WO2007013217A1 - Iron(i) oxide-containing composition and plant growth promoter comprising the same - Google Patents

Abstract

Disclosed are: an iron(I) oxide-containing composition in which bivalent iron ions eluted into water can be prevented from being precipitated in the form of iron(II) hydroxide or the like; and a plant growth promoter comprising the composition. The iron(I) oxide-containing composition comprises iron(I) oxide and a complex oxide, in which the complex oxide has at least one element selected from Ca, Al and Mg. The complex oxide is preferably at least one substance selected from CaAl2O4, FeAl2O4, MgAl2O4, CaFeSi2O6, MgFeSi2O6, CaSi2O5, MgSi2O5, CaFe2O4, MgFe2O4, CaFeO2 and MgFeO2. The plant growth promoter comprises the iron(I) oxide-containing composition and a material containing a chelating substance (e.g., leaf soil, cowpat).

Description

 Specification

 Ferrous oxide-containing composition and plant growth promoter containing the same

 Technical field

 [0001] The present invention relates to a ferrous oxide-containing composition and a plant growth promoter containing the same. More specifically, the present invention relates to a ferrous oxide-containing composition containing ferrous oxide and a composite oxide containing elements such as Ca and A1, and a plant growth promoter containing the same.

 The ferrous oxide-containing composition of the present invention can be used in various applications such as plant growth promoters, mineral supply promoters, and plant sugars, polyphenols and vitamins. In particular, it is useful as a plant growth promoter in the growth of various types of plants. Root vegetables such as potatoes, and sweet potatoes such as sweet potatoes and potatoes can be grown sufficiently in a short period of time to increase the sugar content of fruit vegetables such as melons.

 Background art

 [0002] Iron is an essential element although it is a trace element for plants. Usually, it is contained in crops in an amount of about 1 to 4 OOppm, and even if it is a trace element, deficiency causes a specific deficiency. For example, iron is involved in the formation of chlorophyll, and when deficient, the leaves turn yellow. Iron is also involved in nitrogen metabolism, and deficiency impairs protein synthesis. In order to supply iron, which is an essential element for plant growth, the use of iron powder, converter iron, hydroxy-iron iron, or the like as an iron-containing composition has been proposed (for example, see Patent Document 1).

 [0003] Further, in order to supply iron to plants, an aqueous solution in which iron is poured into sulfuric acid, hydrochloric acid, nitric acid, etc. and dissolved in water as iron sulfate, iron chloride, iron nitrate, etc., respectively, is used as a fertilizer as a liquid. Is provided. The hydrogen ion index (hereinafter referred to as “pH”) of this aqueous solution is usually 2 to 3, and if the pH is 5 or less, the solubility is sufficiently high and kept in a liquid state. A liquid or powder fertilizer containing chelated iron using a chelating agent such as ethylene diamin tetraacetic acid (EDTA) is also provided.

Patent Document 1: Japanese Patent Application Laid-Open No. 8-277183 Disclosure of the invention

 Problems to be solved by the invention

 [0005] However, the iron-containing composition described in Patent Document 1 has a large portion of the eluted iron precipitated as ferric hydroxide, which cannot be taken up by plants, for example, and is essential for plants. He was unable to supply enough elemental iron.

 In addition, even in liquid fertilizers containing iron sulfate and the like, dissolved iron may precipitate as ferric hydroxide and ferric iron due to sunlight and air, and the plant may not be able to take up. Furthermore, chelated iron has a problem that the chelating agent such as EDTA remaining after the iron is supplied to the plant and taken into the plant easily binds to heavy metals in the soil. That is, heavy metals such as Pb and Cd are usually in the form of chelates by combining the remaining remaining chelating agents and heavy metals that exist in the soil as water-insoluble acid oxides. May dissolve and cause heavy metal contamination.

 [0006] The present invention solves the above-mentioned conventional problems, and contains ferrous oxide and a composite oxide, and divalent iron ions eluted in the acid ferrous water Provided is a ferrous oxide-containing composition that is prevented from being precipitated as hydroxide, ferric iron, and the like, and a plant growth promoter containing the composition and capable of efficiently absorbing iron into a plant For the purpose.

 Means for solving the problem

[0007] When ferric oxide is contacted with water, it is easily soluble if the pH is low, but is insoluble if the pH is high. Since the pH of soil is generally around 6.0, ferrous oxide dissolves in water and divalent when a plant growth promoter containing ferrous oxide is used to supply iron to plants. The iron ions are eluted. However, when the pH is about 6.0, ferric hydroxide and the like are easily formed, and divalent iron easily becomes trivalent iron, which becomes insoluble in water and precipitates. Cannot be included.

On the other hand, the ferrous oxide-containing composition of the present invention contains a specific complex oxide having elements such as Ca, A1, and Mg in addition to ferrous oxide. The pH is maintained at 7.0 or higher by gradually eluting Ca ions, A1 ions, Mg ions, etc. from the material. Therefore, the supply of iron is stably continued, and the growth of the plant is promoted. In addition, because iron is stably supplied on the alkali side in this way, it is said to be about 20% of the world soil. When used in alkaline soil, it functions well as a plant growth promoter. In addition, if CaO or the like is added to ferrous oxide, the pH of the soil can be increased. In this case, Ca ions and the like are also eluted at once, and the pH is temporarily reduced to, for example, 12.0. It becomes moderately high. However, it eluted Ca ions flows out like groundwater, subsequent rainfall or the like washed away by want ,, high, because such the absence of Ca ions only to maintain _P H, Sani匕第Ferrous iron, which is hardly soluble in water, becomes ferric hydroxide, ferric iron, etc., and cannot be taken up by plants, and its actions and effects do not continue.

 The present invention has been made based on such knowledge.

 The present invention is as follows.

 1. Ferrous oxide and a complex oxide, wherein the complex oxide contains at least one element of Ca, A1, and Mg Containing composition.

 2. The ferrous oxide-containing composition according to 1 above, wherein the composite oxide further comprises at least one of Fe and Si.

 3. The above complex oxides are CaAl O, FeAl O, MgAl O, CaFeSi O, MgFeSi

 2 4 2 4 2 4 2 6 2

Of O, CaSi O, MgSi O, CaFe O, MgFe O, CaFeO and MgFeO

6 2 5 2 5 2 4 2 4 2 2 The composition containing ferrous oxide according to 1 above, which is at least one.

 4. The above complex oxide is one of CaAl O, FeAl O, CaFeSi O and CaSi O.

 2 4 2 4 2 6 2 5 The ferrous oxide-containing ferrous composition according to 1 above, which is at least one.

 5. When the ferrous oxide-containing composition is 100 parts by mass, the total of the ferrous oxide and the composite oxide is 65 parts by mass or more. Iron-containing composition.

 6. When the total of the ferrous oxide and the composite oxide is 100% by mass, the composite oxide is 0.5 to 10% by mass. Composition.

 7. Add the ferrous oxide-containing composition to an aqueous hydrochloric acid solution with a hydrogen ion index of 2.2 to a mass ratio of 10% by mass, and the pH measured after 24 hours is 8.0 to 12.0. The ferrous oxide-containing composition according to 1. above, wherein the composition has a pH measured after 264 hours of 7.5 to 11.0.

8. 10% by mass of the ferrous oxide-containing composition in a hydrochloric acid aqueous solution with a hydrogen ion index of 2.2 When Al and Ca contained in an aqueous solution prepared by adding so as to have a mass ratio of 165 are quantified after 264 hours, the content of A1 is 70 to 130 mg / liter, and the content of Ca is 90 to The ferrous oxide-containing composition according to 1. above, which is 170 mg / liter.

 9. Granulate the iron-containing dust into a granulated product, then heat the granulated product under vacuum to convert the iron content in the granulated product into FeO, and then contain the FeO The ferrous oxide-containing composition as described in 1. above, obtained by rapidly cooling a powder under vacuum.

 10. A plant growth promoter comprising the ferrous oxide-containing composition as described in 1 above and a chelating substance.

 11. The plant growth promotion according to 10. above, wherein the total amount of the ferrous oxide-containing composition and the chelating substance is 85% by mass or more when the plant growth promoter is 100% by mass. Agent.

 12. The above, wherein the total of the ferrous oxide-containing composition and the chelating substance is 0.1 to 5% by mass, when used in the seedling stage and the plant growth promoter is 100% by mass The plant growth promoter according to 10.

 13. The plant growth promoter as described in 12 above, which is used by contact fertilization.

 14. The plant growth promoter according to any one of 10. to 13, wherein the chelating substance is at least one of humus and cow dung.

 15. The plant growth promoter as described in 10 above, which is used in alkaline soil.

 16. The above, wherein the total of the ferrous oxide-containing composition and the chelating substance is 0.1-5% by mass when used in the seedling stage and the plant growth promoter is 100% by mass 15. The plant growth promoter according to 15.

 17. The plant growth promoter according to 16. above, which is used by contact fertilization.

The invention's effect

When the ferrous oxide-containing composition of the present invention is brought into contact with water, divalent iron ions eluted in the water are suppressed from precipitating as ferric hydroxide or iron. Therefore, the divalent iron ions dissolved in water can be efficiently absorbed by plants. For example, when used as a plant growth promoter, chlorophyll formation and protein synthesis are promoted, and melon Such fruits and vegetables produce effects such as increased sugar content. When the composite oxide further contains at least one of Fe and Si, the composite oxides i CaAl O, FeAl O, MgAl O, CaFeSi O, MgFeSi O, CaSi O, MgSi

 2 4 2 4 2 4 2 6 2 6 2 5 2

If it is at least one of O, CaFe O, MgFe O, CaFeO and MgFeO

5 2 4 2 4 2 2

And composite oxides are small in CaAl 2 O, FeAl 2 O, CaFeSi 2 O and CaSi 2 O.

 2 4 2 4 2 6 2 5 In the case of at least one, it is possible to efficiently suppress the eluted divalent iron ions from ferric hydroxide to ferrous iron.

 Furthermore, when the ferrous oxide-containing composition is 100 parts by mass, the total of ferrous oxide and the composite oxide is 65 parts by mass or more, and the ferrous oxide and the composite oxide When the total content is 100% by mass and the content of the composite oxide is 0.5 to 10% by mass, divalent iron ions can be dissolved in water as they are for a longer period of time. .

 In addition, the ferrous oxide-containing composition was added to a hydrochloric acid aqueous solution having a hydrogen ion index of 2.2 so that the mass ratio was 10% by mass, and the pH measured after 24 hours was 8.0 to 12.0. And when the pH measured after 264 hours is 7.5 to: L 1.0, the divalent iron ion is sufficiently suppressed from precipitating as ferric oxide, etc. When used as a growth promoter, iron can be absorbed by plants over a long period of time, which has a great effect of promoting growth.

 Further, A1 and Ca contained in an aqueous solution prepared by adding the ferrous oxide-containing composition to a hydrochloric acid aqueous solution having a hydrogen ion index of 2.2 to a mass ratio of 10% by mass were added after 264 hours. When the A1 content is 70 to 130 mg / liter and the Ca content is 90 to 170 mgZ liter when quantified, the pH of the solution can be kept higher, and divalent iron ions Sedimentation as dihydrated pig iron is sufficiently suppressed.

 Further, the ferrous oxide-containing composition is granulated by dusting iron-containing dust, and then the granulated product is heated under vacuum and the iron content contained in the granulated product becomes FeO, Next, when the FeO-containing powder is obtained by quenching under vacuum, the precipitation of divalent iron ions as ferric hydroxide or ferrous iron is sufficiently suppressed.

 According to the plant growth promoter of the present invention, it is possible to sufficiently supply iron to the plant and promote the growth of the plant.

In addition, when the plant growth promoter is 100% by mass, it contains the ferrous oxide-containing composition. If the total amount of the chelating substance is 85% by mass or more, the plant can be supplied with iron more fully.

 Furthermore, when the total amount of the ferrous oxide-containing composition and the chelating substance is 0.1 to 5% by mass when used at the seedling stage and the plant growth promoter is 100% by mass, The plant can be supplied with iron more fully.

 In addition, when used by contact fertilization at the seedling stage, the plant can be supplied with iron very efficiently.

 Furthermore, when the chelating substance is at least one of humus and cow dung, the growth of the plant can be further promoted.

 Further, even when used in an alkaline soil where iron is not normally supplied to plants, the plant growth promoter of the present invention can supply iron more fully to plants.

 Further, when the plant growth promoter is used at 100% by mass in an alkaline soil and the plant growth promoter is 100% by mass, the total of the ferrous oxide-containing composition and the chelating agent is 0.1 to 5% by mass. In some cases, despite being alkaline soil, the plant growth promoter of the present invention can more sufficiently supply iron to plants.

 In addition, when it is used by contact fertilization at the seedling stage in alkaline soil, the plant growth promoter of the present invention can extremely efficiently supply iron to the plant even though it is an alkaline soil. Can do.

Brief Description of Drawings

FIG. 1 is a schematic explanatory view of an FeO powder production apparatus used in Example 1. FIG.

 FIG. 2 is an explanatory diagram using an X-ray diffraction chart (2θ is 10 to 50) of the FeO powder produced in Example 1.

 FIG. 3 is an explanatory diagram using an X-ray diffraction chart (2 Θ force 0 to 100) of the FeO powder produced in Example 1.

 FIG. 4 is a graph showing changes in pH of an aqueous solution in which FeO powder is dissolved.

FIG. 5 is a graph showing the change over time of the pH of an aqueous solution in which reagent FeO is dissolved.

[Fig.6] Water solution when the solvent of the aqueous solution in which FeO powder is dissolved is replaced with an acidic solvent in a timely manner. It is a graph which shows the time-dependent change of pH of a liquid.

 FIG. 7 is an explanatory diagram using an SEM photograph of the FeO powder produced in Example 1.

FIG. 8 is an explanatory diagram using an EDX qualitative analysis chart of the FeO powder produced in Example 1.

 FIG. 9 is an explanatory diagram using an SEM photograph of a red rust portion of FeO powder taken out from an aqueous solution in which FeO powder is dissolved after 21 days.

 FIG. 10 is an explanatory diagram using an EDX qualitative analysis chart of the red rust portion of FeO powder taken out from an aqueous solution in which FeO powder is dissolved after 21 days.

 [Fig. 11] An explanatory diagram using a SEM photograph of the red rust of the FeO powder taken out after 21 days from the aqueous solution in which the FeO powder was dissolved.

FIG. 12 is an explanatory diagram using the EDX qualitative analysis chart of the portion where the red rust of the FeO powder taken out from the aqueous solution in which the FeO powder was dissolved after 21 days had elapsed.

FIG. 13 is an explanatory diagram using an X-ray diffraction chart of FeO powder taken out from an aqueous solution in which FeO powder is dissolved after 21 days.

 FIG. 14 is an explanatory diagram using an X-ray diffraction chart of FeO powder taken out from an aqueous solution in which reagent FeO is dissolved after 11 days.

 [FIG. 15] An explanatory view of photographs showing a comparison of the size of ginseng harvested from a cultivation plot using a soil type growth promoter and that from a control plot.

 [FIG. 16] Cultivation plotting power using a soil type growth promoter An explanatory diagram based on a photograph comparing the size of harvested peanuts and peanuts harvested from a control plot.

 [FIG. 17] An explanatory diagram with photographs showing a comparison of the size of Chinese cabbage harvested from a cultivation plot using a soil-type growth promoter and the Chinese cabbage harvested from a control plot.

Explanation of symbols

 1; material supply system, 11; hopper, 2; vacuum heating system, 21; vacuum heating furnace, 211, 212, 213, 214, 215; calo heat chamber, 22; feeder feeder, 23; frame machine, 231; Shaft, 232; rotor blade, 233; stirring member, 234; motor, 24; bottom of vacuum caloric heat furnace, 251, 252, 253, 25 4, 255; heater, 26; cooling system, 4;

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail.

 [1] Ferrous oxide-containing composition

 The “ferrous oxide-containing composition” contains ferrous oxide and a specific composite oxide.

 The above “ferrous oxide” has a NaCl-type crystal structure and is a substance mainly composed of iron and oxygen. This ferrous oxide may contain substances in which some of the iron atoms are replaced with transition metal atoms, etc., and substances in which some of the oxygen atoms are substituted with other elements such as halogen elements. Good. Moreover, the substance which has an atomic vacancy may be contained. This ferrous oxide is usually in powder form.

 The ferrous oxide is preferably contained in an amount of 65% by mass or more when the total of the ferrous oxide and the composite oxide is 100% by mass. This content is more preferably 90 to 99.5% by mass, particularly preferably 93 to 97% by mass. The content of ferrous oxide can be measured by a method such as an X-ray diffraction method.

The “composite oxide” has at least one element of Ca, A1, and Mg.

 Among these elements, it is preferable to have only Ca and Al, only A1, Mg and Al, only Ca or only Mg. Such complex oxides include CaAl O, FeAl O, MgAl O

 2 4 2 4 2 4

, CaFeSi O, MgFeSi O, CaSi O, MgSi O, CaFe O, MgFe O, CaFeO

 2 6 2 6 2 5 2 5 2 4 2 4 and MgFeO. In the composition containing ferrous oxide, these composite oxides

twenty two

 Only one of them may be contained, or two or more may be contained. When two or more kinds of complex oxides are contained, they may be V-type complex oxides and are not particularly limited. The complex oxide may further contain other elements, and the other elements are often at least one of Fe and Si. The composite oxide may have Zn and Mn as other elements.

 [0014] As a complex acid salt, divalent iron ions eluted in acid ferrous water should be sufficiently suppressed from precipitating as hydroxy acid ferric acid or the like. CaAl O, FeAl O,

 2 4 2 4

CaFeSi 2 O and CaSi 2 O force are preferred. These complex oxides also contain only one type

2 6 2 5

2 or more types may be contained. When two or more composite oxides are contained, any composite oxide may be used without particular limitation. Of these complex oxides Among them, CaAl O has a continuous elution of Ca ions and Al ions.

twenty four

 It is preferable because iron ions can be reliably prevented from being precipitated as hydroxide or ferric iron. In addition, FeAl O selectively elutes with hydroxides due to continuous elution of A1 ions.

 twenty four

 Therefore, it is preferable because divalent iron ions eluting with acid ferrous iron are suppressed from being precipitated as hydroxy acid ferric iron or the like. Furthermore, CaFeSi 2 O and CaSi 2 O have Ca ions

 2 6 2 5

 It is preferable because it elutes continuously and divalent iron ions are prevented from precipitating as ferric hydroxide and ferric iron in the same manner as above.

 This composite oxide is produced, for example, when a ferrous oxide-containing composition is produced by the method described later. The type of composite oxide to be produced varies depending on the raw materials used and the manufacturing conditions, and for example, at least one of the above-mentioned various complex oxides is produced. However, if divalent iron ions are prevented from precipitating as ferric hydroxide or the like, the same actions and effects are produced.

[0015] The content of the composite oxide can be set to 0.3 to 15 mass% when the total of the ferrous oxide and the composite oxide is 100 mass%. The content of this complex oxide is preferably 0.5 to: L0% by mass, particularly preferably 3 to 7% by mass. If the content of the composite oxide is 0.3 to 15% by mass, particularly 0.5 to 10% by mass, and further 3 to 7% by mass, divalent iron ions eluted from ferrous oxide into water It is possible to sufficiently suppress the precipitation as ferric oxide.

 [0016] The ferrous oxide-containing composition contains metal iron, MgO, CaO, Al 2 O, Fe 2 O, ZnO, MnO, and the like in addition to ferrous oxide and the specific composite oxide described above. It may be. This

 2 3 2 3

 The content of these other components is preferably not more than 35 parts by mass, particularly not more than 15 parts by mass, when the ferrous oxide-containing composition is 100 parts by mass. More preferably. If the content of other components is 35 parts by mass or less, the content of the ferrous oxide-containing composition is ensured, and as a result, sufficient iron ions can be supplied. Force The divalent iron ions eluted in the water are sufficiently suppressed from precipitating as hydroxide or ferric iron.

Water does not contain negative ions, such as C1 ions, which react with Ca ions and A1 ions, etc., which are eluted by complex acid strength, to form compounds that are insoluble or insoluble in water. If it is contained, the smaller the content, the better.

 [0017] In this acid-iron-ferrous iron-containing composition, when the composition is added to a hydrochloric acid aqueous solution of pH 2.2 so that the mass ratio is 10% by mass, the pH after 24 hours is 8. The pH can be 0 to 12.0, and the pH after 264 hours can be 7.5 to 11.0. This pH can in particular be 9.5 to: L 1.5 after 24 hours and can be 8.0 to 10.0 after 264 hours. If the pH after 24 hours is 8.0 to 12.0, and the pH after 264 hours is 7.5 to: L 1.0, divalent iron ions eluted in ferrous oxide water will be Sedimentation as ferric oxide and ferric iron is sufficiently suppressed. For example, when used as a plant growth promoter, iron can be absorbed efficiently by plants, and plant growth Can be promoted sufficiently.

 [0018] Further, in this acid-iron-ferrous iron-containing composition, A1 contained in an aqueous solution prepared by adding the composition to a pH 2.2 aqueous hydrochloric acid solution to a mass ratio of 10% by mass. When Ca is quantified after 264 hours, the content of A1 can be 70 to 130 mg / liter, particularly 85 to 120 mg, and the content of Ca is 90 to 170 mgZ liter. Can be mgZ liters. In this way, even after the liquid preparation ability has elapsed for a long time, since a large amount of A1 and Ca are eluted, the pH after 264 hours can be kept sufficiently high as described above. It is sufficiently suppressed that the valent iron ions are precipitated as hydroxide or ferric iron.

 Even in the case of a hydrochloric acid aqueous solution having a low pH of 2.0 to 3.0, the Ca content can be 130 to 170 mg / liter, particularly 140 to 160 mg / liter. Thus, even when the initial pH is low, it is presumed that the pH of the liquid can be sufficiently increased by elution of Ca.

 This element can be quantified, for example, by high frequency inductively coupled plasma emission spectroscopy.

 [2] Method for producing ferrous oxide-containing composition

 Although the manufacturing method of the ferrous oxide containing composition of this invention is not specifically limited, For example, the following manufacturing methods are mentioned.

That is, a granulation step for granulating iron-containing dust into a granulated product, and the granulated product under vacuum And a heating step in which the iron content in the granulated product is FeO and a cooling step in which the powdered FeO is rapidly cooled under vacuum.

 Hereinafter, the powder of the ferrous oxide-containing composition produced by such a method is referred to as “FeO powder”.

 As dust containing iron, forged shot dust collected in the forging process, electric furnace dust, blast furnace dust, converter dust, cupola dust, etc. generated in the steel making process can be used.

 [0020] These dusts are not particularly limited as long as they contain iron. Also, the iron content is not limited. The dust is usually a powder, but is not limited thereto, and may be a small piece or a mixture of a powder and a small piece. In the case of powder, the average particle size is usually 3 to 10 m. The iron content is contained in the dust as iron oxide or as a mixture of iron oxide and metallic iron, but the metallic iron contained in the dust is preferably 40% by mass when the total iron content is 100% by mass. In the following, it is particularly preferably 30% by mass or less (may be 0% by mass). Only one type of dust may be used, or two or more types of dust may be used.

 In addition to iron, the dust may contain Zn, Ni, Cu, Mn, etc. These may be a single metal or a compound such as an acid oxide.

 [0021] It is preferable to remove the chlorine content from the dust by washing with water, then remove the washing water in which the chlorine is dissolved, and then granulate. By reducing the concentration of chlorine contained in the dust in this way, dust aggregation during vacuum heating can be suppressed.

 [0022] In the granulation step, dust is used as a granulated product because Fe 2 O, Fe 2 O and

 2 3 3 4

This is to promote the reaction from Fe (single) to FeO. This granulated product is obtained by solidifying a mixture of dust and treatment material, and solidifying the mixture of dust and treatment material in order to solidify the mixture of the dust and treatment material. is there. An appropriate amount of the treatment material is blended depending on the iron content contained in the dust and the types of other metals and their contents.

[0023] The treatment material contains, for example, iron used for the purpose of producing a large amount of FeO powder and efficiently producing FeO powder when the iron content in the dust is small. Examples include cutting waste, polishing waste, and iron powder. In addition, for the purpose of promoting the reaction and recovering other metals contained in the dust as a simple substance, etc. It can also be blended. In particular, dust contains zinc (usually contained as ZnO), and when it is recovered as zinc alone at the same time as the production of FeO powder, cutting waste and polishing waste containing iron, iron powder, etc. In addition, it is preferable to use a reducing agent used for pig iron and steel and the like, and a reducing agent that also has the power of waste materials containing a large amount of carbon such as tire scrap. This reducing agent can be used alone or in combination of two or more.

 [0024] When other processing materials such as a reducing agent are used, the shape is not particularly limited as long as it can be blended with dust to form a granulated product together with dust, but the shape of powder, granules, small pieces, etc. Some can be used. In particular, when used as a reducing agent, in consideration of the efficiency of each reaction and reduction of other metal oxides contained in the dust, the powder is preferably a powder that can be contacted more. . In the case of powder, the average particle diameter is not particularly limited, but can be 200 m or less, and preferably 180 m or less. The lower limit of the average particle size is up to fine powder that is easy to obtain and handle.

 [0025] When the reducing agent is used, the mixing ratio of the dust and the reducing agent is not particularly limited. However, when the dust is 100 parts by mass, the reducing agent is preferably 100 parts by mass or less, particularly preferably 90 parts by mass. Hereinafter, it is more preferably 80 parts by mass or less (usually 30 parts by mass or more). When the reducing agent exceeds 100 parts by mass, the processing efficiency decreases. On the other hand, if it is less than 30 parts by mass, it may not be possible to sufficiently reduce other metal oxides such as zinc oxide.

 [0026] The granulated product is produced by further blending a binder with a mixture of dust and other treatment materials. As the binder, there is used an alumina cement which does not cause a problem of smoke and odor even if it volatilizes and can generate the above-mentioned specific complex oxide. The amount of the alumina cement is preferably 3 to 20 parts by mass, particularly preferably 3 to 15 parts by mass, and more preferably 3 to 15 parts by mass when the total of dust or a mixture of dust and other treatment materials is 100 parts by mass. Preferably it is 3-12 mass parts. If the blending amount is less than 3 parts by mass, it is not easy to produce a granulated product because the binder is too small. If it exceeds 20 parts by mass, the granulated product may become brittle, and the amount of gas derived from the binder is generated. May increase, which is not preferable.

 In order to react efficiently, it is preferable to remove moisture from the granulated product by drying or the like, and then subject it to a caloric heat process.

[0027] The shape of the granulated product is not particularly limited, and a sphere, an ellipsoid, a hemisphere, a cube, a cuboid, a cylinder Any of body, pricket and the like may be used. The granulated product may be a dense body or a porous body. Furthermore, in order to transfer heat to the whole granulated product, or to maintain the shape of the granulated product during heating, the heat conduction from the start of heating until reaching a predetermined temperature is taken into consideration. The diameter (diameter in the case of a sphere, maximum interstitial dimension in the case of other shapes) is preferably 25 mm or less, particularly preferably 15 mm or less, more preferably 10 mm or less (usually 3 mm or more). If the diameter exceeds 25 mm, the inside of the granulated product is difficult to reach the predetermined temperature, which is not preferable. On the other hand, if it is less than 3 mm, the granulated product may aggregate and time may be required for the reaction.

[0028] The heating step is a reaction step for producing FeO powder. That is, it is a process in which the granulated product is heated under vacuum and the iron content in the granulated product is changed to FeO. In addition, when the dust contains other metal oxides such as zinc oxide, the reaction between zinc oxide and metallic iron produces metallic zinc and FeO, which is above 600 ° C. Normally, it evaporates under a high vacuum of about 1.56 kPa, so it can be recovered as metallic zinc in the heating process. In this case, the heating process to convert the iron contained in the dust into FeO is also a recovery process for recovering other metals such as zinc as a simple metal.

 [0029] The degree of vacuum in the heating process is preferably set so that FeO is efficiently generated. This degree of vacuum can be set to 0.1 to 13.3 kPa, preferably 2.6-13. 3 kPa, particularly preferably 4.0 to 6.7 kPa. If the degree of vacuum is too low, a lot of metallic iron tends to remain without being oxidized. On the other hand, if the degree of vacuum is too high, the generated FeO

 34 There is a tendency to be oxidized, and further, other metal oxides such as zinc oxide may be difficult to be reduced.

 In addition, the atmosphere of the force heating process in which a trace amount of oxygen is contained in this vacuum atmosphere may be an inert gas atmosphere having an oxygen partial pressure equivalent to this vacuum atmosphere.

[0030] The heating step is performed in the vacuum atmosphere described above. This heating may be a method in which the granulated product is heated from room temperature to a predetermined temperature and maintained at the predetermined temperature, and the granulated product is put into an atmosphere that has been set lower than the predetermined temperature in advance. Alternatively, a method of raising the temperature to a predetermined temperature and maintaining the predetermined temperature may be used. Alternatively, a method may be used in which the granulated product is put into an atmosphere set in advance at a predetermined temperature and the predetermined temperature is maintained. Among these heating methods The method of raising the temperature of the granulated product to normal temperature power to a predetermined temperature and maintaining the predetermined temperature is particularly preferable because powdering of the granulated product can be further suppressed. Furthermore, the rate of temperature rise when the temperature is raised is not particularly limited.

 [0031] The predetermined temperature in the heating step is preferably 600 to: L100 ° C, particularly preferably 800 to 950 ° C. When the heating temperature is less than 600 ° C, the recovery rate as FeO is low, and when it exceeds 1100 ° C, dust may melt, which is not preferable. Furthermore, in order to recover other metals other than iron as a single metal, when the granulated product containing the reducing agent or the like is subjected to heat treatment, the heating temperature is preferably set to 800 ° C or higher. In addition, if the temperature is high, the heating furnace must have a high heat resistance. In particular, an expensive refractory and a special sealing material for creating a vacuum atmosphere are required. C or less is preferable.

 [0032] The heating time in the heating step is not limited as long as the entire granulated product can be heated to a uniform temperature. The heating time is preferably 30 minutes or more, particularly preferably 30 minutes or more and 6 hours or less. If the heating time is too short, FeO may not be generated sufficiently. On the other hand, if the heating time is too long, the FeO powder tends to agglomerate and the productivity tends to decrease, which is not preferable. The combination of the heating temperature and the heating time is preferably 90 minutes or more when the temperature is 800 to 850 ° C, and 60 hours when the temperature is 850 to 900 ° C. When the temperature is preferably 900 to 950 ° C, the time is preferably 30 minutes or more.

 [0033] 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 powdered by, for example, a stirring means equipped with a stirring blade while moving in the heat treatment furnace. This heat treatment furnace may be equipped with a recovery device for recovering metallic zinc and the like produced by the reduction. The amount of granulated product input to the heat treatment furnace is not particularly limited し Considering heat conduction to the entire granulated product heated in the 1S heat treatment furnace, the average height of the granulated product sprayed on the hearth is Usually, it is preferable that the input amount is 100 mm or less, particularly 80 mm or less, and further 30 mm or less.

[0034] A collector disposed for recovering metallic zinc or the like normally prevents oxidation of metallic zinc or the like. In order to stop or at least suppress acidification, the inside is preferably a vacuum atmosphere. Metal zinc and the like are melted in this collector, and then solidified into an ingot. Ingots are preferable because the recovered metal can be easily handled later.

 The cooling step is a step for holding the FeO powder generated by the heating step as “FeO” powder. In this cooling step, the FeO powder is rapidly cooled in a vacuum atmosphere. The degree of vacuum is preferably 13.3 kPa or less, particularly preferably 6.7 kPa or less, more preferably 1.33 kPa or less (usually 0.133 kPa or more). If the degree of vacuum is low, FeO may be oxidized to Fe 2 O or Fe 2 O or the like. Furthermore, the cooling rate during rapid cooling is 100-45

3 4 2 3

 The temperature can be 0 ° CZ, preferably 200 to 450 ° CZ. If the cooling rate is too small, that is, if it takes a long time to cool down, FeO is oxidized and becomes Fe O or Fe 2 O, etc.

 3 4 2 3

 In this cooling step, it is preferable to cool to 300 ° C. or less, preferably 200 ° C. or less, particularly preferably 150 ° C. or less (usually 100 ° C. or more) under the above conditions.

[0036] In order to increase the recovery rate of FeO powder in the above production method, it is preferable to use a granulated product containing metallic iron. The content of metallic iron is preferably 5% by mass or more, particularly preferably 5 to 85% by mass, and more preferably 8 to 8% when the total amount of iron components contained in the granulated product is 100% by mass. 50% by mass. Thereby, among the powders produced in this production method, the content of FeO powder converted based on the total amount of iron is 80% by mass or more, preferably 85% by mass or more, particularly preferably 90% by mass or more. be able to

[0037] Examples of the raw material constituting the granulated product containing metallic iron as described above include the following. In addition, description of a binder etc. is abbreviate | omitted.

 (1) Forged shot dust collection only,

 (2) Mixture of forged shot dust collection waste and metallic iron such as iron powder (reducing agent)

 (3) Mixture of electric furnace dust and metallic iron such as iron powder (reducing agent)

 (4) Mixture of blast furnace dust and metallic iron such as iron powder (reducing agent)

(5) Converter dust only [0038] Dust cleaning in the dust cleaning step is performed by washing with water. This washing method is not particularly limited. It is sufficient that the chlorine component contained in the dust is sufficiently dissolved and removed in the water during washing, for example, a method of adding water and dust into a container and stirring, and then removing the dust from the container, and For example, water can be continuously flowed into and out of a container filled with dust. In consideration of the amount of water used and the removal efficiency of chlorine, the method of washing in the rotary of the rotary mixer truck is preferred.

 The mass ratio between the dust and the cleaning water, the cleaning time, and the like in the dust cleaning step are not particularly limited.

 [0039] The method for removing the washing water from the dust in the washing water removal step is not particularly limited, and examples thereof include water removal by filtration, filter press, and centrifugation. Among these, a method using a filter press is more preferable.

 It is preferable to reduce the chlorine content in the dust after the washing water removal step to 0.5% by mass or less, particularly 0.4% by mass or less, and further to 0.3% by mass or less. It is more preferable. This dust having a low chlorine concentration makes it difficult for the dust to agglomerate during vacuum heating, thereby preventing the formation of lump dust. In addition, the dust after the washing water removal process may contain moisture, and the remaining moisture can be effectively used in the granulation process. The upper limit of the residual moisture is preferably 20% by mass, particularly preferably 15% by mass, and more preferably 12% by mass when the dust after the washing water removing step is 100% by mass.

 [0040] Further, according to this method for producing FeO powder, it is possible to efficiently produce a large amount of FeO powder by treating iron-containing dust as a recycled raw material. That is, by granulating the dust, uniform heating is performed by the excellent thermal conductivity of the granulated product, and the reaction during vacuum heating proceeds smoothly. Furthermore, FeO produced in the heating process is rapidly cooled under a predetermined pressure of vacuum, so that it can be recovered as FeO without being further oxidized. In other words, FeO can be further oxidized and recovered as FeO without becoming another oxidation state such as Fe 2 O and Fe 2 O. Also granulate

3 4 2 3

By containing a reducing agent such as metallic iron in the product, it is possible to reduce other metal components, for example, acid oxides such as zinc, and recover them as a simple metal in the heating step. [0041] [3] Plant growth promoter

 The ferrous oxide-containing composition of the present invention can be used as a plant growth promoter by blending a substance containing a component chelating iron, that is, a chelating substance. Examples of the components that chelate iron include fulvic acid, and examples of chelating substances containing fulvic acid include humic soil, cow dung, chicken manure, compost, and manure containing cow dung, etc. Can be used. As chelate-containing koji-containing substances, humic soil and cow dung, which are particularly excellent in promoting plant growth, are preferable. This chelate-containing soot substance may be used alone or in combination of two or more.

 When the plant growth promoter is 100% by mass, the total of the ferrous oxide-containing composition and the chelating substance is 85% by mass or more, particularly 90% by mass or more, and further 95% by mass or more (100% by mass) It may be. When the plant growth promoter is used at the seedling stage, the total of the ferrous oxide-containing composition and the chelating substance is 0.1 to 5 when the plant growth promoter is 100% by mass. It is preferable that the content is 5% by mass, particularly 0.5 to 5% by mass, and more preferably 1 to 5% by mass. Furthermore, particularly when used in the seedling raising stage, fertilization is applied to the plant in the immediate vicinity of the seedling, so-called contact fertilization, so that iron can be supplied to the plant extremely efficiently.

 In addition, when the total of the ferrous oxide-containing composition and the chelating substance is 100% by mass, the ferrous oxide-containing composition may be 12-90% by mass, particularly 50-90% by mass. It is preferable. If the content of the ferrous oxide-containing ferrous iron composition is 12 to 90% by mass, plant growth can be sufficiently promoted.

[0042] The plant growth promoter may contain other inorganic components and metals. Inorganic components include iron sesquioxide, iron tetroxide, acid manganese, acid aluminum, silicon oxide, magnesium oxide, titanium oxide, ferrite, calcium sulfate, calcium carbonate, calcium silicate, aluminum silicate, three Examples include acid and antimony. Examples of the metal include iron, manganese, zinc, nickel, copper, calcium, aluminum, molybdenum, and chromium. Moreover, the alloy which has 2 or more types of these metals, or another metal may be contained. Furthermore, carbon, boron, phosphorus, sulfur, etc. may be contained. Each of these inorganic components, metals, alloys, etc. may contain only one type. More than one species may be contained. Furthermore, two or more of inorganic components, metals and alloys may be included. In addition, the shape, size, etc. of each of the inorganic component, metal, alloy, etc. are not particularly limited.

 [0043] When the above-mentioned other components are contained, when the plant growth promoter is 100 parts by mass, the other components are preferably 15 parts by mass or less, particularly 5 parts by mass or less. In addition, when other components are contained, the total content of the ferrous oxide-containing composition and the chelating substance in the plant growth promoter is the property of the medium in which the plant growth promoter is used. It can be adjusted as appropriate according to the type of crop.

 [0044] At the time of use, the plant growth promoter is a mixture of a ferrous oxide-containing composition and a chelating substance.

Can be used. In addition, the ferrous oxide-containing composition and the chelating substance can be mixed in advance before use. When used in pre-mixed prior to use, after the mixing, the temperature 5 to 35 ⁰ C, in Japanese [this 15 to 30 ^o C, at 24-480 [¾, be used after at JP [this 168-240 However, it is preferable because a state in which chelation is sufficiently performed or chelation is likely to occur can be created.

 [0045] This plant growth promoter can sufficiently promote the growth of plants when used in ordinary agricultural land around pH 6.0 in Japan. In addition, pH 7.0 and below 11.0, especially pH 7.5 ~: L 1.0, moreover pH 8.0 ~: L 1.0, use in the saying stomach, norekaji soil, especially norekaji lime soil The plant growth can be sufficiently promoted. Furthermore, even when this plant growth promoter is used in the seedling stage in alkaline soil, the total content of the ferrous oxide-containing composition and the chelating agent in the plant growth promoter should be within the above range. preferable. In particular, when used in the seedling stage, iron can be supplied to plants very efficiently by contact fertilization even in alkaline soil.

[0046] The above alkaline soil refers to 10g of dried soil with 25ml of distilled water, shaken for 1 hour, and when the pH of the resulting suspension is measured, the pH exceeds 7. It means soil. Accordingly, the alkaline soil includes alkaline soil obtained by alkaline conversion of original alkaline soil and non-alkaline soil by, for example, fertilization, desert culturing, or the like. Examples of the above alkaline soil include shell fossil soil, calcareous soil, and soil Examples include soils containing various calcareous components. These may be used alone or in combination of two or more. Furthermore, it is a mixed soil of an alkaline soil containing these various calcareous components and a non-alkaline soil, which includes an alkaline soil as a whole.

[0047] This plant growth promoter can be used for cultivation of various plants. For example, when used for rice, spinach, cabbage, Chinese cabbage, Komatsuna, broccoli, cauliflower, radish, onion, carrot, peanut, sweet potato, potato, watermelon, melon, etc., sufficient growth promoting effect and effect To be played.

 [0048] The amount of the plant growth promoter used is not particularly limited, and should be appropriately adjusted according to the types of plants that grow as described above, the types and amounts of fertilizers used in combination, the types of soil, the pH of the soil, and the like. Is preferred. In addition, it is preferable to appropriately adjust the contents of the FeO powder and the chelating substance in the plant growth promoter.

 Example

 Hereinafter, the present invention will be specifically described with reference to examples.

 [1] Manufacture of ferrous oxide-containing composition

 Example 1

 Electric furnace dust was used as a raw material. This electric furnace dust contains 35.8 mass% Fe, 2.2.7 mass% Zn, 5.95 mass% C, 2.92 mass% Ca, 2.89 mass% Mn and C1 respectively. Si contains 2.16% by mass, Pb contains 1.48% by mass and Cr contains 1.24% by mass. Its average particle size is 10 m. This electric furnace dust 5 tons was washed with a tank charged with 10 tons of water for 1 hour. Thereafter, water was removed with a filter press to obtain a clay-like cake containing 20% by mass of water.

[0050] The cake and the iron powder applied through a 1 mm mesh sieve are put into a mix muller so that the mass ratio of the electric furnace dust and iron powder contained in the cake is 1: 1. Thereafter, alumina cement of 5% by mass of the dry mass of the electric furnace dust (the total of the dry mass of the electric furnace dust and the alumina cement is 100% by mass) was further added. Next, this mixture was kneaded for 1 minute, adjusted to a water content of 10% by mass and discharged. Then, using the discharged mixture, a cylindrical extruder having a diameter of 8 mm and a length of about 20 mm was formed by a vertical extruder. Grained. Next, this granulated product was put in a drying furnace and dried at 400 ° C. for 60 minutes. 410 tons of this granulated product was continuously processed using the equipment shown in Fig. 1.

[0051] Hereinafter, the apparatus of FIG. 1 and the production process of the ferrous oxide-containing composition using this apparatus will be described in detail.

 The granulated product 4 was put into the hopper 11 of the material supply system 1 and replaced with a vacuum atmosphere, and then transferred to the vacuum heating furnace 21 of the vacuum heating system 2. The vacuum heating furnace 21 has four stages of heating chambers 21, each stage is partitioned by a bottom 24, and a heater 25 for heating the granulated product 4 by radiant heat transfer is provided at each stage. In addition, an opening for dropping the granulated product 4 to the lower stage is provided at a predetermined position of the bottom 24. Further, a stirrer 23 is extended through the four-stage heating chamber of the vacuum heating furnace 21. The stirrer 23 includes a shaft 231, a rotating blade 232 attached to the shaft 231, a stirring member 233 disposed so as to extend from the rotating blade 232 toward the bottom 24 of the vacuum heating furnace 21, and a motor 234 Have Then, the rotary blade 232 was continuously rotated by the rotational drive of the motor 234, and the granulated product 4 on the upper surface of the bottom 24 of each stage was stirred. The internal pressure of the vacuum heating furnace 21 is set to 5.3 kPa by a vacuum pump, the heater 251 of the first stage caloric heat chamber 211 is set to 800 ° C, and the heater of the second stage caloric heat chamber 212 is set. 252 is set to 850 ° C, and the temperature of each of the heaters 253, 254, and 255 in the third heating chamber 213, the fourth heating chamber 214, and the heating chamber 215 further below the fourth heating chamber 214 Each was set to 900 ° C.

 [0052] The granulated product 4 was retained with stirring for 30 minutes in each heating chamber while adjusting the rotational speed of the stirrer, and then dropped into the lower heating chamber. Therefore, the granulated product was heated at 800 ° C for 30 minutes, 850 ° C for 30 minutes, and 900 ° C for 1 hour. The granulated product gradually changed to powder by stirring.

Thereafter, the powder produced as described above was discharged to the cooling system 26 by a vacuum atmosphere discharge feeder 22 connected to the vacuum heating furnace 21. Next, this powder was cooled in a cooling system 26 to a temperature of 400 ° C. at a temperature lowering rate of 20 ° C. for 400 ° C. Thereafter, the cooling system 26 was replaced with nitrogen gas, and the system was cooled to 200 ° C at a temperature drop rate of 13 ° CZ. Next, the powder was further cooled, discharged and collected. Zinc was vaporized simultaneously with the above heating and recovered as metallic zinc. [0054] [2] Evaluation of FeO powder

 (l) Evaluation of FeO powder force elution element

 3 g of FeO powder was added to 3 types of pH adjustment solutions adjusted to pH 2.2, 4.2, or 5.0 with hydrochloric acid. After 264 hours, high-frequency inductively coupled plasma emission spectroscopy analysis of this aqueous solution was performed. The eluted elements were quantified. The results are shown in Table 1.

[0055] [Table 1]

[0056] According to the results in Table 1, it can be seen that the elements eluted in large amounts are Ca and A1, and the amounts of Fe and Mg detected at the same time are very small. Since a large amount of Ca and A1 are eluted in this way, it is presumed that the pH of the aqueous solution increases.

[0057] (2) FeO powder and reagent Changes in pH and presence of red rust in a solution of FeO added to water Three types of pH adjusting liquids adjusted to pH 2.2, 4.2 or 5.0 with hydrochloric acid were prepared, and 3 g of FeO powder was added to 30 ml of each pH adjusting liquid. In addition, lg reagent FeO (powder) was added to each of three types of pH adjusting solutions prepared in the same manner. The pH of these solutions was measured after 24 hours and after 96 hours. The results are shown in Table 2. The same measurement was repeated twice for FeO powder, and the results are shown in Table 2.

[0058] [Table 2] Table 2

 [0059] According to the results in Table 2, the pH in the case of FeO powder does not differ greatly depending on the pH of the pH adjusting solution after both 24 hours and 96 hours. 11.0 ~: L1.3, pH after 96 hours is 10.1 ~: L0.8 is high. On the other hand, in the case of the reagent FeO, there is a slight difference in the pH of the solution depending on the pH of the pH adjusting solution.The pH after 24 hours is 5.6 to 6.0, and the pH after 96 hours is 5.0 to 6. It can be seen that 2 and 2 are much lower than those of FeO powder. This result supports the increase in the pH of the solution due to the elution of Ca and A1 in (1) above.

[0060] Further, for each of the FeO powder and the reagent FeO, the occurrence of red rust was observed visually after 24 hours and after 96 hours. As a result, in the FeO powder, no red rust was observed after 24 hours or 96 hours, regardless of the pH of the pH adjusting solution. On the other hand, with the reagent FeO, some red rust was already observed after 24 hours regardless of the pH of the pH adjusting solution, and red rust was observed over the entire surface after 96 hours. Considering these results together with the pH behavior of (2) above, It is inferred that the increase of H to alkalinity suppresses the change of FeO to hydroxy and ferric iron.

[0061] (3) Evaluation of FeO powder by X-ray diffraction

 X-ray diffraction of the granulated product and FeO powder was measured. The X-ray diffraction of the reagent FeO was also measured. The results are shown in FIGS.

 According to Fig. 2 and Fig. 3, the diffraction peak force of CaO in the granulated product disappeared in the FeO powder, while the FeO powder diffraction peak, which was strong in the granulated product, was noticeable in the FeO powder.

 twenty four

 In addition, diffraction peaks such as CaSi 2 O and CaFeSi 2 O are also observed. Thus, Fe

 2 5 2 6

 o It can be seen that the powder contains complex oxides that are strong in the granulated product.

 As shown in FIGS. 11 and 12, the FeO powder was added to the pH adjusting solution, and according to the X-ray diffraction of the FeO powder taken out after a predetermined time, the CaFeSi 2 O diffraction peak disappeared.

 2 6

 ing. From this, Ca also elutes in FeO powder force, and as a result, the pH becomes high and it becomes alkaline, so it is possible to prevent FeO from changing to hydroxide, ferric iron, etc., and no red rust is generated. It is guessed.

 [0062] (4) Change in pH when FeO powder is added to the pH adjustment solution for a long time (no pH adjustment solution replacement)

 Three types of pH adjusting liquids adjusted to pH 2.2, 4.2 or 5.0 with hydrochloric acid were prepared, and 3 g of FeO powder was added to 30 ml of each pH adjusting liquid. In addition, lg reagent FeO (powder) was added to each of three types of pH adjusting solutions prepared in the same manner. The pH of these solutions was determined after 1 day, 4 days, 6 days, 7 days, 8 days and 11 days. Fig. 4 shows the results for FeO powder, and Fig. 5 shows the results for reagent FeO.

 [0063] According to Fig. 4, the FeO powder has the lowest pH, and even when a pH adjusting solution of pH 2.2 is used, the pH after lapse of 11 days is 8.7, and no red rust is generated. It was. On the other hand, according to Fig. 5, with the reagent FeO, the pH after 11 days is 4.9 when the pH adjustment solution of pH 2.2 is used, and 6.2 when the pH adjustment solution of pH 4.2 is used. When pH adjustment solution of pH 5.0 was used, it was 6.3, and red rust occurred regardless of pH of pH adjustment solution after 4 days.

[0064] (5) Changes in pH when FeO powder is added to the pH adjusting solution for a long time (the pH adjusting solution may be replaced) Three types of pH adjusting liquids adjusted to pH 2.2, 4.2 or 5.0 with hydrochloric acid were prepared, and 3 g of FeO powder was added to 30 ml of each pH adjusting liquid. In addition, after 4 days, 6 days, 12 days, and 14 days, the solutions were replaced with unused pH adjusting solutions adjusted to the respective pH values, and the pH values of these solutions were changed to 1, 4, 6 Day, 7th, 8th, 11th, 12th, 13th, 14th, 15th, 18th, 19th, 20th, and 21st days. The result is shown in FIG.

 [0065] According to FIG. 6, when the pH adjusting solution having the lowest pH of 2.2 was used, the pH after 15 days was 3.8, and red rust was generated. On the other hand, when using a pH adjustment solution of pH 4.2 and when using a pH adjustment solution of pH 5.0, the pH rises relatively quickly, and in each case, red rust does not matter regardless of the number of days elapsed. A force that does not occur.

 [0066] (6) Evaluation by scanning electron microscope (SEM) and energy dispersive X-ray analysis (EDX)

 FeO powder was observed by SEM and measured by EDX. In addition, in an experimental example in which red rust was generated after 15 days after adding FeO powder to the pH adjustment liquid adjusted to pH 2.2 in (5) above, the FeO powder taken out from the liquid after 21 days Similarly, it was observed by SEM and measured by EDX. Fig. 7 is an explanatory diagram based on a photograph of FeO powder observed by SEM, and Fig. 8 shows the EDX measurement results of FeO powder. Fig. 9 is an explanatory diagram based on a photograph in which FeO powder was dissolved in a pH adjustment solution and the portion where red rust occurred was observed with an SEM, and Fig. 10 was dissolved in the pH adjustment solution. This is the EDX measurement result of the part where the. Fig. 11 is an explanatory diagram based on a photograph taken by dissolving the FeO powder in the pH adjustment solution and observing the portion where red rust was generated by SEM, and Fig. 12 shows the FeO powder in the pH adjustment solution. This is the EDX measurement result of the part where the melted red rust did not occur.

 [0067] It can be seen from FIGS. 7 and 9 that the outer shape is clearly changed. Also, from Fig. 8 and Fig. 10, when FeO powder is added to the pH adjustment solution, red rust is generated, Ca, A1, etc. are reduced compared to the measurement result of FeO powder that has not been treated at all. This is consistent with the results of Ca, A1, etc. eluting in (1) above. When comparing Fig. 10 and Fig. 12, in Fig. 10, Ca, A1, etc. are slightly smaller than Fig. 12, and the uneven distribution of Ca, A1, etc. affects the occurrence of red rust. It is inferred.

[0068] (7) X-ray diffraction evaluation of FeO powder after addition to pH adjustment solution FeO powder and reagent Each of FeO and FeO powder were added to a pH adjustment solution of pH 2.2 as in (4) above, and the sample after 21 days and FeO powder were adjusted to pH 2. as in (5) above. X-rays of the sample after 21 days, FeO powder added to pH 5.0 pH adjustment solution as shown in (5) above, and the sample after 21 days. Diffraction was measured. The results are shown in Fig. 13. Add reagent FeO to pH 2.2 pH adjustment solution as shown in (4) above, and add sample and reagent FeO after 11 days to pH 5.0 pH adjustment solution as shown in (4) above. Each sample after 11 days was measured for X-ray diffraction. The results are shown in FIG.

[0069] According to FIG. 13, in the FeO powder, FeO is the main component, and in addition, Fe, FeAl 2 O and

 twenty four

Existence of CaAl 2 O and the like was confirmed. On the other hand, according to FIG. 14, the reagent FeO is mainly composed of FeO.

twenty four

 In addition to these, the presence of Fe, Fe 2 O, Fe (OH), etc. was confirmed. in this way,

 3 4 3

 It has been confirmed that the FeO powder contains the reagent FeO but does not contain a specific complex oxide!

 [0070] [3] Action and effect of ferrous oxide-containing composition as plant growth promoter

 Experimental example 1

 FeO powder and humus (Ueda Forestry Co., Ltd., trade name “Kutsuki Bark”) were mixed at a mass ratio of 3: 1 to produce a plant growth promoter. Hereinafter, this is referred to as “soil-type growth promoter”. The soil type growth promoter was allowed to stand for 240 hours at a temperature of 25 to 35 ° C. and then subjected to a cultivation experiment.

[0071] Cultivation experiment 1

 A sandy field in Shonan City, Aichi Prefecture was selected as the experimental site. A cultivation section of 1.2 X 30m was set on a field of about 10a, and 45 kg of the soil type growth promoter produced in Experimental Example 1 was evenly sprayed on the entire surface of the plot, and after curing, it was cured for one week. Thereafter, commercially available fertilizer was evenly applied to the entire surface of the cultivation plot so that N8kg, PI 2kg, and K8kg per 10a were cultivated. Next, cocoons were created, and in September, radish seedlings (variety “Kashige”) were planted. Harvesting took place in November.

 As a control plot, radish seedlings were planted and harvested in the same manner except that the soil type growth promoter was not sprayed on adjacent plots.

[0072] Radish harvested from cultivated plots sprayed with soil type growth promoter (total number is 65) . ) And 10 radishes of average size were selected for each of the radish (the total number was 65) from which the control power was also harvested, and the weight of each was measured. As a result, the average value of 10 radish harvested from the cultivation plot sprayed with the soil type growth promoter was about 3000 g. On the other hand, the average value of 10 radish harvested from the control plot was about 600 g. The radish harvested from the cultivation plots sprayed with the soil type growth promoter in this way weighs about five times as much as the radish harvested from the control plot, and the growth promotion is sufficiently promoted by the soil type growth promoter. ! / I can see you talking.

[0073] Cultivation experiment 2

 In a sandy field of approximately 10a area in Shonan-an, Aichi Prefecture, a 1.2 × 30m cultivation plot was established, and 45 kg of the soil type growth promoter produced in Experiment 1 was evenly sprayed and mixed over the entire plot. After that, it was cured for one week. Thereafter, the mashed lime was evenly spread in advance over the entire surface of the cultivation section, and then compost and fertilizer were applied evenly over the entire surface of the cultivation section and cultivated. Then, in September, planted potato seedlings (variety “Digima”). Harvesting took place in December. As a control plot, potato seedlings were planted and harvested in the same manner except that the soil type growth promoter was not sprayed on the adjacent plot.

 [0074] For each of the potatoes harvested from the cultivation plots sprayed with a soil type growth promoter (total number is 50) and the potatoes that also harvested the control plot power (total number is 50). Ten potatoes of average size were selected for each and weighed. As a result, the average value of 10 potatoes harvested from the cultivation plot sprayed with the soil type growth promoter was approximately 135 g. On the other hand, in the potato that also harvested the control power, the average value of 10 was about 100 g. The potato harvested from the cultivation section sprayed with the soil type growth promoter in this way has a weight about 1.3 times that of the potato harvested from the control zone, and the growth is sufficiently promoted by the soil type growth promoter. I can see that

 [0075] Cultivation experiment 3

In a sandy field of approximately 10a area in Shonan-an, Aichi Prefecture, a 1.2 × 30m cultivation plot was established, and 45 kg of the soil type growth promoter produced in Experiment 1 was evenly sprayed and mixed over the entire plot. After that, it was cured for one week. After that, spread allergen lime on the entire surface of the cultivation area in advance, and then add commercially available fertilizer to the cultivation area so that N, P and K are 8kg per 10a. The entire surface was evenly fertilized and cultivated. Then, in September, planted carrot seedlings (variety “Kurei”). Harvesting took place on December 24 and on January 10 of the following year, 17 days later.

 As a control plot, carrot seedlings were planted in the same manner except that the soil type growth promoter was not sprayed on adjacent plots, and harvested twice in the same manner.

[0076] Carrots harvested from the cultivation plot sprayed with the soil type growth promoter (total number of each at the time of two harvests is 50) and carrot harvested from the control plot (at the time of two harvests) The total number of each was 50.) For each of them, 10 carrots of average size were selected and their weights were measured. As a result, the average value of 10 ginsengs was approximately 260 g for the ginseng that had also been harvested on December 24. On the other hand, for the carrots harvested from the control plot, the average value of 10 was about 170 g. In addition, when harvested on January 10, the average value of carrots collected from the cultivation plots sprayed with the soil type growth promoter was about 350 g. On the other hand, the average value of carrots harvested from the control area was about 270 g. In this way, the carrots harvested from the cultivation plot sprayed with the soil type growth promoter have a weight about 1.3 times that of the carrot harvested from the control plot, and the growth is sufficiently promoted by the soil type growth promoter. I understand that.

 In addition, the carrots harvested from the cultivation plots sprayed with the soil type growth promoter on December 24 had the same weight as the carrots that also harvested the control plots 17 days later. It can be seen that the growth is sufficiently promoted by the type growth promoter.

 In addition, Fig. 15 shows the results of a reference example comparing carrots harvested from other plots in the same manner and carrots harvested from the control plot. This FIG. 15 also reveals the action and effect of the growth promotion of the soil type growth promoter.

[0077] Cultivation experiment 4

In a clay field of approximately 10a in Aku-cho, Chita-gun, Aichi Prefecture, a 1.2 × 30m cultivation plot was established, and 45 kg of the soil type growth promoter produced in Experimental Example 1 was evenly sprayed over the entire plot. After mixing, it was cured for 1 week. After that, organic lime and clay lime are spread evenly over the entire cultivation area in advance, and after 1 week, the fertilizer for beans and beans is cultivated so that N4kg, PI lkg, K15kg, Mglkg and BO. Fertilized evenly over the entire area of the plot. Later, in July, planted a sweet potato seedling (variety “Red East”). Harvesting took place in November. As a control plot, sweet potato seedlings were planted and harvested in the same manner except that the soil type growth promoter was not sprayed on the adjacent plots.

 [0078] For each of the sweet potatoes harvested from the cultivation plot sprayed with the soil-type growth promoter (total number is 120) and the sweet potatoes that also harvested the control power (total number is 120), average. Three sweet potatoes of various sizes were selected, and the weight of each was measured. As a result, the average value of the three pieces of the sweet potato harvested from the cultivation plot sprayed with the soil-type growth promoter was about 86 lg. On the other hand, for the sweet potato harvested from the control plot, the average value of the three was about 37 lg. The sweet potato harvested from the cultivation section sprayed with the soil type growth promoter in this way has a weight about 2.3 times that of the sweet potato harvested from the control plot. It is divided that is done.

 [0079] In addition, one of each of the sweet potatoes harvested from each of the cultivated plot and the control plot was selected to have an average size, and the sugar content was determined using a non-sugar sugar meter (manufactured by Shimadzu Corporation). , Model “AMY-1”). As a result, the sugar content of the sweet potato harvested from the cultivation plot was 12.5, and the sugar content of the sweet potato harvested from the control plot was 11.3. As described above, the sugar content of the sweet potato harvested from the cultivated plot was about 1.11 times higher than that of the harvested sweet potato.

 [0080] Cultivation experiment 5

 In a clay field of approximately 10a in Aku-cho, Chita-gun, Aichi Prefecture, a 1.2 × 30m cultivation plot was established, and 45 kg of the soil type growth promoter produced in Experimental Example 1 was evenly sprayed over the entire plot. After mixing, it was cured for 1 week. After that, organic lime and clay lime are spread evenly over the entire cultivation area in advance, and after 1 week, the fertilizer for beans and beans is cultivated so that N4kg, PI lkg, K15kg, Mglkg and BO. Fertilized evenly over the entire area of the plot. After that, in May, planted peanut seedlings (variety “Shariki”). Harvesting took place in October. As a control plot, peanut seedlings were planted and harvested in the same manner except that the soil type growth promoter was not sprayed on adjacent plots.

[0081] For each of the peanuts harvested from the cultivation plots sprayed with the soil-type growth promoter (total number is 30), and the peanuts that were also harvested from the control plot (total number is 30). Select 10 peanuts each with an average yield and measure the weight excluding leaves, roots and stems. It was. As a result, in peanuts harvested from cultivation plots sprayed with soil type growth promoters

The average value of 10 strains was about 320 g. On the other hand, the average value of 10 strains of peanuts harvested from the control group was about 220 g. In this way, peanuts that have also been harvested with cultivation type power spread with a soil type growth promoter weigh about 1.45 times the peanuts harvested from the control zone, and are sufficiently promoted by the soil type growth promoter. I understand that.

 In addition, Fig. 16 shows the results of a reference example comparing peanuts harvested by cultivating plotting force and peanuts harvested by control plotting force in other cultivation experiments conducted in the same manner. Also from FIG. 16, the action and effect of the growth promotion of the soil type growth promoter is clear.

[0082] Cultivation experiment 6

Select a 0.7 x 20m area in the same field as the cultivation experiment 1 (sandy soil), and the soil type growth promoter produced in Experiment 1 in the 0.7 x 10m section on the south side 2.1 kg ( (Approx. 300gZm ² equivalent) was sprayed and used as a cultivation section. In addition, a soil type growth promoter was not sprayed on the 0.7 × 10m section on the north side, and this section was used as a control section. After that, soil and soil type growth promoter were mixed and cultivated for 1 week in the cultivation section. Next, commercially available fertilizer was uniformly applied to the entire surface of the cultivation plot so that N8kg, PI 2kg, and K8kg per 10a were cultivated. After that, rice cakes were cultivated in each of the cultivation and control plots and seeded with Chinese cabbage in July. Harvesting took place on November 5th and on December 5th, one month later.

[0083] Chinese cabbage harvested from cultivation plots sprayed with a soil type growth promoter (total number of each at the time of two harvests is 20) and Chinese cabbage harvested from the control plot (two harvests) The total number of each time is 20.) For each of the three times, we selected three Chinese cabbages of average size and weighed each one. As a result, the average value of the three Chinese cabbages harvested on November 5 was also about 1900 g. On the other hand, the average value of three Chinese cabbages harvested from the control group was approximately 800 g. In addition, when harvested on December 5, the average value of the three Chinese cabbages harvested from the cultivation plots sprayed with the soil type growth promoter was about 2800 g. On the other hand, the average value of the three Chinese cabbages harvested from the control plot was about 1600 g. The Chinese cabbage harvested from the cultivation plots sprayed with the soil type growth promoter in this way weighs about 1.7 to 2.4 times the Chinese cabbage harvested from the control plot. It can be seen that growth is being promoted. In addition, the Chinese cabbage harvested from the cultivation section sprayed with the soil type growth promoter on November 5th has a weight about 1.2 times that of the Chinese cabbage harvested from the control plot power one month later. It can be seen that the growth is sufficiently promoted by the soil type growth promoter.

 [0084] In addition, from each of the Chinese cabbages that were also harvested in each of the cultivation and control plots, three samples of approximately the same size were each selected as a sample, and the chlorophyll meter (model "SPAD-" manufactured by Minolta Co., Ltd.) was selected. 502 ”), the amount of chlorophyll was evaluated using the green density (SPAD value) as an index. As a result, when the soil type growth promoter was used, the average value of 3 was 38, while the average value of 3 was 33 in the control plot. Thus, the amount of chlorophyll increased in the Chinese cabbage in the cultivation section using the plant growth promoter of the present invention.

 In addition, Fig. 17 shows the results of a reference example comparing Chinese cabbage harvested from the cultivation plot and Chinese cabbage harvested from the control plot in other cultivation experiments conducted in the same manner. This FIG. 17 also reveals the action and effect of the growth promotion of the soil type growth promoter.

 [0085] Cultivation experiment 7

 Komatsuna was cultivated in the same manner as in cultivation experiment 6 except that the seeds were sown in December and harvested on February 4.

[0086] For each of Komatsuna (26 in total) harvested from cultivation plots sprayed with a soil-type growth promoter, and Komatsuna (26 in total) from which control force was also harvested. Ten komatsuna of average size were selected for each and weighed. As a result, the average value of Komatsuna harvested from the cultivation plot sprayed with soil type growth promoter was about 24 g. On the other hand, for Komatsuna, which also harvested the control power, the average value of 10 was about 19g. Komatsuna harvested from the cultivation plots sprayed with the soil type growth promoter in this way has a weight about 1.3 times that of the harvested komatsuna, and the soil type growth promoter can sufficiently promote growth. You can see that it has been done. In addition, each sample of Komatsuna harvested from each of the cultivation plot and the control plot is selected as a sample, one by one, and the amount of chlorophyll is green as in the case of cultivation experiment 6. The concentration (SPAD value) was evaluated as an index. As a result, it was 40 when the soil type growth promoter was used, compared with 36 in the control plot. Thus, the amount of chlorophyll was increased in Komatsuna in the cultivation section using the plant growth promoter of the present invention. [0087] Cultivation experiment 8

 Spinach was cultivated in the same way as in the cultivation experiment 6 except that seeds of spinach were planted in December and harvested on February 4.

 [0088] For each spinach harvested from the cultivation plot sprayed with the soil-type growth promoter (total of 20) and spinach that also harvested the control power (total of 20), average Six spinach plants each were selected and their weights were measured. As a result, the average value of 6 spinach harvested from the cultivation plots sprayed with a soil type growth promoter was approximately 44 g. On the other hand, the average value of the 6 spinach harvested from the control group was about 30g. The spinach harvested from the cultivation plot sprayed with the soil type growth promoter in this way has a weight about 1.5 times that of the spinach harvested from the control plot, and the growth promotion is sufficiently promoted by the soil type growth promoter. I understand that. In addition, three samples of approximately the same size were selected from the harvested spinach in each of the cultivation and control plots, and the amount of chlorophyll was measured in the same way as in cultivation experiment 6 (SPA). D value) was evaluated as an index. As a result, when the soil type growth promoter was used, the average value of the three was 38, while the average value of the three was 36. Thus, the amount of chlorophyll was increased in Komatsuna in the cultivation section using the plant growth promoter of the present invention.

 [0089] Cultivation experiment 9

Select a 20 x 20m area in the same field as the cultivation experiment 1 (sandy soil), divide it into two east and west areas, and 15kg (about 113 kg) of the soil type growth promoter produced in Experiment 1 in the eastern section. gZm ² equivalent) was sprayed, and this section was used as a cultivation section. In addition, no soil type growth promoter was sprayed on the western section, and this section was used as a control section. After that, commercially available fertilizer was evenly fertilized and cultivated on the entire surface of each of the cultivation plot and the control plot so that N14kg, P21kg and K18kg per 10a. Next, in June, mussel melon seedlings were planted in each of the cultivation plot and the control plot. In mid-August, 10 melons were harvested from each of the cultivation and control plots. Thereafter, one of the average size was selected from 10 melons, and the sugar content was measured in the same manner as described above. As a result, in the melon harvested from the cultivation plot, the sugar content near the outer skin was 15.8 and the sugar content in the center was 16.4. On the other hand, contrast In the harvested melon, the sugar content near the outer skin was 14.0 and the sugar content in the center was 15.2. In this way, the melon harvested with cultivated plot power improved the sugar content by about 1.13 times in the vicinity of the hull and about 1.08 times in the center compared to the melon harvested by the control plot.

[0090] Cultivation experiment 10

 Broccoli 1 (varieties are pixels) was cultivated with pot seedlings in Takamatsu-nada, Kagawa Prefecture. Seedlings were purchased from seedling suppliers on April 10. When using 5g of soil type growth promoter manufactured in Experimental Example 1 mixed with 5g / l of commercially available seedling cultivation soil as cultivated soil (Test Example 1), 10g of cultivated soil was used. In the case (Test Example 2), when the soil type growth promoter was mixed, and the cocoon cultivated soil was used (Comparative Test Example), it was examined whether there was a difference in the growth of broccoli. After planting the purchased seedlings in each of Test Example 1, Test Example 2 and Comparative Test Example in 5 pots for 1 month, the fresh weight of the above-ground part of 15 pots of broccoli When weighed, the average value of Test Example 1 was 10.7 g, Test Example 2 was 22. Og, and Comparative Test Example was 9.4 g. In Test Example 1, the power was increased 1.1 times compared to the Comparative Test Example. In Test Example 2, the calorie content increased 2.4 times compared to the Comparative Test Example. When the dry weight of the roots was measured, the average values were 5.lg for Test Example 1, 6.2g for Test Example 2, and 4.6g for Comparative Test Example, and 1. It increased by a factor of 1, and in Test Example 2, it increased by 1.4 times compared to the Comparative Test Example. As described above, it was confirmed that the plant growth promoter of the present invention increased the roots, and as a result, the plant growth was promoted.

[0091] Cultivation experiment 11

 At Takamatsu Pass in Kagawa Prefecture, on June 10, 130g of paddy rice seeds were sown and nurtured in a commercial rice planting nursery tray, and planted on July 1. This field is clayey and pre-applied with commercially available fertilizer on June 3 at N8kg per Oa, PI 2kg and K8kg. In addition, a 3.3m x 9.6m section was provided for each of the test section and the comparative test section, and about 540 seedlings were planted in each section (3 seedlings were planted in one bundle. ) O At the time of planting, 15 g of soil type growth promoter was mixed in the test plot so that it would be in direct contact with the seedling roots.

On July 21st, 45 units were randomly selected for each plot in the test plot and comparative test plot, for a total of 270 The growth status of the book seedlings was confirmed. As a result, the number of tiller bundles was 14 in the comparative test group, whereas the number of tillers increased to 17 in the test group. In addition, the leaf length of the seedlings was 36 cm in the comparative test group, while it was 39 cm in the test group, growing larger.

 Cultivation experiment 12

 A field test was conducted to investigate the growth of paddy rice in alkaline soil. In the test, soil with NPK administered (black 6.4; black botanous soil), which is representative of Japanese soil, and soil with contact fertilization of NPK-only fertilizer that does not contain trace elements in calcareous soil ( pH 9.3; Long treatment zone), soil obtained by contact fertilization with calcined alkaline soil coated fertilizer containing NPK and trace elements (PH9.3; Long Total treatment zone), soil type manufactured in Experimental Example 1 in calcareous alkaline soil The experiment was conducted in 1 district and 3 districts using soil containing a growth promoter (PH9.3; seedling box treatment district).

 As a result of conducting the field test as described above,

When the rice cultivar is “Moonlight”, the number of panicles is 268 Zm ² in the Black Soil District, 0 in the Long Treatment Zone, 254 Zm ² in the Long Total Treatment Zone, and 302 in the Seed Box Treatment Zone. It was Zm ^2. The number of pods per spike was 89.8 in the Black Bota soil zone, 0 in the Long treatment zone, 65.7 in the Long Total treatment zone, and 90.3 in the seedling treatment zone. Yield per 10a was 545.8 kg in the Black Bota soil area, Okg in the Long treatment area, 368.7 kg in the Long Total treatment area, and 592.4 kg in the seedling box treatment area.

If rice cultivars is "Sasa two Shiki", panicle number, 321 present in the black button soil ku / m ^2, Long treatment 0 present at sense Ward Zm ^2, Long Total treatment group at 331 Zm ^2, seedling box treatment It was 463 Zm ² in the ward. The number of pods per spike was 81.6 in the Black Bota soil, 0 in the Long treatment, 68.1 in the Long Total treatment, and 88.1 in the seedling treatment. Yield per 10a was 529.3 kg in the Black Bota soil zone, Okg in the Long treatment zone, 467.9 kg in the Long Total treatment zone, and 729.2 kg in the seedling box treatment zone.

In this way, paddy rice did not grow at all in the Long treatment area, which was fertilized by applying iron as a trace element. In the Long Total treatment area, although the growth of paddy rice was observed, the number of pods and yield per spike were considerably inferior to those of the Black Bota soil area. Meanwhile, soil Thailand In the seedling box treatment area containing the growth promoter, the number of spikes, the number of pods per spike and the yield per 10a are all significantly higher than the black botany, although there are some differences in rice varieties. Has been promoted.

 It should be noted that the present invention is not limited to the above-described embodiments, and various modifications can be made within the scope of the present invention in accordance with the purpose, application, and the like. For example, the dust cake and the reducing agent can be mixed using a mixer such as an Eirich backflow type high-speed mixer. In addition, this plant growth promoter provides a continuous supply of divalent iron ions directly to plant root cells even under alkaline soil conditions. When fertilizer is directly fertilized, the effect of increasing the greenness of the leaves from the initial growth stage is achieved. In addition, plant growth promoters are used by being applied to the soil, and the plant grows by immersing the plant growth promoter in water, especially in the case where the plant takes root force in the underground part and takes in divalent iron ions. Even when a liquid mainly composed of divalent iron ions is used as an iron-based foliar spraying agent for fruit and flower buds, the divalent iron ions can be absorbed directly into the cell through the above-ground tissue force. As a result, the underground force exerts the action and effect of promoting growth in the same way as when iron ions are taken in.

Claims

The scope of the claims

 [I] ferrous oxide and a complex oxide, the complex oxide having at least one element of Ca, A1, and Mg Iron-containing composition.

 [2] The ferrous oxide-containing ferrous oxide composition according to claim 1, wherein the composite oxide further includes at least one of Fe and Si.

 [3] The composite oxide includes CaAl O, FeAl O, MgAl O, CaFeSi O, MgFeSi O,

 2 4 2 4 2 4 2 6 2 6

Less of CaSi O, MgSi O, CaFe O, MgFe O, CaFeO and MgFeO

2. The composition containing ferrous oxide according to claim 1, wherein both of 2 5 2 5 2 4 2 4 2 2 are one kind.

[4] The above composite oxide is at least one of CaAl 2 O, FeAl 2 O, CaFeSi 2 O and CaSi 2 O.

 2 4 2 4 2 6 2 5

 2. The ferrous oxide-containing composition according to claim 1, wherein both are one kind.

[5] The acid solution according to claim 1, wherein the total amount of the ferrous oxide and the composite oxide is 65 parts by mass or more when the ferrous oxide-containing composition is 100 parts by mass.匕 A composition containing ferrous iron.

[6] The oxidizer according to claim 1, wherein the total amount of the complex oxide is 0.5 to 10% by mass when the total of the ferrous oxide and the complex oxide is 100% by mass. Iron-containing composition.

[7] The ferrous oxide-containing composition was added to a hydrochloric acid aqueous solution with a hydrogen ion index of 2.2 to a mass ratio of 10% by mass, and the hydrogen ion index measured after 24 hours was 8.0 to 2. The ferrous oxide-containing composition according to claim 1, which has a hydrogen ion exponent of 7.5 to 11.0 measured after 264 hours.

[8] A1 and Ca contained in an aqueous solution prepared by adding the ferrous oxide-containing composition to a hydrochloric acid aqueous solution with a hydrogen ion index of 2.2 to a mass ratio of 10% by mass for 264 hours When quantified later, A1 content power is S70 ~ 130mgZ liter, Ca content is 90 ~ 1

2. The ferrous oxide-containing composition according to claim 1, which is 70 mgZ liter.

[9] The dust containing iron is granulated into a granulated product, and then the granulated product is heated under vacuum to change the iron contained in the granulated product to FeO, and then containing the FeO. The ferrous oxide-containing composition according to claim 1, obtained by rapidly cooling the powder to be cooled under vacuum.

[10] A plant growth promoter comprising the ferrous oxide-containing composition according to claim 1 and a chelating substance.

[II] When the plant growth promoter is 100% by mass, the ferrous oxide-containing composition and the above 11. The plant growth promoter according to claim 10, wherein the total amount with the chelating substance is 85% by mass or more.

 [12] When used at the seedling stage and the plant growth promoter is 100% by mass, the total of the ferrous oxide-containing composition and the chelating agent is 0.1-5% by mass. The plant growth promoter according to claim 10.

[13] The plant growth promoter according to claim 12, which is used by contact fertilization.

[14] The plant growth promoter according to claim 10, wherein the chelated rice bran substance is at least one of humus and cow dung.

[15] The plant growth promoter according to claim 10, which is used in al-grid soil.

[16] The total of the ferrous oxide-containing composition and the chelating substance used is 0.1 to 5% by mass when used at the seedling stage and the plant growth promoter is 100% by mass. The plant growth promoter according to claim 15.

17. The plant growth promoter according to claim 16, which is used by contact fertilization.