DE3102052A1 - Process for granulating fertiliser mixtures containing iron(II) sulphate - Google Patents

Abstract

Fertiliser mixtures which contain iron(II) sulphate and substances which act as fertilisers are conventionally granulated by adding granulation liquid. According to the invention, it is provided to carry out the granulation process using a mixture which contains iron(II) sulphate having on average 1 to 4 mol of water of crystallisation and additionally a hydrophilic substance which delays the absorption of the granulation liquid by the iron(II) sulphate. Particularly suitable hydrophilic substances are salts of ligninsulphonic acids, surfactants, saccharides, starches, dextrins, silicas and/or kieselguhr, which are expediently employed in an amount of 0.5 to 10% by weight.

Description

Process for granulating ferrous sulphate

containing fertilizer mixtures The invention relates to a method for granulating fertilizer mixtures, the iron (II) result and fertilizing substances contained, with the addition of granulating moisture.

Iron (II) sulfate, known as one of the oldest herbicides, It is widely used, especially as a moss control agent, often in combination with herbicides and fertilizers.

For example, it is known from DE-OS 21 50 910, mixtures from iron (II) sulfate, calcium carbonate, ammonium nitrate and possibly ammonium sulfate e.g. granulate in a rotating rotating drum or in a tubular granulator L) The granulation temperature should be about 60-85 ° C xl.

In the method according to DE-OS 19 31 289 one or more inorganic Iron salts with a urea-formaldehyde condensate to form a micronutrient fertilizer mixed and, if necessary, granulated.

However, it has been shown that - at least on a large scale Scale - not successful, iron (II) sulfate - the commercially available 7 moles of water of crystallization contains - to be granulated together with fertilizer salts such as ammonium sulphate. The at Granulating leads to the necessary addition of water as a result of the very high hydroscopicity to dissolve the iron (II) sulphate, which prevents the formation of granules.

In connection with Armnonsulfat, because of the quick initial effect of the fertilizer Ferroammon sulfate, the so-called Mohrsche, is particularly beneficial Salt, which reduces the herbicidal and fertilizing effects.

If, in the granulation process, the starting product is powdered and non-hygroscopic iron (II) sulfate monohydrate, this is what happens when granulating added water is bound as crystal water and the result is the heptahydrate, the leads to the difficulties mentioned above.

The object of the invention is to provide a method for granulating iron (II) sulfate to provide containing fertilizer mixtures, the known, in particular the aforementioned Does not have disadvantages, is easy to implement and takes into account economic spirit leads to good results.

The task is solved by following the procedure mentioned at the beginning Art is designed according to the invention in such a way that the granulating process carried out with a mixture containing iron (II) sulfate with an average of 1 to 4 mol of water of crystallization as well as a hydrophilic one, the absorption of the granulating moisture by the Contains iron (II) sulphate retarding substance.

The invention causes the inclusion of the granulating required water as crystal water through the addition of certain hydrophilic, water-attracting Substances is delayed so that the granulation process is completed before the Water is finally bound as crystal water. The granulate produced in this way is insensitive to moisture and the herbicidal as well as the fertilizer effect remains fully received. As a hydrophilic, water-repellent substances can all chemical products are deformed, their rate of water absorption is higher than the hydration water absorption of iron (II) sulfate with 1 to 4 mol Water of crystallization and which themselves do not form a hydrate. Particularly suitable hydrophilic Substances are in particular salts of lignosulfonic acid, such as calcium, Sodium, potassium or ammonium salt, surfactants of the sodium octane-l-sulfonate type, Sodium octyl sulfate, sodium dodecyl benzene sulfate, sodium lauryl ether sulfate and oxethylated Glycerine monostearate or fatty alcohol polyglycol ether. Furthermore, saccharides are suitable, Starches and dextrins as well as silicas and diatomaceous earth. A preferred (l-e embodiment the invention provides for the granulation process to be carried out with a mixture, which contains the hydrophilic substance in an amount of 0.5 to 10.0% by weight.

Another advantageous embodiment of the invention is that the herbicidally active component iron (II) sulfate with an average of 1 to 4 moles of water of crystallization with a proportion of 10 to 80% by weight, preferably 40 to 60% by weight, in the to to use granulating mixture.

It is particularly advantageous to add moisture during the granulation process to be dimensioned in such a way that they contribute to the formation of an iron (II) sulfate on average leads to a maximum of 5 moles of water of crystallization.

The optimal embodiment of the invention consists in the granulation process to be carried out with iron (II) sulfate containing an average of approx. 1 mol of water of crystallization and to measure the addition of moisture in such a way that it leads to the formation of an iron (II) sulfate with an average of about 2.5 moles of crystal water.

The mixture to be granulated can be used as fertilizing substances expediently carbon sulfate, solid nitrogen, phosphorus and potash fertilizers, micronutrient fertilizers, Depotdütlger urld natural things are added. The effective fertilizers Substances are added in amounts that match the nutrient uptake of the respective Correspond to crops.

The invention is illustrated by the following example, for example and explained in more detail.

Example 27.6 parts by weight of ammonium sulfate, 5 parts by weight of urea and 55.6 parts by weight Parts by weight of iron (II) sulfate monohydrate were mixed with 3 parts by weight of calcium lignosulfonate (Cell pitch) and mixed in a granulator with the addition of 8.8 parts by weight Granulated water at ambient temperature. The result was a granulate with a middle Particle size from 1 to 3 mm.

The product did not require any further drying, but could be used immediately be packed.

Claims (7)

Claims: 1. Method for granulating fertilizer mixtures, which contain iron (II) sulphate and active fertilizers, with the addition of granulating moisture, characterized in that the granulating process is carried out with a mixture, the iron (II) sulfate with an average of 1 to 4 moles of water of crystallization and, in addition, one hydrophilic, the absorption of the granulation moisture by the ferrous sulphate Contains substance. 2. The method according to claim 1, characterized in that the Granulating process is carried out with a mixture that contains salt as a hydrophilic substance a lignosulfonic acid, surfactants, saccharides, starches, dextrins, silicas and / or Contains diatomaceous earth. 3. The method according to claim 1 or 2, characterized in that one carries out the granulation process with a mixture containing the hydrophilic substance contains in an amount of 0.5 to 10 wt .-%. 4. The method according to claim 1, 2 or 3, characterized in that the mixture to be granulated iron (II) sulfate in amounts of 10 to 80, vorzuysweise 40 to 60% by weight. 5. The method according to one or more of claims 1 to 4, characterized characterized in that the addition of moisture is dimensioned such that it leads to formation of an iron (II) sulfate with an average of a maximum of 5 moles of water of crystallization. 6. The method according to one or more of claims 1 to 5, characterized characterized in that the C.t i C l Vt <1Cll with an iron (II) sulfate with a mixture containing an average of about 1 mol of water of crystallization and the The addition of moisture is such that it leads to the formation of an iron (II) sulfate with an average of about 2.5 moles of crystal water. 7. The method according to one or more of claims 1 to 6, characterized characterized in that one of the mixture to be granulated as fertilizing substances Ammonium sulphate, solid nitrogen, phosphorus and potash fertilizers, micronutrient fertilizers, Adds depot fertilizer and / or natural fertilizer.