DE2039759C3 - Process for the production of a foamed, granulated urea-formaldehyde condensate - Google Patents

Description

60

The invention relates to a novel method for the production of an improved foamed-1, granulated urea-formaldehyde condensate : w. combining one with other components, d. H. with one or more additional : tive components added condensate, with ese additional components in the particles or Granules of the foamed condensate are embedded.

Foamed urea-formaldehyde condensation and combination products and their production methods are already known from German patent specification 15 92 753. You can find them as fertilizers Use alone and in combination with other products.

In the known method, the fertilizer is produced in such a way that initially urea in one aqueous urea-formaldehyde concentrate is dissolved to form a methylol-urea solution, that this solution is foamed and the pH of this foamed material to initiate the Condensation of the methylol urea is reduced and that the material cured and thereupon is dried. The dried material is then ground or otherwise comminuted. The particles those with their size above and below a certain range, namely 0.21 to 2.35 mm lighter Mesh size, lying, are sorted out.

The present invention aims to provide a novel process for the production of foamed urea-formaldehyde fertilizers be created, which is technically superior to the above-mentioned known manufacturing process and thus better Produced fertilizers and better fertilizer ingredients for combination products.

This object is achieved by the invention specified in claim 1.

The invention, like the above-mentioned known method, is concerned with the production of crushed urea-formaldehyde fertilizers that are used by mechanical spreaders as they are for use are formed on lawns and sports turf, can be evenly distributed. To the exact Distribution by means of spreaders, the fertilizer particles must have a largely uniform size. All particles of a given amount of fertilizer should large enough to hold back a sieve with a mesh size of 0.21 mm, but small enough that they fall through a sieve with a mesh size of 2.35 mm.

One of the important advantages of the method according to the invention is that the urea-formaldehyde material assumes a grainy structure during the hardening process) and becomes large part separates into individual grains and lumps of loosely connected grains. These particles are already largely the desired size of 0.21 to 2.35 mm. Accordingly, the The required amount of shredding is reduced, and shrinking techniques are also applicable, in which the urea-formaldehyde material is much less smashed or pulverized will. For obvious reasons, the result is a substantial reduction in the Accumulation of unusable fine material.

Before the condensation reaction is initiated, the solution can contain an anionic or nonionic surface-active agent Means are attached to the formation of the self-granulating structure of the material reinforce during curing. A de-lumping step can also preferably be used within the scope of the invention and / or a prefoaming step can be added to the process in order to produce both the to reinforce the granular character of the product as well as to regulate its bulk density.

The attached procedural sketch refers to a Embodiment of the invention for the production of slow release fertilizers (i.e. fertilizers, which typically have a nitrogen usability index of 45 to 55% and add nitrogen to the s Half or one third contained in a form insoluble in cold water). Furthermore, the attached Process scheme based on embodiments of the Invention for the manufacture of combined products using such fertilizers as a basis to be used. The initial step in all cases is the preparation of an aqueous solution of methylol urea, in which the ratio of urea to formaldehyde is in the range between 1.3: 1 and 2.4: 1 located. This can be done by dissolving solid urea and a urea-formaldehyde concentrate in Water at a temperature in the range between about 54 and about 71 C. For example, are suitable urea-formaldehyde concentrates on the market with 25% urea content ao and 60% formaldehyde content. The pH of the methylol urea solution prepared in this way will be in the range kept from 7.0 to 10.5 by adding caustic material such as sodium hydroxide will. »5

The urea-formaldehyde ratio, temperature and pH range as listed above, are within the scope of the invention for the production of urea-formaldehyde fertilizers and the combined Products according to the invention are extremely important. For example, this is the nitrogen usability index of the resulting product uselessly low when the ratio of urea to Formaldehyde is reduced below the value 1.3: 1. On the other hand, the nitrogen usability index becomes unacceptably high when the urea to formaldehyde ratio rises above 2.4: 1. In this In regard to this, it is an advantage of the invention that fertilizers with gradual nitrogen release characteristics can be generated, d. H. a fertilizer from which the usable nitrogen over a longer period of time is released. If the nitrogen usability index of the product is too high, you can Do not educate characteristic. Instead, in such a case essentially all nitrogen becomes practically * 5 immediately usable when the fertilizer is given up.

Furthermore, it is no longer possible to achieve the desired self-granulating property of the product, if the urea-formaldehyde ratio 3 = is increased above the maximum value given above. There are also other production difficulties.

During the dissolution process, the temperature becomes noticeably below the minimum value of lowered about 54 C, the free urea may not be in the practical feasibility of the process appropriate length of time or, in fact, not going completely into solution at all, depending on the water content the methylol urea solution.

On the other hand, if the temperature during the dissolution process is considerably higher than that recommended above The maximum value of 71 C already occurs in the case of the usability of the product to be manufactured necessary, considered range of the urea-formaldehyde ratio a condensation of methylol urea into methylene urea. But this is true during the solving process Avoid, as this creates a very viscous, difficult-to-treat material. The condensation reactions are also easier to control at a later point in the process to the end product with better characteristics.

The amount of water in which the urea is dissolved is also of great importance. Will the water-urea ratio lowered too much, the urea cannot be dissolved in an acceptable time, even at the maximum temperature is set for the solving process. The influence of the water-urea ratio on the solution time is such that an increase in this ratio is sufficient significantly reduces the solution time by 15%.

On the other hand, the water-urea ratio must not be too high, since in some cases the Methylol urea solution cannot be foamed. In other cases, the solution can be foamed but it does not give the desired self-granulating physical structure.

Regarding the limits within which to keep the pH of the methylol urea solution is, it applies that a harmful condensation of the methylol urea in methylene urea occurs when the The pH of the solution falls below 7.0. On the other hand, the physical and chemical properties of the end product is adversely affected if the pH of the methylol-urea solution is above the Maximum value of 10.5 increases, because then unmanageable changes in the later occurring condensation reactions can enter.

As can also be seen from the sketch, the prepared methylol urea solution can be foamed and the condensation of the methylol urea to methylene urea directly after the preparation of the solution be initiated.

Sources of potassium and phosphate can be used to gradually produce a fertilizer at the same time Methylol-Urns.toff solution are added, since it has been found that this makes a much more uniform Distribution of the additives is achieved as if these materials are added simultaneously. Preferably the phosphate source is added after the potassium source. This is because that phosphates, as they are suitable for fertilizers, have an acidic pH. Tend accordingly such materials to initiate the condensation of the methylol urea, so that the foaming process must be initiated within a very short time after the introduction of the phosphate. It It is therefore impractical to add further additives to the methylol urea solution after the phosphate source has been introduced to mix.

There are a number of suitable sources of both potassium and phosphate. Sources of potassium are at for example potassium sulphite, potassium chloride, potassium phosphate and potassium nitrate. There can be many phosphate « Both natural and synthetic origin with the new fertilizers and combination products Products according to the invention are used, where it is preferred to use phosphate sources with a pH of voi 5.0 or higher to avoid undesired condensation of the methylol urea. A A number of suitable sources of phosphate are given in Commercia Fertilizers, Collings, 5th ed., 1955 McGrawhili New York, in summary. The phosphate sources listed there are ver within the scope of the invention reversible. Another suitable one on the market

Phosphate present has an analysis of 13-52-0. (The fertilizer analyzes used here are conventional, that is, a series of three numbers that each represent the percentage of total nitrogen, the percentage of usable phosphorus, calculated as P ₂ O ₅ , and the percentage of usable potassium, calculated as K ₈ O .)

To facilitate pH control and also the distribution of the additive in the methylol urea solution, the material containing potassium or phosphate is ground to a sieve size of 0.42 mm or applied in liquid form.

The proportions of the potassium and phosphate-containing materials used depend primarily on the desired analysis of the end product. However, there is a limit to the amount that can be used. If the amount of the potassium-containing material and / or the phosphate-containing material goes beyond this limit value, the methylol-urea solution cannot be foamed because all of the methylol-urea is used as a binder and none is left in the one Cell formation can occur. As a typical example, 0 to 60 parts of potassium, calculated as K ₂ O, and 0 to 60 parts of phosphorus, calculated as P ₂ O ₅ , can be used per 100 parts by weight of urea-formaldehyde solution.

The temperature at which these additives are introduced into the methylol urea solution is also essential. Simultaneously with or instead of potassium and / or phosphate sources If necessary, other additives with fertilizer components and trace elements can also be used can be added to the methylol urea solution in order to give the end product special properties.

After the steps described above, a surfactant is added. This will make the Increased tendency of the methylol urea solution to foam.

Any anionic or nonionic surfactants can be used within the scope of the invention to be used.

The surfactant is the methylol urea solution preferably in an amount of about 0.05 to about 2 to 1/2 weight percent of the total solution is added. The amount of surfactant added Means is important in the context of the invention. If less than 0.05% surfactant Agent is added, this does not have the satisfactory effect on the foaming of the solution, so that the desired low bulk density of the end product cannot be achieved. It is also then possibly not possible, the desired self-granulating property of the foamed Achieve solution. On the other hand, if the stated maximum value of 2 to 3% is exceeded, increase the manufacturing costs increase unnecessarily without any substantial improvement being achieved. In addition, the end product becomes a bit rubbery and sticky and is therefore just painful manipulate and distribute with a spreader. There is then also an undesirable reduction in the Plant nutrient content of the final product.

The solution of methylol urea and surfactant, with or without additives, is preferably subjected to a prefoaming step, although this step is in most cases insignificant for carrying out the process and can therefore be omitted. With this prefoaming, products with a lower bulk density can be produced, namely products with bulk densities down to 0.24 to 0.32 g / cm ³ can be produced. If, on the other hand, no prefoaming step is used, the lowest bulk densities are around 0.08 to 0.16 g / cm ³ higher than the bulk densities of products of the same composition without a prefoaming step. The lower bulk densities

ίο are desirable in so far as the product is in desired Quantities using conventional spreaders or other dry spreading equipment can be distributed more evenly.

The pre-foaming is done by stirring the methylol urea solution for a period of 1 to 10 seconds achieved. Air can also be introduced into the solution, preferably in such an amount that the Pre-expanded material contains up to 50 to 75% air to increase the foaming of the solution. With

With stirring alone, the bulk density of the end product can be ^{reduced to about 0.03 to 0.05 g / cm 3} ; the use of air in conjunction with stirring can reduce the bulk density by 0.08 to 0.16 g / cm ³ .

The next step in the process is to lower the pH of the methylol urea solution, to start the condensation of the methylol urea to methylene urea. this is done by stirring the methylol urea

Dissolving and simultaneously adding an acidic material to catalyze the condensation reactions. In a typical example, the catalyst can be dilute sulfuric acid, although it can also be phosphoric acid and other acids can be used instead, if desired. Phosphoric acid is in some This is advantageous because the catalytic effect is not as great as that of sulfuric acid. Therefore have fluctuations in the amount with which the acid is added, less pronounced effect on the reaction and the end product. The catalytically active acid is at a temperature in the range between about 49 and 60 C introduced.

In a typical application example of the invention, the methylol urea solution is in a Kettle placed in which the condensation reaction at a pH of 5 to 8.5 or higher is initiated. Sufficient catalyst is then added to the solution with stirring until completion stirring a pH value of 3.5 to 6.5 is reached). The lowering of the pH of the solution also helps this area is important for determining the properties of the end product. For example, if dei If the pH is too low during the discharge, the material will not stretch properly during the next Curing step. The end product then also has an unusually low nitrogen usefulness ability index.

On the other hand, if the pH value is above the specified limit when the solution is left out, di < Condensation reactions do not depend on the desired extent. Then the mixed party sit down Particles, the material does not develop the self-granulating properties in the subsequent the curing step and it becomes rubbery and sticky.

When initiating the condensation reaction, the degree of stirring must be the temperature of the methylol Urea solution and the residence time (i.e. the time

in which the solution is stirred) within specified As can be seen from the sketch, follows the upper

Limits are kept. The next step is the curing process

In particular, it is important that the temperature processing step. In doing so, the material is converted into a single layer

while stirring the methylol urea solution layer spread, which has an initial thickness of 2t

below a maximum of about 105 "C - 5 to 150 mm.

will. If the temperature rises during stirring The hardening takes place in a temperature range

this maximum, the material reacts in ^c 82-105 C, period of time of at least 1 min. Damii

Reactor and die in it. It is also important to ensure that the condensation of the methylol

that the solution is almost complete while stirring to one Tcmpe-urea to methylene-urea!

temperature of at least about 57 C is heated. When is 10 and a physically stable material is created

this temperature is not reached, the rcak- which is easy to handle. During this time

tion is not complete, as explained above, the material layer expands to 3-fold

has partial consequences. 4 times their original strength, what a

The main purpose of stirring is to considerably reduce the bulk density of the acid Catalyst intimately with the methylol urea to 15 material results. Mix during curing and the solution homogeneous and any step the material also separates into granules and Additives dispersed evenly in the solution to form larger clumps that are made up of only loosely cohesive. (At the point in time at which the material exists from the granules. This means that during The viscosity of the curing step is that of the novel Proschon sufficiently high that the additives do not work and the novel process according to the invention drop). It was found that when stirring, characteristic self-granulating effect in soil Solution occurs in a kettle with a rotating stirrer appearance.

tools Rotational speeds of these stirring tools in the The various parameters described in the above Size of 46 rpm were required to complete a curing step are of considerable importance sufficient mixing of the catalyst and the 35 If so the initial layer thickness is not above Methylol urea solution. If the specified minimum thickness is kept, breaks The lower speed of the stirring tool was the cell-like structure of the material together, and Condensation reaction unstable. The cured product is more dense, not found that additional acid was needed to create a porous structure rather than the desired porous cell structure. Material with the same physical properties as 30 In addition, the cured product is given rubber products, than with a higher stirring speed. These-like characteristics that make it difficult to use is undesirable because a handle due to the additional acid. Furthermore, then the material layer does not hold the End product with an unusually low nitrogen - heat required for the reaction in such a material usability index arises. The maximum stirring catch, as it is for the completion of the condensation effect, is given by the fact that no physical reactions are necessary. As a result, the end result is degradation of the material to be stirred may occur. unsatisfactory fertilizer properties In the above-mentioned stirring device, stirring (i.e., nitrogen utility). On the other hand, if the speeds up to 200 rpm are used without a layer being too thick, the bottom part of the layer breaks down Degradation of the material occurred. : men. This then results in a massive bottom layer of the

In general, greater agitation is preferred.
because the amount of acidic catalyst with regard to the curing temperature can be reduced. The result is a greater care that the condensation reactions are exothermic pH on the outlet side of the agitator and type. If, accordingly, the material layer is kept on a product with a higher nitrogen usability - its specified minimum thickness, it is the keitsindex. On the other hand, increased stirring action does not necessarily result in a denser, more closely grained material to be supplied to the eye during the curing step. As a result, however, above all my is less desirable, or even a material also the temperature of importance, with which the continuous massive structure, so that material is introduced into the layer (ie the tempedie benefits achieved by greater agitation in temperature, with which allows the material to ensure the agitator scope through the associated 50). This temperature is intended to offset the disadvantages in the order of magnitude. between about 60 and 105 C.

With regard to the residence time, in many cases the minimum curing time is necessary to achieve a Acid consumption is required by increasing the stirring time because the product is easy to handle. While

can be significantly reduced. This is desirable because the material can be used after a short time, for example

Then a product with a higher pH value of 55 turns out to be solid after 15 seconds, depending on the pH value

and improved nitrogen utilization properties appears, it is still rubbery and difficult to use

result .. handle.

As already explained above, a pre-expansion It is also important that in the initial stage of the step used in the method according to the invention, curing step avoided any stirring when producing 60 relatively low density products. That would be the desired development will be so. The importance of the pre-foaming cell-like structure in the hardening material was demonstrated by tests in which air could prevent and possibly even lead to was introduced into the solution while stirring, while the material cake or the material layer was introduced together with the acidic catalyst, so as to break the mixture.

To increase foaming of the material without a 65 At the end of the curing step, the material has to use a pre-expansion step. Introducing a moisture content of 16-22%. Zar VerLuft in the stirring device but no WIR had reduction in moisture to about 4 ° _o is the effect on the bulk density of Endprodukis. cured material dried. First, however

the material is preferably de-lumped (i.e. broken), so that the maximum diameter of the dryer inlet need not be larger than 12.5 to 25 mm.

The de-lumped material is passed through drying zones which are kept at successively lower temperatures, whereby the temperature of the material to be dried should not exceed about 93 ° C. in order to avoid polymerization reactions with formation of _{NH 3.} The drying times are between 15 and 25 minutes. The layer thickness during drying is preferably 50 mm, it depends on the drying equipment.

The stated maximum moisture content of the dried product is also practical Use of the present invention of importance. If the material is not up to the recommended When dried border, it develops a considerable tendency to cake and it is difficult to seven.

The dried material is ground to a particle size of the oversized lump To bring 0.21 to 2.35 mm, so that the product with conventional spreaders on the market can be distributed. After milling, the particles are below 0.21 mm and above 2.35 mm removed from the ground material.

The oversized particles are fed back into the grinding and sieving processes. The fines are made into usable size product particles by mixing with an agglomerating agent and introducing the agglomerated material into the inlet of the dryer. Suitable agglomerating agents are water and urea-formaldehyde solutions, with water being preferred as it is a produces better agglomeration. Agglomeration allows the total fertilizer yield raise.

The agglomeration is carried out in a paddle or bar stirrer.

In connection with the process sequence described above, the curing of the methylol-urea solution can typically be carried out on an endless belt. The hardening material tends to adhere to this tape and must be removed accordingly. One step that can be used to clean the tape is to direct jets of water against the tape and wash off the adhering urea-formaldehyde material. This produces an aqueous urea-formaldehyde solution that can be used as an agglomerating agent. The use of this solution is advantageous, since it solves the problem of supplying water as an agglomerating agent and economically considerable amounts of urea-formaldehyde material are also recycled into the process.

As can also be seen from the attached sketch, the method according to the invention can be used for the production of combined products as well as actual fertilizers.

There is no restriction on the type of ingredients that can be incorporated into combined products according to the invention. Ingredients that can advantageously be added are: herbicides, fungicides, growth regulators, insecticides, nematoxides, insect and animal repellants, soil sterilants, trace elements, fertilizers and additives such as dyes, adhesives, solvents and conditioning agents. Examples of such composites of the types described above are known (see, for example, U.S. Patent 32 31 363) and are also described in the following publications: Chemistry of the Pesticides (3rd Edition), Froar, D. Van Nostrand Company, Inc. , New York, NY; Weed Control (2nd Edition), Robbinsetal, McGraw-Hill, Book Company, Inc., New York, NY; Commercial Fertilizers (5th Edition), CoI lings, McGraw-Hill, Book Company, Inc., New York,

jo N. Y. and Farm Chemichals 1969 Handbook, Meister Publishing Company, Willoughby, Ohio.

There are numerous adhesives used in the premixing step and also in the final mixing step can be used to improve the adherence of the attached residues to the fertilizer particles. Examples of such adhesives are: polybutene; polyhydric alcohols such as ethylene, propylene, dipropylene, triethylene and hexylene glycol; 2,2-diethyl-1,3-propanediol; 2-ethyl-2-butyl-1,3-propanediol; 1.5-

ao pentanediol; and 2-ethyl-l-l, 3-hexanediol and polyethylene and higher molecular weight polypropylene glycols.

Other adhesives that have been found useful are: Glycol ethers such as ethylene glycol mono-

ethyl ether; Ethylene glycol monomethyl ether; 1-butoxyethoxy-2-propanol; Diethylene glycol monoethyl ether; Dietary glycol monomethyl ether; Diethylene glycol monobutyl ether; Methoxytriglycol; Ethoxy triglycol and less volatile ketones such as methyl ethyl ketone and diisobutyl ketones.

The premix is applied to the fertilizer product in one by spraying or by means of gravity Zigzag mixer or similar mixer applied to evenly distribute the added Ensure component or the added components. Surprisingly, it was found that the residence time in the mixing device has little influence on the uniformity of the end product Accordingly, it is preferred to use only short dwell times, as this reduces throughput the mixer is increased.

In connection with the mixing with further ingredients, the method according to the invention provides a considerable advantage over the known

Process (see. USA. Patent 32 31363). Because in the context of the invention additives directly in there; Fertilizers can be brought in by yourself. In particular, the added constituents in the products according to the invention are released more easily after fertilization, which is advantageous under many circumstances.

For a better understanding of the invention, some exemplary embodiments are explained in the following.

Embodiment I.

A complete fertilizer with the analysis 32-6-4 was used in above-described process from a urea formaldehyde solution with a urea formaldehyde hyd ratio of 1.9: 1.0 using before phosphoric acid to initiate the condensation reaction tion made. The materials and the proportions in which they were used are as follows:

Material parts by weight Urea (45% nitrogen) 53.16

Urea-formaldehyde solution (11% nitrogen) 26.98

Ammonium phosphate (12% nitrogen,

52% P ₂ O ₅ ) 10.07

Potassium Sulphate (50% K ₂ O) 6.71

Phosphoric acid (40% solution of

H ₃ PO ₄ in water) 2.26

surfactant sodium dodecylbenzenesulfonate (60% aqueous Solution) 0.81

With the exception of urea, all solid constituents had a grain size of less than 0.42 mm.

Chemical analysis of the product after drying to 1.7% moisture content found 32.1% total nitrogen, 6.9% usable P ₂ O _5, and 4.6% usable K ₂ O. Approximately 49.8% of the nitrogen was in insoluble in cold water and the product had a desired nitrogen utility index of 40.8.

The sieve analysis showed approximately 96% in the range between 0.21 and 2.35 mm. Less than 4% were below 0.21 mm. ^ao

Embodiment 2

A complete fertilizer with the analysis 31: 6: 4 was made from urea-formaldehyde solution in the method according to the invention with a urea-formaldehyde ratio of 1.5: 1.0 using dilute sulfuric acid to initiate the condensation reaction. The materials used and conditions were:

material

Parts by weight

30th

35

40

Urea (45% nitrogen) 49.57

Urea-formaldehyde concentrate

(11% nitrogen) 31.72

Ammonium phosphate (12% nitrogen,

52% P ₂ O ₅ ) 9.97

Potassium Sulphate (50% K ₂ O) 7.09

Sulfuric acid (20% aqueous solution

of H ₂ SO ₄ ) 1.23

Sodium dodecylbenzenesulfonate

(60% aqueous solution) 0.42

The resulting fertilizer had the following properties:

Chemical Analysis

4.2% moisture
31.6% nitrogen

6.6% usable P ₂ O ₃

4.1% water-soluble K ₂ O
62.3% cold water insoluble nitrogen 35.7% nitrogen utility index

Sieve analysis 94% 0.21 to 2.35 mm less than 5% were below 0.21 mm.

Embodiment 3

A complete fertilizer with the analysis 31-6-4 was produced in the method according to the invention from a urea-formaldehyde solution with a urea-formaldehyde ratio of 1.3: 1.0 using dilute sulfuric acid to initiate the condensation reaction . The materials and proportions used were :

55

Material parts by weight Urea (45% nitrogen) 45.94

Urea-formaldehyde concentrate (1!% Nitrogen) 36.46

6s ammonium phosphate (12% nitrogen,

52% P ₂ O ₃ ) 6.76

Potassium Sulphate 9.67

Sulfuric acid (20% aqueous solution of H ₂ SO ₄ ) ... '. 0.85

Sodium dodecylbenzenesulfonate (60% aqueous solution) 0.32

The resulting fertilizer had the following properties:

Chemical Analysis

2.8% moisture
31.0% nitrogen

6.1% usable P ₂ O ₅

4.3 "" usable K ₂ O

74.8% cold water insoluble nitrogen 31.0% nitrogen usability index

Sieve analysis

95%: 0.21 to 2.35 mm
less than 4% were below 0.21 mm.

Embodiment 4

A complete fertilizer with the analysis 32: 6-3 was in the method according to the invention from a urea-formaldehyde solution with a urea-formaldehyde ratio of 1.5: 1.0 using dilute sulfuric acid to initiate the condensation reaction, potassium nitrate as Source of the usable K ₂ O and other surfactant prepared. The materials and proportions used were:

Material parts by weight

Urea (45% nitrogen) 49.07

Urea-formaldehyde concentrate

(11% nitrogen) 31.81

Ammonium phosphate (12% nitrogen,

52% P ₂ O ₅ ) 7.60

Potassium nitrate (13% nitrogen,

44% K ₂ O) 8.60

Sulfuric acid (25% aqueous solution

voii H ₂ SO ₄ ) 2.67

surfactant sodium dodecyl sulfonate (90% active

Material) 0.25

The resulting fertilizer had the following properties:

Chemical Analysis

0.6% moisture 32.5% nitrogen

6.5% usable P ₂ O ₅

3.3% usable K ₂ O 55.1% cold water insoluble nitrogen

Sieve analysis

95%: 0.21 to 2.35 mm less than 4% were below 0.21 mm.

Embodiment 5

A complete fertilizer with the analysis 33-6-4 was made in the method according to the invention from a urea-formaldehyde solution with a urea-formaldehyde ratio of 1.5: 1.0 using potassium nitrate as a carrier for the usable K ₂ O and ammonium phosphate as a carrier for the usable P ₂ O ₅ and as a catalyst for introducing the condensate

ation reaction produced. The materials ind conditions used were:

Material parts by weight

Urea (45% nitrogen) 49.98

Urea-formaldehyde concentrate

(11% nitrogen) 32.40

Ammonium phosphate (11% nitrogen,

58% P ₂ O ₅ ) 10.43

Potassium nitrate (13% nitrogen,

44% K ₂ O) 6.95

Sodium dodecylbenzenesulfonate 0.24

The resulting fertilizer had the following properties:

Chemical Analysis
3.7% moisture
33.1% nitrogen

6.6% usable P ₂ O ₅

4.7% usable K ₂ O

63.4% cold water insoluble nitrogen 30.3% nitrogen usability index

Sieve analysis

95%: 0.21 to 2.35 mm
less than 5% were below 0.21 mm.

Embodiment 6

A complete fertilizer with the analysis 32-5-4 was prepared in the method according to the invention from a urea-formaldehyde solution with a urea-formaldehyde ratio of 1.3: 1.0 using dilute sulfuric acid to initiate the condensation reaction, Potassium nitrate is produced as a carrier for the usable K ₂ O and ammonium phosphate as a carrier for the usable P ₂ O ₅ . The materials and proportions used were:

Material parts by weight

Urea <45% nitrogen) 53.52

Urea-formaldehyde concentrate

(11% nitrogen) 26.76

Ammonium phosphate (10% nitrogen,

55% P ₂ O ₅ ) 8.10

Potassium nitrate 10.05

Sulfuric acid (15% aqueous solution

VOnH ₂ SO ₄ ) 1.30

Sodium dodecylbenzenesulfonate 0.27

The resulting fertilizer had the following properties:

Chemical Analysis 6.0% moisture 32.7% nitrogen

5.3% usable P _a O ₆ 5 · =

4.1% usable K ₂ O

40.7% cold water insoluble nitrogen

38.8% nitrogen usability index

Phosphoric acid to initiate the condensation reaction and potassium metaphosphate as a carrier for both the usable P ₂ O ₅ and the usable K ₂ O are produced. The materials and proportions used were:

Material weight parts

Urea (45% nitrogen) 53.34

Urea-formaldehyde concentrate

(11% nitrogen) 34.98

Potassium metaphosphate (58% P ₂ O ₅ ,

36% K ₂ O) 10.49

Phosphoric acid (40% aqueous solution

of H ₃ PO ₄ ) 0.84

Sodium dodecylbenzenesulfonate 0.35

The resulting product had the following properties:

Chemical Analysis
2.0% moisture
32.8% nitrogen
7.75% usable P ₂ O ₅
4.67% usable K ₂ O

59.4% cold water insoluble nitrogen
45.8% nitrogen usability index

Sieve analysis

96%: 0.21 to 2.35 mm
less than 3% were below 0.21 mm.

Sieve analysis

85%: 0.21 to 2.35 mm less than 5% were below 0.21 mm.

Embodiment 7

A complete fertilizer with the analysis 32-7-4 was made in the ⁶ S method according to the invention from a urea-formaldehyde solution with a urea-formaldehyde ratio of 1.5: 1.0 using

Embodiment 8

A simple nitrogen fertilizer with the analysis 38-0-0 was made in the method according to the invention a urea-formaldehyde solution with a urea-formaldehyde ratio of 1.3: 1.0 using dilute sulfuric acid to initiate the condensation reaction. The used Materials and proportions were:

Material parts by weight

Urea (45% nitrogen) 45.94

Urea-formaldehyde concentrate

(11% nitrogen) 36.46

Sulfuric acid (15% aqueous solution). 1.16
Sodium dodecylbenzenesulfonate 0.33

The resulting fertilizer had the following properties:

Chemical Analysis

1.4% moisture 38.1 % nitrogen

65.3% cold water insoluble nitrogen 38.3% nitrogen usability chain index

Sieve analysis

95%: 0.21 to 2.35 mm less than 4% were below 0.21 mm.

Embodiment 9

A combined product with a complete fertilizer and 2,4-dichlorophenoxyacetic acid and 2-methoxy-3,6-dichlorobenzoic acid was prepared by forming a premix of the above pesticides (both lay in liquid form before) and through an adhesive Mixing this pre-mix with a fertilizer produced according to Example 2 had been. The mixing was done in an 8 inch

is

Patterson-Kelly-Zig-Zitck-Mksher for liquids and solids. The materials and proportions used were as follows:

Materials weight

31-6-4 fertilizers according to the example 2 with 0.21 to 2.35 mm particle size 326.59 kg

2-methoxy-3,6-dichlorobenzoic acid (88% active material). 710 g

2,4-dichlorophenoxyacetic acid (technical grade) 3748 g

Adhesive (hexylene glycol) 17,700 g

The mixing ratios and feed quantities were:

Feed rate of fertilizer 3.6287 kg / min

Feed rate of the premix of pesticides and adhesive 246 g / min

Mixer speed 30 rpm

Mixer orientation (inlet end higher than outlet end). 3 ° 24 '

Residence time in mixer 3.26 min

The resulting combination product had a bulk density of 0.476 g / cm ³ . 94.5% of the product had the desired particle size of 0.21 to 2.35 mm mesh.

The mean value of the analyzes of samples taken at 5 minute intervals was: 2,4-dichlorophenoxyacetic acid 1.16%; 2-methoxy-3,6-dichlorobenzoic acid, 0.25%.

The combination product described above is intended for applications in which a plant fertilizer at the same time can be used advantageously as broadleaf weed killing.

Embodiment 10

Another combination product was made from a fertilizer according to embodiment 2, A (N, N-dimethyl-2,2-diphenylacetamide), B (l-N-butyl-3- (3-4-dichlorophenyO-l-l-methylurea), C (1-naphthyl-N-methylcarbamate) and an adhesive. The pesticides were all in solid, granular form and were mixed in a double-shell Patterson-KeMy dry mixer premixed. The premix, the binder, and the fertilizer were then placed in a zigzag mixer as he was related with Example 9 described, mixed. The materials and proportions used were:

Material weight

31-6-4 fertilizers according to embodiment 2 with particle size from 0.21 to
2.35 mm 102.06 kg

A (90% active material) 4340 g

'B (94% active material) 800 g

C (85% active material) 2018 g

Binder (polybutene with a molecular weight of approximately 400) 7550 g

The mixing ratios and feed quantities were:

Feed rate of fertilizer 2.268 kg / min

Feed rate of pesticides 159 g / min

Binder feed rate, 168 g / min

Mixer speed 30 rpm

Mixer orientation (inlet end higher than outlet end) .. 2 ° 42 '

Residence time in the mixer 5.5 min

The resulting combination product had a bulk density of 2.083 g / cm ³ . 89.28% of the product had the desired particle size of 0.21 to 2.35 ram even before the fine particles were agglomerated. Samples taken at 4 minute intervals had the following mean analysis: A, 3.63%; B, 2.00%; C, 0.60%.

This product is particularly useful for fertilization applications including insect killing and killing grassy weeds such as poa annua and broad-leaf weeds such as chicken bite and Oxalis require.

Embodiment 11

Another combination product, which is intended for fertilization and fungicidal effects, was made a fertilizer as in embodiment 2, PMA (phenyl mercury acetate), D (bis [dimethyl dithiocarbamoyl] disulfide), a conditioning agent and a binding agent. The PMA was created in the binder dissolved, and the conditioning agent was mixed with the thiram in a two-case Patterson-Kelly Mixer mixed as described in Example 10. The PMA blend, the premixed Thiram and the fertilizer were then mixed together in a zigzag mixer as in the example of FIG mixed. The materials and weights used were:

Material weight

31-6-4 fertilizers according to embodiment 2 with particle size from 0.21 to
2.35 mm 142.88 kg

PMA (95% active material) ... 927 g

D (99% active material) 6080 g

Conditioning agent (precipitated
amorphous silicon oxide) 189 g

Binder (hexylene glycol) ... 19400 g

The mixing ratios and feed quantities were:

Feed rate of fertilizer 3.18 kg / min

Feed amount of the 1 solution
of PMA in binder 449 g / min

premixed D and conditioning agent 139 g / min

Mixer speed 30 rpm

_{Mixer orientation} (introductory 6o, rungsend higher than execution end) 1 ° 40 '

Residence time in the mixer 3.9 min

The resulting combination product had a bulk density of 2.137 g / cm ³ . 94.6% of the product ⁶ Ii was of the desired particle size of 0.21 to 2.35 mm. The mean active ingredient content of samples taken at 4 minute intervals were: D, 2.93%; PMA, 0.49%.

609 686/166

20th

Embodiment 12

A combination product, which can be used for fertilizing and destroying insects, was made from a fertilizer according to embodiment 2, E (0,0,0, O ^r 'tetraethyl-S, S'-methylenebisphosphorodithioate) and a binding agent. The (previously in liquid form) E was mixed with the binder and the premix obtained was mixed with the fertilizer λ in a zigzag mixer as best as "in Example 9. The materials used and density were:

Material weight

Fertilizers nacsi execution

Example 2 with particle size

from 0.21 to: .35 mm 426.38 kg

E (95% active material) 7060 g

Binder (hexylene glycol) ... 2075 g

The mixing conditions and feed rates were:

Feed rate of fertilizer 3.4 kg / min

Feed quantity of the pre- ^a5

mixed 202 g / min

Mixer speed 30 rpm

Mixer orientation (introductory end higher than execution end) Γ 34 '

Residence time in the mixer 4 min

The resulting combination product had a bulk density of 2.124 g / cm ³ . 88.6% of the product had the desired particle size of 0.21 to 2.35 mm even before the fine particles were agglomerated. Samples taken at 4 minute intervals had an average ethione content of 3.60%.

759

Embodiment 13

A combination product with nitrogen, K ₂ O and P ₄ O ₅ as well as iron for use on areas where chlorosis predominates was made by mixing a fertilizer according to embodiment 2 with iron-ammonium sulfate and a binder in a zigzag described in example 9 Mixer manufactured The mixture was composed of: Material Weight

31-6-4 fertilizers according to embodiment 2 with particle size from 0.21 to

2.35 mm 81.65 kg

Iron ammonium sulfate (14.24%

current iron content) 8770 g

Binder (polybutene with a molecular weight of approximately 400) 14100 g

The mixing conditions and feed rates were:

Feed rate of the fertilizer. 1.81 kg / min feed rate of the iron ammonium sulfate 193 g / min

Binder feed rate 314 g / min

Mixer speed 30 rpm

Mixer orientation (inlet end higher than outlet end) 2 ° 22

Residence time in the mixer 6.15 min

The resulting combination product had a bulk density of 2.147 g / cm ³ . 98.2% of the product had the desired particle size of 0.21 to 2.35 mm. Samples taken at 4 minute intervals had an average content of 1.27% iron ammonium sulfate.

Claims (3)

Patent claims: 1. Process for the production of foamed granulated urea-formaldehyde condensate, that as a step the preparation of a urea-formaldehyde: d solution by dissolving it of firm urine: with stirring in water and Urea formaldehyde concentrate with addition of sufficient organic material to keep the pH in the range 7.0 to 10.5 than further proceedings rode the foaming of these Solution, as a further »· process step lowering the pH value of the i < Solution by introducing acid to initiate the condensation reaction between the urine and the formaldehyde, as a further process step the hardening of the acidified Solution up to the creation of a physically manipulable foam, as another Process step drying this hardened * ° th material and finally the step of comminuting this dried material Contains desired particle size, characterized in that the weight ratio of the urea to formaldehyde in the solution »5 adjusted to a value between 1.3: 1 and 2.4: 1 where the temperature of the solvent at which the urea is dissolved is in the range is kept between 54 and 71 C that an anionic or nonionic surface-active Means the solution is added that the solution of methylol urea and surface-active Means is subjected to a pre-expanding step, the solution being stirred for 1 to 10 seconds and / or a moving gas stream is blown through, that then the pH of the foamed material for the introduction the condensation reaction is reduced to 3.5 to 6.5 that during the condensation the Temperature is kept between 57 and 105 C, that then the acidified solution in a location or a layer of 25 to 150 mm is applied and at least 1 min at a starting temperature of 82 to 105 C is left without stirring, a granular structure is formed and the substance by itself partially disintegrates and hardens, and that then the granulated substance 15 to Is dried for 25 min at a temperature which does not exceed 93.degree. 2. The method according to claim I, characterized in that that before foaming between 5 <> 0.05 to 3% of an anionic or non-ionic surfactant is added to the urea-formaldehyde solution. 3. Use of the urea-formaldehyde condensates prepared by the process from Claims 1 and 2 as fertilizer.