FR2673941A1 - FERTILIZER COMPOSITIONS WITH HIGH HARDNESS AND HIGH STORAGE STABILITY. - Google Patents

Abstract

This fertilizer composition, characterized by high mechanical strength and high anti-agglutination properties, comprises: (a) a compound chosen from the group consisting of urea, ammonium sulphate, nitrogen-potassium-phosphorus granules, phosphate monoammonic, di-ammonium phosphate, potassium chloride and mixtures thereof; and (b) a lignate salt, water soluble, sulfur free, selected from the group consisting of sodium lignates, alkali metal lignates, ammonium lignates, and mixtures thereof, in an amount between 0.1 and 5.0% by weight of the final fertilizer composition, so that said fertilizer formulation has a high mechanical strength and a low tendency to break up lumps without affecting the dissolution capacity of that -this.

Description

FERTILIZER COMPOSITIONS HAVING HIGH HARDNESS AND

HIGH STORAGE STABILITY

  The present invention relates to a method of

  manufacture of a fertilizer composition and on a compound

  sition of fertilizer as such which is characterized by

  high mechanical resistance and anti-

  high agglutination, while retaining the ability to

high dissolution.

  So far, one of the main problems encountered in handling, transporting and storing fertilizers is the fact that fertilizers tend to clump. In addition, known fertilizer compositions do not fail to present an acceptable degree of hardness or resistance to breakage It is common in the prior art to add additives to the fertilizer which modify the crystallization mode of the fertilizer during the transformation of the fertilizer into a final desired product US Patents US-A-3,112,343, US-A-4,160,782 and US-A-4,204,053 describe various methods for the treatment of fertilizers with additives, such as formaldehyde, in an effort to eliminate the problems as mentioned above Formaldehyde has been designated by the United States Environmental Protection Agency as

  being a toxic chemical and a potential substance-

  As a carcinogen, therefore, other additives have been used in fertilizers in an attempt to reduce the fragility of the fertilizer and its tendency to lump. US patent US-A-4,587,358 describes a fertilizer composition which Uses Lignosulfonates as Additives to Improve Previous Properties US Patents US-A-4,743,289 and US-A-4,846,871

  similarly describe improved fertilizer compositions employing additives which tend to increase the mechanical strength of the fertilizer as well as its anti-caking properties.

  Of course, it would be very desirable to provide a fertilizer composition and a method of making it.

  cation thereof, a composition which is characterized by a

  high mechanical resistance and anti properties

  high agglutination, while at the same time being non

  toxic, non-carcinogenic and relatively inexpensive to manufacture. Accordingly, the main object of the present invention is to provide an improved fertilizer composition and a method of making the same, in which composition the fertilizer is characterized by

  high mechanical resistance and anti properties

high agglutination.

  The present invention has the particular objective of providing a fertilizer as described above which comprises an additive in the form of a salt of the type

lignate, soluble in water.

  Another object of the present invention is to provide a fertilizer and a process as indicated above which uses a salt of lignate type, soluble in water, as an additive, the salt of lignate type being derived from materials

  waste developed in pulp mills.

  Another object of the present invention is also

  that of proposing a fertilizer and a process as described above

  above, fertilizer that is cheap, non-toxic and non-toxic

  carcinogenic. Other objectives and advantages of this

  invention will appear in the following.

  In accordance with the present invention, the objectives

  and previous advantages are easily obtained.

  The present invention relates to a fertilizer composition and a method of making the same, wherein the fertilizer is characterized by

  high degree of mechanical resistance and anti-

  agglutination According to the present invention, the fertilizer composition comprises a compound chosen from the group consisting of urea, ammonium sulphate,

  nitrogen-potassium-phosphorus granules, phosphate mono-

  potassium and their mixtures; and a salt of lignate type, soluble in water, free of sulfur, chosen from the group consisting of sodium lignates, alkali metal lignates, ammonium lignates, and their mixtures, in an amount between 0 , 1 and 5.0% by weight of the final fertilizer composition, so that said fertilizer formulation has high mechanical strength and a low tendency to lump without

  affect its dissolution capacity

  In a preferred embodiment of the present invention, the water-soluble lignate salt is a sulfur-free sodium lignate which is derived from waste products from pulp mills Preferred compounds to be used in the composition of fertilizers are urea, ammonium sulfate, chloride

  potassium, mono-ammonium phosphate and di-phosphate

  ammonia, urea being a common nitrogen support By using an addition of a lignate type salt, the resulting fertilizer is characterized by a greater resistance to compression and impact, as well as by a reduced tendency

to the formation of lumps.

  The process for manufacturing the fertilizer of the present invention comprises mixing the compound and the lignate salt so as to produce a homogeneous mixture thereof, then heating the mixture in an oven at a temperature between 120 and 160 @C, and thereafter treating the mixture to obtain a desired form of particulate material In accordance with the preferred embodiment of the process of the present invention, lignate of

  sodium comes from the processing of paper pulp.

  The fertilizer of the present invention and the process for making it result in a non-fertilizer composition

  toxic, non-carcinogenic, which is characterized by high mechanical strength and good anti-agglutination properties.

* 2673941

  The residual material obtained in pulp mills, designated as "soda liquor", consists essentially of a lignate solution. At the processing stage in pulp mills, the raw materials are treated with sodium hydroxide, which leads to a "soda liquor", in which the lignates are mainly sodium lignates. To obtain the additive formed by the type LED

  lignate, soluble in water, for use in the composition

  sition of fertilizer of the present invention, the "soda liquor" is dehydrated so as to give an aqueous solution having a sodium lignate concentration of between 48 and 55% by weight, or else the water is completely eliminated from

  so as to lead to a lignate powder, free of water.

  While sodium lignates are particularly

  Rely suitable as additives in the fertilizer of the present invention, it will be understood that other lignates, such

  than alkali metal lignates and ammonium lignates

  nium, can, in the same way, be used In addition, the lignates can contain other substances such as polysaccharides and / or monosaccharides and / or salts of acids resulting from the degradation of carbohydrates during the operation of pulping These can be present in the lignate without modifying its properties

  relating to mechanical strength and anti-caking

  nation In a preferred embodiment of the present invention, the lignate type salt is derived from a raw material used in the manufacture of paper pulp, which is preferably bagasse from cane sugar; however, other vegetable materials may be used which contain at least 15% by weight of lignin. In accordance with the process of the present invention, the salt of lignate type, soluble in water, is mixed with a compound chosen from the group consisting of urea, ammonium sulphate, nitrogen-potassium-phosphorus granules, mono-ammonium phosphate, diammonium phosphate, potassium chloride and mixtures thereof As has been emphasized above, the salt of lignate type, soluble in water, is chosen from the group consisting of lignates of alkali metals, ammonium lignates, and mixtures thereof, in an amount between 0.1 and 5.0% by weight of the final fertilizer composition, so that said fertilizer formulation has high mechanical strength and low tendency to lump,

  without affecting its dissolution capacity.

  In accordance with the present invention, the preferred water-soluble lignate salt is a sulfur-free sodium lignate, and the compound with which it is mixed is preferably urea When urea is used as compound, the salt of lignate type must be present in the final fertilizer composition at a rate of 0.1 to 1.0% by weight When ammonium sulfate is used as compound, the salt of lignate type, soluble in water, is present in the final fertilizer composition in a

amount from 2.6 to 4.8% by weight.

  In accordance with the present invention, the compound and the water-soluble lignate salt are mixed together so as to give a homogeneous mixture. The homogeneous mixture is subsequently heated to a temperature of 120 to 160 ° C., then transformed, by the well-known technique of

  granulation, in the final particulate form.

  As pointed out above, the lignate type salt is obtained from waste products obtained during the processing of paper pulps, and the raw material used in the processing is usually

sugarcane bagasse.

  The properties of the fertilizer of the composition are comparable to those of known fertilizer compositions, and this will be demonstrated in the following with reference to the examples. The hardness or the mechanical resistance of the fertilizer has two components, the first component being the compressive strength, which is a static force, and the second component being an impact resistance, which is a dynamic force The compressive strength is determined in accordance with the Chatillon Hardness Compression Test, and employs a fabricated device by John Chatillon & Sons according to model no LTCM-3, according to Standard S-115 of the International Fertilizer Development Center The impact resistance is determined according to Standard F-118 of the International Fertilizer Development Center The tendency to lump formation is assessed by means of accelerated agglutination tests. Such tests consist in placing a certain amount of gr null inside a hollow cylinder and trap the granules between two Plexiglass pistons After an established period of time, a cupcake is obtained, which is then subjected to a break The force necessary to

  breaking the cake is determined using a penetrometer.

  The weaker the force, the less agglu-

  tination. The following examples will demonstrate the quality of the fertilizer of the present invention by comparison with

known fertilizer compositions.

EXAMPLE 1

  A "soda liquor", having a total solids content of 8% by weight, was dehydrated so as to obtain a solution having a solids content of 51% by weight. The concentrated liquor was mixed with solid urea in two different batches, so as to obtain a final product in Test 1 at 0.5% by weight of lignate-type salt and, in Test 2, at 0.7% by weight of type salt lignate Each of the test fertilizers was then mixed so as to obtain a homogeneous mixture, then the mixtures were melted in an oven at a temperature of 1400 C. The observation indicated that the lignates became very soluble in molten urea and that the solutions of

  lignate in urea did not show the slightest disorder.

  Then, the mixture was cooled and granulated in a known manner, so as to obtain particles of various diameters After the formation of beads, the granules were sieved, in order to be separated by granular dimensions of 1.68 mm (10 mesh), 1.41 mm (12 mesh) and 1.19 mm (14 mesh). Another fertilizer composition according to a Test 3 was obtained by adding powdered lignate type salt to urea so as to obtain a final fertilizer composition containing 0.5% by weight of lignate type salt Le mixed was then mixed to form a homogeneous mixture, and was heated and granulated, then separated in the same manner as in Tests 1 and 2 To demonstrate the behavior of the fertilizer compositions of the present invention, their strength compression was determined in accordance with Chatillon Hardness Compression and compared with that of two known fertilizer compositions containing urea and an additive and a fertilizer consisting solely of urea The two known fertilizer compositions were as follows : UF-85 R, from Allied Chemicals (USA) and Norlig-HPR, from Daishowa Chemicals (USA) The results of the compression tests are set out below in Table I.

TABLE I

  COMPRESSION RESISTANCE IN N (kg)

  AMOUNT OF ADDITIVE IN AVERAGE GROWTH OF

  UREA (U S Standard Mesh) ADDITIVE RESISTANCE t X by weight) COMPRESSION (% by weight) 1.68 mm 1.41 mm 1.19 mm

(10 MESH) (12 MESH) (14 MESH)

6.87 1.37 5.49 1.47 3.53 * 1.08

  NONE WITHOUT ADDITIVE (0.7 0.14) (0.56 0.15) (0.36 0.11)

8.44 2.06 6.77 0.98 5.00 1.37

  UF-85 0.3 (0.86 0.21) (0.69 0.10) (0.51 0.14) 29

9.03 1.96 6.67 1.18 4.71 0.88

  Nor Lig-HP 0.5 (0.92 0.20) (0.68 0.12) (0.48 0.09) 28 0.5 10.69 1.57 7.46 i 1.28 5, 30 * 1.28 Test I Lignate type set (1.09 * 0.16) (0.76 0.13) (0.54 i 0.13) 47 0.7 10.79 2.65 7.46 i 1.57 5.30 i 1.37 Test II Lignate type set (1.10 i 0.27) (0.76 i 0.16) (0.54 i 0.14) 47 0.5 12, 26 i 1.47 7.85 i 0.98 5.98 i 0.78 Test III Lignate type set (1.25 0.15) (0.80 i 0.10) (0.61 0.08) 63 "l KO oo

  As shown in Table I, the fertilizers of the present invention exhibit resistance to compression.

  which is greater than that of any of the known fertilizer compositions In addition to the above, the impact strength was measured in accordance with Standard IFDC-118, and the results are again presented below

in Table II.

TABLE II

INCREASES-

  QUANTITY RESISTANCE TO SHOCK MENT OF

RESISTANCE ADDITIVE ADDITIVE

SHOCK UREA

  (% by weight) BROKEN GRANULES (% by weight) a% N weight)

NO WITHOUT ADDITIVE 6.7 0.1 _

UF-85 0.3 1.2 0.7 82

  Norlig-HP 0.5 2.4 0.7 64 Test I 0.5 0.6 + 0.4 91 Lignate-type salt Test II 0.7 1.9 + 0.7 72 Lignate-type salt Test III 0 .5 2.9 + 0.757 Lignate-type salt As shown in Table II, the impact resistance of the fertilizer compositions of the present invention is

  comparable to that of known fertilizer compositions.

EXAMPLE II

  The fertilizers used in Example I were subjected to agglutination tests in accordance with the procedure.

  described above, and the results of these agglomeration tests

  tination are presented in Table III below.

TABLE III

  QUANTITY OF ADDITIVE RESISTANCE REDUCTION OF

  ADDITIVE IN THE DURATION OF CAKES AGGLUTINATION

(% by weight) in N (kg) (% by weight)

119.7 2.9

NO WITHOUT ADDITIVE (12.2 0.3)

61.8 + 11.8

UF-85 0.3 (6.3 1.2) 48

27.5 12.8

Norlig-HP 0.5 (2.8 1.3) 77

0.5 54.9 13.7

  Test I Lignate-type salt (5.6 1.4) 54

0.7 38.3 + 8.8

  Test II Lignate type salt (3.9 0.9) 68

0.5 38.3 + 9.8

  Test III Lignate-type salt (3.9 1.0) 68 Again, it can be seen that the agglutination tendencies of the fertilizer compositions of the present invention are, in the worst case, comparable to, and , in many cases better than, trends

  agglutination of known fertilizer compositions.

EXAMPLE III

  To demonstrate the efficacy of other compositions of the fertilizer of the present invention, a lignate powder

  sodium was mixed with nitrogen-potassium granules-

  phosphorus, having a 15-15-15-solid formulation, so

  to give a final composition at 5% by weight of lignate.

  A second formulation was made by mixing

  nitrogen-potassium-phosphorus granules having the formulation 13-

  26-06 with sodium lignates, so as to obtain a final composition at 2.8% by weight of lignate Agglutination tests were again carried out in order to compare

  the effect of the additive of the present invention on these compounds

  it sitions of fertilizer, and the corresponding results are

  given below in Table IV.

TABLE IV

LIGNATE RESISTANCE OF REDUCTION

  TYPE OF FERTILIZER (% by weight) CAKES BY N OF AGGLUTINATION (kg) (% by weight) (% by weight)

0.0 122.6 + 9.8

(12.5 + 1.0)

13-26-06

2.8 73.6 + 10.8

(7.5 + 1.1) 40

0.0 143.2 + 3.9

(14.6 + 0.4) -

-15-15

.0 70.6 + 6.9

(7.20.7) 51

  Table IV shows that the addition compound formed of a lignate-type salt according to the present invention greatly reduces the agglutination tendencies of the fertilizers.

known.

  This invention can be implemented in other forms or implemented in other modes without departing from its spirit or its essential characteristics. The present embodiment must therefore be considered in all its aspects as being illustrative and not limiting, all the modifications which belong to

  the general definition of the invention and the range of equi-

  valence being intended to be included in the field of

  definition of the present invention.

Claims (7)

  1 Fertilizer composition characterized by a   high mechanical strength and anti-caking properties   high tination, comprising: (a) a compound chosen from the group consisting of urea,   ammonium sulfate, nitrogen-potassium granules-   phosphorus, mono-ammonium phosphate, di- phosphate   ammonia, potassium chloride and mixtures thereof; and Z (b) a salt of lignate type, soluble in water, free of sulfur, chosen from the group consisting of sodium lignates, alkali metal lignates, ammonium lignates, and their mixtures, in a an amount between 0.1 and 5.0% by weight of the final fertilizer composition, so that said fertilizer formulation has a high mechanical strength and a low tendency to form lumps without affecting the   ability to dissolve it.   2 fertilizer composition according to claim 1, characterized in that said salt of lignate type, soluble in water, is a sodium lignate free of sulfur. 3 fertilizer composition according to claim 1, characterized in that the compound is urea, and the salt of lignate type, soluble in water, is present in an amount between 0.1 and 1.0% by weight of the final fertilizer composition.   4 fertilizer composition according to claim 1, characterized in that the compound is ammonium sulphate, and the salt of lignate type, soluble in water, is present in an amount between 2.6 and 4, 8% in   weight of the final fertilizer composition.   A method of manufacturing a fertilizer composition characterized by improved high mechanical strength and improved anti-agglomeration properties, comprising the steps of: (a) taking a compound selected from the group consisting of   urea, ammonium sulfate, nitrogen granules-   potassium-phosphorus, mono-ammonium phosphate, diammonium phosphate, potassium chloride and mixtures thereof; (b) adding to said compound a salt of lignate type, soluble in water, free of sulfur, chosen from the group consisting of sodium lignates, alkali metal lignates, ammonium lignates, and their mixtures, in an amount between 0.1 and 5.0% by weight of the final fertilizer composition; (c) mixing said compound and said lignate type salt, so as to produce a homogeneous mixture thereof; and (d) treating said mixture so as to obtain a form desired particulate matter.   6 Method according to claim 5, characterized in that it comprises the operation of taking a sodium lignate free of sulfur as salt type above-mentioned lignate.   7 Method according to claim 5, characterized in that it comprises the stages of heating the mixture of the compound and the salt of lignate type before the treatment for   obtain the desired form of particulate matter.   8 Method according to claim 5, characterized in that it comprises the steps of processing the   "soda liquor" to obtain said lignate type salt.   9 Method according to claim 8, characterized in that said "soda liquor" is the residual liquor from the treatment of sugar cane bagasse with sodium hydroxide to obtain pulp. Additive for a fertilizer composition so as to improve the mechanical resistance and the anti-agglutination properties thereof, which comprises a salt of lignate type, soluble in water, free of sulfur, chosen from the group consisting of sodium lignates, alkali metal lignates, ammonium lignates, and mixtures thereof, in an amount between 0.1 and 5.0% by weight of the final fertilizer composition, such that said formulation he fertilizer has high mechanical strength and a low tendency to lump without affecting its dissolution capacity.