JP2013086981A - System and method for producing phosphatic fertilizer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a system for producing a phosphatic fertilizer having high energy efficiency and high production efficiency, and a method for producing a phosphatic fertilizer having high citrate solubility of phosphoric acid and high solubility of silicic acid.SOLUTION: A system for producing a phosphatic fertilizer or the like includes at least a raw material mixing means for obtaining a mixed raw material by mixing sewage sludge and/or originator thereof and a calcium source, and an incineration calcination means for obtaining a phosphatic fertilizer by performing incineration and calcination continuously to the mixed raw material. In a method for producing a phosphatic fertilizer or the like using the system for producing the phosphatic fertilizer, an incineration temperature is 700-1,000°C and a calcination temperature is 1,150-1,350°C in the incineration calcination means.

Description

  The present invention relates to a phosphate fertilizer manufacturing system and manufacturing method using sewage sludge and / or a derivative thereof as a raw material.

Traditionally, Japan has relied on imports for almost all the amount of phosphorus because it does not produce phosphorus as a natural resource. However, in recent years, natural phosphorus resources have been depleted worldwide, and the price of phosphorus has soared, making it difficult to secure phosphorus. Therefore, in the field of manufacturing phosphate fertilizers, sewage sludge containing a large amount of phosphorus and its derived substances are considered as a supplement or substitute for natural phosphorus resources. Here, examples of the derived material include dehydrated sludge, dried sludge and carbonized sludge obtained by treating sewage sludge.
By the way, in Japan, the derived substances are currently generated in a large amount of about 9 million tons / year, and in order to reduce the volume, they are usually incinerated. It reaches 300,000 tons / year. In recent years, the final disposal site used for incineration of incineration ash has become tight, and the treatment of incineration ash has become a further issue.
Therefore, the technology that uses sewage sludge and / or its derived material (hereinafter referred to as “sewage sludge”) as a raw material for fertilizers is a social issue of final disposal of sewage sludge in addition to the problem of depletion of natural phosphorus resources. It is also extremely important as a means of responding to requests.

In response to this situation, several methods for effectively using sewage sludge as phosphate fertilizer have been proposed.
For example, in Patent Document 1, slurry sludge generated when purifying sewage or the like is concentrated and dewatered, and the dewatered sludge is melted and then cooled and solidified, or the dewatered sludge is incinerated. There has been proposed a method for producing dissolved phosphorus fertilizer (sludge melt solidified body) by melting incinerated ash and then solidifying by cooling.
Patent Document 2 also uses incinerated ash generated by concentrating and dewatering sludge sludge generated when purifying sewage, etc., and incinerating the dewatered sludge in the presence of a desulfurizing agent (CaO, etc.) as a raw material. A method has been proposed in which MgO or the like is added to the raw material, melted at 1350 ° C. or higher in an oxidizing atmosphere, and then cooled and solidified to produce a fertilizer (melted solid).

JP 09-328384 A JP 2003-145093 A

However, since any manufacturing method uses a melting method, energy consumption due to melting is large, and continuous production is not possible. In addition, there is no description on energy saving or productivity improvement means.
In addition, in sewage sludge, dehydrated cake, and the like, there is a problem in the effective use of energy that the thermal energy generated in the incineration process is not effectively used in the subsequent fertilizer process.
Accordingly, an object of the present invention is to provide a phosphate fertilizer manufacturing system and method using sewage sludge and the like as raw materials and having high energy efficiency and production efficiency.

  As a result of intensive studies to achieve the above-mentioned object, the present inventor, as a raw material, sewage sludge, etc., a means for mixing a calcium source to obtain a mixed raw material, and continuously incinerating and firing the mixed raw material And the phosphate fertilizer manufacturing system including at least a means for obtaining the phosphate fertilizer is higher in energy efficiency and production efficiency than the melting method, and effectively uses the energy used for firing. The present invention has been completed.

That is, the present invention provides the following [1] to [12].
[1] Raw material mixing means for obtaining a mixed raw material by mixing sewage sludge and the like with a calcium source, and incineration baking for obtaining a phosphate fertilizer by continuously incinerating and firing the mixed raw material And a phosphate fertilizer production system.
[2] The phosphate fertilizer manufacturing system according to [1], wherein the raw material mixing unit includes a granulation forming unit for granulating or forming the mixed raw material.
[3] The incineration and firing means is a chlorination and volatilization means for volatilizing and removing heavy metals, a chlorine bypass means for removing chlorine, a reduction and firing means for removing heavy metals by firing in a reducing atmosphere, and The phosphate fertilizer production system according to [1] or [2], further including at least one means selected from calcining means for calcining the mixed raw material.
[4] The phosphoric acid fertilizer manufacturing system according to any one of [1] to [3], wherein the incineration and firing means is a fluidized bed incinerator and the firing means is a rotary kiln.
[5] Furthermore, when the raw material is sewage sludge and / or dewatered sludge, the method according to any one of [1] to [4], further including a drying means for drying the raw material or the mixed raw material. Phosphate fertilizer production system.

[6] The phosphate fertilizer manufacturing system according to [5], wherein the drying means includes granulation molding means for granulating or molding the raw material or the mixed raw material.
[7] The above [5] or [6], wherein in the drying means, heat of exhaust gas generated in the incineration and firing means is used as a part or all of heat for drying the raw material or the mixed raw material. Phosphate fertilizer manufacturing system.
[8] Any one of the above [1] to [7], wherein the calcium source is added in at least one means selected from the drying means, the raw material mixing means, and the incineration firing means. The manufacturing system of the phosphoric acid fertilizer of clause.
[9] The phosphate fertilizer according to any one of [1] to [8], further including an exhaust gas treatment means for treating exhaust gas generated in the incineration and firing means and / or the drying means. Manufacturing system.
The exhaust gas generated in the drying means is a gas containing water vapor.
[10] The phosphate fertilizer manufacturing system according to any one of [1] to [9], wherein the exhaust gas treatment unit includes an exhaust gas quenching unit for rapidly cooling the exhaust gas.
[11] A method for producing phosphate fertilizer using the phosphate fertilizer production system according to any one of [1] to [10], wherein the incineration temperature in the incineration and firing means is 700 to 1000 ° C. And the manufacturing method of phosphoric acid fertilizer whose baking temperature is 1150-1350 degreeC.
[12] The phosphoric acid according to [11], wherein the mixed raw material prepared so that the CaO content in the phosphate fertilizer is 30 to 55% by mass is incinerated and calcined at the incineration temperature and the calcining temperature. Fertilizer manufacturing method.

  The phosphate fertilizer manufacturing system of the present invention has high energy efficiency and production efficiency. Moreover, according to the manufacturing method of the phosphate fertilizer of this invention, the phosphate fertilizer with the high solubility rate of phosphoric acid and the solubility rate of a silicic acid can be manufactured.

It is a conceptual diagram which shows an example of the manufacturing system of the phosphate fertilizer of this invention.

As described above, the phosphate fertilizer manufacturing system of the present invention includes the raw material mixing means and the incineration firing means as essential means, and further includes a drying means, an exhaust gas treatment means, and the like as optional means. Moreover, the manufacturing method of the phosphate fertilizer of this invention is a manufacturing method using the manufacturing system of the said phosphate fertilizer, Comprising: An incineration temperature and a calcination temperature are in a specific range.
Hereinafter, the present invention will be described in detail for each component of the invention described in [1] to [12].

1. Phosphate fertilizer manufacturing system (1) Raw material mixing means The means is a means for preparing a mixed raw material by mixing raw material sewage sludge and the like with a calcium source. Specifically, a mixer, Examples thereof include a kneader and air blending. In general, since sewage sludge has a low calcium content, it is necessary to mix calcium sources to supplement calcium in the phosphate fertilizer. If the calcium content in the phosphate fertilizer is within the above range, phosphorus There exists a tendency for the solubility of phosphoric acid in acid fertilizer and the solubility of silicic acid to become high.

Here, as a method for adding sewage sludge and the calcium source, in addition to adding the calcium source to the sewage sludge, the sewage sludge may be added to the calcium source. In addition to the addition of phosphate fertilizer at the manufacturing plant, each process of inflow water treatment or sewage sludge concentration, mixing, digestion, dehydration, drying, incineration, etc. performed in a sewage treatment plant. You may carry out before and after. Mixing of sewage sludge with a high water content and calcium source is relatively easy, and since a homogeneous mixed raw material is obtained, the raw material mixing means can be simplified and the energy efficiency and production of the manufacturing system can be achieved. Efficiency can be improved.
The calcium source may be added in at least one means selected from the raw material mixing means, drying means, and incineration firing means.

  Further, the raw material mixing means preferably has a granulating and forming means for granulating or forming the mixed raw material. Sintering of the granulated product or molded product of the mixed raw material is excellent in producing a stable fertilizer, and can increase the energy efficiency and production efficiency of the production system. Examples of the granulating and forming means include a bread pelletizer, a bread type mixer, a stirring granulator, a briquette machine, a roll press, and an extrusion molding machine. During granulation molding, excipients such as bentonite, cement, solidifying material, thickener, etc. are added, and other fertilizer components such as potash and magnesium are newly added according to the use of fertilizer. It may be added.

Next, the sewage sludge and the calcium source will be described.
(I) Sewage sludge, etc. (sewage sludge, its origin)
Examples of the sewage sludge include at least one selected from sewage sludge, dewatered sludge, dried sludge, and carbonized sludge.
The sewage sludge is a mud containing organic matter and inorganic matter obtained by separating from sewage by sedimentation or filtration in the process of treating sewage such as sewage or drainage in a sewage treatment plant. Sewage sludge also includes digested sludge obtained by microbial treatment (digestion) of the sludge under anaerobic conditions. Further, generally, in a sewage treatment plant, sewage is first led to a sedimentation basin, sedimented sediment and solids in the sewage and primarily separated, then aerated in an aeration facility, and further led to a final sedimentation basin. Separation of sewage sludge is performed by precipitating sludge remaining in each sedimentation basin and filtering.

Here, the dewatered sludge is a sludge having a water content of about 70 to 90% by mass obtained by dewatering sewage sludge by centrifugation or the like. The dewatered sludge may be included in the sewage sludge as a kind of sewage sludge, but in the present invention, the dewatered sludge is handled separately from the sewage sludge.
The dried sludge is a sludge having a water content of approximately 50% by mass or less, obtained by drying the sewage sludge or dewatered sludge by sun drying or drying.
The carbonized sludge is obtained by heating sewage sludge, dewatered sludge, or dried sludge so that part or all of the organic matter contained therein is converted to carbide. The heating temperature is generally 200 to 800 ° C. in a low oxygen state. Since the carbonized sludge becomes a part of the fuel in the production (calcination) of phosphate fertilizer in addition to the raw material, the energy required for the calcination can be saved correspondingly.

(Ii) Calcium source The calcium source is used to adjust the CaO content in the phosphate fertilizer to be within the specific range. As calcium sources, for example, calcium carbonate, calcium oxide, calcium hydroxide, calcium phosphate, calcium chloride, calcium sulfate, limestone, quicklime, slaked lime, cement, steel slag, gypsum, sludge generated from raw concrete, chicken manure, etc. And at least one selected from livestock excrement and its derivatives. Among these, calcium carbonate and limestone are preferable because they are easily available and have a high calcium content. In addition to calcium, the poultry manure and its derivatives have a high content of phosphorus and potash, so even if mixed with sewage sludge, etc., the content of phosphorus in the mixed raw material can be kept high. Potash, which is an important component, is preferable because it can be added to the phosphate fertilizer. Here, examples of the derived material of chicken dung include at least one selected from fermented chicken dung, dried chicken dung, carbonized chicken dung, chicken dung incineration ash, and chicken dung molten slag.

In general, since sewage sludge contains a large amount of SiO ₂ , the silica source is usually added in a small amount. However, when the content of SiO ₂ is low, a silica source such as silica or calcium silicate is appropriately added. May be.

(2) Incineration and firing means The means is a means for continuously incinerating and firing the mixed raw material to obtain a phosphate fertilizer. An incinerator is used as the incineration means, and a firing furnace is used as the firing means. . More specifically, examples of the incinerator include a dry distillation gasification furnace, a stalker type incinerator, a fluidized bed type incinerator, and a rotary kiln type incinerator, and examples of the firing furnace include a rotary kiln and an electric furnace.
Here, “continuously performing incineration and calcination” is intended to exclude an aspect in which incineration and calcination means, after the ash obtained by incineration of the mixed raw material is cooled, the ash is calcined. is there. Therefore, in order to continuously perform incineration and firing, it is preferable that the incinerator and the firing furnace are connected or integrated. Specifically, as an incineration and burning means in which an incinerator and a firing furnace are connected, a fluidized bed incinerator and a rotary kiln connected furnace, a vertical multistage incinerator and a rotary kiln connected furnace, or a rotary kiln type incinerator And a kiln connected with a rotary kiln are preferred. Further, as an incineration and firing means in which an incinerator and a firing furnace are integrated, a method of sequentially performing incineration and firing while moving a mixed raw material in a rotary kiln provided with a temperature region in the range of the incineration temperature and the firing temperature. The furnace is preferred. By using these furnaces, the energy efficiency and production efficiency of the manufacturing system are dramatically improved.

Moreover, it is preferable that the said incineration baking means has at least 1 or more means chosen from a chlorination volatilization means, a chlorine bypass means, a reduction baking means, and a calcination means.
Here, the chlorination volatilization means mainly in the field of non-ferrous refining, in order to effectively use the residue that is a by-product of refining, copper, lead, zinc, etc. contained therein as impurities, It is volatilized and recovered in the form. Specifically, the heavy metal is obtained by adding a chlorine source such as calcium chloride and heat-treating it at a high temperature using a firing furnace such as a rotary kiln. Therefore, by combining such techniques, heavy metals such as lead and zinc contained in sewage sludge and the like can be converted into heavy metal chlorides having a relatively low boiling point, and the chlorides can be volatilized and recovered.
Chlorine bypass means is a basic technology cultivated mainly in the cement manufacturing field, where chlorine sources contained in fuels and raw materials are similarly heated together with alkali sources contained in fuels and raw materials. It volatilizes in the firing kiln and utilizes the property that they are concentrated in part of the firing process. Specifically, the chlorine bypass means generates a part of the combustion gas contained in the volatile state of chlorine contained in the sewage sludge by extracting it from the incinerator or the exhaust gas flow path of the kiln and cooling it. This is a means for separating and recovering dust containing chlorine, which contributes to suppression of chlorine and alkali sources in sewage sludge and the like. When the chlorine source or alkali source is excessive or deficient, it may be adjusted by adding a chlorine source or alkali source from the outside.
Like the chlorination volatilization method, the reduction firing means is a technology developed to remove zinc and lead from low-grade raw materials mainly in the field of non-ferrous smelting, and reduces sewage sludge and the like. It is a means for reducing the heavy metal by calcination in the atmosphere and volatilizing and recovering the heavy metal, and contributes to the removal of heavy metals in sewage sludge and the like, similar to the chlorination volatilization method. The calcining means is a means for calcining the entire mixed raw material or a part thereof at 800 to 1000 ° C. in advance using various waste energies such as exhaust gas in order to increase the energy efficiency of the entire firing process. Yes, for example, a calcining furnace attached to the calcining means is preferable, and among these calcining furnaces, the suspension preheater utilized in the cement manufacturing process or the like functions as a desulfurization tower and is generated by incineration or firing of sludge. SOx is more preferable because it suppresses release into the atmosphere.

(3) Drying means The means is means for drying the raw material or the mixed raw material when the raw material is sewage sludge and / or dehydrated sludge. By using this means to dry the raw materials and the like in advance, the energy required for incineration can be greatly reduced in the subsequent incineration and firing means. Specifically, as such means, convection heat transfer dryers such as box-type dryers and airflow dryers, conduction heat transfer dryers such as vibration dryers and rotary dryers, and radiation transfer such as infrared-far infrared dryers. Examples include a heat dryer.

  Further, the drying means may have a granulation forming means for granulating or forming the mixed raw material. In such a case, the energy efficiency and production efficiency of the manufacturing system can be increased as described above. Examples of the granulating and forming means include a bread pelletizer, a bread type mixer, a stirring granulator, a briquette machine, a roll press, and an extrusion molding machine. During granulation molding, excipients such as bentonite, cement, solidifying material, thickener, etc. are added, and other fertilizer components such as potash and magnesium are newly added according to the use of fertilizer. It may be added.

  In the drying means, it is preferable to use the heat of the exhaust gas generated in the incineration and firing means for part or all of the heat for drying the raw material or the mixed raw material. Thereby, the thermal energy used for drying can be saved.

(4) Exhaust gas treatment means The means is a means for treating exhaust gas generated in the incineration and firing means, and in the case of a production system including the drying means, further treating exhaust gas generated in the drying means. It is. Substances to be removed in the exhaust gas treatment process include soot, sulfur oxides, hydrogen chloride, nitrogen oxides, ammonia, dioxins, volatile organic compounds, and malodorous substances such as ammonia. By treating the generated exhaust gas simultaneously with one exhaust gas processing means, the exhaust gas processing means can be unified and simplified. In particular, when incinerating sludge, the secondary effect that generation of dinitrogen monoxide, which is a warming substance, can be significantly suppressed by the high-temperature heat of the subsequent baking furnace can be achieved.
In addition to cooling devices, adsorption devices, condensing devices, and deodorizing devices as specific exhaust gas treatment means, addition of alkali such as bag filters and electrostatic precipitators for dust removal, lime as a countermeasure against sulfur oxides and hydrogen chloride At least one or more devices selected from a desulfurization / dehydrochlorination device, a scrubber, a non-catalytic denitration device as a nitrogen countermeasure, an ammonia catalytic reduction device, a re-combustion device for complete combustion of unburned components, etc. It is done.

  The exhaust gas treatment means preferably has an exhaust gas quenching means in order to prevent re-synthesis of dioxins. Here, the exhaust gas quenching means is a means for rapidly cooling the exhaust gas temperature to less than 300 ° C., preferably 200 ° C. or less. Specifically, the exhaust gas quenching means includes a cooling tower such as an atmospheric cooling tower, a forced ventilation cooling tower and a spray cooling tower, a heat exchanger, and the like.

2. Next, a method for manufacturing phosphate fertilizer will be described.
(1) Incineration temperature, calcination temperature The method is a method for producing phosphate fertilizer using the phosphate fertilizer production system, wherein the incineration temperature in the incineration and firing means is 700 to 1000 ° C., preferably 800 The firing temperature is 1150 to 1350 ° C, preferably 1200 to 1300 ° C. If the incineration temperature is in the range of 700 to 1000 ° C., the generation of dinitrogen monoxide, which is a greenhouse gas, tends to be reduced. Moreover, if a calcination temperature exists in the range of 1150-1350 degreeC, there exists a tendency for the solubility rate of the phosphoric acid of the obtained phosphate fertilizer and the solubility rate of a silicic acid to become high.
The incineration time and the residence time in the kiln are generally preferably 10 to 60 minutes and more preferably 20 to 40 minutes, although depending on the supply amount of the mixed raw material. If the time is less than 10 minutes, incineration or firing tends to be insufficient, and if it exceeds 60 minutes, the production efficiency decreases.
In the production method of the present invention, after firing, if necessary, other fertilizer components such as nitrogen, potash, and magnesium may be added to and mixed with the obtained phosphate fertilizer. You may granulate from viewpoints, such as a handleability improvement.

(2) Content of CaO in phosphate fertilizer The content of CaO in phosphate fertilizer manufactured (fired) by the manufacturing method of the present invention is preferably 30 to 55% by mass, more preferably 38 to It is 52 mass%, More preferably, it is 40-50 mass%. If the value is in the range of 30 to 55%, as shown in the production examples described later, the solubility of phosphoric acid in the phosphate fertilizer is 60% or more, and the solubility of silicic acid is 40% or more. Get higher.
Here, the solubility of phosphoric acid is the mass ratio (%) of soluble phosphoric acid to the total phosphoric acid in phosphate fertilizer, and the solubility of silicic acid is the total solubility in phosphate fertilizer. It is a mass ratio (%) of soluble silicic acid to silicic acid. Soluble phosphoric acid is obtained by the ammonium vanadomolybdate method specified in the fertilizer analysis method (Agricultural and Environmental Technology Research Institute Act of the Ministry of Agriculture, Forestry and Fisheries). It can be quantified by the chloric acid method.
The quantification of the oxide in the raw material and phosphate fertilizer can be performed by a fundamental parameter method using a fluorescent X-ray apparatus.

(3) Preparation method of mixed raw material As a preparation method of the mixed raw material, for example, after calcining a part of the raw material and the calcium source in an electric furnace or the like, the oxide in the calcined ash is quantified, and the quantitative value and a predetermined value are determined. Based on the formulation, a method of mixing and preparing the raw material and the calcium source can be mentioned. The oxide can be quantified by a fundamental parameter method using a fluorescent X-ray apparatus. Since the chemical composition of the mixed raw material before firing is substantially the same as the chemical composition of the phosphate fertilizer after firing, in order to obtain a phosphate fertilizer having a CaO content in the above range, the CaO content is usually It is sufficient to use a mixed raw material satisfying the above range. However, for the sake of accuracy, a part of the mixed raw material is fired in an electric furnace or the like, and the CaO content in the mixed raw material and the CaO content in the fired product (phosphate fertilizer) It is preferable to grasp the correlation in advance and correct the mixing ratio of the raw material and the calcium source so as to be the CaO content in the target phosphate fertilizer based on the correlation.

(4) Production Example of Phosphate Fertilizer In the state of incinerated ash, dry sludge containing 7.6% by mass of CaO, 15.6% by mass of P ₂ O _{5 and} 36% by mass of SiO ₂ and a reagent as a calcium source A mixed raw material containing 50 mass% CaO, 9 mass% P ₂ O _{5 and} 20 mass% SiO _{2 in} the state of incinerated ash was prepared.
Next, the mixed raw material is incinerated at an incineration temperature of 850 ° C. and a residence time in the incinerator of 20 minutes using an incineration baking furnace in which a fluidized bed incinerator and a rotary kiln are connected. The phosphoric acid fertilizer was obtained by firing at a residence time of 40 minutes.
For the obtained phosphate fertilizer, soluble phosphoric acid dissolved by the ammonium vanadmolybdate method specified in the Fertilizer Analysis Method (Agricultural Environmental Technology Research Institute Act of the Ministry of Agriculture, Forestry and Fisheries) is used. When soluble silicic acid was measured by the chloric acid method, the solubility of phosphoric acid was 84% and the solubility of silicic acid was 100%, both high.

Hereinafter, an example of the phosphate fertilizer manufacturing system of the present invention will be described with reference to FIG.
(I) Flow of raw materials, etc. The dehydrated sludge as the raw material is supplied to the dryer 1 and dried to become dry sludge. Next, the dried sludge enters the mixer 2 through the flow passage 11 and is mixed with a calcium source to become a mixed raw material. Further, the mixed raw material passes through the mixed raw material flow passage 21 and enters the incineration and firing furnace 3, where it is incinerated and fired to become phosphate fertilizer. Finally, the phosphate fertilizer is discharged through the phosphate fertilizer flow passage 31.
On the other hand, the calcium source is supplied to the mixer 2 through the calcium source supply channel 51 and mixed with the dried sludge, and when the dryer 1 and the incineration firing furnace 3 have a mixing function, the calcium source is supplied. Through the paths 52 and 53, they are also supplied to the dryer 1 and the incineration and firing furnace 3, respectively, and mixed with dewatered sludge and the like.

(Ii) Flow of exhaust gas Part or all of the exhaust gas of the dryer 1 and the exhaust gas of the incineration and firing furnace 3 enters the exhaust gas treatment device 4 through the exhaust gas flow paths 12 and 32, respectively, and is exhaustively treated. After that, it is discharged into the atmosphere through the exhaust gas passage 41. Part or all of the exhaust gas in the incineration and firing furnace 3 enters the dryer 1 through the exhaust gas flow path 33, and the heat of the exhaust gas is used to dry the dewatered sludge.

1 dryer (drying means)
11 Flow path of dried sludge 12, 32, 33, 41 Flow path of exhaust gas 2 Mixer (raw material mixing means)
21 Mixed material flow passage 3 Incineration and firing furnace (incineration and firing means)
3a Incinerator 3b Firing furnace 31 Flow path of phosphate fertilizer 4 Exhaust gas treatment device (exhaust gas treatment means)
51, 52, 53 Calcium source supply path

Claims (12)

  A raw material mixing means for obtaining a mixed raw material by mixing a sewage sludge and / or a derivative thereof and a calcium source, and continuously incinerating and firing the mixed raw material to obtain a phosphate fertilizer A phosphate fertilizer manufacturing system including at least an incineration and firing means.   The phosphate fertilizer manufacturing system according to claim 1, wherein the raw material mixing unit has a granulation forming unit for granulating or forming the mixed raw material.   The incineration and firing means is a chlorination and volatilization means for volatilizing and removing heavy metals, a chlorine bypass means for removing chlorine, a reduction and firing means for firing under a reducing atmosphere to remove heavy metals, and a mixed raw material The system for producing phosphate fertilizer according to claim 1 or 2, further comprising at least one means selected from calcining means for calcining the material.   The said incineration baking means WHEREIN: The manufacturing system of the phosphate fertilizer of any one of Claims 1-3 whose incineration means is a fluid bed type incinerator and whose baking means is a rotary kiln.   Furthermore, when the raw material is sewage sludge and / or dewatered sludge, the phosphate fertilizer production system according to any one of claims 1 to 4, further comprising a drying means for drying the raw material or the mixed raw material. .   The phosphate fertilizer manufacturing system according to claim 5, wherein the drying unit has a granulation and molding unit for granulating or molding the raw material or the mixed raw material.   The phosphate fertilizer production according to claim 5 or 6, wherein in the drying means, heat of exhaust gas generated in the incineration and firing means is used as a part or all of heat for drying the raw material or the mixed raw material. system.   The phosphoric acid according to any one of claims 1 to 7, wherein the calcium source is added in at least one means selected from the drying means, the raw material mixing means, and the incineration and firing means. Fertilizer production system.   Furthermore, the manufacturing system of the phosphoric acid fertilizer of any one of Claims 1-8 containing the waste gas processing means for processing the waste gas generated in the said incineration baking means and / or the said drying means.   The phosphoric acid fertilizer manufacturing system according to any one of claims 1 to 9, wherein the exhaust gas treatment means has exhaust gas quenching means for rapidly cooling the exhaust gas.   It is a manufacturing method of the phosphate fertilizer using the manufacturing system of the phosphate fertilizer of any one of Claims 1-10, Comprising: The incineration temperature in the said incineration baking means is 700-1000 degreeC, and a baking temperature is. The manufacturing method of the phosphoric acid fertilizer which is 1150-1350 degreeC.   The method for producing a phosphate fertilizer according to claim 11, wherein the mixed raw material prepared so that the CaO content in the phosphate fertilizer is 30 to 55 mass% is incinerated and fired at the incineration temperature and the firing temperature. .

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