JPS5935083A - Manufacture of granular fertilizer - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing a granular fertilizer, and more specifically, a method for producing a granular fertilizer, in which a suspension obtained by preparing an oversized granulated fertilizer is used as a binder to granulate the fertilizer. Regarding the manufacturing method.

Conventionally, production of granular fertilizer has been carried out by 1, a granulation process in which fertilizer as a raw material is granulated while adding water, a drying process in which the granular fertilizer obtained by granulation is dried, and a sieving process in which the dried granular fertilizer is sieved. At that time, the large grains on the sieve (hereinafter referred to as oversize) produced in the sieving process, that is, those of non-standard size are crushed by a dry grinder and the fine grains under the sieve (non-standard #lI grains) Hereafter referred to as undersize.
Both j) and turtle are returned to the granulation process and used again as raw materials for granular fertilizer.

As mentioned above, the conventional method for producing granular fertilizer requires drying the granulated granular fertilizer, which is uneconomical from a thermoeconomic perspective. The disadvantage of hats is that they generate dust when they are used, so dust-proof measures are required in the working environment.

In addition, in the conventional production method, blackstrap molasses 1. Attempts have been made to use Vulp waste liquid or #'icMc as a binder, but satisfactory results have not necessarily been obtained.

As a result of studying a manufacturing method that does not involve the above-mentioned drawbacks in manufacturing granular fertilizer, the present inventor found that the granular fertilizer after granulation does not necessarily need to be dried when it is sieved, and that the overflow produced during sieving is The present invention was realized based on the knowledge that the above drawbacks can be overcome by using a suspension obtained by pulverizing the particles in the presence of water as a binder for granulation.

! , the present invention does not necessarily require drying when sieving the granulated granular fertilizer, and also eliminates the need to subject the oversize generated during sieving to dry crushing that causes dust generation. It is an object of the present invention to provide a method for producing granular fertilizer with improved efficiency.

The present invention will be explained in detail below.

The main feature of the present invention is that a suspension obtained by pulverizing oatsky size produced when granulating and sieving ice granular fertilizer in the presence of water is used as a binder for granulating fertilizer. It is used by returning it to the granulation process.

In the present invention, first, the raw materials and the fertilizers in steps 1 to 1 are granulated in a conventional manner under the addition of water, and the resulting granular fertilizer is sieved.

In this sieving, the granulated granular fertilizer may be sieved as it is without drying, or it may be sieved after drying. In addition, since the granular fertilizer immediately after granulation has a moisture content of about 10, when it is sieved as it is, the sieve is easily clogged, so the mechanical clogging prevention value is set to 6. It is recommended to use the attached sieve.

In the present invention, the maper size produced when the granular fertilizer is sieved is then introduced into a wet mixing grinder and ground in the presence of water to form a suspension.

As the pulverizer, it is preferable to use, for example, a wet mixing pulverizer consisting of a cylindrical tank and a rotating pulverizer. In wet grinding of this oversize, the oversize obtained by sieving the granular fertilizer immediately after granulation is dried, and it is easier to grind than the sieved product, so the grinding time is significantly shortened. There are benefits to be gained.

Further, the amount of water used in the wet pulverization of the ζ-sized oats is preferably adjusted in consideration of the viscosity of the suspension obtained by the pulverization. In other words, since this suspension is used as a binder for granulating the raw fertilizer, the viscosity of the suspension is adjusted so that the desired hardness can be obtained for the granular fertilizer particles obtained by granulating the suspension. Adjust. Incidentally, the i of the water is generally preferably 60 to 80 for oversize.

The suspension cane obtained in Particular 1- above has an appropriate viscosity and exhibits an extremely excellent binder effect in granulating the raw fertilizer, so that a granular fertilizer with the desired hardness can be obtained, and in addition,
Since the ratio of fertilizer components is the same as that of the raw material fertilizer, there is no risk of unevenness in the fertilizer composition of the granular fertilizer obtained by granulation, which occurs when conventionally known pieiders are used.

Incidentally, the non-standard undersize generated when the granulated granular fertilizer is sieved is directly returned to the granulation process and used as raw material fertilizer for granulation.

As mentioned above, in the present invention, the granulated granular fertilizer
- By using the suspension obtained by pulverizing the size in the presence of water as a binder for granulating raw fertilizer, it is possible not only to improve the granulation efficiency of fertilizer, but also to sieve the granulated granular fertilizer. Since it is not necessary to dry the granulated fertilizer separately, it is possible to omit the drying process of the granulated granular fertilizer in the conventional method. Dust generation can also be prevented. Therefore, according to the present invention, the uneconomical consumption of thermal energy can be eliminated and the working environment can also be improved.

The present invention will be described in more detail below by showing all embodiments based on the accompanying drawings (FIGS. 1 and 92) illustrating process diagrams of the manufacturing method according to the present invention.

Example 1 This example illustrates a case in which a granulated granular fertilizer is sieved as it is without being completely dried.

In Fig. 1, raw fertilizer is measured using scales 1, 2, 3, 4 and 5, mixed so that N:P:K is 12:5:5, and then passed through line 6 to granulator 7. supply to. The granulated fertilizer granulated by the granulator 7 is directly supplied to a sieve 9 (equipped with a clogging prevention device) through a line 8, and the oversize sieved there is passed through a line 10 to a wet mixing pulverizer. 11, where it is pulverized to form a suspension while supplying water from line 12, and introduced into a granulator 7 via line 13 for granulation/? Used as an inder.

- The granular fertilizer that has passed through the dryer 9 is sent via line 14 to a dryer 15 for drying, and then sent via line 16 to a dry vibrating screen 17. The non-standard undersize sieved by this ζ is returned to the granulator 7 via line 18, while the sieved granular fertilizer of standard particles is sent to the cooler 2 via line 19.
0 and then product 21.

According to the above procedure, 17 tons of mixed fertilizer was granulated per hour, and 1
Table 1 shows the results of investigating the granulation efficiency, water usage (amount of water added), fuel oil consumption, and product hardness in the case of continuous operation for 2.5 hours.

For comparison, a similar investigation was conducted in which the process of granulating 17 tons of mixed fertilizer per hour, drying, and sieving was carried out continuously for 2.5 hours according to the conventional method, and the results are shown in Table 1. In addition, in the comparative example, oversize produced in the sieving process was crushed by a dry pulverizer, and returned to the granulation process together with non-standard undersize.

Table ・As seen in Table 1, according to the present invention, compared to the conventional method (7
Since the granulation efficiency is improved by 10% by weight and the amount of water added can be reduced, the consumption of heavy oil for drying can be significantly reduced, and in addition, the hardness of the product is improved.

Example 2 This example illustrates the case where granulated granular fertilizer is dried and then sieved.

In Fig. 2, raw fertilizers are weighed using scales 1, 2, 3, 4 and 5, mixed so that N:P:K is 10:4:4, and fed to granulator 7 through line 6. . The granulated fertilizer granulated by the granulator 7 is sent to a dryer 15 through a line 8 to be dried, and then supplied to a dry vibrating screen 17 through a line 16. The oversize screened here is line 2.
2 into the wet mixing grinder 11, where the line 1
While supplying water from 2, the mixture is crushed to form a suspension, which is introduced into granulation a7 through line 13, and used as granulated pine goo. Among the granular fertilizers that have passed through the sieve 17, non-standard undersized fertilizers are returned to the granulator 7 via a line 18, while sized granules are passed through a cooler 20 tl via a line 19 to become a product 21.

According to the above procedure, 20 tons of mixed fertilizer is granulated per hour.
Table 2 shows the results of investigating the granulation efficiency, amount of water added, basic unit of fuel oil, and product hardness in the case of continuous operation for 12.5 hours. In addition, as a comparison, the process of granulating 20 tons of mixed fertilizer per hour using the conventional method, drying, and then sieving was performed.
Table 2 shows the results of continuous operation for -12.5 hours and a similar investigation for the next case. In addition, in the comparative example, the O-size and E-size produced in the sieving process were pulverized using a dry pulverizer.
It was returned to the granulation process along with the non-standard undersize.

Table 2 As shown in Table 2, in the present invention, even when the granulated granules are dried and then sieved, the granulation efficiency is improved compared to the conventional method, and the amount of water added is reduced, so the amount of heavy oil used for drying is reduced. It also reduces consumption and improves the hardness of the product.

Example 3 This example is a fertilizer composition that is conventionally considered to have extremely low granulation efficiency. Fertilizer lit'fr mixed with N:P:K ratio of 18:10: This is an example of the case where the fertilizer was granulated according to the procedure described in Example 1. Regarding the obtained product, granulation efficiency, amount of water added, basic unit of fuel oil, and product hardness f
, v4 and the results are shown in Table 3.

For comparison, a similar investigation was conducted in the case of granulation using the conventional method, and the results are shown in Table 3.

Table 3 As shown in Table 3, when the oversized suspension produced when the granulated fertilizer of the present invention is sieved while still wet is used as the granulation binder, the granulation efficiency is lower than that of the conventional method. Even in the case of a raw fertilizer with an extremely low fertilizer composition of 28% by weight, the granulation efficiency is improved by 14% by weight, the amount of water added and the amount of heavy oil used can be reduced, and the hardness of the product is also improved.

[Brief explanation of drawings]

FIG. 1 and FIG. 2 are full examples of manufacturing process diagrams for the granular fertilizer according to the present invention. In the figure, 7... Granulator 9... Sieve 11 equipped with a clogging prevention device... Wet mixer 15... Dryer 17... Dry vibrating sieve. Agent Bu Flit now ("Original Procedural Amendment September 1980 Layer: Mr. Kazuo Wakasugi, Commissioner of the Patent Office 1, Indication of Case 1981 Patent Application No. 142484
No. 2, Title of the invention Method for producing granular fertilizer 3, Relationship to the case of the person making the amendment Special M/l Applicant name Name Nippon Hiryo Co., Ltd. Correct accordingly. +11 On page 6, line 11, the statement "The drying process for granular fertilizers may be omitted" is corrected to "The drying process for oversized granular fertilizers may also be omitted."

Claims (2)

[Claims] (1) In the method of producing granular fertilizer f by granulating fertilizer, the granulated granular fertilizer is sieved, and the large particles (oversize) on the sieve that are generated at that time f: in the presence of water. A method for producing a granular fertilizer, characterized in that a suspension obtained by pulverization is used as a binder for the granulation. (2) The manufacturing method according to claim 1, wherein the granulated granular fertilizer is sieved without drying.