CS276407B6 - The method of production by the pressure of shaped multi-component fertilizers - Google Patents

Abstract

The solution relates to a method of producing pressure-formed multi-component fertilizers containing part or all of the nitrogen component in the form of urea-formaldehyde condensate. The essence of the solution lies in the fact that a liquid pre-condensate of urea and formaldehyde is applied to at least one fertilizer component before shaping the mixture under pressure, while stirring. The mixture thus prepared is subjected to pressing-compression pressure at a temperature of 15 to 110 °C, without or in the presence of urea and/or in the presence of ammonium salts and/or in the presence of acid-reactive substances. The production method according to the solution can be advantageously applied in the production of pressure-formed - tableted, briquetted, compacted granulated or extruded organo-mineral or mineral fertilizers, intended primarily for stock fertilization of seedlings of forest, fruit or ornamental trees, decorative plants, for stock fertilization of special crops, or for fertilization of grasslands.

Description

The invention relates to a process for the production of pressure-formed compound fertilizers containing part or all of the nitrogen component in the form of urea-formaldehyde condensate intended primarily for stock fertilization of forest, fruit or ornamental trees, decorative plants, stock fertilization of special crops or grass fertilization.

In forestry. when planting forest tree seedlings, but also when planting ornamental and fruit trees, vines and hops, it is generally very advantageous if the full dose of nutrients and possibly some other biologically active substances can be incorporated in close proximity to the root system of the young plant. growth stimulators, insecticides and fungicides, etc.) that seedlings need for their healthy development during the first 2 to 3 years after planting. The condition for the successful solution of this problem is that the nutrients are gradually released from the incorporated fertilizer during this time as evenly as possible, while the fertilizer must not act phytotoxically even in direct contact with the root system by generating a high concentration of ions in the original solution.

Abroad, some types of special fertilizers are produced for stock fertilization of forest trees. Agriform International Chemicals Inc., offers this type of compound fertilizer under the trade name Agriform. The product is intended for stock fertilization of seedlings of coniferous forest and tropical trees and provides them with the necessary nutrition for the first two years. A similar type of fertilizer is produced under the trade name Fertilinz by the Austrian company Chomie Linz, which is also protected by a patent in the Czechoslovak Socialist Republic. 188 886.

. Tableted NPK fertilizer for forestry after planting consisting of a mixture of (KPO 2) as a source and K 2 O and a condensation product of urea with a saturated aliphatic aldehyde is the subject of English Patent 1,363,388. Japanese Patent 5-2034-261 discloses the preparation of a special fertilizers also intended for stock fertilization of woody plants with nitrogen, the source of which is isobutylidene diurea. Another type of shaped fertilizer is the subject of Hungarian Patent No. 27,409.

Similar types of shaped fertilizers are also used in the cultivation of decorative plants decorated with moldings or flowers. . In connection with the research of the issue of tableted and briquetted fertilizers, several solutions were created in the past period at the level of inventions in the Czechoslovak Socialist Republic (author's certificates No. 201 231, 222 866, 222 867, patent No. 276 123).

Similar types of special fertilizers have been developed abroad and recently in the Czechoslovak Socialist Republic also for the purpose of stock fertilization of grasslands (eg, by the effect of pressure granulated fertilizer DUKOPERT - T). Fertilizers of this type are intended primarily for stock fertilization of special grass areas, such as playgrounds, training grounds, stadiums, swimming pools, park lawns and other recreational and ornamental grassy areas. .

In the case of all types of special shaped fertilizers mentioned above, special attention must be paid to the solution of a suitable source of nitrogen component, while the solutions known so far in our country and abroad state the use of:

- various condensation products of urea with gray types of aldehydes,

- addition of substances retarding the action of the nitrogen component,

- addition of various hydrophobicizing additives and packaging,

- non-traditional sources of nitrogen component of natural or synthetic origin Usually with a protein type of nitrogen bond.

Although the vast majority of the mentioned methods used in connection with ensuring the gradual effectiveness of the nitrogen component in shaped fertilizers allow their preparation and use, these also have several disadvantages, among which can be mentioned

CS 276407 Βδ in particular the following:

- ensuring a gradual release of the nitrogen component during the whole required period of effectiveness of the applied shaped fertilizer;

- the use of hygienically and ecologically not always completely harmless components (aldehydes, mineral oils, inhibitors of the function of microbial and enzymatic stimulating microfluor ...);

- complexity and operational complexity of preparation, resp. treatment of the nitrogen component used and its incorporation into the final shaped fertilizer;

- non-standard efficiency of shaped fertilizers, which is usually dependent on accuracy by adhering to the preparation points, resp. treatment of the nitrogen component used;

- the limited availability niektorých of some of the nitrogen components proposed today in connection with the production of shaped fertilizers (especially in the case of the use of nitrogenous raw materials of a proteinaceous nature);

- difficult biological degradation of high molecular weight nitrogen products, especially of the condensation type;

- relatively low nitrogen concentration in some sources of nitrogen component (especially in the case of high molecular weight condensates obtained by reactions of urea with multi-carbon aldehydes and also in the case of nitrogen-based protein raw materials), resulting in unacceptable dilution of biologically active components in fertilised disadvantageous weighing of a unit particle of shaped fertilizer - tablets, briquettes and the like.

The vast majority of the methods used today for the production of pressure-shaped fertilizers consist of preparation of individual components, weighing, homogenization, which can be associated with hydrophobization of the surface of mixed components, self-forming by pressure (tableting, briquetting®, compaction between scales, extrusion, etc.). ), in the case of compaction and extrusion of Sale from the partial disintegration, sorting and possible surface treatment of the shaped product. In the case of shaping a mixture by extrusion, drying is usually part of the technology.

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Due to the specific purpose of shaped fertilizers of the type in question, due to their more or less long-term operation, special attention needs to be paid to the solution of a suitable source of nitrogen component.

Although the professional and especially patent literature presents several solutions to this - in the case of the group of fertilizers in question - key issue, in production practice the deposition of urea formaldehyde condensates has become most widespread. These are manifested by the condensation of urea with formaldehyde®, the reaction being catalyzed by an acidic or alkaline medium, depending on the type of condensate being prepared. The advantage is that the properties of the condensates can be varied over a wide range by changing the relative proportions, the reactants as well as the pH and the temperature. From the point of view of the subsequent treatment of the condensate, it is also advantageous to carry out the reaction between formaldehyde and urea, in the medium of a suitable solvent, and thus to prepare urea-formaldehyde condensates in the form of a suspension or urea. after separating the solvent in fine powder form. Although it is possible to process urea-formaldehyde condensate in its powder form into the effect of pressure-shaped fertilizers, such a method of producing shaped fertilizers has some disadvantages, among which the following can be mentioned, for example:

- limited availability of urea-formaldehyde condensates in the required quantities and quality;

- non-standard quality of some commercially available types of condensates (mostly products obtained in connection with the removal of formaldehyde® from wastewater), while varying them widely. water solubility and the products also contain other hygienically and undesirable primates;

- problems related to the inhomogeneity of the mixture to be shaped;

- usually poor shaping of the properties of the mixture - flexibility of the condensates, their low adhesiveness, amorphous character of the condensate, etc .;

- the relatively high cost of powdered urea-formaldehyde condensates;

- high dustiness ’when handling this type of nitrogenous raw material;

- low level of hygiene and work culture in the handling and processing of powdered urea-formaldehyde condensates.

Virtually all the above-mentioned disadvantages typical of the process for the production of pressure-shaped fertilizers based on powdered urea-formaldehyde condensate are eliminated and fully solved by the process for the production of such fertilizers according to the invention.

The essence of the solution lies in the fact that a liquid precondensate of urea and formaldehyde is applied to at least one or more components of the fertilizer before the shaping of the mixture by the action of pressure with stirring. The mixture thus prepared is subjected to a pressing-pressing pressure at a temperature of 15 DEG to 110 DEG C., either without or in the presence of urea and / or in the presence of ammonium salts and / or in the presence of acid-reacting substances. The liquid precondensate of urea and formaldehyde used has the character of a solution or a non-Newtonian liquid. It has proven particularly suitable to use some of the urea-formaldehyde adhesives as a liquid urea-formaldehyde condenser. Suitable ammonium salts are preferably one of ammonium sulphates and / or phosphates and / or ammonium chloride.

Carboxylic and / or hydroxycarboxylic and / or mineral acids and / or some of the acid-reactive salts have proven to be particularly suitable acid-reactive substances in the process for the production of pressure-shaped fertilizers according to the invention.

The following examples document and illustrate, but in no way limit, the subject matter of the present invention.

Example 1

10.8 kg of poultry manure dryers enriched during drying with a lignosulfonate concentrate of the trace element complex were introduced into a Dodige mixer. Poultry manure dryings enriched in this way contained:

3.48 wt. % of total nitrogen,

4.29 wt. % of total PgO 2

5.13 wt. % of total KgO

0.88 wt. % Pe

0.11 wt. % Cu

0.35 wt. % Mn

0.06 wt. % Zn

0.2 wt. % B

0.01 wt. % What

0.01 wt. % Mo and 0.06 wt. % Ti.

CS 276407 B6 4

7.0 kg of pre-milled mixture of urea (3.50 kg), technical ammonium dihydrogen phosphate, so-called ammonium phosphate, was introduced into the mixer beforehand. MAP (0.95 kg), potassium sulfate (2.25 kg) and thiourea (0.30 kg).

After short-term homogenization of the contents of the mixer, 3.90 kg of ground phosphorite, 0.4 kg of calcined magnesite, so-called brick flour and 1.0 kg of ground zeolite (ZEOCHEM).

The homogenizer was then closed, the knife stirrer was started, and 25 ml of a 0.5% alcoholic solution of .beta.-indolylacetic acid were first added through the chimney opening. formaldehyde precondensate available under the tradename DIAKOL - DM. The precondensate used had a honey-like consistency (viscosity at room temperature: 800 mPas), according to the manufacturers, the molar ratio of urea to formaldehyde was 1: 1.65-0.5 and its pH was 7.6. Due to the ongoing condensation reaction! the contents of the homogenizer slightly warmed up after the application of the urea-formaldehyde adhesive DIAKOL.

The brown-black homogeneous mixture, after discharging from the mixer, was processed on a tablet machine into tablets with a diameter of 48 mm and an average weight of 43 kg. The tableted organo-mineral fertilizer prepared in this way was used for stock fertilization of forest tree seedlings.

Example 2

In order to prepare an organo-mineral fertilizer intended for stockings of grasslands, the following was homogenized in a lodige homogenizer:

50.0 wt., Parts of dried poultry manure SUHYT

30.0 parts by weight of urea powder

5.0 parts by weight of crystalline magnesium sulphate

3.0 parts by weight of finely ground dolomite and 2.0 parts by weight of crystalline citric acid.

10.0 parts by weight of urea of formaldehyde adhesive DIAKOL - P were slowly added to the homogeneous mixture with stirring. 5 moles of formaldehyde per mole of urea. · ·

After documented homogenization, the prepared mixture was subjected to pressure granulation between yard counter-rotating scales. The endless honeycomb obtained by compaction was subjected to partial disintegration, the production fraction 1 mm d 5 mm being separated from the crushed material by sorting.

The undersized and oversized fiction action was returned for further processing by compaction.

Claims (4)

CS 276407 B6 PATENT CLAIMS A process for producing pressure-formed fertilizers comprising a portion or all of the sub-particulate component in the form of a urea-formaldehyde condensate, characterized in that a liquid urea-formaldehyde precondensate is applied to the at least one fertilizer component prior to molding under pressure, under agitation. the mixture is subjected to a compression-extrusion at 15 to 110 ° C without or in the presence of urea and / or in the presence of ammonium salts or in the presence of acid reactants. 2. A process for producing pressure-formed fertilizers according to claim 1, wherein the liquid urea-formaldehyde precondensate is a liquid urea-dehydrogen adhesive. 3. The process for producing pressure-formed fertilizers according to claim 1, wherein the ammonium salt is sulfate and / or phosphate and / or chloride. 4. The process for producing pressure-formed fertilizers according to claim 1, wherein the acidic reactant is one of the acidic salts and / or one of the carboxylic and / or hydroxycarboxylic acid and / or mineral acids.