).
6.Blanktest
Carry out a blank test following the same procedure and using the same
quantities of all reagents.
7.Expressionofresults
The content of combustible ingredients (C), expressed as carbon, as a
percentage by mass of the sample, is given by the formula:
C%¼0;06/C2V1/C0V2
E
where:
E = the mass in grams of the test portion;
V1= the total volume in ml of 0,1 M hydrochloric acid added after the
change in colour of the phenolphthalein;
V2= the volume in ml of the 0,1 M sodium hydroxide solution used
for back titration.1987L0094 — EN — 06.01.1988 — 001.001 — 10
Figure 2
A = Absorption tube filled withsoda lime
B = Reaction flask
C′ = Vigreux fractionating column 150 mm long
C = Double surface condenser 200 mm longD = Drechsel bottle 250 ml
E = Ice bath
F
1and F2= Absorption vessels 32 to 35 mm diameter assembled withsph erical ground joints Gas
distributor with10 mm disc of low-porosity sintered glass
G = Suction-regulating device
▼B1987L0094 — EN — 06.01.1988 — 001.001 — 11
▼B
METHOD 4. DETERMINATION OF THE pH VALUE
1.Scopeandfieldofapplication
This document defines the procedure for measuring the pH value of a
solution of a straight ammonium nitrate fertilizer of high nitrogen
content.
2.Principle
Measurement of the pH of an ammonium nitrate solution by means of a
pH meter.
3.Reagents
Distilled or demineralized water, free from carbon dioxide.
3.1.Buffer solution, pH 6,88 at 20 ºC
Dissolve 3,40 ± 0,01 grams of potassium dihydrogen orthophosphate
(KH2PO4) in approximately 400 ml of water. Then dissolve 3,55 ± 0,01
gram of disodium hydrogen orthophosphate (Na2HPO4) in approximately
400 ml of water. Transfer the two solutions without loss into a 1 000-ml
standard flask, make up to the mark and mix. Keep this solution in an
airtight vessel.
3.2.Buffer solution, pH 4,00 at 20 ºC
Dissolve 10,21 ± 0,01 grams of potassium hydrogen phthalate
(KHC8O4H4) in water, transfer without loss into a 1000-ml standard flask,
make up to the mark and mix.
Keep this solution in an airtight vessel.
3.3. Commercially available pH standard solutions may be used.
4.Apparatus
pH meter, equipped withglass and calomel electrodes or equivalent,
sensitivity 0,05 pH unit.
5.Procedure
5.1.Calibration of the pH meter.
Calibrate the pH meter (4) at a temperature of 20 (± 1) ºC, using the
buffer solutions (3.1), (3.2) or (3.3). Pass a slow stream of nitrogen onto
the surface of the solution and maintain this throughout the test.
5.2.Determination
Pour 100,0 ml of water onto 10 (± 0,01) grams of the sample in a 250-ml
beaker. Remove the insolubles by filtering, decanting or centrifuging the
liquid. Measure the pH value of the clear solution at a temperature of 20
(± 1) ºC according to the same procedure as for the calibration of the
meter.
6.Expressionofresults
Express the result in pH units, to the nearest 0,1 unit, and state the
temperature used.
METHOD 5. DETERMINATION OF THE PARTICLE SIZE
1.Scopeandfieldofapplication
This document defines the procedure for the test sieving of straight
ammonium nitrate fertilizers of high nitrogen content.
2.Principle
The test sample is sieved on a nest of three sieves, either by hand or by
mechanical means. The mass retained on each sieve is recorded and the
percentage of material passing the required sieves are calculated.
3.Apparatus
3.1. 200-mm-diameter woven-wire test sieves withapertures of 2,0 mm,
1,0 mm and 0,5 mm respectively of standard ranges. One lid and one
receiver for these sieves.1987L0094 — EN — 06.01.1988 — 001.001 — 12
▼B
3.2. Balance to weighto 0,1 gram.
3.3. Mechanical sieve shaker (if available) capable of imparting both vertical
and horizontal motion to the test sample.
4.Procedure
4.1. The sample is divided representatively into portions of approximately 100
grams.
4.2. Weigh one of these portions to the nearest 0,1 gram.4.3. Arrange the nest of sieves in ascending order; receiver, 0,5 mm, 1 mm,
2 mm and place the weighed test portion on the top sieve. Fit the lid to
the top of the nest of sieves.
4.4. Shake by hand or machine, imparting both a vertical and horizontal
motion and if by hand, tapping occasionally. Continue this process for
10 minutes or until the quantity passing through each sieve in one minute
is less than 0,1 gram.
4.5. Remove the sieves from the nest in turn and collect the material retained,
brush gently from the reverse side with a soft brush, if necessary.
4.6. Weigh the material retained on each sieve and that collected in the
receiver, to the nearest 0,1 gram.
5.Evaluationoftheresults
5.1. Convert the fraction masses to a percentage of the total of the fraction
masses (not of the original charge).
Calculate the percentage in the receiver (i.e. < 0,5 mm): A %
Calculate the percentage retained on the 0,5 mm sieve: B %Calculate the percentage passing 1,0 mm, i.e. (A + B) %The sum of the fraction masses should be within 2 % of the initial mass
taken.
5.2. At least two separate analyses should be carried out and the individual
results for A should not differ by more than 1,0 % absolute and for B
by more than 1,5 % absolute. Repeat the test if this is not the case.
6.Expressionofresults
Report the mean of the two values obtained for A on the one hand and
for A + B on the other.
METHOD 6. DETERMINATION OF THE CHLORINE CONTENT (AS
CHLORIDE ION)
1.Scopeandfieldofapplication
This document defines the procedure for the determination of the chlorine
content (as chloride ion) of straight ammonium nitrate fertilizers with a
high nitrogen content.
2.Principle
Chloride ions dissolved in water are determined by potentiometric titra-
tion withsilver nitrate in an acidic medium.
3.Reagents
Distilled or demineralized water, free from chloride ions.
3.1. Acetone AR.3.2. Concentrated nitric acid (density at 20 ºC = 1,40 g/ml)
3.3. Silver nitrate 0,1 M standard solution. Store this solution in a brown glass
bottle.
3.4. Silver nitrate 0,004 M standard solution — prepare this solution at the
time of use.1987L0094 — EN — 06.01.1988 — 001.001 — 13
▼C1
▼B
▼C1
▼B
▼B
3.5. Potassium chloride. 0,1 M standard reference solution. Weigh, to the
nearest 0,1 mg, 3,7276 grams of analytical-grade potassium chloride,
previously dried for one hour in an oven at 130 ºC and cooled in a desic-
cator to ambient temperature. Dissolve in a little water, transfer the
solution without loss into a 500 ml standard flask, dilute to the mark
and mix.
3.6. Potassium chloride, 0,004 M standard reference solution — prepare this
solution at the time of use.
4.Apparatus
4.1. Potentiometer withsilver indicating electrode and calomel reference elec-
trode, sensitivity 2 mV, covering the range − 500 to + 500 mV.
4.2. Bridge, containing a saturated potassium nitrate solution, connected to the
calomel electrode (4.1), fitted at the ends with porous plugs.
Note:This bridge is not necessary if silver and mercury (1) sulphate
electrodes are used.
4.3. Magnetic stirrer, witha Teflon-coated rod.
4.4. Microburette withfine-pointed tip, graduated in 0,01 ml divisions.
5.Procedure
5.1.Standardization of the silver nitrate solution
Take 5,00 ml and 10,00 ml of the standard reference potassium chloride
solution (3.6) and place in two low-form beakers of convenient capacity
(for example 250 ml). Carry out the following titration of the contents of
eachbeaker.
Add 5 ml of the nitric acid solution (3.2), 120 ml of the acetone (3.1) and
sufficient water to bring the total volume to about 150 ml. Place the rod
of the magnetic stirrer (4.3) in the beaker and set the stirrer in motion.
Immerse the silver electrode (4.1) and the free end of the bridge (4.2) in
the solution. Connect the electrodes to the potentiometer (4.1) and, after
verifying the zero of the apparatus, note the value of the starting poten-
tial.
Titrate, using the microburette (4.4), adding initially 4 or 9 ml respec-
tively of the silver nitrate solution corresponding to the standard
reference potassium chloride solution used. Continue the addition in
0,1 ml portions for the 0,004 M solutions and in 0,05 ml portions for
the 0,1 M solutions. After each addition, await the stabilization of the
potential.
Record the volumes added and the corresponding values of the potential
in the first two columns of a table.
In a third column of the table, record the successive increments ( ∆1E) of
the potential E. In a fourth column, record the differences ( ∆2E) positive
or negative, between the potential increments ( ∆1E). The end of the titra-
tion corresponds to the addition of the 0,1 or 0,05 ml portion (V1)o ft he
silver nitrate solution which gives the maximum value of ∆1E.
In order to calculate the exact volume (Veq) of the silver nitrate solution
corresponding to the end of the reaction, use the formula:
Veq¼V0þV1/C2b
B/C18/C19
where:
V0is the total volume, in ml, of the silver nitrate solution immediately
lower than the volume which gives the maximum increment of ∆1E;
V1is the volume, in ml, of the last portion of the silver nitrate solution
added (0,1 or 0,05 ml);
b is the last positive value of ∆2E;
B is the sum of the absolute values of the last positive values of ∆2E and
the first negative value of ∆2E (see example in Table 1).
5.2.Blank test
Carry out a blank test and take account thereof when calculating the final
result.1987L0094 — EN — 06.01.1988 — 001.001 — 14
▼B
The result V4of the blank test on the reagents is given, in ml, by the
formula:
V4=2 V3−V2
where:V
2is the value, in ml, of the exact volume (Veq) of the silver nitrate solu-
tion corresponding to the titration of 10 ml of the potassium chloride
standard reference solution used;
V3is the value, in ml, of the exact volume (Veq) of the silver nitrate solu-
tion corresponding to the titration of 5 ml of the potassium chloride
standard reference solution used.
5.3.Check test
The blank test can at the same time serve as a check that the apparatus is
functioning satisfactorily and that the test procedure is being implemented
correctly.
5.4.Determination
Take a portion of sample in the range 10 to 20 grams and weigh to the
nearest 0,01 gram. Transfer quantitatively to a 250-ml beaker. Add 20 ml
of water, 5 ml of nitric acid solution (3.2), 120 ml of acetone (3.1) and
sufficient water to bring the total volume to about 150 ml.
Place the rod of the magnetic stirrer (4.3) in the beaker, place the beaker
on the stirrer and set the stirrer in motion. Immerse the silver electrode
(4.1) and the free end of the bridge (4.2) in the solution, connect the elec-
trodes to the potentiometer (4.1) and, after having verified the zero of the
apparatus, note the value of the starting potential.
Titrate with the silver nitrate solution, by additions from the microburette
(4.4) in increments of 0,1 ml. After eachaddition, await th e stabilization
of the potential.
Continue the titration as specified in 5.1, starting from the fourth para-
graph: ‘Record the volumes added and the corresponding values of the
potential in the first two columns of a table ….’.
6.Expressionofresults
Express the result of the analysis as the percentage of chlorine contained
in the sample as received for analysis.
Calculate the percentage of chlorine (C1) content from the formula:
Cl %¼0;03545 /C2T/C2V5/C0V4 ðÞ /C2 100
m
where:
T is the molarity of silver nitrate solution used;
V4is the result, in ml, of the blank test (5.2);
V5is the value, in ml, of Veqcorresponding to the determination. (5.4);
m is the mass, in grams, of the test portion.1987L0094 — EN — 06.01.1988 — 001.001 — 15
▼B
Table 1
EXAMPLE
Volume of the silver
nitrate solution
VPotential
E∆1E ∆2E
ml mV
4,80 176
35
4,90 211 + 37
72
5,00 283 − 49
23
5,10 306 − 10
13
5,20 319
Veq¼4;9þ0;1/C237
37þ49¼4;943
METHOD 7. DETERMINATION OF COPPER
1.Scopeandfieldofapplication
This document defines the procedure for the determination of copper
content of straight ammonium nitrate fertilizers of high nitrogen content.
2.Principle
The sample is dissolved in dilute hydrochloric acid and the copper
content is determined by atomic absorption spectrophotometry.
3.Reagents
3.1. Hydrochloric acid (density at 20 ºC = 1,18 g/ml).
3.2. Hydrochloric acid, 6 M solution.3.3. Hydrochloric acid 0,5 M solution.3.4. Ammonium nitrate.3.5. Hydrogen peroxide, 30 %.3.6. Copper solution(
1) (stock): weigh, to the nearest 0,001 gram, 1 gram of
pure copper, dissolve in 25 ml 6 M hydrochloric acid solution (3.2), add
5 ml of hydrogen peroxide (3.5) in portions and dilute to 1 litre with
water. 1 ml of this solution contains 1000 µg of copper (Cu).
3.6.1. Copper solution (dilute): dilute 10 ml of stock solution (3.6) to 100 ml
with water and then dilute 10 ml of the resulting solution, to 100 ml
withwater, 1 ml of th e final dilution contains 10 µg of copper (Cu).
Prepare this solution at the time of use.
4.Apparatus
Atomic absorption spectrophotometer with a copper lamp (324,8 nm).1987L0094 — EN — 06.01.1988 — 001.001 — 16
(1) Commercially available standard copper solution may be used.
▼B
5.Procedure
5.1.Preparation of the solution for analysis
Weigh, to the nearest 0,001 gram, 25 grams of the sample, place it in a
400 ml beaker, add carefully 20 ml of hydrochloric acid (3.1) (there may
be a vigorous reaction due to carbon dioxide formation). Add morehydrochloric acid, if necessary. When effervescence has stopped, evapor-
tate to dryness on a steam bath, stirring occasionally with a glass rod.
Add 15 ml 6 M hydrochloric acid solution (3.2) and 120 ml of water.
Stir with the glass rod, which should be left in the beaker, and cover the
beaker witha watchglass. Boil th e solution gently until dissolution is
complete and then cool.
Transfer the solution quantitatively into a 250 ml graduated flask, by
washing the beaker with 5 ml 6 M hydrochloric acid (3.2), and twice
with 5 ml of boiling water, make up to the mark with 0,5 M hydrochloric
acid (3.3) and mix carefully.
Filter through a copper-free filter paper(
1), discarding the first 50 ml.
5.2.Blank solution
Prepare a blank solution from which only the sample has been omitted
and allow for this in the calculation of the final results.
5.3.Determination
5.3.1. Preparation of sample and blank test solutions
Dilute the sample solution (5.1) and the blank test solution (5.2) with
0,5 M hydrochloric acid solution (3.3) to a concentration of copper within
the optimal measuring range of the spectrophotometer. Normally no dilu-
tion is needed.
5.3.2. Preparation of the calibration solutions
By diluting the standard solution (3.6.1) with 0,5 M hydrochloric acid
solution (33), prepare at least five standard solutions corresponding to
the optimal measuring range of the spectrophotometer (0 to 5,0 µg/
mlCu). Before making up to the mark, add to every solution ammonium
nitrate (3.4) to give a final concentration of 100 mg per ml.
5.4.Measurement
►C1Set up the spectrophotometer (4) at a wavelength of 324,8 nm. Use
an oxidizing air-acetylene flame. Spray successively, in triplicate, the
calibration solutions (5.3.2), the sample solution and the blank solution
(5.3.1), washing the instrument through with distilled water between
eachspraying ◄. Plot the calibration curve using the mean absorbances
of every standard used as the ordinates and the corresponding concentra-
tions of copper in µg/ml as the abscissae
Determine the concentration of copper in the final sample and blank solu-
tions by reference to the calibration curve.
6.Expressionoftheresults
Calculate the copper content of the sample taking into account the weight
of the test sample, the dilutions carried out in the course of the analysis
and the value of the blank. Express the result as mg Cu/kg.1987L0094 — EN — 06.01.1988 — 001.001 — 17
(1) Whatman 541 or equivalent.▼C1
▼B
▼B
ANNEX III
DETERMINATIONOFRESISTANCETODETONATION
1.Scopeandfieldofapplication
This document defines the procedure for the determination or resistance
to detonation of straight ammonium nitrate fertilizers of high nitrogen
content.
2.Principle
The test sample is confined in a steel tube and subjected to detonation
shock from an explosive booster charge. Propagation, of the detonation
is determined from the degree of crushing of lead cylinders on which
the tube rests horizontally during the test.
3.Materials
3.1. Plastic explosive containing 83 to 86 % penthrite
Density: 1 500 to 1 600 kg/m3
Detonation velocity: 7 300 to 7 700 m/s
Weight: 500 ± 1 gram
3.2. Seven lengths of flexible detonating cord with non-metallic sleeve
Filling weight: 11 to 13 g/mLengthof eachcord: 400 ± 2 mm
3.3. Compressed pellet of secondary explosive, recessed to receive detonator
Explosive: hexogen/wax 95/5 or tetryl or similar secondary explosive,
with or without added graphite
Density: 1 500 to 1 600 kg/m
3
Diameter: 19 to 21 mm
Height: 19 to 23 mm
Central recess to receive detonator: diameter 7 to 7,3 mm, depth12 mm
3.4. Seamless steel tube as specified in ISO 65 — 1981 — Heavy
Series, withnominal dimensions DN 100 (4 ″)
Outside diameter: 113,1 to 115,0 mm
Wall thickness: 5,0 to 6,5 mmLength: 1 005 (± 2) mm
3.5. Bottom plate
Material: steel of good weldable qualityDimensions: 160 × 160 mmThickness: 5 to 6 mm
3.6. Six lead cylinders
Diameter: 50 (± 1) mm
Height: 100 to 101 mm
Materials: soft lead, at least 99,5 % purity
3.7. Steel block
Length: at least 1000 mm
Width: at least 150 mmHeight: at least 150 mm
Weight: at least 300 kg if there is no firm base for the steel block1987L0094 — EN — 06.01.1988 — 001.001 — 18
▼C1
▼B
▼C1
▼B
▼B
3.8. Plastic or cardboard cylinder for booster charge
Wall thickness: 1,5 to 2,5 mmDiameter: 92 to 96 mm
Height: 64 to 67 mm
3.9. Detonator (electric or non-electric) withinitiation force 8 to 10
3.10. Wooden disc
Diameter: 92 to 96 mm. diameter to be matched to the internal diameter
of the plastic or cardboard cylinder (3.8)
Thickness: 20 mm
3.11. Wooden rod of same dimensions as detonator (3.9)
3.12. Dressmaking pins (maximum length20 mm)
4.Procedure
4.1.Preparation of booster charge for insertion into steel tube
There are two methods of initiation of the explosive in the booster
charge, depending on the availability of equipment.
4.1.1. Seven-point simultaneous initiation
The booster charge prepared for use is shown in Figure 1.
4.1.1.1. Drill holes in the wooden disc (3.10) parallel to the axis of the disc
through the centre and through six points symmetrically distributed
around a concentric circle 55 mm in diameter. The diameter of the
holes must be 6 to 7 mm (see Section A-B in Figure 1), depending on
the diameter of the detonating cord used (3.2).
4.1.1.2. Cut seven lengths of flexible detonating cord (3.2) each 400 mm long,
avoiding any loss of explosive at eachend by making a clean cut and
immediately sealing the end with adhesive. Push each of the seven
lengths through the seven holes in the wooden disc (3.10) until their
ends project a few cm on the other side of the disc. ►
C1Then insert
a small dressmaking pin (3.12) transversally into the textile sleeve of
each length of cord 5 to 6 mm from the end and apply adhesive around
the outside of the lengths of cord in a band 2 cm wide adjacent to the
pin.◄Finally, pull the long piece of each cord to bring the pin into
contact withth e wooden disc.
4.1.1.3. Shape the plastic explosive (3.1) to form a cylinder 92 to 96 mm in
diameter, depending on the diameter of the cylinder (3.8). Stand this
cylinder upright on a level surface and insert the shaped explosive.
Then insert the wooden disc(1) carrying the seven lengths of detonating
cord into the top of the cylinder and press it down onto the explosive.
►C1Adjust the height of the cylinder (64 to 67 mm) so that its top
edge does not extend beyond the level of the wood. Finally, fix the
cylinder to the wooden disc, for instance with staples or small nails,
around its entire circumference. ◄
4.1.1.4. Group the free ends of the seven lengths of detonating cord around the
circumference of the wooden rod (3.11) so that their ends are all level
in a plane perpendicular to the rod. Secure them in a bundle around the
rod by means of adhesive tape(2).
4.1.2. Central initiation by a compressed pellet
The booster charge prepared for use is shown in Figure 2.1987L0094 — EN — 06.01.1988 — 001.001 — 19
(1) The diameter of the disc must always correspond to the inside diameter of the cylinder.
(2)NB:When the six peripheral lengths of cord are taut after assembly, the central cord
must remain slightly slack.▼C1
▼B
▼C1
▼B
▼B
4.1.2.1. Preparing a compressed pellet
Taking the necessary safety precautions, place 10 grams of a secondary
explosive (3.3) in a mould withan inside diameter of 19 to 21 mm and
compress to the correct shape and density.
(The ratio of diameter: height should be roughly 1:1.)
In the centre of the bottom of the mould there is a peg, 12 mm in
height and 7,0 to 7,3 mm in diameter (depending on the diameter of
the detonator used), which forms a cylindrical recess in the compressed
cartridge for subsequent insertion of the detonator.
4.1.2.2. Preparing the booster charge
Place the plastic explosive (3.1) into the cylinder (3.8) standing upright
on a level surface, then press it down with a wooden die to give the
explosive a cylindrical shape with a central recess. Insert the
compressed pellet into this recess. Cover the cylindrically shaped explo-
sive containing the compressed pellet with a wooden disc (3.10) having
a central hole 7,0 to 7,3 mm in diameter for insertion of a detonator.
Fix the wooden disc and the cylinder together with a cross of adhesive
tape. Ensure that the hole drilled in the disc and the recess in the
compressed pellet are coaxial by insetting the wooden rod (3.11).
4.2.Preparing steel tubes for the detonation tests
At one end of the steel tube (3.4), drill two diametrically opposed holes
4 mm in diameter perpendicularly through the side wall at a distance of
4 mm from the edge.
Butt weld the bottom plate (3.5) to the opposite end of the tube,
completely filling the right angle between the bottom plate and the
wall of the tube with weld metal around the entire circumference of
the tube.
4.3.Filling and charging the steel tube
(See figures 1 and 2)
4.3.1. The test sample, the steel tube and the booster charge must be condi-
tioned to temperatures of 20 (± 5) ºC. 16 to 18 kg of the test sample
are needed for two detonation tests.
4.3.2. Place the tube upright with its square bottom plate resting on a firm,
flat surface, preferably concrete. Fill the tube to about one-third of its
height with the test sample and drop it 10 cm vertically onto the floor
five times to compact the prills or granules as densely as possible in the
tube. To accelerate compaction, vibrate the tube by striking the side
wall witha 750- to 1 000-gram h ammer between drops for a total of
10 times.
Repeat this charging method with another portion of the test sample.
Finally; a further addition shall be made such that, after compaction
by raising and dropping the tube 10 times and a total of 20 intermittent
hammer blows, the charge fills the tube to a distance of 70 mm from its
orifice.
The filling height of the sample must be adjusted in the steel tube so
that the booster charge (4.1.1 or 4.1.2) to be inserted later will be in
close contact withth e sample over its entire surface.
4.3.3. Insert the booster charge into the tube so that it is in contact with the
sample; the top surface of the wooden disc must be 6 mm below the
end of the tube. Ensure essential close contact between explosive and
test sample by adding or removing small quantities of sample. As
shown in Figures 1 and 2, split pins should be inserted through the
holes near the open end of the tube and their legs opened flat against
the tube.1987L0094 — EN — 06.01.1988 — 001.001 — 20
▼C1
▼B
▼C1
▼B
▼C1
▼B
▼C1
4.4.Positioning of the steel tube and lead rylinders (see figure 3)
4.4.1. Number the bases of the lead cylinders (3.6) 1 to 6. Make six marks
150 mm apart on the centre line of a steel block (3.7) lying on a hori-
zontal base, with the first mark at least 75 mm from the edge of the
block. Place a lead cylinder upright on each of these marks, with the
base of eachcylinder centred on its mark.
4.4.2. Lay the steel tube prepared according to 4.3 horizontally on the lead
cylinders so that the axis of the tube is parallel to the centre line of
the steel block and the welded end of the tube extends 50 mm beyond
lead cylinder No 6. To prevent the tube from rolling, insert small
wooden wedges between the tops of the lead cylinders and the tube
wall (one on eachside) or place a cross of wood between th e tube and
the steel block.
Note:Make sure that the tube is in contact with all six lead cylinders; a
slight curvature of the tube surface can be compensated for by rotating
the tube about its longitudinal axis; if any of the lead rylinders is too
tall, tap the cylinder in question carefully with a hammer until it is the
required height.
4.5.Preparation for detonation
4.5.1. Set up the apparatus according the 4.4 in a bunker or suitably prepared
underground site (e.g. mine or tunnel). Ensure that the temperature of
the steel tube is kept at 20 (± 5) ºC before detonation.
Note:Should such firing sites not be available, the work can, if neces-
sary, be done in a concrete-lined pit covered over withwooden beams.
Detonation can cause steel fragments to be projected withh ighkinetic
energy, therefore, firing must be carried out at a suitable distance from
dwellings or thoroughfares.
4.5.2. If the booster charge with seven-point initiation is used, ensure that the
detonation cords are stretched out as described in the footnote to 4.1.1.4
and arranged as horizontally as possible.
4.5.3. Finally, remove the wooden rod and replace with the detonator. Do not
carry out firing until the danger zone has been evacuated and the test
personnel have taken cover.
4.5.4. Detonate the explosive.4.6. Allow sufficient time for the fumes (gaseous and sometimes toxic
decomposition products suchas nitrous gases) to disperse, th en collect
the lead cylinders and measure their heights with a vernier caliper.
Record, for each of the marked lead rylinders, the degree of crushing
expressed as a percentage of the original height of 100 mm. If the
cylinders are crushed obliquely, record the highest and the lowest
values and calculate the average.
4.7. A probe for continuous measurement of the detonation velocity can be
used; the probe should be inserted longitudinally to the axis of the tube
or along its side wall.
4.8. Two detonation tests per sample are to be carried out.
5.Testreport
Values for the following parameters are to be given in the test report
for eachof th e detonation tests
— the values actually measured for the outside diameter of the steel
tube and for the wall thickness,
— the Brinell hardness of the steel tube,
— the temperature of the tube and the sample shortly before firing,
— the packing density (kg/m
3) of the sample in the steel tube,
— the height of each lead cylinder after firing, specifying the corre-
sponding cylinder number,
— method of initiation employed for the booster charge.1987L0094 — EN — 06.01.1988 — 001.001 — 21
▼B
▼C1
▼B
▼C1
▼B
▼C1
▼B
▼C1
5.1.Evaluation of test results
If, in each firing, the crushing of at least one lead cylinder is less than
5 %,the test shall be considered conclusive and the sample in confor-
mity withth e requirements of Annex II to Directive 80/876/EEC.1987L0094 — EN — 06.01.1988 — 001.001 — 22
▼C1
Figure 1
Boosterchargewithseven-pointinitiation
1987L0094 — EN — 06.01.1988 — 001.001 — 23
▼C1
Figure 2
Boosterchargewithcentral initiation
1987L0094 — EN — 06.01.1988 — 001.001 — 24
▼B
Figure 3
Positioningofthesteeltubeonthefiringsite
1987L0094 — EN — 06.01.1988 — 001.001 — 25