WO2014024845A1

WO2014024845A1 - Nitrolime-containing granular fertilizer and method for producing same

Info

Publication number: WO2014024845A1
Application number: PCT/JP2013/071148
Authority: WO
Inventors: 洋一郎古川; 博志佐々木; 普志坂下; 和己野澤; 佳史野坂; 島本　聡; 高須　栄一; 貴市那須川
Original assignee: 電気化学工業株式会社; コープケミカル株式会社
Priority date: 2012-08-06
Filing date: 2013-08-05
Publication date: 2014-02-13
Also published as: JPWO2014024845A1; JP6129840B2

Abstract

Provided is a nitrolime-containing granular fertilizer low in quicklime, high in cyanamide, low in dicyandiamide and melamine, and having reduced ammonia generation. A nitrolime-containing granular fertilizer comprising an organic additive or inorganic additive for suppressing the hydration reaction of quicklime; nitrate or hydrochloride as a granulation aid; and already-slaked nitrolime.

Description

Lime nitrogen-containing granular fertilizer and production method thereof

The present invention relates to a lime nitrogen-containing granular fertilizer and a production method thereof.

Lime nitrogen fertilizer is a slow-acting fertilizer mainly composed of calcium cyanamide, and has a pesticide effect, and has been used for many years. Lime nitrogen is industrially produced by nitriding calcium carbide and usually contains about 13 to 20% by weight of CaO. When granular fertilizer is produced using powdered lime nitrogen as a raw material, CaO may still remain after granulation. In this case, other than moisture of binder used during granulation and lime nitrogen It may react with the moisture contained in the fertilizer, or in the long term, the moisture in the air to cause volume expansion, and eventually the granulated fertilizer may be destroyed or weathered powder may be generated.

For this reason, it is important to reduce CaO at the time of shaping, or to eliminate CaO in lime nitrogen at the stage of the raw material before shaping, and granular lime nitrogen using only powdered lime nitrogen as the raw material In the case of producing, it is preferable to reduce the CaO content with respect to lime nitrogen.

In dehydrating CaO, it is more efficient if the temperature condition during the decontamination reaction is high, but on the other hand, the hydrolysis reaction of calcium cyanamide itself, which is the main component of lime nitrogen, advances and volatilizes as ammonia. As a fertilizer component, there is a problem that production of by-products such as dicyandiamide, whose content is limited, cannot be ignored due to the fertilizer control law. On the other hand, there is a problem that the soothing reaction is difficult to proceed at a low temperature with little by-product formation.

The amount of water required for refining is theoretically equivalent to that of CaO, but the theoretical amount cannot be sufficiently reconstituted due to loss of evaporation due to heat generated by refining. In addition to the reduction of nitrogen due to the volatilization of ammonia from calcium cyanamide, further loss of nitrogen is caused if excess adhering moisture is not dried, and the rate of loss of effective nitrogen components such as cyanamide nitrogen increases during the decontamination process. There was a problem.

For the above-mentioned circumstances, various proposals have been made regarding the method for eliminating lime nitrogen, including the soaking temperature, the amount of water added, the timing of water addition, and combinations thereof.

Patent Document 1 discloses a method for producing a lime-nitrogenous fertilizer in which quick lime in lime nitrogen is hydrated with water vapor while maintaining a temperature of 80 ° C. or higher. Patent Document 2 discloses a lime nitrogen modifier containing a substance that delays the hydrolysis rate of lime nitrogen. In Patent Document 3, after mixing lignin sulfonic acid with powdered lime nitrogen in which quick lime in lime nitrogen is hydrated, other ingredients are further mixed, and granulated water in which calcium nitrate is dissolved is further added. And granulating.

JP 2001-31485 A Japanese Patent Laid-Open No. 10-297985 JP 2002-12488 A

However, the prior art described in the above literature has room for improvement in the following points.

First, in the method of Patent Document 1, when the quick lime in lime nitrogen is sublimated, for example, as shown in Example 1, it is close to an actual plant size in which 4.0 kg of water is added to 40 kg of lime nitrogen. In the reaction, the temperature rapidly increases, and as described later, there is a problem in that the production of by-products such as dicyandiamide, which is limited in content, cannot be ignored as a fertilizer component, and the content of cyanamide is lowered. In addition, ammonia may be generated after hydrated granulation drying, and when the package is opened at the time of use, the user may feel uncomfortable due to the strong ammonia odor and turn away.

Secondly, in the method of Patent Document 2, a granular fertilizer is manufactured by adding a substance that delays the hydrolysis rate of lime nitrogen to lime nitrogen that has already been subjected to the decontamination treatment. For this reason, heat generation is not suppressed at the time when the uncalculated lime nitrogen is treated with an aqueous solution, and production of by-products such as dicyandiamide, which has a limited content as a fertilizer component, is specified as a fertilizer component as described later. Cannot be ignored, and there is a problem that the content of cyanamide decreases. In addition, the granular fertilizer containing a substance that delays the hydrolysis rate of lime nitrogen has a problem in handling property and dispersibility because the crushing strength decreases as described later.

Thirdly, in the method of Patent Document 3, since drying is performed at 110 ° C., as described later, production of by-products such as dicyandiamide, which has a limited content, cannot be ignored as a fertilizer component. There is a problem that the content of cyanamide is lowered.

The present invention has been made in view of the above circumstances, and provides a granular fertilizer containing lime nitrogen in which the content of quick lime is small, the content of cyanamide is large, the content of dicyandiamide is small, and the generation of ammonia is suppressed. With the goal.

According to the present invention, an organic additive or an inorganic additive that suppresses the hydration reaction of quicklime, a nitrate or hydrochloride as a granulating aid, and a lime nitrogen that has been subjected to a decontamination treatment, the decontamination treatment A lime nitrogen-containing granular fertilizer having a dicyandiamide content of 2.0% by mass or less of the used lime nitrogen is provided.

According to this configuration, as shown in the examples described later, a lime nitrogen-containing granular fertilizer in which the content of quick lime is small, the content of cyanamide is large, the content of dicyandiamide is small, and the generation of ammonia is suppressed is obtained. .

Further, according to the present invention, adding water or an aqueous solution used for soaking to an unsettled lime nitrogen-containing composition, and soaking lime nitrogen under conditions where the exothermic peak temperature is less than 110 ° C. And a step of granulating the lime nitrogen-containing composition that has been subjected to decontamination treatment, and a method for producing lime nitrogen-containing granular fertilizer.

According to this method, as shown in the examples described later, a lime nitrogen-containing granular fertilizer with a low content of quick lime, a high cyanamide content, a low dicyandiamide content, and suppressed ammonia generation is obtained. .

According to the present invention, a lime nitrogen-containing granular fertilizer in which the content of quick lime is small, the content of cyanamide is large, the content of dicyandiamide is small, and the generation of ammonia is suppressed is obtained.

It is a graph for demonstrating the heat_generation | fever behavior by the difference in the quantity of the water used for soaking in the conditions of environmental temperature 50 degreeC. It is a graph for demonstrating the heat_generation | fever behavior at the time of adding the aqueous solution used for soothing containing water or various organic additives on the conditions where environmental temperature is 50 degreeC to lime nitrogen.

Hereinafter, embodiments of the present invention will be described in detail. In this specification, when A to B are described, it means A or more and B or less.

<Mechanism of calcification of lime nitrogen>
As shown in the chemical reaction below, unconsolidated lime (CaO) contained in lime nitrogen mainly undergoes volume expansion due to a change in form and heat generation of calcium compounds when hydrolyzing by reacting with moisture in the air. This causes a collapse from granular form to powder form and requires care and storage as a fertilizer. For this reason, the decontamination processed goods which preliminarily dehydrated the uncalculated lime (CaO) with water are distribute | circulating.

CaO + H ₂ O → Ca (OH) ₂ ΔH = 15.3 Kcal
CaCN ₂ + 2H ₂ O → Ca (OH) ₂ + H ₂ CN ₂ ΔH = 3.4 Kcal

As can be seen from the above reaction formula, water acts on both quicklime and lime nitrogen, but is preferentially used for CaO having a large ΔH. However, there is a problem that some water comes into contact with CaCN ₂ and undergoes hydrolysis, leading to the following reaction and reducing the active ingredient of the fertilizer.
H ₂ CN ₂ + 2H ₂ O → CO ₂ + 2NH ₃

In addition, when quick lime is hydrated with water, if the reaction temperature is maintained at a temperature of 80 ° C. or higher, dicyandiamide or the like is by-produced as shown in the examples described later, and cyanamide, which is an effective fertilizer component, is produced. There is also the problem of being easily lost. In addition, ammonia may be generated after hydrated granulation drying, and when opening the package at the time of use, the ammonia odor is strong, so the user may feel uncomfortable and turn away.

In view of the above circumstances, the present inventors, as shown in the examples described later, as a result of repeated experiments, by suppressing the exothermic peak temperature due to the quick lime in the lime nitrogen to less than 110 ° C., Surprisingly, it has been found that a lime nitrogen-containing granular fertilizer with a low content of quicklime, a high content of cyanamide, a low content of dicyandiamide, and a suppressed generation of ammonia is obtained.

Moreover, when the aqueous solution used for this soaking contains the organic additive or the inorganic additive which suppresses the hydration reaction of quick lime, as shown in FIG. 2, as shown in FIG. Since it becomes easy to suppress the exothermic peak temperature due to soaking to less than 110 ° C., a lime nitrogen-containing granular fertilizer in which the content of cyanamide is higher, the content of dicyandiamide is lower, and the generation of ammonia is suppressed is obtained. I found out. However, the present inventors notice that the crushing strength of the lime nitrogen-containing granular fertilizer tends to decrease when the aqueous solution used for soaking contains an organic additive or an inorganic additive that suppresses the hydration reaction of quicklime. It was. Therefore, as a result of various experiments, the present inventors have found that when the aqueous solution used for granulation of the lime nitrogen-containing granular fertilizer contains a granulation aid of either nitrate or hydrochloride, the lime nitrogen-containing granular fertilizer I noticed that this weakness could be overcome because of the improved crushing strength of.

<Lime nitrogen-containing granular fertilizer>
The lime nitrogen-containing granular fertilizer according to the present embodiment includes an organic additive or an inorganic additive that suppresses the hydration reaction of quicklime, nitrate or hydrochloride, and lime nitrogen that has been subjected to decontamination treatment. Lime nitrogen includes nitrogenous fertilizer produced by absorbing and combining nitrogen at high temperature with limestone carbide. Calcium cyanamide, the main component of lime nitrogen, is converted into cyanamide by hydrolysis and exhibits agricultural chemical effects (insecticide, weeding, sterilization), and then decomposed into fertilizer components in the soil.

The lime nitrogen that has been subjected to the decontamination treatment used in the present embodiment includes lime nitrogen that has been obtained by decontamination of uncalculated lime nitrogen with an aqueous solution or water vapor. In the lime nitrogen that has been dehydrated for use in this embodiment,
CaO + H ₂ O → Ca (OH) ₂
It is preferable that most quick lime (unslaked lime (CaO)) is changed to slaked lime (slaked lime (Ca (OH) ₂ )) by the chemical reaction.

The lime nitrogen that has been subjected to the decontamination treatment used in the present embodiment preferably has a quick lime content of, for example, 5% by mass or less. When quick lime contained in lime nitrogen mainly reacts with moisture in the air and hydrolyzes, it causes a change in the shape of the calcium compound, and it is accompanied by heat generation and volume expansion. It is for suppressing. Or the content rate of the quick lime contained in the lime nitrogen after the decontamination process used for this embodiment is 5.0 mass%, 4.5 mass%, 4.0 mass%, 3.5 mass%, 3.0. % By mass, 2.5% by mass, 2.0% by mass, 1.5% by mass, 1.0% by mass, 0.5% by mass, 0.1% by mass or less, or any of these values It may be within a range of two values.

The lime nitrogen that has been subjected to the decontamination treatment used in the present embodiment preferably has a cyanamide nitrogen content of 10% by mass or more. It is because the fertilizer effect with respect to soil becomes high, so that there are many cyanamide which is an effective agrochemical component and a fertilizer component. Alternatively, the content of cyanamide nitrogen contained in the lime nitrogen that has been subjected to decontamination treatment used in the present embodiment is 10% by mass, 12% by mass, 14% by mass, 16% by mass, 18% by mass, 20% by mass, and 22% by mass. %, 24 mass%, 26 mass%, 28 mass% or more, or any two of these values.

The lime nitrogen that has been subjected to the decontamination treatment used in the present embodiment preferably has a dicyandiamide content of 2.0% by mass or less. This is because as the dicyandiamide content increases, the cyanamide content decreases accordingly. Alternatively, the content of dicyandiamide contained in the lime nitrogen that has been subjected to the decontamination treatment used in the present embodiment is 2.0% by mass, 1.5% by mass, 1.0% by mass, 0.5% by mass, and 0.1% by mass. It may be less than or equal to any value of%, or within the range of any two of these values.

The lime nitrogen that has been subjected to the decontamination treatment used in this embodiment preferably has a content of melamine as an impurity of 0.4% by mass or less, and more preferably 0.2% by mass or less. This is because as the content of melamine increases, the content of cyanamide decreases accordingly. Or the content rate of the melamine contained in the lime nitrogen after the decontamination process used for this embodiment is 0.4 mass%, 0.35 mass%, 0.30 mass%, 0.25 mass%, 0.20 mass. %, 0.15% by mass, 0.10% by mass, 0.05% by mass, 0.025% by mass, 0.020% by mass, 0.015% by mass, 0.010% by mass or less, Or it may be in the range of these arbitrary two values.

The organic additive or inorganic additive that suppresses the hydration reaction of quicklime used in the present embodiment, as shown in the examples described later, suppresses the quicklime hydration reaction, thereby reducing the quicklime in the lime nitrogen. It becomes possible to keep the exothermic peak temperature due to the lower, and to keep the temperature of lime nitrogen during the soaking below 110 ° C. and to facilitate the flattening of the hydration reaction. Alternatively, the temperature of lime nitrogen during soaking may be less than any of 100 ° C, 110 ° C, and 120 ° C. Therefore, if an organic additive or inorganic additive that suppresses the hydration reaction of quicklime is used, the content of cyanamide nitrogen is high, the content of dicyandiamide and melamine is low, and the lime nitrogen-containing granular fertilizer in which the generation of ammonia is suppressed Is obtained.

Examples of the organic additive that suppresses the hydration reaction of quicklime used in the present embodiment include oxycarboxylic acids such as glucoheptonic acid, gluconic acid, galactonic acid, citric acid, tartaric acid, malic acid, and salts thereof, and ketocarbon such as pyruvic acid. Acids or salts thereof, itaconic acid or salts thereof, sugar alcohols such as sorbitol and mannitol, sugars such as glucose, mannose, galactose, fructose, arabinose, sucrose (sucrose), lactose, maltose, raffinose, dextrin, xylose, starch, It preferably contains one or more organic substances selected from the group consisting of aromatic sulfonic acids or salts thereof, lignin sulfonic acids or salts thereof, and inositol. This is because the present inventors have confirmed that these organic substances actually have a function of suppressing the hydration reaction of quicklime, as shown in the examples described later. Moreover, these organic substances are also preferable in terms of safety when used as raw materials for agricultural chemicals or fertilizers.

Further, the organic additive for suppressing the hydration reaction of quicklime used in this embodiment may be one selected from the group consisting of molasses, corn syrup, and pulp waste liquid. This is because the present inventors have confirmed that these organic substances actually have a function of suppressing the hydration reaction of quicklime, as shown in the examples described later. These organic substances have been confirmed to be safe when used as raw materials for agricultural chemicals or fertilizers, and are also preferable in terms of easy availability and low purchase costs. In the present specification, “waste molasses” includes a viscous black-brown liquid containing components other than sugar, which are generated when sugar is refined. That is, molasses is contained in molasses. In addition, the molasses may be obtained when sugarcane is purified, may be obtained when sugarbeet is purified, or may be obtained when other raw materials are purified.

Moreover, the inorganic additive which suppresses the hydration reaction of the quicklime used in this embodiment is magnesium silicofluoride, phosphoric acid, phosphate, boric acid, borate, potassium dihydrogen phosphate, ammonium dihydrogen phosphate. Inorganic salts such as dihydrogen phosphate, calcium nitrate, calcium chloride, and magnesium chloride are preferable. Of these, boric acid, potassium dihydrogen phosphate, magnesium silicofluoride, calcium nitrate, calcium chloride, and magnesium chloride are particularly preferable.

About the minimum of the compounding quantity with respect to the lime nitrogen of an organic additive or an inorganic additive, although it changes with kinds and combination of the organic additive or an inorganic additive to be used, it is 0.1 mass part with respect to 100 mass parts of lime nitrogen at the time of soaking. By blending the above-mentioned appropriate amount, the hydration reaction of quicklime can be suppressed, and the above requirements can be met.

In addition, the upper limit of the amount of the organic additive or inorganic additive to lime nitrogen is not particularly required, but a large amount of the organic additive or inorganic additive results in a decrease in nitrogen content. . In addition, when a large amount of organic or inorganic additive is added, a delay effect of hydrolysis rate of lime nitrogen appears as a secondary effect of the organic or inorganic additive. The rate of hydrolysis of nitrogen is slower than expected, and when used as normal lime nitrogen, the condition is poor. Therefore, it is desirable to add in the range of 0.1 to 5 parts by mass with respect to 100 parts by mass of the lime nitrogen that has been subjected to the decontamination treatment in which the decomposition delay effect due to the organic additive or inorganic additive does not appear remarkably. Or the compounding quantity of the organic additive or the inorganic additive with respect to the lime nitrogen after the decontamination process used for this embodiment is 0.1 mass part, 0.2 mass part, 0.3 with respect to 100 mass parts of lime nitrogen. Parts by weight, 0.4 parts by weight, 0.5 parts by weight, 1.0 parts by weight, 1.5 parts by weight, 2.0 parts by weight, 2.5 parts by weight, 3.0 parts by weight, 3.5 parts by weight It may be within a range of any two values of 4.0 parts by mass, 4.5 parts by mass, and 5.0 parts by mass.

Nitric acid or a salt thereof or hydrochloric acid or a salt thereof used in the present embodiment improves the crushing strength of the lime nitrogen-containing granular fertilizer as shown in Examples described later. Therefore, the use of nitric acid or its salt or hydrochloric acid or its salt compensates for the weak point that the crushing strength of the lime nitrogen-containing granular fertilizer of the organic additive or inorganic additive mentioned above is easily compensated for in handling and dispersibility. An excellent lime nitrogen-containing granular fertilizer can be obtained. Furthermore, the present inventors have found that the production of dicyandiamide and melamine is also effective.

The nitrate or hydrochloride used in the present embodiment preferably contains, for example, one or more salts selected from the group consisting of calcium nitrate, calcium chloride, and magnesium chloride. As shown in the examples described later, these nitrates or hydrochlorides actually improve the crushing strength of lime nitrogen-containing granular fertilizer, and further have the effect of suppressing the formation of dicyandiamide and melamine. Because they have confirmed. Further, these nitrates or hydrochlorides are also preferable in view of safety when used as raw materials for agricultural chemicals or fertilizers.

About the minimum of the compounding quantity with respect to the lime nitrogen of nitrate or hydrochloride, although it changes with kinds and combinations of nitrate or hydrochloride to be used, it mix | blends an appropriate quantity of 3 mass parts or more with respect to 100 mass parts of lime nitrogen at the time of granulation. Thus, the crushing strength of the lime nitrogen-containing granular fertilizer can be improved, and the above request can be met. In addition, the upper limit of the blending amount of nitrate or hydrochloride with respect to lime nitrogen is not particularly required, but addition of a large amount of nitrate or hydrochloride results in a decrease in cyanamide content. Therefore, it is desirable to add nitrate or hydrochloride in the range of 3 to 20 parts by mass with respect to 100 parts by mass of lime nitrogen that has been subjected to the decontamination treatment. Or the compounding quantity of the nitrate or hydrochloride with respect to the lime nitrogen after the decontamination process used for this embodiment is 3 mass parts, 4 mass parts, 5 mass parts, 6 mass parts, 7 mass with respect to 100 mass parts of lime nitrogen. Part, 8 parts by mass, 9 parts by mass, 10 parts by mass, 12 parts by mass, 14 parts by mass, 16 parts by mass, 18 parts by mass, and 20 parts by mass.

The lime nitrogen-containing fertilizer is desired to be granular because it is likely to be scattered during work in the case of powder. One of the methods of this embodiment uses an aqueous solution used for soaking that contains an organic additive or an inorganic additive that suppresses the hydration reaction of quicklime in the soaking operation. And as the liquid used at the time of granulation, the aqueous solution used for granulation containing nitrate or hydrochloride which raises the crushing strength of lime nitrogen content granular fertilizer is used. Therefore, according to one of the methods of this embodiment, the content of quick lime is small and the crushing strength is excellent, the content of cyanamide is large, the content of dicyandiamide and melamine is small, and the generation of ammonia is suppressed. A lime nitrogen-containing granular fertilizer is obtained.

When trying to obtain a granulated product, an aqueous solution used for soaking containing an organic additive or an inorganic additive is added to an unsettled lime nitrogen-containing fertilizer powder, and a soaking reaction is performed. After that, the aqueous solution used for granulation containing nitrate or hydrochloride is added to the lime nitrogen-containing fertilizer powder that has been subjected to decontamination treatment, generally kneaded to increase uniformity, and then granulation methods such as extrusion and embossing Or, it is granulated by a conventionally known method such as granulating from a powder using a bread type granulator, kiln type granulator, drum type granulator or the like, and dried by means such as heating or blowing. Thus, a granulated product can be easily obtained. In addition, for the mixture with powdered phosphate fertilizer and potato fertilizer, and the granulated product after mixing with powdered phosphate fertilizer and kari fertilizer, this embodiment is used to relieve the quick lime in lime nitrogen. And can then be granulated.

The lime nitrogen-containing granular fertilizer of this embodiment is excellent in crushing strength because it is obtained by soaking and granulating in this way. For example, crushing strength (granulation by a Kiyama-type hardness meter (Model Number 02040001) is used. The average value obtained by measuring 20 object diameters of 2 to 4 mm) is preferably 0.5 kgf or more. This is because the higher the crushing strength of the lime nitrogen-containing granular fertilizer, the better the handleability and sprayability. Alternatively, the crushing strength of the lime nitrogen-containing granular fertilizer of the present embodiment is 0.5 kgf, 1.0 kg, 1.5 kgf, 2.0 kgf, 2.5 kgf, 3.0 kgf, 3.5 kgf, 4.0 kgf, 5. It may be greater than or equal to any of 0 Kgf, 5.5 Kgf, 6.0 Kgf, 6.5 Kgf, and 7 Kgf, or may be within a range of any two values.

The lime nitrogen-containing granular fertilizer of the present embodiment is sealed and packaged in a predetermined amount in a synthetic resin bag having moisture-proof performance to become a final product. Then, until the packaging bag is opened and used as fertilizer, it is placed in various storage environments. In order to investigate the storage stability of granular fertilizer as a product during storage, “Regarding materials attached to registration application forms for agricultural chemicals” (Notice of Director of Production, Ministry of Agriculture, Forestry and Fisheries, No. 13 Production No. 3987 dated January 10, 2002) ) The storage stability was examined in accordance with the conditions described in the description (a severe test at 40 ° C. for one month is treated as equivalent to a one-year test at room temperature). In the examples described later, two weeks corresponding to half a year are adopted as the storage period, and the storage stability performance evaluation is examined by the crushing strength of the grains.

The lime nitrogen-containing granular fertilizer of the present embodiment preferably has a crushing strength of 0.5 kgf or more measured after 40 ° C. and 2 weeks in this way. This is because the higher the crushing strength, the better the storage stability. Alternatively, the crushing strength is 0.5 kgf, 1.0 kg, 1.5 kgf, 2.0 kgf, 2.5 kgf, 3.0 kgf, 3.5 kgf, 4.0 kgf, 5.0 kgf, 5.5 kgf, 6.0 kgf. , 6.5Kgf, 7Kgf or more, or any two values.

<Production method of lime nitrogen-containing granular fertilizer>
The method for producing lime nitrogen-containing granular fertilizer according to the present embodiment adds an aqueous solution used for soaking to an unsettled lime nitrogen-containing composition, and soaks lime nitrogen under conditions where the exothermic peak temperature is less than 110 ° C. And a step of granulating the lime nitrogen-containing composition that has been subjected to the decontamination treatment. In addition, the production method of the lime nitrogen containing granular fertilizer of this embodiment may further include the process of drying the granulated lime nitrogen containing granular fertilizer. In this way, when quick lime in lime nitrogen is sublimated while the exothermic peak temperature is less than 110 ° C., the lime content is low, the cyanamide content is high, and dicyandiamide and melamine, as shown in the examples described later. Thus, a lime nitrogen-containing granular fertilizer in which the generation of ammonia is suppressed is obtained.

At this time, the soaking reaction does not need to be performed by the aqueous solution used for soaking, and lime nitrogen may be sanitized by water vapor generated from the soaking aqueous solution. For example, unsettled lime nitrogen and an aqueous solution used for soaking are placed in a mixer, and after stirring, the mixer is sealed, and the water vapor of the aqueous solution used for soaking evaporated by the heat of the soaking reaction in the mixer May be performed.

FIG. 1 is a graph for explaining the heat generation behavior due to the difference in the amount of water used for soaking under the condition of an environmental temperature of 50 ° C. As shown in this figure, the greater the amount of water used for soaking, the higher the exothermic peak temperature during the soothing reaction. Therefore, to obtain a lime nitrogen-containing granular fertilizer with a low content of quick lime, a low content of cyanamide, a low content of dicyandiamide and melamine, and a suppressed generation of ammonia, the amount of water used for soaking can be reduced. It will be good.

In addition, the present inventors further effectively reduced the exothermic peak temperature itself during the sublimation by adding an organic additive or an inorganic additive that suppresses the hydration reaction of quicklime to the aqueous solution used for the sublimation. I found out that I can make it.

FIG. 2 is a graph for explaining an exothermic behavior when an aqueous solution used for soaking containing various organic additives is added to lime nitrogen under a condition where the environmental temperature is 50 ° C. As shown in the figure, the exothermic peak temperature can be greatly suppressed by adding various organic additives to the water used for soaking to obtain an aqueous solution. In particular, 10% (w / v) glucose, fructose, sucrose, xylose, starch, gluconic acid, waste molasses (main components: glucose, fructose, sucrose, etc.), sun extract C (lignin sulfonate), lignin sulfone When the aqueous solution of the acid Ca is added, the exothermic peak temperature can be effectively suppressed. Although not shown in FIG. 2, the same effect can be obtained by adding an aqueous solution containing an inorganic additive instead of the organic additive.

However, when the present inventors simply add various organic additives or inorganic additives to the water used for soaking to obtain an aqueous solution, the exothermic peak temperature itself during soaking can be lowered. Instead, he noticed that the crushing strength of lime nitrogen-containing granular fertilizer tends to decrease. Therefore, as a result of various experiments, the present inventors have found that when the aqueous solution used for granulation of the lime nitrogen-containing granular fertilizer contains a granulation aid of either nitrate or hydrochloride, the lime nitrogen-containing granular fertilizer I noticed that this weakness could be overcome because of the improved crushing strength of.

In addition, when drying the granulated lime nitrogen-containing granular fertilizer, the present inventors, if the drying temperature is too high, dicyandiamide, melamine, and the like are by-produced in the drying step as shown in the examples described later. They also noticed that cyanamide, an effective fertilizer component, was easily lost.

Therefore, the inventors further add a step of drying the granulated lime nitrogen-containing granular fertilizer using a fluidized dryer under a condition of 100 ° C. or less to the method for producing the lime nitrogen-containing granular fertilizer of the present embodiment. Has been found to be preferable. If it is dried using a fluid dryer at 100 ° C or less, it can be efficiently dried at a low temperature and in a short time, so that dicyandiamide and the like are hardly produced as a by-product in the drying process, and the content of cyanamide, an effective fertilizer component Can be kept high. Alternatively, the temperature of this drying step is 100 ° C, 95 ° C, 90 ° C, 85 ° C, 80 ° C, 75 ° C, 65 ° C, 60 ° C, 55 ° C, 50 ° C, 45 ° C, 40 ° C or less. Or it may be in the range of any two values.

As mentioned above, although embodiment of this invention was described, these are illustrations of this invention and various structures other than the above can also be employ | adopted.

In the above embodiment, the drying process is performed by a fluidized dryer, but there is no particular limitation, and other dryers may be used as long as they can be dried at a low temperature and in a short time. For example, a vibration dryer, a kiln dryer, a blower dryer, a vacuum dryer, or the like can be suitably used.

Hereinafter, the present invention will be further described with reference to examples, but the present invention is not limited thereto.

<Experimental example 1>
As shown in Table 1, 40 kg of lime nitrogen is put into a concrete mixer having a diameter of 1 m and a depth of 40 cm, and then 5.0 kg of water (12.5 parts by mass with respect to 100 parts by mass of lime nitrogen) is added in a lump with rain dew. Then, a conical lid with a hole having a diameter of 5 cm was formed at the top for vapor removal, and the mixture was immediately stirred for 3 minutes and left as it was. As a result of measuring the product temperature by inserting a thermometer through the top hole, the peak temperature of the soaking reaction reached 124.1 ° C. After completion of the soaking reaction, sacrificial lime nitrogen was collected and used for the next bread granulation step.

Water is added to the lime nitrogen that has been subjected to decontamination treatment so that the amount of granulated water is 34.5 (v / w)%, and granulation is performed over a period of 23 minutes using a general bread type granulator. Done the grain. Of the obtained granular fertilizer, only those having a desired diameter of 2 to 4 mm were sieved using a sieve, and the granulation rate of the desired diameter was 53.3% (w / w). Only these granular fertilizers with the desired diameter were selected and used in the next drying step.

In the next drying step, the sample was dried using a fluid dryer at (1) a drying temperature of 80 ° C., a drying time of 5 minutes and 10 minutes. As a result, a dried granular fertilizer having a moisture content of 0.4% (w / w) and a crushing strength of 1.0 kgf / mm ² or more (indicated as ++ in Table 1) was obtained. The crushing strength was determined by selecting 20 arbitrary granulated products having a diameter of 2 to 4 mm obtained by sieving and measuring with a Kiyama-type hardness meter (Model Number 02040001).

Further, when the dried fertilizer was analyzed, as shown in Table 1, the content of quick lime in the lime nitrogen was 0.14% by mass and 0.21% by mass. The content of quicklime was determined by using an X-ray diffractometer and a measured value from a calibration curve prepared with the reagent CaO and the peak intensity of the sample. Moreover, when the dry-processed granular fertilizer was analyzed, the content rate of cyanamide-type nitrogen among lime nitrogen was 15.59 mass% and 17.99 mass%. The content of cyanamide-type nitrogen was measured by the Ministry of Agriculture, Forestry and Fisheries, National Institute for Agro-Environmental Technology “Fertilizer Analysis”, 1992, cyanamide nitrogen and silver nitrate method. Moreover, the content rate of the dicyandiamide in lime nitrogen was 4.52 mass% and 3.65 mass%. The content of dicyandiamide was measured by high performance liquid chromatography, Agricultural, Forestry and Fisheries Consumption Safety Technology Center, Fertilizer Research Report (2), 25-31, 2009.

Moreover, the trained panelist conducted a sensory test on the ammonia odor of the granular fertilizer that had been dried. The results of the sensory test were evaluated as follows.
◎: No ammonia odor ○: Little ammonia odor △: A little ammonia odor ×: Ammonia odor is bad

Crushing strength of hydrated granulated product Also, the crushing strength of dried granulated fertilizer is calculated as an average value of 20 granulated diameters measured from 2 to 4 mm using a Kiyama-type hardness meter (Model Number 02040001). did. These detailed conditions and evaluation results are shown in Table 1. In Table 1, the crushing strength is expressed as follows.
++: 1.0 kgf / mm ² or more +: 0.5 kgf / mm ² or more less than 1.0 kgf / mm ² +-: 0.2 kgf / mm ² or more less than 0.5 kgf / mm ^2- : 0.05 kgf / mm ² Above 0.2 Kgf / mm < ² > /: not measured Note that the same applies to Tables 2 and 3 described later.

Crushing strength after storage at 40 ° C for 2 weeks In addition, for dry fertilized granular fertilizers, "Regarding the materials attached to agricultural chemical registration applications, etc." (Ministry of Agriculture, Forestry and Fisheries, No. 13 Production No. 3987 dated January 10, 2002 Notification of the Director of Production) According to the conditions described in the description (stress tests at 40 ° C for one month are equivalent to one-year tests at room temperature for inspections related to stability over time), storage stability after two weeks at a constant temperature bath of 40 ° C The crushing strength, a measure of sex, was measured. These detailed conditions and evaluation results are shown in Table 1. The measuring method and notation of the crushing strength after storage at 40 ° C. for 2 weeks are the same as the measuring method and the notation of the crushing strength of the hydrated granulated product. The same applies to Table 3 described later.

<Experimental example 2>
As an aqueous solution used for soaking, a 10% (w / v) concentration molasses aqueous solution is basically an experimental example except that only 12.5 parts by mass is added to 100 parts by mass of lime nitrogen. In the same manner as in Example 1, a lime nitrogen-containing granular fertilizer was produced. Detailed conditions and evaluation results are shown in FIG.

<Experimental example 3>
As an aqueous solution used for soaking, 5% (w / v) concentration of carboxymethyl cellulose (CMC) / M30000 aqueous solution was added at 12.5 parts by mass with respect to 100 parts by mass of lime nitrogen, and a drying temperature of 60 ° C. A lime nitrogen-containing granular fertilizer was produced basically in the same manner as in Experimental Example 1 except that the drying time was 20 minutes. Detailed conditions and evaluation results are shown in Table 2.

<Experimental example 4>
A 10% (w / v) concentration lignin sulfonic acid Na aqueous solution as an aqueous solution used for soaking was added at 12.5 parts by mass with respect to 100 parts by mass of lime nitrogen, and a drying temperature of 60 ° C. and a drying time. A lime nitrogen-containing granular fertilizer was produced basically in the same manner as in Experimental Example 1, except that the time was 20 minutes. Detailed conditions and evaluation results are shown in FIG.

<Experimental example 5>
As an aqueous solution used for soaking, a starch aqueous solution having a concentration of 10% (w / v) was added at 12.5 parts by mass with respect to 100 parts by mass of lime nitrogen, and a drying temperature of 60 ° C. and a drying time of 20 minutes Except for this point, a lime nitrogen-containing granular fertilizer was produced basically in the same manner as in Experimental Example 1. Detailed conditions and evaluation results are shown in Table 2.

<Experimental example 6>
As an aqueous solution used for soaking, a sucrose aqueous solution having a concentration of 10% (w / v) was added at 12.5 parts by mass with respect to 100 parts by mass of lime nitrogen, and a drying temperature of 60 ° C. and a drying time of 60 minutes Except for this point, a lime nitrogen-containing granular fertilizer was produced basically in the same manner as in Experimental Example 1. Detailed conditions and evaluation results are shown in Table 3.

<Experimental example 7>
As an aqueous solution used for soaking, a 10% (w / v) concentration molasses aqueous solution is 12.5 parts by mass with respect to 100 parts by mass of lime nitrogen, and 6 parts by mass of calcium nitrate with respect to 100 parts by mass of lime nitrogen. A lime nitrogen-containing granular fertilizer was produced basically in the same manner as in Experimental Example 1 except that the batch addition was performed and the drying temperature was 80 ° C. and the drying time was 60 minutes. Detailed conditions and evaluation results are shown in Table 3.

<Experimental Example 8>
As an aqueous solution used for soaking, a 10% (w / v) sucrose aqueous solution is added to 12.5 parts by mass with respect to 100 parts by mass of lime nitrogen, and 3 parts by mass of calcium nitrate with respect to 100 parts by mass of lime nitrogen. Basically, except that the calcium nitrate and 3 parts by mass with respect to 100 parts by mass of lime nitrogen were added together with the granulated water at the time of granulation, and the point that the drying temperature was 80 ° C. and the drying time was 60 minutes. Produced a lime nitrogen-containing granular fertilizer in the same manner as in Experimental Example 1. Detailed conditions and evaluation results are shown in Table 3.

<Experimental Example 9>
As an aqueous solution used for soaking, a 16% (w / v) concentration aqueous glucose solution was added to 12.5 parts by mass with respect to 100 parts by mass of lime nitrogen, and calcium nitrate was added to 100 parts by mass of lime nitrogen. Except for 3 parts by weight and 3 parts by weight of calcium nitrate with 100 parts by weight of lime nitrogen together with granulated water at the time of granulation, and the point at which the drying temperature was 80 ° C. and the drying time was 60 minutes. Basically, a lime nitrogen-containing granular fertilizer was produced in the same manner as in Experimental Example 1. Detailed conditions and evaluation results are shown in Table 3.

<Consideration of results>
From the experimental results of the above experimental examples 1 to 9, in the case of the experimental examples 2, 4 to 9, the exothermic peak temperature is suppressed to be lower than 110 ° C. compared to the case of the experimental examples 1 and 3. It can be seen that a lime nitrogen-containing granular fertilizer having a high content of cyanamide nitrogen, a low content of dicyandiamide and melamine, and a suppressed ammonia odor can be obtained. In addition, in Experimental Examples 7 to 9, it can be seen that a lime nitrogen-containing granular fertilizer having excellent crushing strength and storage stability can be obtained.

Further, as shown in Experimental Examples 6 to 9 in Table 3, the storage stability was examined for combinations of organic additives and nitrates or hydrochlorides while changing the addition amount and the addition timing. As a result, as in Experimental Examples 7 to 9, it was found that a system in which calcium nitrate is combined with sucrose or glucose which is a sugar among organic additives (waste molasses contains sucrose and glucose) is particularly excellent in storage stability. .

In the above, this invention was demonstrated based on the Example. It is to be understood by those skilled in the art that this embodiment is merely an example, and that various modifications are possible and that such modifications are within the scope of the present invention.

Claims

An organic additive or an inorganic additive that suppresses the hydration reaction of quicklime;
Nitrate or hydrochloride as a granulating aid,
With lime nitrogen that has been treated
Including
The content of dicyandiamide in the lime nitrogen that has been subjected to the decontamination treatment is 2.0% by mass or less.
Lime nitrogen-containing granular fertilizer.
Of the lime nitrogen that has been treated, the content of quick lime is 5% by mass or less.
The lime nitrogen-containing granular fertilizer according to claim 1.
The organic additive is oxycarboxylic acids such as glucoheptonic acid, gluconic acid, galactonic acid, citric acid, tartaric acid, malic acid or salts thereof, ketocarboxylic acids such as pyruvic acid or salts thereof, itaconic acid or salts thereof, sorbitol, mannitol Sugar alcohols such as glucose, mannose, galactose, fructose, arabinose, sucrose (saccharose), sugars such as lactose, maltose, raffinose, dextrin, xylose, starch, aromatic sulfonic acid or salt thereof, lignin sulfonic acid or salt thereof Including one or more organic substances selected from the group consisting of inositol,
The inorganic additive includes one or more inorganic substances selected from the group consisting of boric acid, potassium dihydrogen phosphate, magnesium silicofluoride, calcium nitrate, calcium chloride, magnesium chloride,
The lime nitrogen-containing granular fertilizer according to claim 1 or 2.
The organic additive is one selected from the group consisting of molasses, corn syrup, and pulp waste liquid.
The lime nitrogen containing granular fertilizer in any one of Claim 1 or 2.
The granulation aid contains one or more salts selected from the group consisting of calcium nitrate, calcium chloride, and magnesium chloride.
The lime nitrogen-containing granular fertilizer according to any one of claims 1 to 4.
The amount of the organic additive or inorganic additive is 0.1 to 5 parts by mass with respect to 100 parts by mass of the lime nitrogen that has been subjected to the decontamination treatment.
The lime nitrogen-containing granular fertilizer according to any one of claims 1 to 5.
The blending amount of the granulation aid is 3 to 20 parts by mass with respect to 100 parts by mass of the lime nitrogen that has been subjected to the decontamination treatment.
The lime nitrogen-containing granular fertilizer according to any one of claims 1 to 6.
The content of cyanamide nitrogen in the lime nitrogen that has been subjected to the sacrificial treatment is 10% by mass or more.
The lime nitrogen-containing granular fertilizer according to any one of claims 1 to 7.
The lime nitrogen-containing granular fertilizer according to any one of claims 1 to 8, wherein the content of melamine in the lime nitrogen that has been subjected to decontamination treatment is 0.4 mass% or less.
Crushing strength is 0.5 kgf or more,
The lime nitrogen-containing granular fertilizer according to any one of claims 1 to 9.
The organic additive contains at least one saccharide selected from the group consisting of saccharides such as glucose, mannose, galactose, fructose, arabinose, sucrose (saccharose), lactose, maltose, raffinose, dextrin, xylose, or a salt thereof,
The granulation aid comprises calcium nitrate;
The crushing strength after 2 weeks at 40 ° C. is 0.5 kgf or more.
The lime-nitrogen-containing granular fertilizer according to any one of claims 1 to 10.
Adding water or an aqueous solution to be used for soaking to the unsettled lime nitrogen-containing composition, and sanitizing lime nitrogen under conditions where the exothermic peak temperature is less than 110 ° C;
A step of granulating the lime nitrogen-containing composition that has been subjected to sacrificial treatment,
Production method of lime nitrogen-containing granular fertilizer.
The step of granulating includes the step of granulating by adding any of water, an aqueous solution of nitrate or an aqueous solution of hydrochloride to the lime nitrogen-containing composition that has been subjected to decontamination treatment,
The method for producing lime nitrogen-containing granular fertilizer according to claim 12.
The step of decontamination includes a step of decontamination of the lime nitrogen with water vapor generated from water or an aqueous solution used for the decontamination.
The method for producing lime nitrogen-containing granular fertilizer according to claim 12 or 13.
The aqueous solution used for the soaking contains an organic additive or an inorganic additive that suppresses the hydration reaction of quicklime,
The method for producing lime nitrogen-containing granular fertilizer according to any one of claims 13 to 14.
Further comprising the step of drying the granulated lime nitrogen-containing granular fertilizer using a fluid dryer under conditions of 100 ° C. or less,
The method for producing lime nitrogen-containing granular fertilizer according to any one of claims 12 to 15.