GB1603645A - Process for producing an animal manure-supplemented artificial chemical fertilizer - Google Patents

Description

(54) A PROCESS FOR PRODUCING AN ANIMAL MANURE-SUPPLEMENTED ARTIFICIAL CHEMICAL FERTILIZER (71) I, ENCIK LEET KENG CHOON, a Citizen of Malaysia of No. 230, Jalan 5/50, Petaling Jaya, Selangor, Malaysia, do hereby declare the invention for which I pray that a patent may be granted to me, and the method by which it is to be performed, to be particularly described in and by the following statement: This invention relates to a process for providing mixtures of animal manure and artifical chemical fertilizers in pellet, granule or similar agglomerated form.

Natural farm manure and other "organic" fertilizers are important sources of the primary plant nutrients nitrogen, phosphorus and potassium. These plant nutrients are all eventually broken down into soluble form (this applies particularly to the phosphates) which renders them freely available to the plants. Furthermore, natural farm manure and other organic fertilizers tend to prevent the formation of insoluble complexes in the soil which would make the fertilizers unavailable to the plants, and they also slow down the leaching process which can occur in the soil whereby mineral salts are removed from the soil by percolating water.

Additional advantages of natural organic fertiliers are that they provide a medium for the growth of micro-organisms which contribute to the fertility of the soil, and they also improve the structure of the soil by rendering it more friable; this allows for better aeration of the plant roots and the soil micro-organisms.

There are, however, certain disadvantages associated with organic fertilizers, and for this reason it has proved advantageous to use such fertilizers merely to supplement artificial chemical fertilizers. The composition of manure generally averages about 0.5% N, 0.25% P2 05 and 0.5% K2O, which represent comparatively low levels of the primary plant nutrients. Furthermore, organic manure is generally not in a form best suited for application; it is bulky and, because of the low levels of plant nutrients, must be applied in large quantities to be effective. In addition, the plant nutrient content of the organic manure varies greatly, rendering it difficult to calculate the optimum amount which should be applied.These disadvantages, coupled with the fact that organic manure provides a breeding ground for flies and other undesirable organisms, render the use of farm manure on its own disadvantageous. The supply of such manure is, in any case, erratic and generally inadequate for use alone, since the amount available has been reduced by the adoption of tractors to replace horses. However, there are still, significant amounts available from farms which specialize in animal products such as milk, beef or poultry. With good farm management, the manure can be used profitably as a supplemental fertilizer, even though handling costs are relatively high.

It is recognised that the solubility of the plant nutrients determines the rate at which they dissolve in the soil and become available to the plant. The solubility may be affected by such factors as the particle size of the fertilizer and the pH of the soil, and, accordingly, it has proved advantageous to regulate the particle size of the fertilizer in accordance with the pH of the soil. High solubility is not necessarily beneficial in all instances and low solubility is not necessarily undesirable, since, for example, when phosphate is applied in finely-divided form to acidic soils, immobilization or fixation can occur in which the applied nutrient compound reacts with constituents in the soil to give compounds less soluble and less available to the plant.If the particle size is increased by granulation, the reduction in surface area has the effect of slowing down the immobilization reactions thereby allowing more complete utilization of the phosphate by the plant. In contrast, high water solubility is desirable in high pH, calcareous soils, because immobilization reactions are not so prevalent and the rate of dissolution becomes the controlling factor. The net effect of different degrees of phosphate solubility is difficult to analyse, but, in general, the trend is towards larger particle size in fertilizers which favours a high water solubility.

It has been known to use prilling techniques for nitrogen fertilizers which involve turning the fertilizer into pellet form by melting and letting the drops solidify in falling. However, these techniques are not very applicable to multinutrient fertilizers because many of the compounds involved either have high melting points or decompose partially when they are melted. Prilling is feasible if the formulation contains a high proportion of low-melting salts to serve as carriers of high-melting ones, but most formulations do not meet this criterion.

For the mixtures of high-melting materials normally found in multinutrient fertilizers, a process that involves sticking small solid particles together to make larger ones is the method most often used. In all cases it is necessary to have sufficient liquid phase present to serve as the sticking agent.

The present invention provides a process for providing an animal manure-supplemented artifical chemical fertilizer in the form of a pellet, granule or similar agglomerate which process comprises mixing finely ground animal manure with a specified artifical chemical fertilizer, which mixture is then moisturised if necessary, cured, pelletised or granulated or formed into similar agglomerates and dried.

The animal manure used in this process may be farm manure which can be in finely ground form or a mixture of such animal manures. The artificial chemical fertilizer or fertilizers may be in solid or liquid form. The artificial chemical fertilizers used are ammonia, ammonium nitrate, ammonium sulphate, urea, normal super phosphate (commonly called phosphate rock and made by treating phosphate ore with enough sulphuric acid to convert the phosphate to monocalcium phosphate), tripple superphosphate (made by treating phosphate rock with enough phosphoric acid to convert all the phosphate from both rock and acid to monocalcium phosphate) and ammonium phosphates (made by reacting phosphoric acid with ammonia to give solid products).

The ratio in which the animal manure(s) and artificial chemical fertilizer(s) are mixed will depend upon the use for which the mixed fertilizer is intended. Accordingly, it will depend upon the particular plant nutrients and levels thereof required, the pH of the soil to which the fertilizer is to be applied and the required solubility of, for example, the phosphates.

In the next step of the process, the mixture is, if necessary, moisturised. According to this step, enough liquid is added to cause the fertilizer particles to stick together. Of course, if a liquid artifical chemical fertilizer has been used, the moisturising step may not be necessary.

The resulting moisturised mixture is then plasticised for example with the application of steam; this helps to plasticise the mix.

Following plasticising agglomerates of the required size are formed before being dried.

Of course, the size of the agglomerates will depend upon whether a high or low surface area is required, depending upon the solubility requirements for the plant nutrients. The mixture may, for example, be formed into pellets or into granules or it may, if desired, be first partially pelletised and then granulated before being dried. In the case of fertilizers prepared according to this invention which contain, for example, at least 30% of animal-derived constituents it is preferable to pelletise the mixture partially first and then to granulate it in order to obtain a high percentage of large granules.

The granules, pellets or agglomerates so produced are firm and keep well. It is believed that each granule, pellet or agglomerate of the fertilizer contains the artificial chemical fertilizer(s) partially dissolved in, and coated with, the animal manure components.

The product may finally be graded and then packed ready for use. It can easily be applied by hand or by mechanical spreaders.

A specific Example of a fertiliser prepared in accordance with the process of this invention consists of pellets 2 to 5 mm in diameter prepared from a mixture of the following constituents (commercial grade code name -9/16/9/15+TE): Raw material Ammonium Sulphate 4.60 Urea 4.60 Ammonium Phosphate 33.20 Muriate of Potash 13.00 Sulphate of Potash and Magnesia 5.40 Animal manure 39.20 100.00 WHAT WE CLAIM IS: 1.A process for preparing an animal manure-supplemented artificial chemical fertilizer which is ammonia, ammonium nitrite, ammonium sulphate, urea, super phosphate, triple super phosphate or ammonium phosphate in the form of a pellet, granule or agglomerate, which process comprises mixing finely-ground animal manure with a said artificial chemical fertilizer, which mixture is optionally moisturised, then plasticised, pelletised or granulated or formed into agglomerates, and dried.

2. A process according to claim 1 wherein about 30% by weight of animal manure is mixed with about 70% by weight of artificial chemical fertilizer.

3. A process according to claim 1 or 2 wherein the mixture is plasticised by contacting it with steam.

4. A process according to claim 1 2 or 3 wherein the plasticised mixture is first at least partially granulated.

5. A process according to claim 1 wherein the constituents of the fertilizer and their proportions are as indicated in the Example.

6. An animal manure supplemented said artificial chemical fertilizer whenever prepared by a process as claimed in any one of the preceding claims.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims (6)

1. **WARNING** start of CLMS field may overlap end of DESC **.

   A specific Example of a fertiliser prepared in accordance with the process of this invention consists of pellets 2 to 5 mm in diameter prepared from a mixture of the following constituents (commercial grade code name -9/16/9/15+TE): Raw material Ammonium Sulphate 4.60 Urea 4.60 Ammonium Phosphate 33.20 Muriate of Potash 13.00 Sulphate of Potash and Magnesia 5.40 Animal manure 39.20

   100.00 WHAT WE CLAIM IS: 1.A process for preparing an animal manure-supplemented artificial chemical fertilizer which is ammonia, ammonium nitrite, ammonium sulphate, urea, super phosphate, triple super phosphate or ammonium phosphate in the form of a pellet, granule or agglomerate, which process comprises mixing finely-ground animal manure with a said artificial chemical fertilizer, which mixture is optionally moisturised, then plasticised, pelletised or granulated or formed into agglomerates, and dried.
2. 2. A process according to claim 1 wherein about 30% by weight of animal manure is mixed with about 70% by weight of artificial chemical fertilizer.
3. 3. A process according to claim 1 or 2 wherein the mixture is plasticised by contacting it with steam.
4. 4. A process according to claim 1 2 or 3 wherein the plasticised mixture is first at least partially granulated.
5. 5. A process according to claim 1 wherein the constituents of the fertilizer and their proportions are as indicated in the Example.
6. 6. An animal manure supplemented said artificial chemical fertilizer whenever prepared by a process as claimed in any one of the preceding claims.