JPWO2007013218A1 - Iron supply agent for plants and method for producing the same - Google Patents

Abstract

The present invention provides an iron supply agent, an iron supply agent for plants, and the like capable of obtaining an aqueous solution having a high Fe 2+ ion concentration and in which oxidation of Fe 2+ ions is suppressed. The agent comprises an aqueous solution obtained by dissolving an organic acid (particularly citric acid) having a carboxyl group and / or a hydroxyl group and FeO. Moreover, the other iron supply agent of this invention removes water from the aqueous solution obtained by melt | dissolving the organic acid (especially citric acid) which has a carboxyl group and / or a hydroxyl group, and FeO. These iron supply agents have a dissolution step of heating a mixture containing organic acid powder (particularly citric acid powder), FeO powder, and water to obtain an aqueous solution obtained by dissolving the organic acid and FeO. It can be obtained by a method. The FeO powder to be used is a vacuum after heating a granulated product obtained by granulating iron-containing dust and / or a granulated product obtained by granulating iron-containing dust and a reducing agent. It is preferably obtained by rapid cooling. [Selection] Figure 1

Description

The present invention relates to an iron supplier, an iron supplier for plants containing the same, and a method for producing the same. More specifically, the present invention relates to an iron supply agent having a high Fe ²⁺ ion concentration in an aqueous solution state, in which oxidation of Fe ²⁺ ions is suppressed, a plant iron supply agent containing the same, and a method for producing the same.

It is known that iron is a trace essential element for plants, and deficiency causes specific symptoms such as yellowing of leaves and impaired protein synthesis reaction. Also, iron is taken up in an ionized state. However, among Fe ions, Fe ³⁺ ions are known to be difficult to obtain a satisfactory effect on plants even if they are supplied. For this reason, the device which supplies iron as Fe2 ⁺ ion conventionally is made | formed. However, Fe ²⁺ ions are easily oxidized to become Fe ³⁺ , and it is desired that Fe ²⁺ ions can be stably supplied over a long period of time.
As a composition for supplying iron to this plant, the use of iron powder, converter slag, iron hydroxide and the like has been proposed (see, for example, Patent Document 1). Furthermore, a method using a water-soluble inorganic iron salt such as iron sulfate and iron nitrate, a method using an EDTA iron complex with ethylenediaminetetraacetic acid (hereinafter simply referred to as “EDTA”), and the like are known.

JP-A-8-277183

However, most of the iron content eluted from the iron-containing composition described in Patent Document 1 is Fe ³⁺ , and it is considered difficult for plants to take up. Moreover, the water-soluble inorganic iron salt does not easily maintain the Fe ²⁺ state and is easily oxidized to Fe ³⁺ . Furthermore, there is a problem that salt accumulation is caused as in the conventional case. That is, water-soluble inorganic metal salts have been used for a long time as various fertilizers, and the strong acid anions constituting these water-soluble metal salts combine with other elements in the soil to form water-insoluble salts. It has become a problem to accumulate. A water-soluble inorganic iron salt cannot solve this problem. Further, it is substantially trivalent iron that is used as the EDTA iron complex. Moreover, EDTA is a strong chelating agent, and there are concerns that fixing heavy metals in the soil and causing soil contamination, and dissolving in groundwater to cause water contamination.

The present invention solves the above-described conventional problems, and has a high Fe ²⁺ ion concentration in an aqueous solution state and an iron supply agent in which oxidation of Fe ²⁺ ions is suppressed, and an iron supply agent for plants containing the same. An object of the present invention is to provide a manufacturing method thereof.

The present inventors paid attention to an organic acid having a chelating power against iron, and examined the organic acid iron. As a result, for example, conventionally known ferrous citrate obtained by boiling metal iron and an aqueous citric acid solution, citric acid obtained by reacting Fe (OH) ₃ with an aqueous citric acid solution Of the ferric iron, ferrous citrate (Fe ²⁺ ) is poor in water solubility and does not sufficiently supply Fe ²⁺ , but ferric citrate (Fe ³⁺ ) is sufficiently soluble in water. about 1/4 of Fe ions only contains ^{Fe 2+} ion, it was found that ^{Fe 2+} ion amount is insufficient. Furthermore, a compound having strong ion binding properties, such as iron ammonium citrate, has been difficult to obtain a sufficient effect of inhibiting oxidation of Fe ²⁺ ions.
On the other hand, solids and pastes obtained by boiling citric acid powder, FeO powder and water, and solids obtained by drying an aqueous solution obtained by purifying these are each water-soluble. It was found that the Fe ²⁺ ion concentration was specifically high when it was applied, and that the Fe ²⁺ ions were not easily oxidized. The present invention has been completed based on this finding.

The present invention is as follows.
(1) An iron supplier comprising an aqueous solution obtained by dissolving an organic acid having a carboxyl group and / or a hydroxyl group and FeO (hereinafter referred to as “iron supplier of the first invention”) ).
(2) The above, wherein Fe ²⁺ ions and Fe ³⁺ ions are contained, and the total of the Fe ²⁺ ions and the Fe ³⁺ ions is 100% by mass, and the Fe ²⁺ ions are 50 to 90% by mass ( The iron supply agent according to 1).
(3) The iron supplier according to (1), wherein the Fe ²⁺ ion concentration observed in the aqueous solution after standing for 168 hours is 75% or more of the Fe ²⁺ ion concentration observed immediately after the start of measurement.
(4) The iron supply agent according to (1), which contains at least citric acid as the organic acid.
(5) and one Fe ²⁺ dimeric complexes of citric acid and / or citric acid ions were two coordinated to the ion, citric acid and / or citric acid ions are three for one Fe ²⁺ ions The iron supplier according to (4) above, which contains a coordinated trimer complex.
(6) An iron supply agent for plants containing the iron supply agent according to any one of (1) to (5) above (hereinafter referred to as “the iron supply agent for plants of the first invention”) ).
(7) The iron supplier for plants according to (6) above, which contains a biodegradable binder.
(8) The iron supply agent for plants according to the above (6), which contains a biodegradable extender.
(9) The plant iron supply agent according to (6), which contains 5% by mass or more of the iron supply agent when the total amount of the iron supply agent for plants is 100% by mass.
(10) An iron supply agent characterized by removing water from an aqueous solution obtained by dissolving an organic acid having a carboxyl group and / or a hydroxyl group and FeO (hereinafter referred to as “second invention”). Iron supply)).
(11) an aqueous solution obtained by dissolving this iron supplying agent, when containing the ^{Fe 2+} ions and ^{Fe 3+} ions, and the total of the ^{Fe 2+} ions and the ^{Fe 3+} ions is 100 mass%, the Fe The iron supply agent according to (10), wherein ²⁺ ions are 50 to 90% by mass.
(12) The aqueous solution obtained by dissolving the present iron supplier has an Fe ²⁺ ion concentration found in the aqueous solution after standing for 168 hours is 75% or more of the Fe ²⁺ ion concentration found immediately after the dissolution. The iron supply agent according to (10).
(13) The iron supply agent according to (10), which contains at least citric acid as the organic acid.
(14) an aqueous solution obtained by dissolving this iron supply agent, a dimeric complex of citric acid and / or citric acid ions were two coordinated to one Fe ²⁺ ions, for one Fe ²⁺ ions The iron supplier according to (13) above, comprising a trimeric complex in which three citric acids and / or three citrate ions are coordinated.
(15) An iron supply agent for plants containing the iron supply agent according to any one of (10) and (14) above (hereinafter referred to as “the iron supply agent for plants of the second invention”) ).
(16) The iron supplier for plants according to the above (15), which contains a biodegradable binder.
(17) The plant iron supply agent according to the above (15), which contains a biodegradable extender.
(18) The iron supply agent for plants according to (15), which contains 5% by mass or more of the iron supply agent when the total iron supply agent for plants is 100% by mass.
(19) containing citric acid as the organic acid,
Containing peat as the biodegradable extender,
The matrix composed of the biodegradable extender contains the citric acid and the FeO,
The plant iron supply agent according to the above (17), which is used in alkaline soil.
(20) An iron supplier comprising an organic acid having a carboxyl group and / or a hydroxyl group and FeO (hereinafter referred to as “iron supplier of the third invention”).
(21) an aqueous solution obtained by dissolving this iron supplying agent, when containing the ^{Fe 2+} ions and ^{Fe 3+} ions, and the total of the ^{Fe 2+} ions and the ^{Fe 3+} ions is 100 mass%, the Fe The iron supply agent according to (20), wherein ²⁺ ions are 50 to 90% by mass.
(22) The aqueous solution obtained by dissolving the present iron supplier has an Fe ²⁺ ion concentration found in the aqueous solution after standing for 168 hours is 75% or more of the Fe ²⁺ ion concentration found immediately after the dissolution. The iron supply agent according to (20).
(23) The iron supply agent according to (20), which contains at least citric acid as the organic acid.
(24) an aqueous solution obtained by dissolving this iron supply agent, a dimeric complex of citric acid and / or citric acid ions were two coordinated to one Fe ²⁺ ions, for one Fe ²⁺ ions The iron supplier according to (23) above, comprising a trimeric complex in which three citric acids and / or three citrate ions are coordinated.
(25) An iron supply agent for plants containing the iron supply agent according to any one of (20) to (24) above (hereinafter referred to as “the iron supply agent for plants of the first invention”) ).
(26) The iron supply agent for plants according to the above (25), which contains a biodegradable binder.
(27) The iron supply agent for plants according to the above (25), which contains a biodegradable extender.
(28) The plant iron supply agent according to (25), which contains 5% by mass or more of the iron supply agent when the total amount of the iron supply agent for plants is 100% by mass.
(29) containing citric acid as the organic acid,
Containing peat as the biodegradable extender,
The matrix composed of the biodegradable extender contains the citric acid and the FeO,
The plant iron supply agent according to (27), which is used in alkaline soil.
(30) A dissolution step of heating an organic acid powder having a carboxyl group and / or hydroxyl group, an FeO powder, and water to obtain an aqueous solution obtained by dissolving the organic acid and FeO is provided. A method for producing an iron supply agent.
(31) The manufacturing method of the iron supply agent as described in said (30) provided with the drying process which removes water from the said aqueous solution.
(32) The method for producing an iron supply agent according to (30), which contains at least citric acid as the organic acid.
(33) The FeO powder is prepared by vacuum heating a granulated product obtained by granulating iron-containing dust and / or a granulated product obtained by granulating iron-containing dust and a reducing agent. The method for producing an iron supply agent according to the above (30), which is FeO powder obtained by vacuum quenching.

According to the iron supply agent of the first invention, a high Fe ²⁺ ion concentration can be obtained. That is, for example, a high Fe ²⁺ ion concentration can be obtained even in soil, and iron can be supplied with high probability. Furthermore, since the obtained Fe ²⁺ ions are effectively suppressed from oxidation, iron can be supplied with high probability. Moreover, since an organic acid (especially citric acid) is used, there is no environmental impact and it is safe to use. Furthermore, when used on plants, germination promoting effects and growth promoting effects can be obtained.
In the case of a predetermined Fe ²⁺ ion ratio, iron can be supplied with a particularly high probability.
When the Fe ²⁺ ion concentration after standing for a predetermined time is 75% or more immediately after the start of measurement, the Fe ²⁺ ions have a particularly high anti-oxidation property and can stably supply Fe ²⁺ ions for a long period of time.
When at least citric acid is contained as the organic acid, the above effects can be obtained particularly greatly.
When the dimer complex and the trimer complex are contained, a high Fe ²⁺ ion concentration is obtained, and a particularly high antioxidant property is exhibited.

According to the plant iron supply agent of the first invention, a high Fe ²⁺ ion concentration can be obtained. That is, for example, even when water is dissolved in soil, a high Fe ²⁺ ion concentration can be obtained, and iron can be supplied with high probability. Furthermore, since the obtained Fe ²⁺ ions are effectively suppressed from oxidation, iron can be supplied with high probability. Moreover, since an organic acid (especially citric acid) is used, there is no environmental impact and it is safe to use. Furthermore, a germination promoting effect and a growth promoting effect can be obtained.
When it contains a biodegradable binder, it can be set as the iron supply agent for plants which has the sustained release property which supplies Fe2 ⁺ stably gradually over a long period of time. Furthermore, it can be set as the solid substance which contained other components other than an iron supply agent simultaneously.
When the biodegradable extender is contained, the Fe ²⁺ supply amount can be easily kept within an appropriate range, and the versatility is excellent.
When the iron supply agent is contained in an amount of 5% by mass or more, the Fe ²⁺ supply effect can be obtained particularly reliably.

According to the iron supply agent of the second invention, an aqueous solution having a high Fe ²⁺ ion concentration can be obtained. That is, for example, even when water is dissolved in soil, a high Fe ²⁺ ion concentration can be obtained, and iron can be supplied with high probability. Furthermore, since the Fe ²⁺ ions obtained by dissolving in water are effectively inhibited from oxidation, iron can be supplied with high probability. Moreover, since an organic acid (especially citric acid) is used, there is no environmental impact and it is safe to use. Moreover, when it uses with respect to a plant, the germination promotion effect and the growth promotion effect are acquired.
In the case of a predetermined Fe ²⁺ ion ratio, iron can be supplied with a particularly high probability.
When the Fe ²⁺ ion concentration after standing for a predetermined time is 75% or more immediately after dissolution, the Fe ²⁺ ions have a particularly high antioxidation property and can stably supply Fe ²⁺ ions for a long period of time.
When at least citric acid is contained as the organic acid, the above effects can be obtained particularly greatly.
When the dimer complex and the trimer complex are contained, a high Fe ²⁺ ion concentration is obtained, and a particularly high antioxidant property is exhibited.

According to the plant iron supply agent of the second invention, a high Fe ²⁺ ion concentration can be obtained. That is, for example, even when water is dissolved in soil, a high Fe ²⁺ ion concentration can be obtained, and iron can be supplied with high probability. Furthermore, since the obtained Fe ²⁺ ions are effectively suppressed from oxidation, iron can be supplied with high probability. Moreover, since an organic acid (especially citric acid) is used, there is no environmental impact and it is safe to use. Furthermore, a germination promoting effect and a growth promoting effect can be obtained.
When it contains a biodegradable binder, it can be set as the iron supply agent for plants which has the sustained release property which supplies Fe2 ⁺ stably gradually over a long period of time. Furthermore, it can be set as the solid substance which contained other components other than an iron supply agent simultaneously.
When the biodegradable extender is contained, the Fe ²⁺ supply amount can be easily kept within an appropriate range, and the versatility is excellent.
When the iron supply agent is contained in an amount of 5% by mass or more, the Fe ²⁺ supply effect can be obtained particularly reliably.
When citric acid is contained, peat is contained as a biodegradable extender, citric acid and FeO are contained in a matrix composed of the biodegradable extender, and used in alkaline soil, Fe ²⁺ is converted to Fe ³⁺ It is possible to supply iron with high probability even in alkaline soil.

According to the iron supply agent of the third invention, an aqueous solution having a high Fe ²⁺ ion concentration can be obtained. That is, for example, even when water is dissolved in soil, a high Fe ²⁺ ion concentration can be obtained, and iron can be supplied with high probability. Furthermore, since the Fe ²⁺ ions obtained by dissolving in water are effectively inhibited from oxidation, iron can be supplied with high probability. Moreover, since an organic acid (especially citric acid) is used, there is no environmental impact and it is safe to use. Moreover, when it uses with respect to a plant, the germination promotion effect and the growth promotion effect are acquired.
In the case of a predetermined Fe ²⁺ ion ratio, iron can be supplied with a particularly high probability.
When the Fe ²⁺ ion concentration after standing for a predetermined time is 75% or more immediately after dissolution, the Fe ²⁺ ions have a particularly high antioxidation property and can stably supply Fe ²⁺ ions for a long period of time.
When at least citric acid is contained as the organic acid, the above effects can be obtained particularly greatly.
When the dimer complex and the trimer complex are contained, a high Fe ²⁺ ion concentration is obtained, and a particularly high antioxidant property is exhibited.

According to the iron supply agent for plants of the third invention, a high Fe ²⁺ ion concentration can be obtained. That is, for example, even when water is dissolved in soil, a high Fe ²⁺ ion concentration can be obtained, and iron can be supplied with high probability. Furthermore, since the obtained Fe ²⁺ ions are effectively suppressed from oxidation, iron can be supplied with high probability. Moreover, since an organic acid (especially citric acid) is used, there is no environmental impact and it is safe to use. Furthermore, a germination promoting effect and a growth promoting effect can be obtained.
When it contains a biodegradable binder, it can be set as the iron supply agent for plants which has the sustained release property which supplies Fe2 ⁺ stably gradually over a long period of time. Furthermore, it can be set as the solid substance which contained other components other than an iron supply agent simultaneously.
When the biodegradable extender is contained, the Fe ²⁺ supply amount can be easily kept within an appropriate range, and the versatility is excellent.
When the iron supply agent is contained in an amount of 5% by mass or more, the Fe ²⁺ supply effect can be obtained particularly reliably.
When citric acid is contained, peat is contained as a biodegradable extender, citric acid and FeO are contained in a matrix composed of the biodegradable extender, and used in alkaline soil, Fe ²⁺ is converted to Fe ³⁺ It is possible to supply iron with high probability even in alkaline soil.

According to the production method of the present invention, an iron supplier comprising an aqueous solution obtained by dissolving the organic acid of the present invention and FeO can be stably and reliably obtained.
When a drying step for removing water from an aqueous solution is provided, an iron supplier obtained by removing water from the aqueous solution obtained by dissolving the organic acid of the present invention and FeO can be stably and reliably obtained. it can.
When the FeO powder is an FeO powder obtained by vacuum-cooling the granulated product after vacuum heating, an iron supply agent having a particularly high antioxidant property can be obtained reliably and stably.

It is a graph which shows the correlation with the elapsed time which left the aqueous solution which melt | dissolved the iron supply agent of this invention product (Experimental example 1-1 to 1-4), and Fe2 ⁺ ion concentration. It is a graph which shows the correlation with the elapsed time and the Fe2 ⁺ ion density ^| concentration at the time of performing an oxidation acceleration test with respect to the aqueous solution which melt | dissolved the iron supply agent of this invention product (Experimental Examples 5 and 6). It is a chart by mass spectrometry, in which the upper stage is an aqueous solution in which the iron supply agent of the product of the present invention (Experimental Example 7) is dissolved, the middle stage is iron (III) citrate, and the lower stage is anhydrous citric acid. It is the chart obtained by making Ar gas collide further about the peak of mass 439 in the chart of the iron supply agent of the product of the present invention (Experimental example 7) in the upper part of FIG. It is explanatory drawing of the early blooming cosmos which watered this-article product (experimental example 8). It is explanatory drawing of the early blooming cosmos which watered this-article product (experimental example 8). It is explanatory drawing of the Hayasaki cosmos which watered the reference goods (reference example 1). It is explanatory drawing of the Hayasaki cosmos which watered the reference goods (reference example 1). It is explanatory drawing of the banana bell pepper which watered the product of this invention (Experimental example 8). It is explanatory drawing of the banana bell pepper which watered the reference goods (reference example 1). It is explanatory drawing of the spray chrysanthemum which watered this-article product (Experimental example 8). It is explanatory drawing of the spray chrysanthemum which watered the reference goods (reference example 1). It is explanatory drawing of the all-day-saki pine needle button which watered this-article product (Experimental example 8). It is explanatory drawing of the all-day Saki Matsuba button which watered the reference goods (reference example 1). Breeding of rice seedlings grown in the seedling culture soil containing the plant iron supply agent of the present invention product (Experimental Examples 9 and 10) and rice seedlings grown in the seedling culture soil not containing this (Reference Example 2) It is explanatory drawing which compared these. Rice seedlings grown in the seedling culture soil containing the plant iron supply agent of the present invention product (Experimental Examples 9-1 and 9-2), and rice seedlings grown in the seedling culture soil not containing this (Reference Example 2) It is explanatory drawing which compared the mode of upbringing. Rice seedlings grown in the seedling culture medium containing the plant iron supply agent of the present product (Experimental Examples 10-1 and 10-2), and rice seedlings grown in the seedling culture medium not containing this (Reference Example 2) It is explanatory drawing which compared the mode of upbringing.

Hereinafter, the present invention will be described in detail.
[1] Iron supply agent The iron supply agent of the first invention is characterized by comprising an aqueous solution obtained by dissolving an organic acid having a carboxyl group and / or a hydroxyl group and FeO.
The iron supply agent according to the second invention is characterized by removing water from an aqueous solution obtained by dissolving an organic acid having a carboxyl group and / or a hydroxyl group and FeO. That is, the other iron supply agent is obtained by removing water from the iron supply agent.
The iron supply agent of the third invention is characterized by containing an organic acid having a carboxyl group and / or a hydroxyl group and FeO.

(1) Iron supply agent of 1st invention The said "organic acid" is an acid provided with a carboxyl group and / or a hydroxyl group. Examples of the organic acid include citric acid (including anhydrous citric acid), acetic acid, tartaric acid, and oxalic acid as organic acids having a carboxyl group. Examples of the organic acid having a hydroxyl group include ascorbic acid. Moreover, citric acid and tartaric acid are mentioned as an organic acid which has both a carboxyl group and a hydroxyl group. These may use only 1 type and may use 2 or more types together. Of these, citric acid, acetic acid, tartaric acid and oxalic acid are preferred because of their excellent stability. Furthermore, when an aqueous solution containing an organic acid and FeO is prepared, citric acid, acetic acid, and tartaric acid are preferable because the Fe ²⁺ ion concentration is high relative to the organic acid concentration. Of these, citric acid is most preferred because it has no irritating odor and has a particularly high Fe ²⁺ ion concentration relative to the organic acid concentration when an aqueous solution containing an organic acid and FeO is prepared.

The “aqueous solution” is an aqueous solution obtained by dissolving an organic acid and FeO. That is, the aqueous solution does not contain undissolved organic acid and FeO. However, it may be a supernatant in a solid-liquid coexisting liquid containing undissolved organic acid and / or undissolved FeO.
Moreover, the dissolved state in the aqueous solution of organic acid and FeO is not specifically limited. That is, for example, this aqueous solution can contain an organic acid iron complex and an organic acid ion. Among these, an organic acid iron complex is particularly preferably contained. Furthermore, when citric acid is contained as described above, a citric acid complex is preferably contained. This iron citrate complex is preferably a multimeric complex in which citric acid and / or a plurality of citrate ions are coordinated with respect to one Fe ²⁺ ion, particularly a dimeric complex (one Fe ²⁺ ion It is preferable that citrate and / or a complex in which two citrate ions are coordinated), and further, a dimer complex and a trimer complex (citrate and citrate and one Fe ²⁺ ion and And / or a complex in which three citrate ions are coordinated) is more preferable.

  The amount of organic acid and FeO dissolved in this aqueous solution is not particularly limited, but usually the organic acid (especially citric acid) per 100 ml of water is 0.05 g or more (preferably 0.5 g to the temperature of the organic acid at the temperature of the aqueous solution. Solubility limit). On the other hand, FeO per 100 ml of water is 10 to 25 parts by mass (particularly 20 to 25 parts by mass) when the content of the organic acid is 100 parts by mass.

  Moreover, the water which comprises this aqueous solution is not specifically limited, Various water can be used. Highly purified water such as pure water and ion-exchanged water may be used, and water usually used such as tap water, industrial water, agricultural water, and groundwater may be used.

  The method for obtaining this aqueous solution is not particularly limited, but can be obtained by the production method described later. That is, (1) It can be obtained by heating a mixture containing organic acid powder, FeO powder and water. In addition, (2) FeO powder can be added to an organic acid aqueous solution in which the entire amount has been dissolved in advance and heated. Alternatively, (3) an organic acid powder and a FeO powder may be further added to an organic acid aqueous solution in which a predetermined amount is dissolved in advance and heated. Further, (4) it can be obtained by mixing organic acid powder, FeO and water without heating. Further, (5) in addition to the above (1) to (4), when an organic acid that cannot be completely dissolved and FeO that is dissolved and not clean are contained, a step of separating them by a method such as filtration can be provided. .

The iron supply agent of 1st invention can contain a wood vinegar liquid for anti-fungal. When the wood vinegar solution is contained, the content of the wood vinegar solution is preferably 10% by mass or less (usually 1% by mass or more) of the whole iron supply agent. Furthermore, ultraviolet irradiation can be performed in advance for the same purpose. Although ultraviolet irradiation conditions etc. are not specifically limited, It is preferable to use the ultraviolet-ray with a wavelength of 200-380 nm. Moreover, when performing irradiation, it is preferable to irradiate 72 * 10 < ⁴ > microwatt * s / cm < ² > or more. Furthermore, when storing, it is preferable to store at a low temperature. The temperature is not particularly limited, but is preferably 15 ° C. or lower.
The properties of the iron supply agent of the first invention will be described later.

(2) Iron supply agent of 2nd invention On the other hand, the iron supply agent of 2nd invention is obtained by removing water from the said aqueous solution.
The above “removal” means an operation of removing a part or all of water from the aqueous solution, but usually the water content with respect to the whole iron supply agent of the first invention is 90% by mass or less. In particular, the solid content is 10% by mass or less (preferably 5% by mass or less), and the pasty product is 60 to 90% by mass (preferably 65 to 85% by mass). The iron supply agent of the second invention may be a solid material from which substantially all the water has been removed from the aqueous solution, or may be a paste-like material from which a part of the water has been removed from the aqueous solution. Of these, solids are preferred.
Moreover, the method of this removal is not specifically limited, Means such as reduced pressure heating drying, normal pressure heating drying, non-heating reduced pressure drying, and freeze drying can be used. Of these, drying under reduced pressure is preferred. This is because it is possible to prevent Fe ^{2+ from} being oxidized in the process of removing water. In addition to drying under reduced pressure, drying under low oxygen may be used.

When heating is performed when removing water, the heating temperature of the aqueous solution is not particularly limited, but is preferably maintained at 150 ° C. or lower. This is because if it exceeds 150 ° C., the Fe ³⁺ ion concentration tends to increase. The temperature of the aqueous solution by this heating is more preferably 140 ° C. or lower, still more preferably 135 ° C. or lower, and particularly preferably 130 ° C. or lower. On the other hand, the lower limit temperature is not particularly limited and may be any temperature that causes transpiration of water under a pressure environment when water is removed. For example, 60 ° C. or higher is preferable, and 80 ° C. or higher is more preferable. 100 degreeC or more is further more preferable, 115 degreeC or more is especially preferable, and 120 degreeC or more is especially preferable. These upper limit temperature and lower limit temperature at the time of heating can be combined. That is, for example, 60 to 150 ° C is preferable, 100 to 140 ° C is more preferable, and 110 to 130 ° C is still more preferable. Combinations other than these may be used.

  Furthermore, when reducing pressure when removing water, the pressure is not particularly limited, but is preferably 0.1 to 50 kPa, more preferably 0.1 to 20 kPa, still more preferably 3 to 15 kPa, and particularly preferably 4 to 10 kPa. preferable.

  The iron supply agent of the second invention can usually be dissolved almost entirely in water having a temperature of 15 ° C. or higher. For example, 0.1 g or more (further 0.1-120 g, especially 0.1-50 g, especially 0.1-15 g) can be dissolved in 100 ml of pure water at a temperature of 25 ° C. The properties of the aqueous solution in which the iron supplier is dissolved will be described later.

(3) Iron supply agent of 3rd invention The iron supply agent of 3rd invention contains the organic acid provided with a carboxyl group and / or a hydroxyl group, and FeO. That is, for example, an iron supply agent containing organic acid powder and FeO powder. As a result of this iron supply agent, the iron supply agent (aqueous solution) of the first invention is obtained by rain, irrigation, moisture in the soil, and the like. That is, the organic acid iron aqueous solution (particularly iron citrate aqueous solution) is formed. Thereby, the effect by the iron supply agent of the said 1st invention is obtained as it is. This iron supply agent is obtained, for example, by mixing organic acid powder and FeO powder.
In addition, this iron supply agent may contain water. That is, the iron supply agent which mixed organic acid aqueous solution and FeO powder, the iron supply agent which mixed organic acid aqueous solution (for example, saturated aqueous solution), organic acid powder, and FeO powder, etc. are contained.
Moreover, this iron supply agent can reduce the elution rate of an organic acid using the biodegradable binder etc. which are mentioned later. Thereby, it is possible to provide a release property.
Each of the above-mentioned organic acids, FeO, water and the like can be applied as they are.

(4) Matters common to the iron supply agents of the first, second and third inventions The iron supply agent of the first invention, the aqueous solution in which the iron supply agent of the second invention is dissolved in water, and the iron of the third invention aqueous solution obtained by water supply agent, each with ^{Fe 2+} ions and ^{Fe 3+} ions are contained, in the case where the sum of the ^{Fe 2+} ions and ^{Fe 3+} ions is 100 mass%, ^{Fe 2+} ions 50 to 90 wt% (Furthermore, it can be 60 to 90% by mass, particularly 70 to 90% by mass). That is, Fe ³⁺ ions can be 10 to 50% by mass (further 10 to 40% by mass, particularly 10 to 30% by mass). That is, an aqueous solution containing Fe ²⁺ at a high concentration can be obtained. However, each ion concentration is a value measured by a measurement method of an example described later.

In particular, when citric acid is used as the organic acid, the iron supplier of the first invention, the aqueous solution in which the iron supplier of the second invention is dissolved in water, and the aqueous solution in which the iron supplier of the third invention is dissolved in water A dimer complex in which two citrates and / or citrate ions are coordinated with one Fe ²⁺ ion, and three citrate and / or citrate ions are coordinated with one Fe ²⁺ ion And a trimer complex. The content of each complex is not particularly limited. Moreover, the content rate of each complex with respect to each iron supply agent whole is not specifically limited.

In addition, in the aqueous solution in which the iron supply agent of the first invention, the iron supply agent in the second invention is dissolved in water, and the aqueous solution in which the iron supply agent of the third invention is dissolved in water, Fe ²⁺ ions recognized when left standing for 168 hours The concentration can be 75% or more of the Fe ²⁺ ion concentration (mg / liter) observed immediately after dissolution (immediately after measurement in the iron supplier of the first invention). That is, long-term stability and can retain the Fe ²⁺ ions, can be oxidized to Fe ³⁺ can be supplied with excellent Fe ²⁺ ions in oxidation resistance was suppressed. However, the above-mentioned leaving is performed in a dark place at a temperature of 25 ° C. where substantially no ultraviolet rays are applied. Each ion concentration is a value measured by a measurement method of an example described later.

Furthermore, the aqueous solution in which the iron supply agent of the first invention, the iron supply agent of the second invention are dissolved in water, and the aqueous solution in which the iron supply agent of the third invention is dissolved in water are irradiated with ultraviolet rays (in particular, a wavelength of 200 to 380 nm). Thus, the Fe ²⁺ ion concentration can be improved. In particular, for an aqueous solution in which the Fe ²⁺ ion concentration is 80% or less (particularly 70% or less, usually 50% or more) of the total Fe ion concentration (mg / liter), ultraviolet light having a wavelength of 253 nm is 72 × 10 ⁴ μw · s / When irradiated with cm ² , the Fe ²⁺ ion concentration (mg / liter) can be improved to 85% or more (further 90% or more, particularly 95% or more, usually 99.9% or less). In addition, the measurement of this ion concentration shall be based on the measuring method of the Example mentioned later.

The iron supply agent of the first invention, the iron supply agent of the second invention, and the iron supply agent of the third invention can be used as an iron supply agent for plants, which will be described later, and an iron supply agent for livestock (chicken, pig, cow, etc.) It can be used as an iron supply agent for seafood (cultured fish, cultured shellfish, etc.). In addition, it can be used in various fields that require supply of various Fe ²⁺ ions. When used as an iron supply agent for various uses other than those for plant use, for example, the iron supply agent of the second invention may contain a biodegradable binder as in the iron supply agent for plants described later. It can contain biodegradable extenders and can contain other components.

[2] Plant iron supply agent The plant iron supply agent of the first invention contains the iron supply agent of the first invention.
The iron supply agent for plants of 2nd invention contains the iron supply agent of 2nd invention, It is characterized by the above-mentioned.
The iron supply agent for plants of the 3rd invention contains the iron supply agent of 3rd invention, It is characterized by the above-mentioned.
These plant iron suppliers of the present invention may be used alone or in combination of two or more.

  The content of the iron supplier of the first invention, the iron supplier of the second invention or the iron supplier of the third invention (hereinafter also simply referred to as “iron supplier”) contained in each plant iron supplier is particularly Although not limited, when the whole plant iron supply agent is 100% by mass, it is preferably contained in an amount of 5% by mass or more in terms of the iron supply agent of the second invention (in terms of complete dry mass). If it is this range, the effect containing an iron supply agent can fully be acquired. The content is preferably 95% by mass or less, more preferably 50% by mass or less, and particularly preferably 30% by mass or less. Since iron is a trace essential element for plants, it is not necessary to give it excessively, and a sufficient supply amount can be maintained within the above range.

Furthermore, the iron supply agent for plants of the present invention can contain a biodegradable binder. By containing a biodegradable binder, the iron supply is gradually released as the binder is decomposed to produce Fe ²⁺ . Therefore, Fe ²⁺ ions can be supplied stably over a long period of time. That is, sustained release can be imparted to the plant iron supplier.
As the biodegradable binder, a biodegradable plastic can be used. Biodegradable plastics include polyalkylene succinate resins (polybutylene succinate resin, polyethylene succinate resin, etc.), polylactic acid resins, urea resins, polycaprolactone resins, cellulose resins, starch resins, polyvinyl alcohol resins. Examples thereof include resins. These may use only 1 type and may use 2 or more types together.
The content of the biodegradable binder is not particularly limited, but is 10% by mass or less (more preferably 2 to 7% by mass, usually 1% by mass or more) when the total amount of plant iron supply is 100% by mass. It is preferable.

Moreover, the iron supply agent for plants of this invention can contain a biodegradable extender. The biodegradable extender is a component other than the binder having biodegradability. Examples of the biodegradable extender include peat, straw, shochu, sake lees, citric acid lees, rice husks, snow flora, lees, humus, chicken manure, compost, cow manure, bone meal and clay. These may use only 1 type and may use 2 or more types together. In addition, the biodegradable extender may or may not have a predetermined function for plants. Examples of the component having a predetermined function include components that serve as nutrients for plants.
Although content of this biodegradable extender is not specifically limited, When the whole plant iron supply agent is 100 mass%, it can be set to 50-94 mass% (preferably 70-94 mass%). If it is this range, even when a trace amount iron supply agent is mixed with respect to a lot of soil, a suitable quantity can be mixed.

  The iron supply agent for plants of the present invention can contain other components in addition to the iron supply agent, the biodegradable binder and the biodegradable extender. Other components include lipoic acid, oryza oil, various vitamins, Mn, Zn, Cu, Cr, Si, Mg, Ca, Co, Mo, Ni, B, etc. (for example, metal state, metal oxide) Etc.), and compounds such as S and Cl. These may use only 1 type and may use 2 or more types together. The other components are preferably 10 parts by mass or less when the total of the iron supplier, the biodegradable binder and the biodegradable extender contained in the plant iron supplier is 100 parts by mass.

  The usage method of the iron supply agent for plants of this invention is not specifically limited. For example, if it is in liquid form, it is sprayed (irrigation, foliar spraying, etc. to the root of the target plant, etc.) and immersed (used as a culture solution for hydroponics, etc. The root of the target plant is immersed, etc.) , And use methods such as mixing with soil. If it is solid, use it for mixing with soil (powdered or lump), spreading on soil (powdered), filling in soil (powdered or lump) A method is mentioned.

Particularly, among the plant iron supply agents of the present invention, (1) plant iron supply agents containing the iron supply agent of the first invention, or (2) plant irons containing the iron supply agent of the second invention. A supply agent,
And when it contains citric acid as an organic acid, it contains a biodegradable extender, and if it is a plant iron supply agent that contains citric acid and FeO in a matrix composed of this biodegradable extender It can be suitably used in alkaline soil.
As the biodegradable extender used in this case, the biodegradable extender can be applied as it is. Among these biodegradable extenders, peat, straw, shochu, sake lees and citrate lees are preferable, and peat is particularly preferable. These biodegradable extenders may be used alone or in combination of two or more.

Among plant iron supply agents containing citric acid and a biodegradable extender, those containing peat as a biodegradable extender are particularly preferred.
This peat may be used as it is collected, may be used after being subjected to various modification treatments, or may be a mixture thereof. Examples of the various reforming treatments include alkali extraction treatment, neutralization treatment (such as phosphoric acid neutralization treatment and bitter lime neutralization treatment).
Examples of the peat include grassy peat (mainly organic components derived from various peats, mosses and moss), woody peat, and the like. Furthermore, peat which modified these is mentioned. These may use only 1 type and may use 2 or more types together.

The peat has a water repellent effect. For this reason, for example, when a plant iron supply agent is used in alkaline soil, an aqueous solution having a high pH from the surroundings is prevented from entering the plant iron supply agent. Accordingly, the pH is kept low, the decrease in solubility of FeO is suppressed, and the oxidation of Fe ²⁺ ions is further suppressed. Therefore, Fe ²⁺ ions can be supplied stably over a long period of time. That is, excellent sustained release can be imparted by this plant iron supplier.

Furthermore, when the total of citric acid, FeO and peat is 100% by mass, it is preferable that citric acid is contained in an amount of 5 to 15% by mass and FeO is contained in an amount of 5 to 10% by mass. The citric acid content is more preferably 7 to 13% by mass, and the FeO content is more preferably 7 to 8% by mass. Thus, reduction in the solubility of FeO is sufficiently suppressed, and be more sufficiently suppressed the oxidation of Fe ²⁺ ions, it can be supplied stably Fe ²⁺ ions over a long period.

  Moreover, it is preferable to consist of the granule which contained the citric acid and FeO in the matrix which consists of a biodegradable extender. The shape of the particles constituting the granular body is not particularly limited, and may be any of a sphere, an ellipsoid, a hemisphere, a cube, a cuboid, a cylinder, a briquette, and the like. Further, the granular body may be a dense body or a porous body. Further, the particle diameter (diameter when spherical, shortest dimension when other shapes) is preferably 50 mm or less (more preferably 10 mm or less, still more preferably 6 mm or less, usually 0.5 mm or more).

By suppressing the contact of citric acid and FeO with the external environment with the water-repellent biodegradable extender as described above, for example, when this plant iron supplier is used in alkaline soil, An increase in pH of the product is suppressed. Thereby, the fall of the solubility of FeO is suppressed. Furthermore, since the oxidation of citric acid by oxygen in the air is also suppressed, the effect of suppressing the oxidation of FeO by citric acid is also obtained, and Fe ²⁺ ions can be supplied more stably over a long period of time. it can.

  The alkaline soil is a soil whose pH exceeds 7 when 25 ml of distilled water is added to 10 g of air-dried soil and shaken for 1 hour and the pH of the resulting suspension is measured. Say. Accordingly, the alkaline soil includes an alkaline soil obtained by alkalizing an original alkaline soil and a non-alkali soil (fertilization, desertification, etc.). Examples of the basic alkaline soil include soil containing various calcareous components such as shell fossil soil, calcareous soil, and sandy soil. These may be used alone or in combination of two or more. Furthermore, a mixed soil of a soil containing these various calcareous components and a non-alkaline soil, which is an alkaline soil as a whole is included.

Moreover, the manufacturing method of this plant iron supply agent is not particularly limited. For example, the plant iron supply agent of the second invention is obtained by mixing and granulating the iron supply agent of the second invention and peat. Can do. Moreover, the iron supply agent for plants of 3rd invention can be obtained by mixing and granulating the iron supply agent (namely, for example, citric acid powder and FeO powder) of 3rd invention, and peat.
The mixing method is not particularly limited, and may be dry blend using a mortar mixer, an omni mixer, or the like, or may be mixed by an extruder or the like. Further, the granulation method is not particularly limited, but it is usually granulated by an extrusion method. Further, it is preferable that the mixing and granulation are continuously performed by extrusion molding because the process can be simplified. The temperature for the dry blending and extrusion molding is not particularly limited, and may be room temperature (for example, 15 to 35 ° C.) or may be heated to about 40 to 90 ° C. as necessary.
About this citric acid powder and FeO powder, each description in the manufacturing method of the following [4] iron supply agent is applicable as it is.

[3] Method for Producing Iron Supply The production method of the present invention is not particularly limited as described above, and various methods can be used. For example, a mixture containing organic acid powder, FeO powder, and water. And a dissolution step of obtaining an aqueous solution obtained by dissolving the organic acid and FeO.

The “organic acid powder” is a powder containing the organic acid as a main component (usually a purity of 99% or more), and the particle shape and the like are not particularly limited as long as the purity and the powder form.
The “FeO powder” is a powder mainly composed of FeO. The amount of FeO contained in the FeO powder is not particularly limited, but is usually 50% by mass or more (preferably 65% by mass or more and 100% by mass may be sufficient) based on the entire FeO powder. As this FeO powder, any FeO powder may be used. FeO powder described later (granulated product obtained by granulating iron-containing dust and / or granulated iron-containing dust and reducing agent) And a granulated product obtained by vacuum heating and vacuum quenching) and various commercially available FeO powders. Among these, FeO powder obtained by heating the above-mentioned granulated product in a vacuum and then rapidly cooling in a vacuum is preferable.
As the “water”, any water can be used as described above.

  The amount of the organic acid powder, FeO powder, and water charged in the “mixture” is not particularly limited. For example, when citric acid is used, citric acid powder (assuming purity 100%): FeO powder (purity 100%) Assumed): The mass ratio of water (assuming purity of 100%) is preferably 60 to 90: 7 to 28: 3 to 20, preferably 65 to 85:10 to 24: 5 to 17.5. It is more preferable to use it in a ratio, and it is particularly preferable to use it in a ratio of 68 to 72:10 to 22:10 to 15.

  In addition to the organic acid powder, FeO powder and water, the above mixture may or may not contain other components. When other components are contained, they may be contained in a state dissolved in water or in a state not dissolved in water. Examples of other components include methanol and ethanol. By containing these, water can be removed more smoothly even under a reduced pressure environment. These may use only 1 type and may use 2 or more types together.

The heating conditions in the “heating” are not particularly limited, but the heating temperature is preferably maintained at 150 ° C. or lower. This is because if it exceeds 150 ° C., the Fe ³⁺ ion concentration tends to increase. The temperature of the aqueous solution by this heating is more preferably 140 ° C. or lower, still more preferably 135 ° C. or lower, and particularly preferably 130 ° C. or lower. On the other hand, the lower limit temperature is not particularly limited, and is preferably 40 ° C. or higher, more preferably 50 ° C. or higher, and particularly preferably 60 ° C. or higher. These upper limit temperature and lower limit temperature at the time of heating can be combined. That is, for example, 40 to 150 ° C is preferable, 50 to 140 ° C is more preferable, and 60 to 130 ° C is still more preferable. Combinations other than these may be used. In addition, the pressure conditions in the case of a heating are not specifically limited.
By this heating, more citric acid is dissolved in water, and the amount of FeO dissolved is increased accordingly, and the concentration of the target Fe ²⁺ ion or Fe ²⁺ ion complex is considered to increase.

  In the manufacturing method of this invention, the process of removing a water-insoluble component can be provided after the said melt | dissolution process. Examples of the water-insoluble component include organic acid powder that cannot be completely dissolved and FeO powder that cannot be completely dissolved. Although the removal method is not particularly limited, it can usually be performed by filtration. That is, a filtration step can be provided. The filtration conditions at this time are not particularly limited. For example, it is preferable to use a membrane filter having a pore size of 10 μm or less (more preferably 5 μm or less, more preferably 3 μm or less) as the filtration filter.

Moreover, when obtaining the iron supply agent of 2nd invention, the drying process which removes water from the said aqueous solution can be further provided after the said melt | dissolution process. The drying conditions in this drying step are not particularly limited, and natural drying may be performed, but it is preferable to use the above-described removal method and drying conditions. That is, it is preferable to remove water by heating under reduced pressure. It is considered that the Fe ²⁺ ion component (Fe ²⁺ complex, etc.) that is water-soluble and excellent in antioxidant properties is concentrated by gradually reducing the water content by heating, and the iron supplier of the second invention is obtained.

  Furthermore, when obtaining the iron supply agent of the said 2nd invention, a refinement | purification process can also be further provided. The purification process is a process for purifying water-soluble components. That is, for example, after an aqueous solution obtained by removing water from the aqueous solution is brought into contact with water to dissolve the dissolvable part, an extraction step for removing and extracting water-insoluble components in the same manner as described above, A re-drying step of removing water from the aqueous extraction solution obtained in this extraction step.

The FeO powder used in the production method of the present invention is a granulated product obtained by granulating iron-containing dust and / or a granulated product obtained by granulating iron-containing dust and a reducing agent. It is preferable that the FeO powder is obtained by vacuum heating and vacuum quenching.
This FeO powder (FeO powder obtained using the above granulated product and / or granulated product) is usually CaAl ₂ O ₄ , FeAl ₂ O ₄ , CaFe ₂ Si ₂ O ₆ , CaSi in addition to FeO. _This is because at least one double oxide of ₂ O ₅ and MgFe ₂ O ₄ is contained. These double oxides may contain only 1 type and 2 or more types may contain them. Further, the content of the composite oxide is preferably 0.5 to 10% by mass when the entire FeO powder is 100% by mass. If it is this range, the iron supply agent excellent in antioxidant property can be obtained.
Further, the shape of the particles constituting the FeO powder is not particularly limited, but is a FeO powder having a particle size of 5000 μm or less, mixed with powders of various particle sizes, and further containing porous particles. May be.

The above “dust containing iron” (hereinafter also simply referred to as “dust”) is one containing iron (such as dust collection powder). Examples of the iron component include iron oxide, other iron compounds, and metallic iron. Only 1 type may contain these and 2 or more types may contain. The amount of iron contained in the dust is not particularly limited, but usually 30% by mass or more (more preferably 35 to 90% by mass, still more preferably 40 to 80% by mass) in terms of metallic iron when the total amount of dust is 100% by mass. %). The dust may contain other components in addition to iron. Examples of other components include Zn, Ni, Cu, and Mn. These may be a single metal or a compound such as an oxide. Furthermore, these may contain only 1 type and 2 or more types may contain.
The shape of the dust is not particularly limited, and may be a small piece or a mixture of powder and small pieces, but is usually a powder. The average particle size of the powder is not particularly limited, but is preferably 3 to 10 μm.

  As this dust, forged shot dust collection powder generated in the forging process (powder collected during the process of driving the forging shot ball into the iron-based member to be processed), and various dust generated in the steel making process {iron-based Examples include powders (electric furnace dust, blast furnace dust, converter dust, cupola dust, etc.) collected for the purpose of preventing fumes during the process of melting members and the like in various furnaces to produce iron-based products. These may use only 1 type and may use 2 or more types together. In particular, dust from which the chlorine content has been removed by washing in advance (part or all) is preferred. In particular, the chlorine content in the dust is preferably 0.5% by mass or less (more preferably 0.4% by mass or less, and still more preferably 0.3% by mass or less).

The “granulated product” contains dust, or dust and a reducing agent. Thereafter, the granulated product is promoted to be reduced or oxidized from Fe ₂ O ₃ , Fe ₃ O ₄ and Fe (single) to FeO during vacuum heating.
The shape of the particles constituting the granulated product is not particularly limited, and may be any of a sphere, an ellipsoid, a hemisphere, a cube, a cuboid, a cylinder, a briquette, and the like. Furthermore, the granulated product may be a dense body or a porous body. Further, the particle diameter (diameter when spherical, shortest dimension when other shapes) is preferably 25 mm or less (more preferably 15 mm or less, still more preferably 10 mm or less, usually 3 mm or more).

The “reducing agent” is a component that reduces an iron compound that has been oxidized to a divalent or higher valence. As the reducing agent, metallic iron, a mixture thereof, carbon, a mixture thereof, or the like can be used. In particular, reducing agents used for iron cutting scraps, iron polishing scraps, iron powder, pig iron and steel, various waste materials (tire scraps, wood waste materials, etc.) and the like are preferable. These may use only 1 type and may use 2 or more types together.
The shape of the reducing agent is not particularly limited. However, since it is preferable that the contact area with dust is large, powder, granules, small pieces, and the like are preferable, and powder is particularly preferable. Further, the average particle size is preferably 200 μm or less (preferably 180 μm or less).
The content of the reducing agent in the granulated product is not particularly limited, but when the dust is 100 parts by mass, it is 100 parts by mass or less (more preferably 90 parts by mass or less, more preferably 80 parts by mass or less, usually 30 parts by mass). Above) is preferable.

  The granulated product usually contains a binder. Although the kind of binder is not limited, Alumina cement is preferable. The blending amount is preferably 3 to 20 parts by mass (more preferably 3 to 15 parts by mass, still more preferably 3 to 12 parts by mass) when the total amount of dust or dust and reducing agent is 100 parts by mass. In this range, granulation can be performed smoothly, and embrittlement of the granulated product can be suppressed.

By performing the “vacuum heating”, the FeO concentration in the FeO powder can be increased. Although the vacuum degree at the time of performing this vacuum heating is not specifically limited, 0.1-13.3 kPa (more preferably 2.6-13.3 kPa, especially preferably 4.0-6.7 kPa) is preferable. In this range, it is possible to effectively suppress the residual metallic iron and oxidation of FeO to Fe ₃ O ₄ or the like. Even under an inert gas that reproduces the partial pressure of oxygen in this vacuum atmosphere, FeO powder can be obtained by heating in the same manner instead of this vacuum heating.

The heating temperature (measured value obtained by measuring the granulated product itself) during vacuum heating is preferably 600 to 1100 ° C (more preferably 800 to 950 ° C). However, when a granulated product contains a reducing agent, it is preferable to set it as 800 degreeC or more. In this range, an FeO powder having a particularly high FeO content can be obtained, and dust can be prevented from melting during the heating process.
The heating time is not particularly limited, but is preferably 30 minutes or longer (more preferably 30 minutes or longer and within 6 hours).
When zinc oxide or the like is contained in the dust, it is reduced to metal zinc, which can be recovered by evaporation under a vacuum of 600 ° C. or higher and about 1.56 kPa. Thereby, the purity of FeO can further be improved.

  The granulated product is usually heated using a heat treatment furnace. The heat treatment furnace is not particularly limited as long as it includes at least a heater and can uniformly heat the granulated product to be charged. Examples of the heat treatment furnace include a roller hearth furnace and a rotary kiln. The granulated product is pulverized by, for example, a stirring means having a stirring blade while moving in the heat treatment furnace. This heat treatment furnace may be provided with a recovery device for recovering metallic zinc or the like produced by the reduction. The amount of granulated product input to the heat treatment furnace is not particularly limited, but considering the heat conduction to the entire granulated product heated in the heat treatment furnace, the average height of the granulated product sprayed on the hearth is usually The input amount is preferably 100 mm or less, particularly 80 mm or less, and more preferably 30 mm or less.

  The “vacuum quenching” can cool the high-temperature FeO powder generated by vacuum heating without being oxidized. The degree of vacuum during the vacuum quenching is not particularly limited, but is preferably 13.3 kPa or less (more preferably 6.7 kPa or less, usually 5.3 kPa or more). Further, the temperature lowering rate is not particularly limited, but is preferably 5 to 150 ° C./min. In this vacuum quenching, it is preferable to cool to 300 ° C. or less (more preferably 200 ° C. or less, particularly preferably 150 ° C. or less).

  In particular, for the purpose of obtaining FeO powder having a higher FeO content, it is preferable to use a granulated product containing metallic iron. The content of metallic iron is preferably 5% by mass or more (more preferably 5 to 85% by mass, still more preferably 8 to 50% by mass) when the total amount of iron contained in the granulated product is 100% by mass. . When this granulated product is used, for example, an FeO powder having an FeO content of 80% by mass or more (more preferably 85% by mass or more, particularly 90% by mass or more) with respect to the total iron content can be obtained.

  As the dust {the following (3) and (4)} and the combination of the dust and the reducing agent {the following (1), (2) and (5)} constituting the granulated product containing metallic iron as described above (1) Mixture of electric furnace dust and metallic iron (iron powder, etc.), (2) Mixture of blast furnace dust and metallic iron (iron powder, etc.), (3) Converter dust only, (4) Forging shot dust collection Only powder, (5) a mixture of forged shot dust collection powder and metallic iron (iron powder, etc.), and the like. These may use only 1 type and may use 2 or more types together.

Hereinafter, the present invention will be specifically described by way of examples.
[1] Production of FeO powder (1) FeO powder using electric furnace dust Fe (35.8 mass%), Zn (22.7 mass%), C (5.95 mass%), Ca (2.92) Mass), Mn (2.89 mass%), Cl (2.89 mass%), Si (2.16 mass%), and the like, and an average particle size of 10 μm in electric furnace dust (steelmaking dust) It was granulated into a cylindrical shape having a diameter of 8 mm and a length of about 20 mm using 6% by mass, 47.6% by mass of iron powder having an average particle diameter of 75 μm, and 4.8% by mass of alumina cement. The obtained granulated product was vacuum heated in a vacuum heating tank (roller hearth furnace) at 800 ° C. for 30 minutes, then at 850 ° C. for 30 minutes, and then at 900 ° C. for 1 hour.
Next, vacuum quenching is performed in a vacuum quenching bath at a cooling rate of 20 ° C./min to 400 ° C., and the atmosphere in the vacuum cooling bath is replaced with nitrogen, and further cooling is performed at a cooling rate of 13 ° C./min. The temperature was lowered to room temperature to obtain FeO powder.
In addition, when FeO contained in this FeO powder was quantified by a calibration curve prepared in advance by an X-ray diffraction method using a mixed powder obtained by mixing a reagent FeO powder and a silicon powder at a predetermined ratio, the content was It was 65 mass%.

(2) FeO powder using forged shot dust collection powder (used in [4] and [8] below)
Fe (80.0 mass%), Zn (0.02 mass%), Ca (0.01 mass%), Mn (0.06 mass%), Si (0.06 mass%), etc. are contained, and the average A cylindrical shape having a diameter of 8 mm and a length of about 20 mm using 82% forged shot dust collection powder having a particle size of 100 μm, 10% iron powder having an average particle size of 75 μm, 5% alumina cement, and 3% bentonite. Granulated. The obtained granulated product was heated in a vacuum heating tank (roller hearth furnace) at 800 ° C. for 30 minutes, then at 850 ° C. for 30 minutes, and then at 900 ° C. for 1 hour.
Next, vacuum quenching is performed in a vacuum quenching bath at a cooling rate of 20 ° C./min to 400 ° C., and the atmosphere in the vacuum cooling bath is replaced with nitrogen, and further cooling down to 200 ° C. at a cooling rate of 13 ° C./min. The temperature was lowered to room temperature to obtain FeO powder composed of an aggregate of spherical particles having a diameter of 1.8 mm.
In addition, when FeO contained in this FeO powder was quantified by a calibration curve prepared in advance by an X-ray diffraction method using a mixed powder obtained by mixing reagent FeO powder and silicon powder at a predetermined ratio, the content was It was 90% by mass.

[2] Manufacture of iron supply agent (1) Use citric acid as an organic acid 15.4 kg of citric acid (purity 99% or more) and 5.6 kg of water are mixed in a pressure vessel, and the liquid temperature is 80 ° C. The temperature was gradually raised to. When the temperature reached 80 ° C., 3.3 kg of the FeO powder obtained in the above [1] (1) was added. Thereafter, the liquid temperature was raised to 130 ° C. over 4 hours. When the liquid temperature reached 130 ° C., the inside of the container was decompressed to about 8 kPa, and this state was maintained for 100 minutes. As a result, 17 kg of massive iron supply agent was obtained. After that, the massive iron supply agent was pulverized by a pulverizer into powder.

(2) Use of acetic acid as an organic acid 12 kg of acetic acid (purity 99% or more) and 5.6 kg of water were mixed in a pressure vessel, and the liquid temperature was gradually raised to 80 ° C. When the temperature reached 80 ° C., 7.3 kg of the FeO powder obtained in the above [1] (1) was added. Thereafter, the liquid temperature was raised to 130 ° C. over 4 hours. When the liquid temperature reached 130 ° C., the inside of the container was decompressed to about 8 kPa, and this state was maintained for 100 minutes. As a result, 17.5 kg of massive iron supply agent was obtained. After that, the massive iron supply agent was pulverized by a pulverizer into powder.

(3) Using tartaric acid as an organic acid 15 kg of tartaric acid (purity 99% or more) and 5.6 kg of water were mixed in a pressure vessel, and the liquid temperature was gradually raised to 80 ° C. When the temperature reached 80 ° C., 7.3 kg of the FeO powder obtained in the above [1] (1) was added. Thereafter, the liquid temperature was raised to 130 ° C. over 4 hours. When the liquid temperature reached 130 ° C., the inside of the container was decompressed to about 8 kPa, and this state was maintained for 100 minutes. As a result, 20 kg of massive iron supply agent was obtained. After that, the massive iron supply agent was pulverized by a pulverizer into powder.

(4) Use of oxalic acid as an organic acid 18 kg of oxalic acid (purity 99% or more) and 5.6 kg of water were mixed in a pressure vessel, and the liquid temperature was gradually raised to 80 ° C. When the temperature reached 80 ° C., 7.3 kg of the FeO powder obtained in the above [1] (1) was added. Thereafter, the liquid temperature was raised to 130 ° C. over 4 hours. When the liquid temperature reached 130 ° C., the inside of the container was decompressed to about 8 kPa, and this state was maintained for 100 minutes. As a result, 21 kg of massive iron supply agent was obtained. After that, the massive iron supply agent was pulverized by a pulverizer into powder.

[3] Measurement of Fe ²⁺ ion concentration (1) Fe ²⁺ ion concentration The temperature of 20 ° C. was adjusted so that the iron supplier obtained in [2] (1) had a concentration of 10 g / liter (1.0% by mass). The mixture was dissolved in ion-exchanged water while stirring (approximately 5 minutes). Thereafter, the solution was filtered using a membrane filter (pore size 1 μm), and immediately thereafter, a water quality measurement pack was attached to an ultraviolet / visible light spectrophotometer (manufactured by Shimadzu Corporation, type “UV1240”), and the resulting aqueous solution was obtained. Fe ²⁺ ions and the total amount of Fe ions contained in the sample were measured (the amount obtained by subtracting the amount of Fe ²⁺ ions from the total amount of Fe ions was converted as the amount of Fe ³⁺ ions). Further, the Fe ²⁺ ion concentration was measured by phenanthroline spectrophotometry based on JIS K0102. In this measurement, the work was always performed in a room where direct sunlight was not inserted.

As a result of this measurement, the Fe ²⁺ ion concentration was 389 mg / liter, the Fe ³⁺ ion concentration was 186 mg / liter, and when the total of Fe ²⁺ ions and Fe ³⁺ ions was 100% by mass, Fe ²⁺ ions were 68%. It was mass%. That is, it can be seen that the obtained aqueous solution contains Fe ³⁺ ions → Fe ²⁺ ions 2.1 times as much as Fe ³⁺ ions, and an aqueous solution having a high Fe ²⁺ ion concentration is obtained.

(2) Fe ²⁺ ion concentration at each concentration of each iron supply In the same manner as in (1) above, four types of iron supply with different organic acids obtained in [2] (1) to (4) above were used. The concentrations shown in Table 1 were prepared, and the Fe ²⁺ ion concentration in each aqueous solution was measured. The results are shown in Table 1.

From the results in Table 1, it can be seen that oxalic acid has almost no change in the Fe ²⁺ ion concentration from a low concentration to a high concentration. It can also be seen that acetic acid has a high concentration and a high Fe ²⁺ ion concentration, but a low concentration has a lower Fe ²⁺ ion concentration than other organic acids. Furthermore, although citric acid and tartaric acid do not have the above-mentioned problems, it is understood that citric acid has a higher Fe ²⁺ ion concentration per mass of the iron supply agent than tartaric acid. That is, it can be seen that Fe ²⁺ ions can be supplied most efficiently.

[4] Evaluation of antioxidant property (1) Antioxidant property when left indoors [2] The above [3] and [3] are obtained by using three types of iron supply agents different in organic acid obtained in (1) to (3). Similarly, iron supply agent aqueous solutions of Experimental Examples 1-1 to 3-4 were prepared so that the concentration of each iron supply was the value shown in Table 2. The Fe ²⁺ ion concentration was measured in the same manner as in [3] above for the aqueous solutions of each of these experimental examples, then left in the room as it was, and the Fe ²⁺ ion concentration was measured in the same manner for each time shown in Table 2. The results are also shown in Table 2. In Table 2, Experimental Examples 1-1 to 1-4 using citric acid are graphed and shown in FIG.

Further, 2.5 g of ascorbic acid was dissolved in 500 ml of distilled water to prepare an ascorbic acid aqueous solution. Thereafter, 1.0 g of the FeO powder obtained in [1] (2) above was added to this aqueous solution, stirred for 30 minutes, and then filtered to remove impurities. Thereafter, 20 milliliters were collected from the aqueous solution after filtration and put into two containers, respectively, and the aqueous solution in one container was adjusted to pH 6.0 with an aqueous sodium hydroxide solution (Experimental Example 6-2). The pH of the other iron ascorbate aqueous solution (Experimental Example 6-1) that was not adjusted for pH was 3.4. For these two types of iron ascorbate aqueous solutions (Experimental Examples 6-1 and 6-2), the Fe ²⁺ ion concentration was measured in the same manner, and the pH measurement (added under the Fe ²⁺ ion concentration in Table 2) was also performed. went. The results are also shown in Table 2.

From the results of Table 2, when the organic acid is citric acid, tartaric acid, acetic acid and ascorbic acid, the fluctuation from the initial concentration is suppressed to be small regardless of the concentration of the iron supply agent. It turns out that it has the outstanding antioxidant property. That is, for example, as shown in FIG. 1, in Experimental Example 1-1, it is 82.3% or more of the initial value, and in Experimental Example 1-2, it is 81.9% or more of the initial value. in 80.7% or more with respect to the initial value, and 87.3% or more with respect to the initial value in examples 1-4, a long period of time the ion concentration of 80% or more with respect to the initial ^{Fe 2+} concentration in both Is held over. Therefore, it turns out that it has the outstanding antioxidant property. Moreover, in the iron supply agent using ascorbic acid of Experimental example 6-1 and 6-2, it turns out that pH fluctuation is also suppressed small.

(2) Antioxidant property by oxidation acceleration test Experimental example obtained in the same manner as in the above [3] using two types of iron supply agents having different organic acids obtained in the above [2] (1) to (2) An oxidation acceleration test was performed on each of the aqueous solutions of 4 {iron supplier concentration 10 g / liter (0.1 mass%)} and Experimental Example 5 {iron supplier concentration 5 g / liter (0.5 mass%)}. That is, 0.6 liters of air per minute was sent into each aqueous solution (200 milliliters) of Experimental Examples 5 and 6 using an air pump, and bubbling was performed at the times shown in Table 3 in the same manner as in [3] above. ^{The 2+} ion concentration was measured. The results are also shown in Table 3. Further, Table 3 is shown as a graph in FIG.

From Table 3 and FIG. 2, it can be seen that when the organic acid is citric acid, the concentration fluctuation is suppressed to be small even in the oxidation acceleration test, and it has excellent antioxidant properties. In particular, in Experimental Example 4 having a concentration of 1.0% by mass, it can be seen that the Fe ²⁺ concentration of 77% is maintained even after 288 hours (after 12 days) with respect to the initial value.

[5] Evaluation by UV irradiation Experimental example 6 {iron supplier concentration 6 g / liter (0.6% by mass) in the same manner as [3] above using the iron supplier obtained in [2] (1) above } Aqueous solution was obtained. The Fe ion concentration immediately after the preparation of the obtained aqueous solution of Experimental Example 6 was a total Fe ion concentration of 824 mg / liter, of which the Fe ²⁺ ion concentration was 534 mg / liter.
Thereafter, 90 liters of the aqueous solution of Experimental Example 6 was irradiated with 72 × 10 ⁴ μw · s / cm ² of ultraviolet rays (wavelength 253 nm) for 18 hours. The Fe ion concentration immediately after irradiation of the aqueous solution of Experimental Example 6 obtained by ultraviolet irradiation was 824 mg / liter of total Fe ion concentration, and Fe ²⁺ ion concentration was 810 mg / liter. Moreover, when the aqueous solution after the ultraviolet irradiation of Experimental Example 6 was stored in the dark, the Fe ²⁺ ion concentration immediately after the preparation was recovered after 21 days.

From this result, it can be seen that the reaction is proceeded by which Fe ³⁺ ions are converted into Fe ²⁺ ions without being oxidized by ultraviolet irradiation. Therefore, it can be seen that, unlike a conventional Fe ²⁺ ion solution containing an inorganic compound as a main component, there is no problem of oxidative deterioration due to sunlight or ultraviolet rays, and the storage stability is excellent.

[6] Evaluation by Mass Spectrometry Using the iron supplier obtained in [2] (1) above, in the same manner as in [3] above, Experimental Example 7 {Iron supplier concentration 10 g / liter (1.0% by mass) } Aqueous solution was obtained. The Fe ion concentration immediately after the preparation of the obtained aqueous solution of Experimental Example 7 was a total Fe ion concentration of 486 mg / liter, of which the Fe ²⁺ ion concentration was 330 mg / liter.
Thereafter, the aqueous solution of Experimental Example 7 was diluted 10 times with methanol. The substance contained in the diluted solution was subjected to mass spectrometry using electrospray ionization mass spectrometry (ESIMS). Micromass type “Q-TOF” was used for the measuring apparatus, and electrospray ionization (ESI) was used for the ionization method. Furthermore, the ionization mode was positive ion mode, the capillary voltage was 3000 V, the cone voltage was 20 V, and the solvent removal temperature was 120 ° C. The resulting chart is shown in FIG.

Furthermore, when mass analysis was performed on the peak of mass 439 in the obtained chart by colliding Ar gas (Collision Energy: 120 eV), a peak was generated at mass 55.9. As a result, it was found that the compound constituting the peak of mass 439 contains Fe. The resulting chart is shown in FIG.
Further, as a result of the comparative test, a similar solution of iron (III) citrate (Wako Pure Chemical Industries, FeC ₆ H ₅ O ₇ , total Fe ion concentration 584 mg / liter, Fe ²⁺ ion concentration 142 mg / liter) was measured. The chart obtained by measuring the same solution of anhydrous citric acid (manufactured by Wako Pure Chemicals, C ₆ H ₈ O ₇ ) is shown in FIG.

From the results of FIG. 3 and FIG. 4, the mass 215 ([C ₆ H ₈ O ₇ + Na] ⁺ ) and the mass 407 ([2 (C ₆ H ₈ O) recognized in the chart according to Experimental Example 7 from the chart with citric anhydride. ₇ ) + Na] ⁺ ) peak is considered to be derived from citric acid.
Further, from the result of reanalysis of the mass 439, it can be seen that the compound constituting the peak of the mass 439 contains Fe. When the mass corresponding to Fe is subtracted, it becomes the mass of two citric acids, and the peak of mass 439 is due to a dimer complex in which two citric acids and / or two citrate ions are coordinated with Fe ions. it is conceivable that. Similarly, the peak at mass 631 is considered to be due to a trimeric complex in which three citric acids and / or three citrate ions are coordinated with Fe ions, and the peak at mass 823 is citric acid with respect to Fe ions. It is thought to be due to a tetramer complex in which four acids and / or citrate ions are coordinated.

Furthermore, when compared with an aqueous solution in which iron (III) citrate is dissolved (total Fe ion concentration 584 mg / liter, Fe ²⁺ ion concentration 142 mg / liter), the peaks of mass 439 and mass 631 are small and the relative content is small. Is predicted.
Summing up these results, the iron supply agent of the present invention specifically contains more dimer complexes and trimer complexes than the aqueous iron (III) citrate solution. It is considered that Fe ²⁺ ions are generated and has high antioxidant property, and is stable against ultraviolet rays, but rather an increase in Fe ²⁺ ions is recognized.

[7] Evaluation of plant iron supply agent (liquid) (1) Preparation of plant iron supply liquid (used as irrigation solution) In the same manner as in [3] above, the concentration of iron supply agent was 10 g / liter (1.0 mass). %) Was obtained. This aqueous solution was diluted 1000 times with water to obtain an aqueous irrigation solution (iron supply solution for plants, product of the present invention—Experimental Example 8). The total Fe ion concentration in the obtained irrigation solution (Experimental Example 8) is 0.5 mg / liter, of which the Fe ²⁺ ion concentration is 0.3 mg / liter.
For comparison, a commercially available aqueous solution containing Fe ²⁺ ions (manufactured by Menedal Co., Ltd., product name “Plant Vigor Elemental Menedale”, aqueous solution containing ferrous sulfate) was diluted 100 times to prepare an irrigation solution (Reference Example 1). Obtained. The total Fe ion concentration in the obtained irrigation solution is 0.4 mg / liter, and the Fe ²⁺ ion concentration is 0.4 mg / liter.

(2) Preparation of Experimental Culture Zone A commercially available seedling growth soil was spread as an experimental soil in a plastic container having a length of 30 cm, a width of 28 cm, and a depth of 4 cm to form a depth of 4 cm.

(3) Sowing, irrigation, and growth On April 1st, each of the above-mentioned experimental cultivated areas has the same area ratio for each of the four types of seeds of early blooming cosmos, banana pepper, spray chrysanthemum, and all-day blooming pine needle buttons. Each irrigation solution was irrigated with 1 liter water evenly. Thereafter, each of the above experimental irrigation waters (Experimental Example 8 and Reference Example 1) was irrigated evenly with a liter of water twice a day at 8 am and 5 pm each day. Continued.

(4) Results (i-1) Hayasaki Cosmos (using the irrigation solution of Experimental Example 8)
Germination was confirmed on April 6. FIG. 5 shows an explanatory diagram of an image obtained by digitally photographing this cultivation area on April 13. Further, FIG. 6 shows an explanatory diagram based on an image obtained by digitally photographing this cultivation area on April 20.
(I-2) Hayasaki Cosmos (using the irrigation solution of Reference Example 1)
Germination was confirmed on April 8. FIG. 7 shows an explanatory diagram of an image obtained by digitally photographing this cultivation area on April 13. Further, FIG. 8 shows an explanatory diagram of an image obtained by digitally photographing this cultivation area on April 20.
From the above results, germination is fast in the cultivation area using Experimental Example 8. Furthermore, compared with FIG. 5 and FIG. 7, the cultivation leaves using Reference Example 1 are in a stage where true leaves have started to appear, whereas the cultivation leaves using Experimental Example 8 have already started to grow large leaves. It can be seen that the subsequent growth is fast.

(Ii-1) Banana pepper (using the irrigation solution of Experimental Example 8)
Germination was confirmed on April 6. FIG. 9 shows an explanatory diagram based on an image obtained by digitally photographing this cultivation area on April 13.
(Ii-2) Banana bell pepper (using the irrigation solution of Reference Example 1)
Germination was confirmed on April 8. FIG. 10 shows an explanatory diagram based on an image obtained by digitally photographing this cultivation area on April 16.
From the above results, it can be seen that germination is fast in the cultivation section using Experimental Example 8. Further, the growth after that was faster when Experimental Example 8 was used.

(Iii-1) Spray chrysanthemum (using the irrigation solution of Experimental Example 8)
Germination was confirmed on April 13. FIG. 11 shows an explanatory diagram based on an image obtained by digitally photographing this cultivation area on April 13.
(Iii-2) Spray chrysanthemum (using the irrigation solution of Reference Example 1)
Germination was confirmed on April 16. FIG. 12 shows an explanatory diagram of an image obtained by digitally photographing this cultivation area on April 13.
From the above results, it can be seen that germination is fast in the cultivation section using Experimental Example 8. Further, the growth after that was faster when Experimental Example 8 was used.

(Iv-1) All day Sakimatsuba button (using the irrigation solution of Experimental Example 8)
Germination was confirmed on April 13. FIG. 13 shows an explanatory diagram of an image obtained by digitally photographing this cultivation area on April 13.
(Iv-2) All day Saki Matsuba button (using the irrigation solution of Reference Example 1)
Germination was confirmed on April 16. FIG. 14 shows an explanatory diagram of an image obtained by digitally photographing this cultivation area on April 16.
From the above results, it can be seen that germination is fast in the cultivation section using Experimental Example 8. There were also many germinations.

[8] Evaluation when using an iron supply agent for plants for rice seedlings (1) Iron supply agent for plants (dried aqueous solution, Experimental Example 9)
800 g of anhydrous citric acid (purity 99.8%) and 2 liters of water were put into a stainless steel beaker and stirred at room temperature (20 ° C.) to dissolve anhydrous citric acid in water. Thereafter, 100 g of the FeO powder obtained in the above [1] (2) was added, and stirring was further continued for 30 minutes. Next, the filtrate obtained by filtering this liquid (using filter paper) was dried for 72 hours in a drier adjusted to 90 ° C. to obtain a paste, and further cooled to room temperature to obtain a lump. The obtained lump was pulverized in a mortar and then passed through a sieve having an opening of 1.0 mm to obtain an iron supply agent for plants (Experimental Example 9) having a particle size of 1.0 mm or less.

(2) Production of iron supply agent for plants (containing peat, Experimental Example 10) FeO powder obtained in the above [1] (2), anhydrous citric acid (purity 99.8% or more), and peat processed soil After mixing the improving agent (made by Nippon Fertilizer Co., Ltd., trade name “Kumiai Hyhumin Special No. A”) in a ratio of 7.5% by mass: 10.0% by mass: 82.5% by mass, It was granulated into a cylindrical shape having a length of about 6 mm to obtain an iron supply agent for plants (Experimental Example 10) containing peat.

(3) Rice seedlings Rice (variety: Nihonbare) seeds were germinated for 2 days, with a petri dish laid with tissue paper moistened at room temperature. Thereafter, the following seedling culture soil was introduced into each cultivation pot, and 20 grains of the sprouting rice were directly sown per 1 pot (seeding on January 15). At the time of sowing, rice seeds were embedded at a depth of about 0.5 cm from the surface of the soil. Each pot for cultivation was placed in an artificial meteorograph, and rice was grown until March 10 under the following seedling conditions, and the effect of the iron supply agent for plants was evaluated.

(4) Culture medium for raising seedlings used Reference Example 2: Fertilizer (manufactured by Chisso Asahi Fertilizer Co., Ltd., trade name “Long Total 70”, the following for 300 mL of shell fossil soil (containing about 70% by mass of CaCO ₃ ) Similarly, soil containing 1 g was used as seedling culture soil.
Experimental Example 9-1: A soil in which 300 g of the fossil shell soil was mixed with 1 g of the above fertilizer and 0.1 g of the iron supply agent for plants of Experimental Example 9 was used as a seedling culture medium.
Experimental Example 9-2: A soil in which 300 g of the above fossil shell fossil soil was mixed with 1 g of the above fertilizer and 1.0 g of the plant iron supplier of Experimental Example 9 was used as a seedling culture medium.
Experimental Example 10-1: A soil obtained by mixing 300 g of the above fossil shell soil with 1 g of the above fertilizer and 1.0 g of the plant iron supplier of Experimental Example 10 was used as a seedling culture medium.
Experimental Example 10-2: A soil in which 300 g of the above fossil shell soil was mixed with 1 g of the above fertilizer and 2.0 g of the iron supply agent for plants of Experimental Example 10 was used as a seedling culture medium.

(5) Seedling conditions Using an artificial meteorograph (manufactured by Nippon Medical Instrumentation, model “LH-100S”), sunshine for 14 hours (illuminance is 1500 lux, temperature is 25 ° C.), night time is 10 hours (temperature is 20 ° C.) ) Adjusted to drive. In addition, irrigation was performed by initially adding 50 ml of distilled water to each pot so that the mass of each pot was maintained at 400 g every day throughout the seedling raising period. Furthermore, each pot was randomly repositioned every day throughout the growing period so that illumination (sunshine) was evenly irradiated.

On March 10, when the seedlings were finished, the plant height of 20 plants in each pot was measured, and the average value was calculated. Furthermore, the SPAD value (green concentration, which is an index of the amount of chlorophyll) was measured using a chlorophyll meter (model “SPAD-502” manufactured by Minolta Co., Ltd.). Next, seedlings were taken out from each pot, sieved with root soil, and digitally photographed (an explanatory diagram based on the obtained image is shown in FIG. 15). Then, it was dried for 7 days, and almost the entire amount of the soil of the roots was screened off, and then the above-ground dry matter weight and root dry matter weight (total of root dry matter weight and dredged weight) were measured. The results are shown in Table 4.
In addition, about the plant height and SPAD value of a seedling, the average value and standard deviation of 20 seedlings of each pot were described.

(6) Evaluation results From the results in Table 4 and FIGS. 15 to 17, the seedlings according to Reference Example 2 that gave fertilizer but did not give the plant iron supplier had a plant height of 15.9 cm, a SPAD value of 13.0, As a result, the dry weight of the above-ground part was 0.38 g, and the dry weight of the root part was 0.31 g.
On the other hand, in Experimental Example 9-1 in which 0.1 g of the iron supply agent for plants of Experimental Example 9 was given, the plant iron supply agent was blended even in alkaline soil, although the blending amount was small. The effect was confirmed. That is, with respect to Reference Example 2, the plant height and SPAD value are 1.5 times, the above-ground dry matter weight is 2.6 times, and the root dry matter weight is 1.7 times, both being superior to Reference Example 2. I understand that.
Furthermore, in Example 9-2 where the amount of the iron supply agent for plants was increased to 10 times the amount of Example 9-1, the effect of increasing the amount was recognized. In other words, the plant height is 1.1 times smaller than that of Experimental Example 9-1, but the SPAD value is 1.4 times, the above-ground dry weight is 1.4 times, and the root dry weight is 2.4 times. there were. Moreover, in Experimental Example 9-2, the standard deviation of the plant height and the SPAD value is large, which may indicate the threshold value of the iron supply amount. For this reason, it is thought that it is better to mix more iron supply agents for plants.

Moreover, the effect which mix | blended the plant iron supply agent was recognized also about the experiment example 10-1 which gave the iron supply agent for plants of 1.0 g of experiment example 10 also in alkaline soil. That is, the plant height is 1.7 times, the SPAD value is 2.1 times, the above-ground dry matter weight is 2.9 times, and the root dry matter weight is 2.8 times that of Reference Example 2. It turns out that it is superior.
Furthermore, in Experimental Example 10-2 in which the blending amount of the plant iron supply agent was increased to twice that of Experimental Example 10-1, the plant height and SPAD value were 1.1 times that of Experimental Example 10-1. The above-ground dry weight was 0.65 times and the root dry weight was 0.77 times. Thus, although the clear difference at the time of comparing Experimental example 10-1 and Experimental example 10-2 is hard to be recognized, this is considered because the delayed action effect by containing a biodegradable bulking agent appears. It is done. That is, it can be seen that the plant iron supplier of Experimental Example 9 has an immediate effect, whereas the plant iron supplier of Experimental Example 10 has a delayed effect. Therefore, it is considered that the difference will be recognized by raising the seedling for a longer period.

  The iron supply agent of the present invention is widely used in the field of agriculture, forestry and fisheries. That is, for example, it is widely used for the production of agricultural products, the production of horticultural plants, the production and maintenance of parks and golf courses, the maintenance of forests, the breeding of livestock, and the cultivation of seafood. The plant iron supply aqueous solution and plant iron supply agent of the present invention are widely used in the field of agriculture and forestry. That is, for example, it is widely used for production of agricultural products, hydroponics, production of horticultural plants, production and maintenance of parks and golf courses, forest maintenance, and the like. In particular, it is useful as a plant growth promoter in the production field of various agricultural products. It can also be used to solve food problems by growing plants on barren lands around the world and to improve the global environment by promoting absorption of carbon dioxide.

The present invention relates to an iron supply agent for plants and a method for producing the same. More particularly, it has a high Fe ²⁺ ion concentration in aqueous solution, for plants iron supply oxidized is suppressed in Fe ²⁺ ions and a method of manufacturing the same.

The present invention solves the above-described conventional problems, and provides an iron supply agent for plants having a high Fe ²⁺ ion concentration in an aqueous solution state and suppressing oxidation of Fe ²⁺ ions, and a method for producing the same. With the goal.

The present invention is as follows.
(1) and citric acid powder, and FeO powder, by heating a mixture comprising water, Ri Do from an aqueous solution the citric acid and FeO is obtained is dissolved,
The FeO powder is a FeO is more than 50% by weight, based on the total the FeO powder, and _{CaAl 2 O 4, FeAl 2 O} 4, of _{CaFe 2 Si 2 O 6, CaSi} 2 O 5 and MgFe ₂ O ₄ Containing at least one double oxide of
Containing and Fe ²⁺ ions and ^{Fe 3+} ions, when the total Fe ion content was 100 wt%, for plants iron supply agent the ^{Fe 2+} ions and wherein 50 to 90% by mass Rukoto (hereinafter , Referred to as “the iron supply agent for plants of the first invention”).
(2) The iron supplier for plants according to (1) above , wherein the Fe ²⁺ ion concentration observed in the aqueous solution after standing for 168 hours is 75% or more of the Fe ²⁺ ion concentration observed immediately after the start of measurement .
(3) and one Fe ²⁺ dimeric complexes of citric acid and / or citric acid ions were two coordinated to the ion, citric acid and / or citric acid ions are three for one Fe ²⁺ ions The iron supplier for plants according to (2) above, comprising a coordinated trimer complex.
(4) The Fe ²⁺ ion concentration observed in the aqueous solution after standing for 168 hours is 75% or more of the Fe ²⁺ ion concentration recognized immediately after the start of measurement ,
A dimeric complex of citric acid and / or citric acid ions were two coordinated to one Fe ²⁺ ion, citric acid and / or citric acid ions are three coordinated to one Fe ²⁺ ions A trimer complex, and
The mixture includes citric acid powder, FeO powder, and water in a mass ratio of 60 to 90: 7 to 28: 3 to 20,
The FeO powder is vacuum-cooled after vacuum heating of a granulated product obtained by granulating iron-containing dust and / or a granulated product obtained by granulating iron-containing dust and metallic iron. FeO powder obtained by
The iron supply agent for plants according to (1) above, wherein the amount of iron contained in the dust containing iron is 30% by mass or more in terms of metallic iron when the total amount of dust is 100% by mass.
(5) A mixture containing citric acid powder, FeO powder and water is heated to remove water from the aqueous solution obtained by dissolving the citric acid and FeO.
The FeO powder is a FeO is more than 50% by weight, based on the total the FeO powder, and _{CaAl 2 O 4, FeAl 2 O} 4, of _{CaFe 2 Si 2 O 6, CaSi} 2 O 5 and MgFe ₂ O ₄ Containing at least one double oxide of
The aqueous solution obtained by dissolving the plant iron supplier contains Fe ²⁺ ions and Fe ³⁺ ions, and when the total Fe ion amount is 100% by mass, the Fe ²⁺ ions are 50 to 90% by mass. A plant iron supply agent (hereinafter referred to as "the plant iron supply agent of the second invention").
(6) an aqueous solution obtained by dissolving this plant for iron supply agent in the Fe ²⁺ ion concentration found in the aqueous solution after standing for 168 hours is observed immediately after the start of measurement Fe ²⁺ ion concentration less than 75% Yes,
A dimeric complex of citric acid and / or citric acid ions were two coordinated to one Fe ²⁺ ion, citric acid and / or citric acid ions are three coordinated to one Fe ²⁺ ions A trimer complex, and
The mixture includes citric acid powder, FeO powder, and water in a mass ratio of 60 to 90: 7 to 28: 3 to 20,
The FeO powder is vacuum-cooled after vacuum heating of a granulated product obtained by granulating iron-containing dust and / or a granulated product obtained by granulating iron-containing dust and metallic iron. FeO powder obtained by
The iron supply agent for plants as described in said (5) whose iron content contained in the said dust containing iron is 30 mass% or more in conversion of metal iron, when the whole dust is 100 mass%.
(7) containing citric acid powder, FeO powder and peat,
The FeO powder is a FeO is more than 50% by weight, based on the total the FeO powder, and _{CaAl 2 O 4, FeAl 2 O} 4, of _{CaFe 2 Si 2 O 6, CaSi} 2 O 5 and MgFe ₂ O ₄ An iron supply agent for plants comprising at least one double oxide of the following (hereinafter referred to as "the iron supply agent for plants of the third invention") .
(8) A method for producing an iron supply agent for plants as described in (1 ) above,
A heating step comprising heating a mixture containing citric acid powder, FeO powder and water to obtain an aqueous solution obtained by dissolving the citric acid and FeO;
The FeO powder is a FeO is more than 50% by weight, based on the total the FeO powder, and _{CaAl 2 O 4, FeAl 2 O} 4, of _{CaFe 2 Si 2 O 6, CaSi} 2 O 5 and MgFe ₂ O ₄ A method for producing an iron supply agent for plants comprising at least one double oxide of the following (hereinafter referred to as “the method for producing an iron supply agent for plants of the fourth invention”) .
(9) The mixture includes citric acid powder, FeO powder, and water in a mass ratio of 60 to 90: 7 to 28: 3 to 20,
The FeO powder is vacuum-cooled after vacuum heating of a granulated product obtained by granulating iron-containing dust and / or a granulated product obtained by granulating iron-containing dust and metallic iron. FeO powder obtained by
The amount of iron contained in the iron-containing dust is 30% by mass or more in terms of metallic iron when the entire dust is 100% by mass,
The granulated product has a particle size of 25 mm or less,
The degree of vacuum in the vacuum heating is 0.1 to 13.3 KPa and the heating temperature is 600 to 1100 ° C.,
The degree of vacuum in the vacuum quenching is 5.3 to 13.3 KPa, and the plant iron supply agent according to (8) is cooled to a temperature of 300 ° C. or less at a temperature drop rate of 5 to 150 ° C./min. Production method.
(10) A method for producing the plant iron supplier according to (5 ) above,
A melting step of heating a mixture containing citric acid powder, FeO powder and water to obtain an aqueous solution obtained by dissolving the citric acid and FeO;
A drying step of removing water from the aqueous solution,
The FeO powder is a FeO is more than 50% by weight, based on the total the FeO powder, and _{CaAl 2 O 4, FeAl 2 O} 4, of _{CaFe 2 Si 2 O 6, CaSi} 2 O 5 and MgFe ₂ O ₄ method for producing a plant for iron supply agent characterized that you contain at least one mixed oxide (hereinafter, referred to as "method for producing a plant for iron supply agent of the fifth invention").
(11) The mixture includes citric acid powder, FeO powder, and water in a mass ratio of 60 to 90: 7 to 28: 3 to 20,
The FeO powder is vacuum-cooled after vacuum heating of a granulated product obtained by granulating iron-containing dust and / or a granulated product obtained by granulating iron-containing dust and metallic iron. FeO powder obtained by
The amount of iron contained in the iron-containing dust is 30% by mass or more in terms of metallic iron when the entire dust is 100% by mass,
The granulated product has a particle size of 25 mm or less,
The degree of vacuum in the vacuum heating is 0.1 to 13.3 KPa and the heating temperature is 600 to 1100 ° C.,
The degree of vacuum in the vacuum quenching is 5.3 to 13.3 KPa, and the plant iron supply agent according to (10) is cooled to a temperature of 300 ° C. or less at a temperature decrease rate of 5 to 150 ° C./min. Production method.

It is a graph which shows the correlation with the elapsed time which left the aqueous solution which melt | dissolved the iron supplier of Experimental example 1-1 to 1-4, and Fe2 ⁺ ion concentration. It is a graph which shows the correlation with the elapsed time at the time of performing an oxidation acceleration test with respect to the aqueous solution which melt | dissolved the iron supply agent of Experimental example 5 and 6, and Fe2 ⁺ ion concentration. It is a chart by mass spectrometry, in which the upper stage is an aqueous solution in which the iron supply agent of Experimental Example 7 is dissolved, the middle stage is iron (III) citrate, and the lower stage is anhydrous citric acid. It is the chart obtained by making Ar gas collide about the peak of the mass 439 in the chart of the iron supply agent of the experiment example 7 of the upper stage of FIG. It is explanatory drawing of the early blooming cosmos which watered this-article product (experimental example 8). It is explanatory drawing of the early blooming cosmos which watered this-article product (experimental example 8). It is explanatory drawing of the Hayasaki cosmos which watered the reference goods (reference example 1). It is explanatory drawing of the Hayasaki cosmos which watered the reference goods (reference example 1). It is explanatory drawing of the banana bell pepper which watered the product of this invention (Experimental example 8). It is explanatory drawing of the banana bell pepper which watered the reference goods (reference example 1). It is explanatory drawing of the spray chrysanthemum which watered this-article product (Experimental example 8). It is explanatory drawing of the spray chrysanthemum which watered the reference goods (reference example 1). It is explanatory drawing of the all-day-saki pine needle button which watered this-article product (Experimental example 8). It is explanatory drawing of the all-day Saki Matsuba button which watered the reference goods (reference example 1). Breeding of rice seedlings grown in the seedling culture soil containing the plant iron supply agent of the present invention product (Experimental Examples 9 and 10) and rice seedlings grown in the seedling culture soil not containing this (Reference Example 2) It is explanatory drawing which compared these. Rice seedlings grown in the seedling culture soil containing the plant iron supply agent of the present invention product (Experimental Examples 9-1 and 9-2), and rice seedlings grown in the seedling culture soil not containing this (Reference Example 2) It is explanatory drawing which compared the mode of upbringing. Rice seedlings grown in the seedling culture medium containing the plant iron supply agent of the present product (Experimental Examples 10-1 and 10-2), and rice seedlings grown in the seedling culture medium not containing this (Reference Example 2) It is explanatory drawing which compared the mode of upbringing.

Hereinafter, the present invention will be described in detail.
[1] Iron supply agent The first iron supply agent is composed of an aqueous solution obtained by dissolving an organic acid having a carboxyl group and / or a hydroxyl group and FeO.
A 2nd iron supply agent removes water from the aqueous solution obtained by melt | dissolving the organic acid provided with a carboxyl group and / or a hydroxyl group, and FeO, It is characterized by the above-mentioned. That is, the other iron supply agent is obtained by removing water from the iron supply agent.
The third iron supplier contains an organic acid having a carboxyl group and / or a hydroxyl group and FeO.

(1) 1st iron supply agent The said "organic acid" is an acid provided with a carboxyl group and / or a hydroxyl group. Examples of the organic acid include citric acid (including anhydrous citric acid), acetic acid, tartaric acid, and oxalic acid as organic acids having a carboxyl group. Examples of the organic acid having a hydroxyl group include ascorbic acid. Moreover, citric acid and tartaric acid are mentioned as an organic acid which has both a carboxyl group and a hydroxyl group. These may use only 1 type and may use 2 or more types together. Of these, citric acid, acetic acid, tartaric acid and oxalic acid are preferred because of their excellent stability. Furthermore, when an aqueous solution containing an organic acid and FeO is prepared, citric acid, acetic acid, and tartaric acid are preferable because the Fe ²⁺ ion concentration is high relative to the organic acid concentration. Of these, citric acid is most preferred because it has no irritating odor and has a particularly high Fe ²⁺ ion concentration relative to the organic acid concentration when an aqueous solution containing an organic acid and FeO is prepared.

The first iron supply agent can contain a wood vinegar solution for anti-fungal. When the wood vinegar solution is contained, the content of the wood vinegar solution is preferably 10% by mass or less (usually 1% by mass or more) of the whole iron supply agent. Furthermore, ultraviolet irradiation can be performed in advance for the same purpose. Although ultraviolet irradiation conditions etc. are not specifically limited, It is preferable to use the ultraviolet-ray with a wavelength of 200-380 nm. Moreover, when performing irradiation, it is preferable to irradiate 72 * 10 < ⁴ > microwatt * s / cm < ² > or more. Furthermore, when storing, it is preferable to store at a low temperature. The temperature is not particularly limited, but is preferably 15 ° C. or lower.
The nature of the first iron supplier will be described later.

(2) Second Iron Supply Agent On the other hand, the second iron supply agent is obtained by removing water from the aqueous solution.
The above “removal” means an operation of removing a part or all of water from the aqueous solution, but usually the water content with respect to the entire first iron supply agent is 90% by mass or less. In particular, the solid content is 10% by mass or less (preferably 5% by mass or less), and the pasty product is 60 to 90% by mass (preferably 65 to 85% by mass). The second iron supply agent may be a solid material from which substantially all water has been removed from the aqueous solution, or may be a paste-like material from which part of the water has been removed from the aqueous solution. Of these, solids are preferred.
Moreover, the method of this removal is not specifically limited, Means such as reduced pressure heating drying, normal pressure heating drying, non-heating reduced pressure drying, and freeze drying can be used. Of these, drying under reduced pressure is preferred. This is because it is possible to prevent Fe ^{2+ from} being oxidized in the process of removing water. In addition to drying under reduced pressure, drying under low oxygen may be used.

  The second iron supply agent can usually be dissolved almost entirely in water having a temperature of 15 ° C. or higher. For example, 0.1 g or more (further 0.1-120 g, especially 0.1-50 g, especially 0.1-15 g) can be dissolved in 100 ml of pure water at a temperature of 25 ° C. The properties of the aqueous solution in which the iron supplier is dissolved will be described later.

(3) Third iron supply agent The third iron supply agent contains an organic acid having a carboxyl group and / or a hydroxyl group and FeO. That is, for example, an iron supply agent containing organic acid powder and FeO powder. As a result of this iron supply agent, the first iron supply agent (aqueous solution) is obtained due to rainfall, irrigation, moisture in the soil, and the like. That is, the organic acid iron aqueous solution (particularly iron citrate aqueous solution) is formed. Thereby, the effect by the said 1st iron supply agent is obtained as it is. This iron supply agent is obtained, for example, by mixing organic acid powder and FeO powder.
In addition, this iron supply agent may contain water. That is, the iron supply agent which mixed organic acid aqueous solution and FeO powder, the iron supply agent which mixed organic acid aqueous solution (for example, saturated aqueous solution), organic acid powder, and FeO powder, etc. are contained.
Moreover, this iron supply agent can reduce the elution rate of an organic acid using the biodegradable binder etc. which are mentioned later. Thereby, it is possible to provide a release property.
Each of the above-mentioned organic acids, FeO, water and the like can be applied as they are.

(4) Items common to the first, second and third iron supply agents The first iron supply agent, the aqueous solution in which the second iron supply agent is dissolved in water, and the third iron supply agent in water solution is contained in the respective ^{Fe 2+} ions and ^{Fe 3+} ions, in the case where the sum of the ^{Fe 2+} ions and ^{Fe 3+} ions is 100 mass%, ^{Fe 2+} ions is 50 to 90 wt%, even 60 It can be made -90 mass%, especially 70-90 mass%. That is, Fe ³⁺ ions can be 10 to 50% by mass (further 10 to 40% by mass, particularly 10 to 30% by mass). That is, an aqueous solution containing Fe ²⁺ at a high concentration can be obtained. However, each ion concentration is a value measured by a measurement method of an experimental example described later.

In particular, when citric acid is used as the organic acid, the first iron supply agent, the aqueous solution in which the second iron supply agent is dissolved in water, and the aqueous solution in which the third iron supply agent is dissolved in water a dimeric complex of citric acid and / or citric acid ions were two coordinated against Fe ²⁺ ions, trimeric citric acid and / or citric acid ions were three coordinated to one Fe ²⁺ ions And a body complex. The content of each complex is not particularly limited. Moreover, the content rate of each complex with respect to each iron supply agent whole is not specifically limited.

Moreover, in the aqueous solution in which the first iron supply agent, the second iron supply agent is dissolved in water, and the aqueous solution in which the third iron supply agent is dissolved in water, the Fe ²⁺ ion concentration observed when left standing for 168 hours is: It can be 75% or more of the Fe ²⁺ ion concentration (mg / liter) observed immediately after dissolution (immediately after measurement in the first iron supplier). That is, long-term stability and can retain the Fe ²⁺ ions, can be oxidized to Fe ³⁺ can be supplied with excellent Fe ²⁺ ions in oxidation resistance was suppressed. However, the above-mentioned leaving is performed in a dark place at a temperature of 25 ° C. where substantially no ultraviolet rays are applied. Each ion concentration is a value measured by a measurement method of an example described later.

Further, the aqueous solution in which the first iron supply agent, the second iron supply agent is dissolved in water, and the aqueous solution in which the third iron supply agent is dissolved in water are irradiated with ultraviolet rays (particularly, a wavelength of 200 to 380 nm), whereby Fe ²⁺ ion concentration can be improved. In particular, for an aqueous solution in which the Fe ²⁺ ion concentration is 80% or less (particularly 70% or less, usually 50% or more) of the total Fe ion concentration (mg / liter), ultraviolet light having a wavelength of 253 nm is 72 × 10 ⁴ μw · s / When irradiated with cm ² , the Fe ²⁺ ion concentration (mg / liter) can be improved to 85% or more (further 90% or more, particularly 95% or more, usually 99.9% or less). In addition, the measurement of this ion concentration shall be based on the measuring method of the Example mentioned later.

The first iron supply agent, the second iron supply agent and the third iron supply agent can be used as an iron supply agent for plants, which will be described later, as well as an iron supply agent for livestock (chicken, pig, cattle, etc.), seafood It can be used as an iron supply agent (cultured fish, cultured shellfish, etc.). In addition, it can be used in various fields that require supply of various Fe ²⁺ ions. When used as an iron supplier for various uses other than these plant uses, for example, the second iron supplier can contain a biodegradable binder as in the iron supplier for plants described later. The biodegradable extender can be contained, and other components can be further contained.

[2] Plant iron supply agent The plant iron supply agent of the first invention was obtained by heating a mixture containing citric acid powder, FeO powder and water to dissolve the citric acid and FeO. Consisting of an aqueous solution,
The FeO powder is a FeO is more than 50% by weight, based on the total the FeO powder, and _{CaAl 2 O 4, FeAl 2 O} 4, of _{CaFe 2 Si 2 O 6, CaSi} 2 O 5 and MgFe ₂ O ₄ Containing at least one double oxide of
Fe ²⁺ ions and Fe ³⁺ ions are contained, and when the total Fe ion amount is 100 mass%, the Fe ²⁺ ions are 50 to 90 mass%.
That is, the iron supply agent for plants of the first invention is a first iron supply comprising an aqueous solution obtained by heating a mixture containing citric acid powder, FeO powder and water and dissolving the citric acid and FeO. Contains agents.
The iron supply agent for plants of the second invention comprises heating a mixture containing citric acid powder, FeO powder and water to remove water from the aqueous solution obtained by dissolving the citric acid and FeO. ,
The FeO powder is a FeO is more than 50% by weight, based on the total the FeO powder, and _{CaAl 2 O 4, FeAl 2 O} 4, of _{CaFe 2 Si 2 O 6, CaSi} 2 O 5 and MgFe ₂ O ₄ Containing at least one double oxide of
The aqueous solution obtained by dissolving the plant iron supplier contains Fe ²⁺ ions and Fe ³⁺ ions, and when the total Fe ion amount is 100% by mass, the Fe ²⁺ ions are 50 to 90% by mass. It is characterized by being.
That is, the iron supply agent for plants of the second invention removes water from the aqueous solution obtained by dissolving the citric acid and FeO by heating a mixture containing citric acid powder, FeO powder and water. containing a second iron supply agent comprising Te.
The iron supply agent for plants of the third invention contains citric acid powder, FeO powder and peat,
The FeO powder is a FeO is more than 50% by weight, based on the total the FeO powder, and _{CaAl 2 O 4, FeAl 2 O} 4, of _{CaFe 2 Si 2 O 6, CaSi} 2 O 5 and MgFe ₂ O ₄ It contains at least one kind of double oxide.
That is, the iron supply agent for plants of the 3rd invention contains the 3rd iron supply agent containing a citric acid powder and FeO powder, and also contains peat as a biodegradable extender .
These plant iron suppliers of the present invention may be used alone or in combination of two or more.

  The content of the first iron supply agent, the second iron supply agent or the third iron supply agent (hereinafter also simply referred to as “iron supply agent”) contained in each plant iron supply agent is not particularly limited. When the whole plant iron supply agent is 100% by mass, it is preferably contained in an amount of 5% by mass or more in terms of the second iron supply agent (completely dry mass conversion). If it is this range, the effect containing an iron supply agent can fully be acquired. The content is preferably 95% by mass or less, more preferably 50% by mass or less, and particularly preferably 30% by mass or less. Since iron is a trace essential element for plants, it is not necessary to give it excessively, and a sufficient supply amount can be maintained within the above range.

In particular, among the plant iron supply agents of the present invention, (1) a plant iron supply agent containing a first iron supply agent, or (2) a plant iron supply agent containing a second iron supply agent. If it is a plant iron supply agent containing a biodegradable extender and citric acid and FeO are contained in a matrix made of this biodegradable extender, it can be suitably used in alkaline soil. it can.
As the biodegradable extender used in this case, the biodegradable extender can be applied as it is. Among these biodegradable extenders, peat, straw, shochu, sake lees and citrate lees are preferable, and peat is particularly preferable. These biodegradable extenders may be used alone or in combination of two or more.

Moreover, the manufacturing method of this plant iron supply agent is not particularly limited. For example, the plant iron supply agent of the second invention can be obtained by mixing and granulating the second iron supply agent and peat. it can. Moreover, the iron supply agent for plants of 3rd invention can be obtained by mixing and granulating the 3rd iron supply agent (namely, citric acid powder and FeO powder) and peat.
The mixing method is not particularly limited, and may be dry blend using a mortar mixer, an omni mixer, or the like, or may be mixed by an extruder or the like. Further, the granulation method is not particularly limited, but it is usually granulated by an extrusion method. Further, it is preferable that the mixing and granulation are continuously performed by extrusion molding because the process can be simplified. The temperature for the dry blending and extrusion molding is not particularly limited, and may be room temperature (for example, 15 to 35 ° C.) or may be heated to about 40 to 90 ° C. as necessary.
About this citric acid powder and FeO powder, each description in the manufacturing method of the following [4] iron supply agent is applicable as it is.

[3] Manufacturing method of iron supply agent
The method for producing the iron supplier is not particularly limited as described above, and various methods can be used. A dissolution step of obtaining an aqueous solution obtained by dissolving FeO can be provided.
Moreover, the manufacturing method of the iron supply agent for plants of this 4th invention is a manufacturing method of the iron supply agent for plants of this 1st invention, Comprising:
A heating step comprising heating a mixture containing citric acid powder, FeO powder and water to obtain an aqueous solution obtained by dissolving the citric acid and FeO;
The FeO powder is a FeO is more than 50% by weight, based on the total the FeO powder, and _{CaAl 2 O 4, FeAl 2 O} 4, of _{CaFe 2 Si 2 O 6, CaSi} 2 O 5 and MgFe ₂ O ₄ It contains at least one kind of double oxide.
That is, it includes a specific dissolving step in the method for producing the first iron supply agent described later.
Furthermore, the manufacturing method of the iron supply agent for plants of this 5th invention is a manufacturing method of the iron supply agent for plants of this 2nd invention, Comprising:
A melting step of heating a mixture containing citric acid powder, FeO powder and water to obtain an aqueous solution obtained by dissolving the citric acid and FeO;
A drying step of removing water from the aqueous solution,
The FeO powder is a FeO is more than 50% by weight, based on the total the FeO powder, and _{CaAl 2 O 4, FeAl 2 O} 4, of _{CaFe 2 Si 2 O 6, CaSi} 2 O 5 and MgFe ₂ O ₄ It contains at least one kind of double oxide.
That is, it comprises a specific dissolving step and a drying step in the method for producing a second iron supplier to be described later.

The “organic acid powder” is a powder containing the organic acid as a main component (usually a purity of 99% or more), and the particle shape and the like are not particularly limited as long as the purity and the powder form.
The “FeO powder” is a powder mainly composed of FeO. The amount of FeO contained in this FeO powder is 50% by mass or more (preferably 65% by mass or more and may be 100% by mass) of FeO with respect to the entire FeO powder. As this FeO powder, any FeO powder may be used. FeO powder described later (granulated product obtained by granulating iron-containing dust and / or granulated iron-containing dust and reducing agent) And a granulated product obtained by vacuum heating and vacuum quenching) and various commercially available FeO powders. Among these, FeO powder obtained by heating the above-mentioned granulated product in a vacuum and then rapidly cooling in a vacuum is preferable.
As the “water”, any water can be used as described above.

In the manufacturing method of an iron supply agent, the process of removing a water-insoluble component can be provided after the said melt | dissolution process. Examples of the water-insoluble component include organic acid powder that cannot be completely dissolved and FeO powder that cannot be completely dissolved. Although the removal method is not particularly limited, it can usually be performed by filtration. That is, a filtration step can be provided. The filtration conditions at this time are not particularly limited. For example, it is preferable to use a membrane filter having a pore size of 10 μm or less (more preferably 5 μm or less, more preferably 3 μm or less) as the filtration filter.

Moreover, when obtaining a 2nd iron supply agent, the drying process which removes water from the said aqueous solution can be further provided after the said melt | dissolution process. The drying conditions in this drying step are not particularly limited, and natural drying may be performed, but it is preferable to use the above-described removal method and drying conditions. That is, it is preferable to remove water by heating under reduced pressure. It is considered that the Fe ²⁺ ion component (Fe ²⁺ complex or the like) that is water-soluble and excellent in antioxidant properties is concentrated by gradually reducing the water content by heating, and the second iron supplier is obtained.

  Furthermore, when obtaining said 2nd iron supply agent, a refinement | purification process can also be further provided. The purification process is a process for purifying water-soluble components. That is, for example, after an aqueous solution obtained by removing water from the aqueous solution is brought into contact with water to dissolve the dissolvable part, an extraction step for removing and extracting water-insoluble components in the same manner as described above, A re-drying step of removing water from the aqueous extraction solution obtained in this extraction step.

The FeO powder used in the method for producing an iron supply agent is a granulated product obtained by granulating iron-containing dust and / or a granulated product obtained by granulating iron-containing dust and a reducing agent. It is preferable that the product is an FeO powder obtained by vacuum heating and vacuum quenching.
In addition to FeO, this FeO powder (FeO powder obtained by using the granulated product and / or the granulated product) includes CaAl ₂ O ₄ , FeAl ₂ O ₄ , CaFe ₂ Si ₂ O ₆ , and CaSi ₂ O. _This is because at least one double oxide of ₅ and MgFe ₂ O ₄ is contained. These double oxides may contain only 1 type and 2 or more types may contain them. Further, the content of the composite oxide is preferably 0.5 to 10% by mass when the entire FeO powder is 100% by mass. If it is this range, the iron supply agent excellent in antioxidant property can be obtained.
Further, the shape of the particles constituting the FeO powder is not particularly limited, but is a FeO powder having a particle size of 5000 μm or less, mixed with powders of various particle sizes, and further containing porous particles. May be.

Furthermore, when compared with an aqueous solution in which iron (III) citrate is dissolved (total Fe ion concentration 584 mg / liter, Fe ²⁺ ion concentration 142 mg / liter), the peaks of mass 439 and mass 631 are small and the relative content is small. Is predicted.
Taking these results together, the iron supplier specifically contains more dimer and trimer complexes than the aqueous iron (III) citrate solution, resulting in higher amounts of Fe ²⁺ ions. It is considered that this is a factor in which an increase in Fe ²⁺ ions is observed.

  The plant iron supply aqueous solution and plant iron supply agent of the present invention are widely used in the field of agriculture and forestry. That is, for example, it is widely used for production of agricultural products, hydroponics, production of horticultural plants, production and maintenance of parks and golf courses, forest maintenance, and the like. In particular, it is useful as a plant growth promoter in the production field of various agricultural products. It can also be used to solve food problems by growing plants on barren lands around the world and to improve the global environment by promoting absorption of carbon dioxide.

Claims (33)

An iron supplier comprising an aqueous solution obtained by dissolving an organic acid having a carboxyl group and / or a hydroxyl group and FeO. Containing and Fe ²⁺ ions and ^{Fe 3+} ions, in the case where the total of the ^{Fe 2+} ions and the ^{Fe 3+} ions is 100 mass%, according to claim 1 wherein the ^{Fe 2+} ion is 50 to 90 wt% Iron supplier. The iron supplier according to claim 1, wherein the Fe ²⁺ ion concentration observed in the aqueous solution after standing for 168 hours is 75% or more of the Fe ²⁺ ion concentration observed immediately after the start of measurement. The iron supply agent according to claim 1, comprising at least citric acid as the organic acid. A dimeric complex of citric acid and / or citric acid ions were two coordinated to one Fe ²⁺ ion, citric acid and / or citric acid ions are three coordinated to one Fe ²⁺ ions The iron supply agent according to claim 4 containing a trimer complex. An iron supplier for plants comprising the iron supplier according to any one of claims 1 to 5. The iron supply agent for plants according to claim 6 containing a biodegradable binder. The iron supplier for plants according to claim 6 containing a biodegradable extender. The plant iron supply agent according to claim 6, which contains 5% by mass or more of the iron supply agent when the total amount of the iron supply agent for plants is 100% by mass. An iron supplier obtained by removing water from an aqueous solution obtained by dissolving an organic acid having a carboxyl group and / or a hydroxyl group and FeO. Aqueous solution obtained by dissolving this iron supplying agent contains a ^{Fe 2+} ions and ^{Fe 3+} ions, in the case where the total of the ^{Fe 2+} ions and the ^{Fe 3+} ions is 100 mass%, the ^{Fe 2+} ions The iron supply agent according to claim 10, which is 50 to 90% by mass. The aqueous solution obtained by dissolving the present iron supplier has an Fe ²⁺ ion concentration observed in the aqueous solution after standing for 168 hours is 75% or more of the Fe ²⁺ ion concentration observed immediately after the dissolution. Iron supplier as described. The iron supply agent according to claim 10, containing at least citric acid as the organic acid. Aqueous solution obtained by dissolving this iron supply agent, a dimeric complex of citric acid and / or citric acid ions were two coordinated to one Fe ²⁺ ion, citric acid for one Fe ²⁺ ions And / or a trimer complex in which three citrate ions are coordinated. An iron supplier for plants comprising the iron supplier according to any one of claims 10 to 14. The plant iron supplier according to claim 15, comprising a biodegradable binder. The plant iron supply agent according to claim 15 containing a biodegradable extender. The plant iron supply agent according to claim 15, which contains 5% by mass or more of the iron supply agent when the total amount of the iron supply agent for plants is 100% by mass. Containing citric acid as the organic acid,
Containing peat as the biodegradable extender,
The matrix composed of the biodegradable extender contains the citric acid and the FeO,
The iron supply agent for plants according to claim 17 used in alkaline soil. An iron supplier comprising an organic acid having a carboxyl group and / or a hydroxyl group and FeO. Aqueous solution obtained by dissolving this iron supplying agent contains a ^{Fe 2+} ions and ^{Fe 3+} ions, in the case where the total of the ^{Fe 2+} ions and the ^{Fe 3+} ions is 100 mass%, the ^{Fe 2+} ions The iron supply agent according to claim 20, which is 50 to 90% by mass. The aqueous solution obtained by dissolving the present iron supplier has a Fe ²⁺ ion concentration found in the aqueous solution after standing for 168 hours is 75% or more of the Fe ²⁺ ion concentration found immediately after the dissolution. Iron supplier as described. The iron supply agent according to claim 20, comprising at least citric acid as the organic acid. Aqueous solution obtained by dissolving this iron supply agent, a dimeric complex of citric acid and / or citric acid ions were two coordinated to one Fe ²⁺ ion, citric acid for one Fe ²⁺ ions And / or a trimeric complex in which three citrate ions are coordinated. An iron supply agent for plants comprising the iron supply agent according to any one of claims 20 to 24. The plant iron supplier according to claim 25, which contains a biodegradable binder. The plant iron supplier according to claim 25, which contains a biodegradable extender. The iron supply agent for plants according to claim 25, wherein the iron supply agent is contained in an amount of 5% by mass or more when the total iron supply agent for plants is 100% by mass. Containing citric acid as the organic acid,
Containing peat as the biodegradable extender,
The matrix composed of the biodegradable extender contains the citric acid and the FeO,
The plant iron supplier according to claim 27, which is used in alkaline soil. It comprises a dissolution step of heating an organic acid powder having a carboxyl group and / or hydroxyl group, an FeO powder, and water to obtain an aqueous solution obtained by dissolving the organic acid and FeO. A method for producing an iron supply agent. The manufacturing method of the iron supply agent of Claim 30 provided with the drying process which removes water from the said aqueous solution. The method for producing an iron supply according to claim 30, wherein the organic acid contains at least citric acid. The FeO powder is vacuum-cooled after a vacuum heating of a granulated product obtained by granulating iron-containing dust and / or a granulated product obtained by granulating iron-containing dust and a reducing agent. The method for producing an iron supply according to claim 30, wherein the FeO powder is obtained.