Sept 6, 1932-> A
r-:. JoHNsoN
,
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y
1,876,501
PROCESS OF MANUFACTURING CONCENTRATED FERTILIZERS
Filed Oct. 4. 1930
/
JMW@
Fatented Sept. 6, 1932
1,876,501
STATES
PATENT OFFICE
ERLING: JOHNSON, OF ODLDA, NORWAY, ASSIGNOR TO THE FIRM: ODDA. SMELTEVERK '
A/S, 0F ODDA, NORWAY~
‘
PROCESS OF MANUFACTURING CONCENTRATED FERTILIZERS
Application filed October 4, 1930,' Serial No. 486,507, and in Norway October 11, 1929.
In my pending patent application 391,506 phoric acid of the solution. For this purpose
I have described a process of converting phos` only 1/3 of the total calcium'nitrate of the
phate rock into soluble compounds and of solution is removed as crystals as represented '
separating its content of lime and phosphoric by the equation;
'
.
`
. -'
y
5 acid. According to said process the vphosî
phate rock is by means of nitric acid con
verted into a solution of calcium nitrate and
free phosphoric acid and from this solution a
leaves the process.
considerable part of the calcium nitrate is _ The- mother liquor frointhe operation 2b.
0 crystallized out, leaving a mother liquor 1s subjected to neutralization with ammonia
which besides phosphoric acid contains more or ammonium carbonate according to the re
or less calcium nitrate and some nitric acid.
action:
’
55
’
My present invention relates to a method
ik
of manufacturing concentrated universal fer
tilizers from said mother liquor and potas
sium chloride.
60
Di-calcium phosphate is precipitated and
rThe accompanying How sheet illustrates is- íiltered off and washed. The remaining l
liquid contains ammonium nitrate.
4
cated by full lines, and the steps which may,
This solution is caused to react with po- '
but need not necessarily be used in the process tassium chloride according to the equation: 65
the process. The essential steps are indi
9.
are indicated by dotted lines. .
y
The invention is based upon the combina
tion of reactions set forth below.
The phosphate rock is first dissolved in
nitric acid according to the reaction
Potassium nitrate 'and ammonium chlo
ride are formed, which latter leaves the proc
70
ess. By treating the ammonium chloride
This> solution is divided into two portions with lime, ammonia may be recovered, while
which are treated separately. One half, or calcium chloride leaves the process.
any other convenient fraction of the solution,
' The potassium nitrate obtained according 75
to reaction (4) is mixed with and dissolves
tration, intensive cooling etc. that the great in the phosphoric acid solution resulting
est possible quantity of calcium nitrate is from reaction (2a) andthe mixture is neu
s caused to crystallize as represented by the fol tralized with ammonia:
is treated under such conditions of concen
lowing equation
which gives a mixture of potassium nitrate
and di-ammonium phosphate. The final
products leaving the process are: calcium
The second portion 1s likewise subJect-ed to nitrate according to Equations 2a. and 2b.,
a crystallization but this crystallization is di-ealcium phosphate (Equation 3) ammoni
only carried to that extent at which sufficient um chloride (Equation 4) and as -main prod»
leaves the prow-
l
.
.
.
.
calcium nitrate is still retained in the solution uct (Equation 5) a universal fertilizer con~
1 tf» forni di-calcium phosphate with the phos» taining 4 mol potassium nitrate to two mol eo
2
1,876,501
iii-ammonium phosphate With the following
content of plant-food components:
the
andmanner
such like
that
is the
injected
liquorinto
by means
an ammoniacal
of nose~r
K
2
atmosphere. Under these conditions a dry
neutralized product ready for use may im
Relative ratio
188 parts of :O = 8 per cent 1, 7
142 parts of P2j05=21 “ “ .
112 parts of N. :16.5 “ “ 1.
A* ¿KNOB
(NHUZHPO‘
mediately be obtained.
It is immediately evident that according
`
The neutralization' With ammonia may be
'to the conditions of Working that is, the de continued to the di-ammonium phosphate
grec of crystallization of the calcium nitrate, stage or only until mono-ammonium phos
the apportionment of mother liquor >among phate is formed. The former is supposed
the reactions 2a. and l2b'. and consequently inthe-products A and C above, thel latter
according tothe quantity of di-calcium phos in the product B. The neutralization may
phate precipitated in reaction (3) , the qualiti however be continued to a mixture of the
ty of ammoniumv nitrate converted into po two salts in any desired proportion. The
Ed taissium nitrate etc., products may be ob composition of the ñnished product may
tained in Which the ratio of plant-food coin vary somewhat according to special purposes
ponents may be varied at will Within wide
limits.
`
and requirements.
80
’ u
The (ii-calcium phosphate leaving the
.
lt is to be pointed out that in practical process may be utilized separately or it may
2@ Work it is not possible to realize a quite com be added to the finished compoundproduct in
plete crystallization of calcium nitrate as suitable proportions in order to augment its
supposed in- Equation 2a. An output of 85 content of phosphoric acid by some citrate
per cent of crystals is however easily reached. soluble one, Which may lead to fertilizers
Yet, this fact has no’detrimental influence of physiologically neutral or alkaline nature.
25 upon the carrying out of the process: At
Further compound fertilizers of physio
85
Worst theïrest of the calcium retained 1n so logically alkaline reactions may be prepared
lution may result in that some l() per cent of separately from the di-calcium phosphate and
the phosphoric acid present in the mixed the calcium nitrate obtained in this process.
product is only citrate-soluble, While the rest Such fertilizers free from inactive substances
30 of the phosphoric acid is Water-soluble. If 4are for example obtained when the calcium
desired the rest of the calcium may however nitrate from the reactions 2a. and 2?). is
be removed as calcium sulphate by precipi mixed with ycli-phosphate and potassium ni
tation withO sulphur-ic acid, ammonium-or trate, to which some urea may be added in
potassium sulphates etc. The precipitant order to increase the content of nitrogen. if
85 may be recovered. As it is only a fraction for example two mol of (li-calcium phosphate
of the initial calcium content Which eventual are mixed With two mol of potassium nitrate
ly is to be removed, no large quantities of which are not used in Example C above and
preeipitants are necessary and need be cir
culated.
40
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f
when further one mol. of calcium nitrate
fromthe process and 2 mol. of urea are added
The greater or smaller surplus of nitric a product is obtained which in the dry state
acid, which may be present in the primary has the following composition :
solution of phosphate rock in nitric acid en
Relative
'
ratio
ters the ñnal product in the shape of am 2 mol. of CaHPO on O
"' 2
l42partsoi`P2O5=1?L7percent1~1
l
mol.
ofCa
(NO3
monium nitrate.
95 pai-twingo ~»_~ 11. 2 “ “ o. 5
2 mol. of CO (NH )EHBO
128partsofN.
:15.0 “
“ 1. 0
As already mentioned the relative ratio of 2m01.0fKNO3 2
components in the finished product may be
varied at will Within Wide limits.
lf desired the content of potassium nitrate
B lslight modiiications, of the process, may be augmented materially by addition of
prod’ucts may be obtained of the following potassium nitrcte produced by conversion of
compositions ;
B.
210
the calcium nitrate obtained in the process
Relative ratio
131 parte of K2O=21 per cent 1. 3
BKNOs
lNHiNO:
Z105
.
142 parts of P2Oi=23
ZNHiHiPOi
98 parts of N.
“
“
1.4
:16 “
“
1.0
with potassium salts.
.
lf the phosphoric acid containing mother
lil@
liquor is so apportioned that no part of the
liquor is used according to reaction 2a. the
55
ln this product 4/7 of thev nitrogen is in phosphoric acid is exclusively obtained in
the form of nitrate, 3/7 in the form of am
monia.
O. 2KNOn
£30
0.5NH4NO3
2(NH4)2HPO4
Relative ratio
95 parts of K2O=19 per cont 1.0
142 parts of P2O5=28 “
98 parts of N. :19 "
“ 1.5
“ 1.0
the citrate soluble form as (li-calcium phos
phate according to reaction (3) and a mixed
product may be prepared with the entire
phosphoric acid in this form., The potassium
l2@
nitrate for admixture may in this case be pre
pared by converting the ammonium nitrate
325
@f the nitrogen some 1/3 is nitrate nitrogen formed in the process with potassium chlo
and 2/3 ammonia nitrogen.
ride. It is evident that the composition of
rEhe neutralization of the liquors With am the product, and the ratio of components
monia may conveniently be eii'ected in coun may be Widely varied.‘accordi-ngA to the quan
ter-current with ammonia gas7 for instance in tity of ammonium nitrate which is used 'for
isc
3
1,876,501
conversion with potassium chlcride. .If the prior methods. An important merit is to be
total quantity of ammonium nitrate is con
seen in the fact that the reactions may be car
verted into potassium nitrate acccrding to ried out in relatively concentrated solutions,
reaction (4) and if the entire quantity of po
so that- evaporation costs are reduced to a
tassium nitrate so obtained is adiniXed, a
minimum.
compound fertilizer of the _following com
Instead of lusing potassium chloride for 70
preparing the potassium nitrate from the
ammonium nitrate solution, potassium sul
position results.
2 CÉIHPQ4
4: KNOB
10
.
phate may serve for said purpose. The
choice of potassium salt to be used is essen
with a theoretical content of 7.5 _per cent tially a question of market prices. As is well 76
nitrogen, 19 per cent phosphoric acid, 24 per known, the reaction of ammonium nitrate
cent potash, and 15 per cent calcium oxide with potassium sulphate is most convenientlv`
with a relative ratio between the three first carried out in presence of free nitric acid,
components
of 1 :2.5 : 3.2. If the ammonium whereby ammonium sulphate or ammonium
15
nitrate solution is only partly converted with sulphate-nitrate is formed and -leaves the
potassium chloride and a part of the am
process.
monium nitrate is admixed as. such, prod
.iets for example of the following composi
20
tion may be obtained:
25
2 KNOS
2 Nil-LNOs
with 10.4 per cent nitrogen, 17.6 per cent cit
_
_
Besides by conversion of the ammonium
nitrate available in the process, potassium
nitrate may be prepared from the ycalcium
nitrate, resulting in the reactions 2dr/land 2b. 85
by conversion withipotassium sulphate or
chloride.
Iclaim:
.
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l. A process of manufacturing concen
rate-soluble phosphoric acid, _11.8 per cent trated universal fertilizers, comprising dis
potash and 14% lime as di-calcium phosphate solving phosphate rockin nitric acid to form
with a relative ratio between the three first a solution containing calcium nitrate and
components of 1: 1.7:1.1.
Si@
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free phosphoric acid, dividing the solution so
Further, cli-calcium phosphate may be re obtained into two portions, cystallizing from
turned to the process for treatment with nitric the first of said portions as much as possible 95i
acid together with a fresh portion of phos
of the calcium nitrate present, and separa
ting the _crystals from the remaining mother
In this last-named way the total phos liquor, subjecting also the second portion of
phate rock.
.
phoric acid of the phosphate rock used may the initial solution to crystallization- of cal
' be transformed according to reaction (5) into cium nitrate but only to such> extent that 100
a mixed fertilizer with exclusively water sufficient lime in the shape of nitrate is re
soluble phosphoric acid.
The di-calcium phosphate may even, be
fore‘it
is returned for treatment with nitric
4@
acid be subjected to a treatment with am
monia or ammonium carbonate .whereby a
tained in solution to form di-calcium phos
phate with all the phosphoric acid present,
separating the crystals of calcium nitrate
from the solution, adding ammonia to the ios
latter to precipitate di-calcium phosphate
certain quantity of di-ammonium phos and to give a solution of ammonium nitrate,
phate is obtained in solution and may be separating di-calcium phosphate from the so
lution, converting the ammonium nitrate of
The tri-calcium phosphate _ the solution by means of potassium salts into
I or the mixture of di-phosphate and calcium potassium nitrate, which is crystallized out
carbonate obtained by this reaction is filtered and asolution of ammonium salt, separating
used as admixture for- preparing'the com
’ pound fertilizer.
110
off and is returned to treatment with nitric the potassium nitrate crystals from said so
50
55
acid together with fresh quantities cf phos lution, adding said potassium nitrate to the
phate rock. By this manner of working only Vfirst portion of mother liquor poor in calcium iis
a minimum of phosphatic residue needs be nitrate, neutralizing the mixture with am
monia and bringing the product to dryness.
returned to the system.
-_ '
2. A process of manufacturing concen
In the process described only very simple,
easily performable reactions are used. Dur
ing the sequence of reactions the racting sub
trated universal fertilizers, comprising dis- ‘
solving phosphate rock in nitric acid to form>
stancesand the products formed are to the a solution containing calcium nitrate and
greatest possible extent withdrawn from cir
free phosphoric acid, dividing the solution so
obtained into two portions, crystallizingv I
60 turning of any components of reaction and from the first of said portions as much as pos 12s
culation.
lt is even possible to avoid the re
still to obtain finished products of desired sible of the .calcium nitrate present, sepa
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65
composition and well-balanced rati-o of com rating the crystals from the mother liquor,
ponents. ri‘he process is therefore exceeding removing from said mother liquor the rest
ly economical and accommodable and offers of calcium by precipitation as calcium sul
considerable advantages as compared with phate, subjecting the second portion of the
'
al.
neraeor
' initial solution to crystallization of calcium
nitrate to such extent thatsu?îicient calcium to precipitate cli-calcium >phosphate and to
nitrate is retained in solution to form di-cal give a solution _of ammonium nitrate, sepa
cium phosphate with the phosphoric acid rating di-calcium phosphate from the solu
tion, converting the ammonium nitrate of the
'n present, separating'the crystals of calcium solution
means oi’ a potassium salt into po
nitrate from the solution, adding ammonia tassium by
nitrate
which crystallizes out and
to the latter to precipitate di-calcium phos
phate and to give a solution of ammonium a solution of ammonium salt, separating the
nitrate crystals from said solution, y
nitrate, separating di-calcium phosphate potassium
adding said potassium nitrate to the first
lo from the solution, converting the ammonium portion
of mother liquor poor in calcium ni
nitrate of the solution by means of potassium
salts into potassium nitrate, which crystal trate, neutralizing the mixed liquor with am
lizes out, and a solution of ammonium salt, monia, adding a convenient quantity of di
separating the potassum nitrate crystals calcium phosphate obtained in the process to
the neutralized product and bringing the
115 from said solution, adding said potassium ni mixture
to dryness.
’
trate to the first portion of mother liquor-
testimony that l claim the foregoing
free from calcium nitrate, neutralizing the as ln
my
invention I have signed my name.
mixed liquor with ammonia and bringing the
2@
product to dryness.
3. A. process of manufacturing concen
ERLlNG JOHNSON.
trated universal fertilizers, comprising dis
$5
solving phosphate rock in nitric acid to term
a solution containing calcium nitrate and
free phosphoric acid, dividing the .solution
so obtained into two portions, crystallizing
from the Íirst of said portions as much as
possible of the calcium nitrate present, sepa
' rating the crystals from the mother liquor,
t3@
subjectingr the second portion of the initial
solution to crystallization of calcium nitrate
to such extent that sufficient calcium nitrate
is retained in solution to form di-calcium
phosphate with the phosphoric acid present,
separating the calcium nitrate crystals from
the solution, adding ammonia to the latter
to precipitate di-calcium phosphate 'and to
give a solution of ammonium nitrate, sepa
rating di-calcium phosphate from ‘the solu
tion, converting tie ammonium nitrate of
the solution by means of a potassium salt
into potassium nitrate Which crystallizes out
and a solution of ammonium salt, separating i
the potassium nitrate crystals from said solu
tion, adding said potassium nitrate to the
first portion >of mother liquor poor in calcium
nitrate and neutralizing the mixed liquor
with ammonia by distribution in an atmos
phere of ammonia gas for obtaining immedi
d@
ately a dry, neutralized product.
,
¿la A process of manufacturing concentrat
ed universal fertilizers, comprising dissolv
ing phosphate roclr in nitric acid to form a
solution containing calcium nitrate and tree
phosphoric acid, dividing the solution so ob-
tained into two portions, crystallizing from
the first of said portions as much as possible
of the calcium nitrate present, separating
the crystals from the mother liquor, subject
ing the second portion of the initial solution
to crystallization of calcium nitrate to such
extent that suñcient calcium nitrate is re
tained in solution to form di-calcium phos
phate with the phosphoric acid present, sepa
rating the crystals of calcium nitrate from
the solution, adding ammonia to the latter
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