WO2002092537A1 - Materiau pour engrais phosphate et procede de production associe - Google Patents
Materiau pour engrais phosphate et procede de production associe Download PDFInfo
- Publication number
- WO2002092537A1 WO2002092537A1 PCT/JP2002/004785 JP0204785W WO02092537A1 WO 2002092537 A1 WO2002092537 A1 WO 2002092537A1 JP 0204785 W JP0204785 W JP 0204785W WO 02092537 A1 WO02092537 A1 WO 02092537A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- hot metal
- phosphate fertilizer
- slag
- raw material
- dephosphorization
- Prior art date
Links
Classifications
-
- C—CHEMISTRY; METALLURGY
- C05—FERTILISERS; MANUFACTURE THEREOF
- C05B—PHOSPHATIC FERTILISERS
- C05B19/00—Granulation or pelletisation of phosphatic fertilisers, other than slag
-
- C—CHEMISTRY; METALLURGY
- C05—FERTILISERS; MANUFACTURE THEREOF
- C05B—PHOSPHATIC FERTILISERS
- C05B5/00—Thomas phosphate; Other slag phosphates
-
- C—CHEMISTRY; METALLURGY
- C05—FERTILISERS; MANUFACTURE THEREOF
- C05D—INORGANIC FERTILISERS NOT COVERED BY SUBCLASSES C05B, C05C; FERTILISERS PRODUCING CARBON DIOXIDE
- C05D3/00—Calcareous fertilisers
- C05D3/04—Calcareous fertilisers from blast-furnace slag or other slags containing lime or calcium silicates
Definitions
- the present invention relates to a raw material for a phosphate fertilizer comprising a slag containing phosphoric acid generated by a dephosphorization reaction of hot metal and a method for producing the same.
- the most widely known phosphate fertilizer made from slag is Thomas Ji-Fei.
- this technology is hardly used at present because of limitations and problems such as the use of high-phosphate iron ore, the high P concentration of hot metal after dephosphorization, and the large amount of slag generated. '
- the concentration in the hot metal before demolition is 0.1 to 0.2 raass. /. Therefore, the concentration of phosphoric acid in the dephosphorized slag generated and recovered by the conventional general dephosphorization treatment method is about 5 mass%. It does not contain high concentrations of phosphoric acid that can be used as a raw material for phosphate fertilizers.
- Hot metal dephosphorization is performed in two stages, and the slag produced in the first hot metal dephosphorization is charged into the blast furnace as a part of the blast furnace charging material.
- a method of increasing the concentration and recovering slag containing a high concentration of phosphoric acid in the second hot metal dephosphorization Japanese Patent Laid-Open No. 8-3612 '
- a converter refined after hot metal dephosphorization A method in which phosphorus-containing slag is charged into the blast furnace as a part of the blast furnace charging material, thereby increasing the P concentration in the hot metal discharged from the blast furnace and recovering the slag containing a high concentration of phosphoric acid in hot metal dephosphorization. (Japanese Unexamined Patent Publication No. 8-3613)
- the phosphorus-containing slag obtained by dephosphorizing hot metal with a P concentration of 0.15 raass% or less is put into a hot metal bath, and P in the slag is reduced and extracted into the hot metal bath to reduce the P concentration.
- a method for recovering a slag containing a high concentration of phosphoric acid by using 0.5 to 3 mass% hot metal and subjecting the hot metal after the slag to a dephosphorization treatment under predetermined conditions Japanese Patent Application Laid-Open No. H11-15885) 26
- An object of the present invention is to provide a fertilizer raw material comprising a slag containing phosphoric acid generated by a solution dephosphorization reaction, which has excellent fertilizer characteristics.
- Another object of the present invention is to provide a method for producing a raw material for phosphate fertilizer suitable for obtaining the raw material for phosphate fertilizer.
- Another object of the present invention is to provide a phosphate fertilizer using the above-mentioned phosphate fertilizer raw material, in particular, without causing problems such as scattering during fertilization, runoff due to rainwater, and impairment of ground water permeability and air permeability.
- Another object of the present invention is to provide a phosphate fertilizer having good handling properties.
- the present inventors have: (1) increased the concentration of phosphoric acid in slag to a level that is easy to use as fertilizer in relation to the amount of fertilizer, etc., without adding a special process as in the conventional technology. (2) To secure excellent fertilizer properties by increasing the concentration of citrate-soluble phosphoric acid (phosphoric acid: phosphoric acid that can be absorbed by plants releasing acid from the roots) of the phosphoric acid contained in slag. From the viewpoint of slag, the composition and production method of slag were examined, and as a result, the following findings were obtained.
- a CaO source and an oxygen source are added to hot metal with a sufficiently reduced Si content.
- the treatment can be performed with a much higher dephosphorization efficiency (dephosphorization reaction efficiency) as compared with the conventional technology, and the amount of slag generated is extremely reduced.
- the P concentration in the hot metal was about 0.1 to 0.2 mass%.
- hot metal obtained from ordinary blast furnaces with a high concentration it is possible to use a high concentration of hot metal that is suitable as a raw material for phosphate fertilizer in one P extraction process without adding a special process such as enrichment of P concentration in hot metal.
- a slag containing phosphoric acid can be obtained.
- the slag recovered in the dephosphorization process contains fluorine in a concentration corresponding to the amount of added CaF 2, but the fluorine fixes the phosphoric acid in the slag and the proportion of the soluble phosphoric acid Since fluorinated compounds (fluorapatite) are produced with a low content, there is a problem that when slag is used as a raw material for fertilizers, it is not possible to secure a sufficient concentration of soluble soluble acid. In order to solve such a problem, the slag with an increased phosphoric acid concentration as obtained in the above (1) is required to be used as a fertilizer by controlling the slag composition with the phosphoric acid concentration and the fluorine concentration regulated to predetermined conditions.
- the phosphoric acid concentration can be sufficiently ensured.
- C a F 2 amount of very small reduction (or C a F 2 no addition) for stably obtained in the process conditions can be fluorine content also very small reduction
- the raw materials for phosphate fertilizer provided by the present invention are as follows.
- a raw material for phosphate fertilizer showing good phosphoric acid solubility is provided by including 7 raass% or more of soluble phosphate.
- a raw material for a phosphate fertilizer exhibiting particularly good solubility in phosphoric acid is provided by containing 1% Omass% or more of soluble phosphate.
- the slag which is a raw material for the phosphate fertilizer, has as low a fluorine content as possible in order to increase the content of soluble phosphoric acid as much as possible.
- the slag is substantially free of fluorine. Most preferably, it does not contain fluorine other than fluorine which is inevitably mixed.
- the raw material for the phosphate fertilizer is used as it is as a phosphate fertilizer, or is used as a main raw material of the phosphate fertilizer. Accordingly, the present invention provides such a phosphate fertilizer.
- the phosphate fertilizer raw material is used as a phosphate fertilizer
- the phosphate fertilizer raw material is preferably subjected to a pulverizing treatment and / or sizing.
- the above-mentioned raw material for phosphate fertilizer is subjected to a granulation step using an appropriate binder to be converted into a phosphate fertilizer. Problems such as scattering of rainfall, runoff by rainwater, and impeded water permeability and ventilation of the ground are unlikely to occur. In addition, since the shape is regular, close to spherical, and not square, it is easy to handle.
- starch As the binder used in the above granulation step, starch, magnesium sulfate, and lignin are particularly suitable in terms of granulation properties and the disintegration of fertilizer particles after fertilization, and one or more of these are mainly used as binders. It is preferable to use it as a component. Among them, starch is the most suitable in that it can obtain granules having high hardness.
- the methods for producing such slag include: (1) a method of adding an oxygen source and a CaO source to a hot metal with a sufficiently reduced Si concentration to cause a dephosphorization reaction of the hot metal; the C a O source and gaseous oxygen are supplied in a particular form and condition Te method causes a dephosphorization reaction of molten iron, but is particularly suitable, due to these production methods lever, very little C a F 2 A slag (a raw material for a phosphate fertilizer) containing a high concentration of phosphoric acid can be produced efficiently and at low cost without substantially adding the F 2 in the amount added.
- the C a O source and gaseous oxygen are Already in by performing the supply and processed, together with C a F 2 amount of very small reduction or C a F 2 higher in enzyme-free pressurized conditions de ⁇ ratio is obtained, and smaller amount of C a 0 source Therefore, the amount of slag generated is small. Therefore, a slag containing a high concentration of phosphoric acid and having a very small amount of fluorine can be efficiently produced at low cost without adding a special step.
- the present invention provides the following production method.
- a method for producing a raw material for phosphate fertilizer comprising recovering a slag containing slag as a raw material for phosphate fertilizer.
- a CaO source and an oxygen source are added to the container holding the hot metal to cause a dephosphorization reaction of the hot metal, and the slag containing phosphoric acid generated by the dephosphorization reaction is collected as a raw material for phosphate fertilizer.
- the supply speed in terms of Ca ⁇ of the Ca a source sprayed onto the hot metal bath surface B (kg / min / hot metal ton) force S, the supply speed A (in gaseous oxygen equivalent) of the oxygen source supplied to the vessel A method for producing a raw material for phosphate fertilizer, characterized by satisfying the following formula (3), preferably the following formula (4), with respect to NmVmin / hot metal ton).
- a CaO source and an oxygen source are added to a pot-type or torpedo-car-type vessel holding hot metal to cause a dephosphorization reaction of the hot metal, and a slag containing phosphoric acid generated by the defamation reaction is added.
- a method for producing a raw material for phosphate fertilizer comprising blowing a gas containing powder into hot metal through an immersion lance or / and a blowing nozzle.
- the Si content is 0.07 mass. /.
- the following (preferably 0.05 mass% or less, particularly preferably 0.3 mass% or less) is subjected to a treatment for adding a CaO source and an oxygen source to cause a dephosphorization reaction.
- the obtained high phosphorous distribution L p by the high basicity of the slag dephosphorization efficiency is obtained higher without substantially adding Therefore very little C a F 2 amount or C a F 2
- the amount of slag generated is extremely small.
- the manufacturing method (2) the following operation and effect can be obtained.
- a large amount of FeO is generated on the hot metal bath surface (particularly, the hot metal bath surface region to which gaseous oxygen is supplied), which greatly promotes CaO slagging.
- a large amount of FeO is generated in this way, and a CaO source is sprayed on the hot metal bath surface where a large amount of phosphorous oxide is present, and Fe generated in the slag by the supply of oxygen. Since the CaO source is supplied at a supply rate that is commensurate with the amount of O generated, Ca0 can efficiently exist around FeO and the phosphorous oxide. Phosphorus reaction efficiency is obtained.
- the manufacturing method (3) the following operation and effect can be obtained.
- gaseous oxygen is blown onto the hot metal bath surface
- a large amount of FeO is generated on the hot metal bath surface (particularly, the hot metal bath surface region to which gaseous oxygen is supplied), which greatly promotes the slagging of CaO.
- This is an advantageous condition. Therefore, by spraying the CaO source onto the hot metal bath surface where a large amount of FeO is generated, it is possible to effectively promote the slagging of CaO.
- gas containing powder is blown into the hot metal through the immersion nozzle or the blowing nozzle, the hot metal is agitated and reacts on the reaction interface.
- a raw material for fertilizer is manufactured using the raw material for phosphate fertilizer obtained by each of the above-mentioned production methods. Accordingly, the present invention provides a method for producing such a phosphate fertilizer. In that case, it is preferable to carry out the above-mentioned crushing and / or sizing step of the raw material for phosphate fertilizer, and the granulation step with the addition of a binder.
- FIG. 1 is a graph showing the phosphoric acid solubility of slag having the composition shown in Table 1 arranged in relation to the fluorine content in the slag.
- FIG. 2 is a graph showing the slag composition conditions of the raw material for acid acid fertilizer of the present invention.
- FIG. 3 is an explanatory diagram showing an example of a granulation step of a raw material for a phosphate fertilizer of the present invention.
- FIG. 4 is an explanatory diagram showing another example of the granulation step of the raw material for a phosphate fertilizer of the present invention.
- Figure 5 is a graph showing the relationship between the Si content in the hot metal before the dephosphorization reaction and the dephosphorization efficiency.
- FIG. 6 is a graph showing the relationship between the hot metal temperature at the start of the dephosphorization reaction and the dephosphorization efficiency.
- FIG. 7 is a graph showing the relationship between the hot metal temperature at the end of the dephosphorization reaction and the dephosphorization efficiency.
- Figure 8 shows the hot metal temperature and dephosphorization efficiency at the start of the dephosphorization reaction when the CaO source and the oxygen source were supplied to the same position as when they were supplied to the bath surface in the vessel or to separate positions in the bath.
- 6 is a graph showing a relationship with the graph.
- Figure 9 shows the case where calcined lime was used as the CaO source and the CaO source and the oxygen source were supplied to the bath surface in the vessel or at separate locations in the bath.
- 4 is a graph showing the relationship between the hot metal temperature at the start of the dephosphorization reaction treatment and the debinding efficiency when an eO-CaO-based solvent is used.
- FIG. 10 is an explanatory diagram showing an example of an implementation state of the method of the present invention using a converter-type vessel.
- Figure 1 1 is in the dephosphorization reaction process C
- F 2 no additive is a graph showing the relationship between hot metal temperature and dephosphorization lime efficiency of S i concentration and dephosphorization the reaction process is completed in the hot metal.
- FIG. 12 is a graph showing the relationship between the amount of CaF 2 added and the efficiency of lime removal in the dephosphorization reaction process at a hot metal temperature of 1360 to 1450 at the end of the process.
- Fig. 13 is a graph showing the effect of the ratio XZY of the rate of addition of the CaO source and the rate of addition of gaseous oxygen, XZY, on the dephosphorization rate in the dephosphorization reaction using a pot-shaped vessel.
- Figure 14 shows that in the dephosphorization reaction using a pan-shaped vessel, the entire amount of CaO source is sprayed onto the hot metal bath surface through the top blowing lance and into the hot metal through the immersion lance or / and the blowing nozzle.
- C a O through top blowing lance when adding by blowing 4 is a graph showing a relationship between a ratio of a source addition amount to a total addition amount of a CaO source and a dephosphorization rate.
- Fig. 15 is a graph showing the relationship between the Si concentration in hot metal and the required amount of CaO source (lime) before the dephosphorization reaction in the method of the present invention and the conventional method using a pot-shaped vessel.
- FIG. 16 is an explanatory diagram showing an example of an implementation state of the method of the present invention using a pot-shaped container.
- Figure 17 shows the ratio between the supply rate A of oxygen and the supply rate B of the CaO source in Example 2.
- the raw material for a phosphate fertilizer of the present invention is a slag containing phosphoric acid generated by a dephosphorization reaction of hot metal, and has a phosphoric acid content satisfying the following formula (1), preferably the following formula (2). You.
- a representative example of such slag is hot metal dephosphorization slag recovered in a blast furnace hot metal pretreatment step, but is not limited thereto, and slag used as a raw material for the phosphate fertilizer of the present invention is used. Includes slag obtained by any production method.
- the blast furnace hot metal pretreatment process is a process for the purpose of dephosphorization and desulfurization of hot metal performed prior to the decarburization process of hot metal, of which hot metal dephosphorization is performed mainly for dephosphorization.
- a refining agent (lime, etc.) as a CaO source and an oxygen source (gas oxygen or solid oxygen source) are added, and the P in the hot metal is fixed to the generated slag by a dephosphorization reaction to remove the hot metal. Perform phosphorous.
- Table 1 shows that the hot metal discharged from the blast furnace is subjected to desiliconization and desulfurization in order, and then a CaO source and an oxygen source are added to the hot metal to cause a hot metal delamination reaction ( Hereinafter, this is referred to as “phosphorus treatment”.
- a converter-type vessel is used, (1) a method in which gas oxygen is blown from the top blowing lance onto the hot metal bath surface and lump lime (CaO source) is placed on top, and (2) An oxygen source and a CaO source are supplied in two ways: blowing lime powder (CaO source) from the top blowing lance onto the hot metal bath using gaseous oxygen as a carrier gas. The test was performed with the added amount of F 2 .
- Figure 1 shows the phosphoric acid solubility of slag of each composition shown in Table 1 arranged in relation to the fluorine content in slag.
- the solubility of phosphoric acid in slag that does not substantially contain fluorine is approximately 100% (99%), while the slag containing fluorine contains more phosphoric acid as the fluorine content increases.
- the solubility of phosphorus decreases, the lower limit of the solubility of phosphoric acid is about 50% regardless of the fluorine content.
- the specified value (lower limit value) of the amount of soluble phos- phoric acid required as a raw material for phosphate fertilizer is set to 7 maSS %, preferably in consideration of the effectiveness when the fertilizer is applied to farmland. Set it to 10 mass%.
- the amount of quosoluble phosphoric acid in the fertilizer is 7 mass% or more, preferably 1 Omass% or more, the fertilizer does not require a large amount of fertilizer, so that the usefulness as a fertilizer is sufficiently ensured.
- phosphoric acid that is soluble in fluorinated apatite is 5.6 X [F].
- the click-soluble phosphate to contain more than 7Raass% is a phosphoric acid comprising fluoride Apatai DOO, must be added to the click-soluble phosphate content of the target, therefore, the phosphoric acid content in the slag [P 2 0 5] (mass%) and the fluorine content [F] (mass%) must satisfy the following equation (1).
- the click-soluble phosphate to contain more than 1 Omass% is phosphoric acid content [P 2 0 5] (mass %) and fluorine content [F] (mass%) is satisfies the following expression (2) There is a need to.
- FIG. 2 (a) shows the range of the phosphoric acid content and the fluorine content defined by the above formula (1) (the range indicated by hatching in the figure), and FIG. 2 (b) shows the above (2) ) Shows the range of phosphoric acid content and fluorine content defined by the formula (the range shown by hatching in the figure).
- the amount of phosphoric acid and the amount of soluble phosphoric acid in all the slags of each composition shown in Table 1 are shown in a vertical relationship. According to the figure, only when the above equations (1) and (2) are satisfied, It can be seen that the amount of soluble phosphoric acid was secured.
- the slag which is a raw material for the phosphate fertilizer, has as low a fluorine content as possible in order to increase the content of soluble phosphoric acid as much as possible.
- the slag is substantially free of fluorine. Most preferably, it does not contain fluorine other than fluorine which is inevitably mixed. Therefore to minimize the C a F 2 amount added in to the dephosphorization reaction hot metal, preferably C a F 2 does not substantially added (i.e., C a F 2 other than C a which inevitably mixed F 2 not added) it is desirable.
- the raw material for the phosphate fertilizer is used as it is as a phosphate fertilizer, or is used as a main raw material of the phosphate fertilizer. In the latter case, other fertilizer components are appropriately blended.
- the raw material for the phosphate fertilizer is pulverized and / or sized to obtain a phosphate fertilizer.
- pulverization can be performed using a pulverizer such as a jaw crusher, a rod mill, a fred mill, an impeller pre-strength, or the like.
- the sieving may be performed using any sieving apparatus or the like, and the sizing may be performed after the raw material for the phosphate fertilizer is pulverized.
- the raw material for the phosphate fertilizer that has been pulverized or sized is preferably subjected to a granulation step using an appropriate binder to form a phosphate fertilizer, and the phosphate fertilizer thus granulated is subjected to fertilization. It is unlikely to cause problems such as scattering at the time, runoff due to rainwater, and impaired water permeability and ventilation of the ground.
- the shape is regular, nearly spherical, and not angular Therefore, it is easy to handle.
- a general granulation method can be adopted.
- a pulverized material obtained by the above-mentioned pulverization process and a binder are mixed with a mixer, and an appropriate amount of water is mixed.
- the granules can be granulated with a granulator while adding the water, and then dried.
- the granulator those generally used, for example, a rotating dish granulator, a rotating cylindrical granulator, and the like can be used. Those which do not fall within a predetermined particle size range after granulation can be used directly. It is preferable to adopt a continuous granulation method in which after the treatment such as contacting or pulverizing, the mixture is returned to the mixer again and reused as a part of the raw material.
- Fig. 3 shows an example of the process of granulating the raw material for phosphate fertilizer.
- the pulverized material (raw material for phosphate fertilizer) 10 obtained by the above-mentioned pulverization process is loaded into the hopper 11 by a shovel loader or the like.
- the measured and crushed material 10 is supplied from the hopper 11 to the drum type rotary granulator 13 via the conveyor 12.
- a predetermined amount of the binder 14 stored in the container 15 is also supplied to the drum-type rotary granulator 13, and the pulverized material 10 and the binder 14 are rotated by the rotation of the drum-type rotary granulator 13. Are mixed and granulated.
- the granulated material is dried by a dryer 16, supplied to a sieving device 18 by an elevator 17 and sieved, and further cooled by a cooler 19 to become a granulated fertilizer. It is also possible to use granulated fertilizer by sieving after cooling in cooler 19.
- FIG. 4 shows another example of the granulation process of the raw material for phosphate fertilizer.
- the crushed material 10 obtained by the above-mentioned crushing treatment was charged into the hopper 21 and the weighed crushed material 10 was weighed. Is charged from the hopper 21 to the mixer 24. Also, a predetermined amount of the binder 14 stored in the container 23 is charged into the mixer 24. Then, the powder 10 and the binder 14 are mixed in the mixer 24, and the mixture is supplied to the dish granulator 25, and is granulated in the dish granulator 25. Granules granulated by dish granulator 25 The material is placed on a belt conveyor 26, and thereafter, as in the process of FIG. 3, dried by a drier 16 and supplied to a sieving device 18 by an elevator 17 to be sieved, and further cooled by a cooler 19 It becomes a granulated fertilizer.
- binder used in the granulation process.
- phosphoric acid clay, bentonite, polyvinyl alcohol, canoleboxy methinole cellulose, polyacrylic acid, molasses, lignin, magnesium sulfate, starch, etc.
- starch, magnesium sulfate, and lignin are suitable in terms of granulation properties and disintegration of fertilizer particles after fertilization. It is preferable to use at least one selected from the above as the main component of the binder.
- the properties required for the binder are: 1) excellent granulation properties; 2) fertilizer particles after fertilization. (Granulated material) can easily disintegrate and disperse in soil; (3) it has a hardness so that particles do not collapse during production and handling from distribution to fertilization;
- the starch, magnesium sulfate, and lignin all satisfy these characteristics.
- starch when starch is used, the hardness of the granulated fertilizer particles is particularly high, and the starch dissolves in rain or moisture in the soil and breaks down the fertilizer particles at an appropriate speed. Therefore, it is particularly preferable.
- starch is gelatinized by adding water and then solidified by drying, so that it has excellent granulation properties, and is further degraded by soil microorganisms, which adversely affects plants and the environment. Not even.
- starch used as a binder include those made from corn, tapiochi, wheat, potato, rice, and the like. These starches have different ratios of amylose (d-glucose bound in a long linear chain) and R-mylobectin (d-glucose bound in a branched chain) depending on the raw material. , The percentage of amylopectin is high in waxy rice and waxy corn.
- type of starch may be raw starch as it is or processed starch treated with heat, acid, alkali, salt, enzyme or the like. Regardless of the type of starch, those having a gelatinizing property are suitable as a granulated binder.
- the average particle size of the phosphate fertilizer thus granulated is preferably 0.5 to 6 mm. If the average particle size is less than 0.5 mm, it will be blown away by the wind during fertilization, making it difficult to handle. On the other hand, if the average particle size exceeds 6 mm, it will be difficult to spray uniformly. A more preferred particle size is 1-5 mm.
- the production method uses special processes to increase the concentration of phosphoric acid in slag (for example, to concentrate P in hot metal. It must be as simple and cost-effective as possible without adding additional steps. These requirements are met by several new manufacturing methods as described below.
- the first production method provided by the present invention performs treatment on hot metal having a sufficiently reduced Si concentration, and according to such a production method, the amount of C a F 2 added slag with resulting high dephosphorization efficiency even at very small reduction or C a F 2 of the absence of addition, generate S i 0 2 small amount of, yet which already Mutame by adding amount less of C a O source, to produce the The amount is small. For this reason, slag containing a high concentration of phosphoric acid and extremely low fluorine content can be efficiently and cost-effectively added without adding a special process. Can be manufactured.
- the second and third production methods provided by the present invention perform the treatment by supplying a Ca 0 source and gaseous oxygen in a specific form and under a specific condition. Therefore, high dephosphorization efficiency can be obtained even when the amount of added Ca F 2 is minimized or no C a F 2 is added, and the amount of added Ca O source can be reduced, so that the amount of slag generated is small. . Therefore, a slag containing a low concentration of phosphoric acid and extremely low fluorine content can be produced efficiently and at low cost without adding a special process.
- the present inventors have studied a method capable of producing a slag having a high phosphoric acid concentration with a high dephosphorization reaction efficiency by a demetalizing reaction treatment of hot metal, and as a result, the Si content is 0.07 mass% or less,
- a CaO source and an oxygen source to a hot metal of preferably 0.05 mass% or less, particularly preferably 0.03 mass% or less and performing a dephosphorization reaction treatment, less with C a F 2 amount or in highly have dephosphorization efficiency without the addition of C a F 2 substantially is obtained, the amount of slag to be produced is extremely small, this result, the fluorine content is extremely small
- a raw material (slag) for phosphoric fertilizers containing a high concentration of phosphoric acid can be produced.
- hot metal having a Si content of 0.07 mass% or less, preferably 0.05 mass% or less, particularly preferably 0.03 mass% or less is used.
- slag which is a raw material for phosphate fertilizer, is manufactured by performing a dephosphorization reaction treatment by adding a CaO source and an oxygen source.
- the hot metal temperature at the start of the process and the hot metal temperature at the end of the process should be optimized.Furthermore, the CaO source and the oxygen source should be supplied under specified conditions. It has been found that the phosphorus content improves the dephosphorization efficiency further, so that a more preferable raw material for phosphate fertilizer can be stably produced in terms of the phosphoric acid concentration and the fluorine content. Fig.
- FIG. 5 shows the case where hot metal with de-siliconization and adjusted Si content in hot metal was subjected to a dephosphorization reaction using a converter-type vessel (hot metal temperature at the start of processing: more than 1280 ° C)
- the Si content in the hot metal before the dephosphorization reaction and the dephosphorization efficiency (phosphorus distribution Lp)
- the Si content in the hot metal subjected to the dephosphorization reaction treatment is 0.07 mass% or less, the phosphorus becomes an index of dephosphorization efficiency by increasing the basicity of slag.
- the concentration of phosphoric acid in the slag generated during the above-mentioned hot metal dephosphorization reaction treatment depends on the P concentration in the hot metal before and after the treatment, the amount of slag generated, etc., but in general, it is 7 mass% or more. (Usually about 7 to 10 mass%).
- a CaO source as described later is projected (sprayed) onto the bath surface from above the bath surface of the reaction vessel, and more preferably, the ratio of the supply rates of the aO source and the oxygen source is regulated to a specific range. In such a method, a higher phosphoric acid concentration, that is, a phosphoric acid concentration of generally 1 Omass% or more (usually about 10 to 15 mass%) can be obtained.
- the Si content in the hot metal exceeds the above upper limit (0.07 mass%, preferably 0.05 mass%, particularly preferably 0.03 mass%) when performing the depilatory reaction treatment.
- desiliconization is performed in advance to reduce the Si content in the hot metal to the upper limit or less, and then dephosphorization is performed.
- hot metal drawn from a blast furnace etc. contains Si of about 0.3 to 0.5 O mass%, and in the case of such normal hot metal at the Si level, desiliconization is performed. It is essential.
- the desiliconization treatment may be performed in either a hot metal desiliconization step (for example, floor desiliconization) or in a vessel.
- a ladle such as a hot metal pot or a charging pan, a torpedo, etc. are used as containers, and a desiliconization agent is added to the container and stirred to efficiently desiliconize. It can be performed.
- Either solid acid (usually iron oxide such as mill scale) or gaseous acid (gaseous oxygen or oxygen-containing gas) may be used as the desiliconizing agent, or both may be used in combination.
- the desiliconization process performed in the ladle can sufficiently stir the hot metal due to the shape of the hot metal holding, so that the desiliconization efficiency is higher than that of other hot metal desiliconization processes (for example, the desiliconization process using a hotbed or a torpedo). good. Therefore, when the amount of Si in the hot metal is relatively high, desiliconization in the ladle or bed desiliconization is performed before desiliconization in the ladle. Is preferably performed.
- the conventional desiliconization of a bed has a problem that not only the efficiency of desiliconization is low but also the temperature of hot metal decreases because only a solid acid (such as mill scale) is used as a desiliconizing agent.
- gaseous oxygen can be supplied as a desiliconization agent, so that the hot metal temperature can be easily maintained and stabilized, and a solid oxygen source can be supplied together. In addition, it is easy to adjust the hot metal temperature.
- a hot metal having a Si content of 0.07 mass% or less, preferably 0.05 mass% or less, particularly preferably 0.03 mass% or less a Ca It is performed by adding Usually, this dephosphorization reaction is performed using a hot metal pot or a converter type vessel, but there is no special restriction on the vessel used, and in some cases, the desiliconization treatment is performed in the same vessel. And a dephosphorization reaction treatment may be sequentially performed. In this case, at least a part of the debris is removed after the desiliconization treatment, and then a dephosphorization reaction treatment is performed.
- quick lime is used as the source of Ca, but it is not limited to this.
- These C a O source and solid acid are added into the processing vessel by a method such as overhead addition or injection.
- the gaseous acid is generally added by blowing oxygen gas into the hot metal using a lance, a bottom-blown nozzle, or the like, and then adding or blowing Z-gas.
- There are no particular restrictions on the method or conditions for performing the dephosphorization reaction but in order to perform the treatment particularly efficiently, it is preferable to perform the treatment under the following conditions, thereby reducing the fluorine content.
- a slag containing a small amount and a high concentration of phosphoric acid can be obtained more stably.
- the hot metal temperature at the end of the dephosphorization reaction is 1280 to 1360 ° C (more preferably 1300 to 1340 ° C).
- a FeO-CaO-based solvent is added.
- the initial slagging is promoted by setting the hot metal temperature at the start of the dephosphorization reaction process to a reference value or higher, and molten FeO is generated early. It is effective.
- the hot metal temperature at the start of the dephosphorization reaction treatment is preferably 1280 ° C or higher, more preferably 1320 ° C or higher.
- Figure 6 shows the relationship between the hot metal temperature at the start of the dephosphorization reaction and the dephosphorization efficiency when the dephosphorization reaction was performed in the converter type vessel and when the dephosphorization reaction was performed in the hot metal pot (at the end of the dephosphorization reaction processing).
- Hot metal temperature 1280 to 1360 ° C
- content of Si in hot metal before dephosphorization reaction 0.07 nmss% or less
- Converter type container Quick lime placed on top
- Hot metal pot Quick lime placed on top
- by setting the hot metal temperature at the start of treatment to 1280 ° C or more, more preferably 1320 ° C or more, it is possible to obtain particularly excellent de-coaling efficiency (phosphorus distribution Lp). I understand.
- the dephosphorization reaction using a converter-type vessel has a higher stirring efficiency than the dephosphorization reaction using a hot metal pot, so the processing time is limited. It turns out that high dephosphorization efficiency is obtained. Then, such high Te cowpea to dephosphorization efficiency and generated slag amount is small is obtained, with no addition of C a F 2 amount of very small reduction or C a F 2 it becomes possible, in slag This effectively increases the phosphoric acid concentration of the fertilizer, thereby stably producing a raw material (slag) for phosphate fertilizer having excellent fertilizer performance.
- the dephosphorization efficiency of hot metal is better in terms of equilibrium when the hot metal temperature is relatively low, but if the hot metal temperature is too low, CaO slagging does not occur.
- the dephosphorization efficiency is rather reduced because it is sufficient, and the treatment is performed within the upper limit of the operation time. Therefore, the treatment temperature has an appropriate range in terms of the dephosphorization efficiency.
- This appropriate temperature range is 1280 to 1360 ° C, more preferably 1300 to 1340 ° C at the hot metal temperature at the end of the dephosphorization reaction, and it is better to end the dephosphorization at this hot metal temperature. Dephosphorization efficiency can be secured.
- Figure 7 shows the relationship between the hot metal temperature and the dephosphorization efficiency at the end of the dephosphorization reaction treatment (the method of adding the CaO source was charging on top of quick lime) in a converter type vessel (dephosphorization efficiency).
- Hot metal temperature at the start of the reaction process 1280 ° C or higher
- Si content in the hot metal before the dephosphorization reaction process 0.07 ma SS % or less
- the hot metal temperature at the end of the dephosphorization reaction process It can be seen that a particularly excellent dephosphorization efficiency (phosphorus distribution Lp) can be obtained by setting the temperature to 1280 to 1360 ° C, more preferably 1300 to 1340 ° C.
- the CaO source and the oxygen source must be supplied to the bath surface in the processing vessel or to the same position in the bath, that is, the point of generation of FeO by the supplied oxygen source.
- Figure 8 shows the dephosphorization reaction using a converter type vessel (hot metal temperature at the end of the dephosphorization reaction: 1280 to 1360 ° C, the Si content in the hot metal before the dephosphorization reaction: 0.007111353%
- the CaO source and oxygen source were supplied to the bath surface in the vessel or at separate locations in the bath (quick lime: overhead addition, gaseous oxygen: top blowing)
- the CaO source and oxygen The graph shows the relationship between the hot metal temperature at the start of the dephosphorization reaction and the dephosphorization efficiency when the source is supplied to the bath surface in the vessel or to the same position in the bath (quick lime + gaseous oxygen: top blowing).
- a CaO source and an oxygen source are used by using a FeOaO-based solvent containing Ca ⁇ and a solid oxygen source as part or all of the CaO source.
- a FeOaO-based solvent containing Ca ⁇ and a solid oxygen source as part or all of the CaO source.
- the Fe0_CaO-based solvent calcium ferrite, a sintered product of a mixture of calcium hydroxide and ferrite, and the like can be used.
- Figure 9 shows the de-sintering reaction using a converter-type vessel (hot metal temperature at the end of the de-phosphorization reaction: 1280 to 360 ° C, the Si content in the hot metal before the de-phosphorization reaction: 0 07111353% or less), when quicklime is used as the CaO source, and this CaO source and oxygen source are supplied to the bath surface in the vessel or to separate locations in the bath (quicklime: overhead addition, gas Oxygen: top blowing) and when a FeO-CaO-based medium solvent (mixed sinter of FeO + CaO) is used as the CaO source (medium solvent: overhead addition, gaseous oxygen) : Top blowing) shows the relationship between the hot metal temperature at the start of the dephosphorization reaction and the dephosphorization efficiency.
- a converter-type vessel hot metal temperature at the end of the de-phosphorization reaction: 1280 to 360 ° C, the Si content in the hot metal before the de-phosphorization reaction: 0 07111353% or
- the use of the FeOCaO-based solvent as the CaO source is more advantageous than the supply of the CaO source and oxygen source to the bath surface in the vessel or to separate locations in the bath. It can be seen that relatively excellent dephosphorization efficiency (phosphorus distribution Lp) can be obtained. Then, by such a high dephosphorization efficiency is obtained ⁇ one generation amount of slag is small, with no addition of C a F 2 amount of very small reduction or C a F 2 becomes possible, phosphoric acid concentration in the slag Is effectively increased, and a raw material (slag) for phosphate fertilizer having excellent fertilizer performance is stably manufactured. Also, as shown in FIG.
- a particularly large effect can be obtained when the dephosphorization reaction is performed using a converter type vessel. This is because the converter-type vessel has a larger freeboard compared to a ladle or a torpedo, so that the stirring power can be increased, thereby causing rapid slagging and P mass transfer.
- the dephosphorization efficiency can be further increased by adding a CaO source, particularly preferably a CaO source and an oxygen source in a specific form, and as a result,
- the phosphoric acid concentration of the slag can be further increased by minimizing the amount of added CaF 2 or by adding no CaF 2 .
- a processing vessel containing hot metal At least a portion of the CaO source to be added into the treatment vessel is added to the vessel by projecting (spraying) the carrier surface from above the bath surface using a carrier gas into the treatment vessel.
- Supply rate of CaO conversion of CaO source projected on bath surface using carrier gas B (kg Zm in Z hot metal ton) force S, supply of gaseous oxygen equivalent of the above oxygen source supplied into vessel
- Such a form of addition of the CaO source and the oxygen source supplies the CaO source at a supply rate corresponding to the amount of FeO generated in the slag due to the supply of oxygen.
- the efficiency of the dephosphorization reaction can be further improved.
- the supply of CaO is excessive with respect to the supply of oxygen, so the amount of FeO generated in the slag is small, and the CaO is not contained in the slag. And remains in a solid state and does not effectively act on the dephosphorization reaction.
- a / B exceeds 7, the amount of CaO required for the dephosphorization reaction becomes insufficient with respect to the supply amount of oxygen. Therefore, in either case, it is not preferable from the viewpoint of improving the dephosphorization efficiency and concomitantly increasing the concentration of phosphoric acid in the slag.
- the CaO source added so as to satisfy the above-mentioned supply rate ratio is a CaO source that is sprayed onto the bath surface from above the bath surface using a carrier gas in the vessel.
- the effect is obtained by optimizing the feed rate ratio between the C and O sources. This is because FeO and phosphorous oxide (phosphorus oxide generated by the reaction of oxygen with [P] in the metal) generated by oxygen added to the furnace mainly exist on the metal bath surface. This is because the dephosphorization reaction is effectively promoted by supplying a Ca source to the bath surface and causing CaO to be present around the phosphor oxide.
- the entire amount of the CaO source to be added into the container is sprayed onto the bath surface from above the bath surface in the container by using a carrier gas. It is preferable that at least about 1 to 3 of the CaO source to be added is sprayed onto the bath surface from above the bath surface using a carrier gas.
- a top blowing lance As a means for spraying the bath surface from above the bath surface using a carrier gas, a top blowing lance is generally used, and nitrogen, an inert gas, or gaseous oxygen (pure oxygen gas or oxygen-containing gas) is used as a carrier gas. ) Is used.
- the oxygen source supplied into the container may be either gaseous oxygen or solid oxygen source, or both may be used in combination.
- the gaseous oxygen used may be either pure oxygen gas or an oxygen-containing gas, and iron oxide or milk scale may be used as a solid oxygen source.
- the acid can be supplied by any method such as top blowing with a lance, injecting into hot metal, or bottom blowing, and
- a solid oxygen source it can be supplied into the hot metal by any method such as injection or overhead charging.
- the dephosphorization reaction treatment is performed by up-blowing with a lance when using a converter type vessel or hot metal pot, and when using a torpedo, the lance is used. Injection into hot metal is common.
- gaseous oxygen pure oxygen gas or oxygen-containing gas
- gaseous oxygen that becomes at least a part of the oxygen source
- gaseous oxygen is blown up onto the bath surface together with the CaO source.
- the hot metal in order to further improve the dephosphorization reaction efficiency, it is preferable to agitate the hot metal with gas.
- This gas stirring is performed by blowing an inert gas such as a nitrogen gas or an argon gas into the hot metal through, for example, an injection lance or a bottom blowing nozzle.
- the supply amount of such stirring gas is 0.02 Nm Vmin / hot metal ton or more, and too strong stirring in the bath will reduce the rate of C reduction in the hot metal from the generated FeO to 0.3 Nm Vm in Z hot metal is preferably set to ton or less.
- C a F 2 amount of very small reduction or C a F 2 can be further enhanced dephosphorization efficiency under the conditions of no addition, as a result, concentration of phosphoric acid slag is further enhanced, produced more stably feedstock phosphate fertilizer (slag) is having excellent fertilizer characteristics Will be.
- a slag having a phosphoric acid concentration of generally 10 mass% or more (usually about 10 to 15 mass%) can be obtained.
- C a F 2 a without the use, by dephosphorization reaction treatment of hot metal, rather base to find a method capable of producing a high concentration of phosphoric acid slag have high dephosphorization reaction efficiency, a converter
- C a F 2 plays an important role in ensuring the slag's meltability, and even in our experiments, no C a F 2 was added or the amount added When the content was low, the added C a O source did not seem to be slag, and the efficiency of the dephosphorization reaction decreased.
- the dephosphorization reaction changes greatly depending on the supply rate of oxygen and the supply rate of CaO during repeated experiments.
- FeO is generated in the slag by supplying oxygen.
- the supply rate of oxygen is too low in the ratio of the supply rates of oxygen and CaO, the amount of FeO generated in the slag is small, and the CaO remains in a solid state and undergoes the dephosphorization reaction.
- gaseous oxygen when gaseous oxygen is blown onto the hot metal bath surface through the top blowing lance, a large amount of Fe0 is generated by the gaseous oxygen colliding with the bath surface, which is a very advantageous condition for promoting the slagging of the CaO source.
- gas oxygen is blown onto the hot metal bath surface through the upper blowing lance, and at least a part of the CaO source is blown through the upper blowing lance, particularly preferably the hot metal bath supplied with gaseous oxygen. Spraying on the surface region (ie, the region where FeO is generated) was found to be very effective in promoting the dephosphorization reaction.
- a CaO source and an oxygen source are added to the container holding the hot metal to cause a hot metal depolymerization reaction, which contains the phosphoric acid generated by the dephosphorization reaction.
- a hot metal depolymerization reaction which contains the phosphoric acid generated by the dephosphorization reaction.
- at least part of the gaseous oxygen and Ca0 source is sprayed onto the surface of the hot metal bath through a top blowing lance to perform a dephosphorization reaction on the hot metal.
- the supply rate B (kg / min / hot metal ton) of the CaO source blown onto the surface is the supply rate A (NmVm in in gaseous oxygen equivalent) of the oxygen source supplied into the vessel. / Hot metal ton) to satisfy the following equation (3).
- the supply rate B (kg / in / hot metal ton) of the CaO source and the supply rate A (gas Nm 3 / min / hot metal ton) preferably satisfies the following formula (4).
- the concentration of phosphoric acid in the slag generated during the above-mentioned hot metal dephosphorization reaction treatment depends on the P concentration in the hot metal before and after the treatment, the amount of slag generated, etc., but in general, it is 7 mass% or more. (Generally about 7 to 10 mass%), and a treatment under particularly preferable conditions can obtain a phosphoric acid concentration of 1 Omass% or more (generally about 10 to 15 mass%).
- the amount of FeO generated in the slag due to the supply of oxygen must be supplied at a supply rate that is commensurate with the amount of FeO generated. Is important, and if this balance is lost, the dephosphorization rate decreases.
- the AZB in the range of 1.2 to 2.5, the supply of oxygen
- the balance between the amount of Fe ⁇ produced and the amount of CaO supplied is further optimized, and particularly high dephosphorization efficiency can be obtained.
- the effect of optimizing the supply rate ratio of oxygen and CaO source in the present invention largely depends on the supply method of CaO source. That is, in the present invention, the CaO source added so as to satisfy the above formula (3), preferably the above formula (4), is supplied to the hot metal bath surface using a carrier gas from an upper blowing lance above the bath surface in the vessel. This is the source of the CaO that is sprayed on the surface, and this is the first time that the effect of optimizing the supply rate ratio between the oxygen and the CaO source can be obtained. This is because, as described above, FeO and phosphorous oxide (phosphorus oxide generated by the reaction of oxygen with [P] in hot metal) generated by oxygen added to the furnace are mainly present on the hot metal bath surface. This is because the dephosphorization reaction is effectively promoted by supplying a CaO source to the hot metal bath surface and causing CaO to be present around the phosphate.
- the CaO source added so as to satisfy the above formula (3), preferably the above formula (4) is supplied to the hot metal
- gaseous oxygen is blown onto the hot metal bath surface through the top blowing lance, but when gaseous oxygen is supplied in this manner, a large amount of FeO is generated by the gaseous oxygen that collides with the hot metal bath surface, so that C
- This is a very advantageous condition for promoting the slagging of the aO source, and the slagging of the CaO can be achieved by directly supplying the CaO source through the top blowing lance to the area where a large amount of FeO is generated. Can be effectively promoted.
- the CaO source is applied using a carrier gas other than gas oxygen (for example, an inert gas such as N 2 or Ar).
- gas oxygen for example, an inert gas such as N 2 or Ar.
- the hot metal bath surface may be sprayed, but even in this case, it is preferable to spray part or all of the CaO source onto the hot metal bath surface region to which gaseous oxygen is supplied (sprayed). This is because the hot metal bath area to which gaseous oxygen is supplied is the place where FeO is generated by oxygen supply, and the CaO slag is formed by directly adding CaO to such a bath surface area. Is effectively promoted, and the contact efficiency between CaO and FeO is increased, which can significantly promote the efficiency of the defamation reaction.
- a carrier gas other than gas oxygen for example, an inert gas such as N 2 or Ar.
- the CaO source is generated by the upward blowing of gaseous oxygen, especially in the hot metal bath surface area supplied with gaseous oxygen. Most preferably, it feeds into an area called the "fire point".
- This hot spot is the hot metal bath surface area where the temperature becomes the highest due to the collision of the gaseous oxygen gas jet, and the oxygen reaction due to gaseous oxygen is concentrated and is strongly stirred by the gaseous oxygen gas jet. It can be said that this is the region where the effect of the supply of the most remarkable is obtained.
- gaseous oxygen as a carrier gas for spraying the CaO source onto the hot metal bath surface.
- gaseous oxygen is blown onto the hot metal bath surface together with the Ca0 source, Since the CaO source is supplied directly to the fire point, the contact efficiency between CaO and FeO on the hot metal bath surface is maximized, and the dephosphorization reaction is particularly remarkably promoted. it can.
- the method of spraying the gaseous oxygen and CaO source onto the hot metal bath surface using the top blowing lance there is no particular limitation on the method of spraying the gaseous oxygen and CaO source onto the hot metal bath surface using the top blowing lance.
- some of the plurality of lance holes of the top blowing lance are used.
- the gaseous oxygen alone from the lance hole of the lance hole, and the gaseous oxygen or a gas other than the gaseous oxygen for example, an inert gas such as nitrogen or Ar
- an inert gas such as nitrogen or Ar
- a top lance with a main lance hole at the center of the tip of the lance and a plurality of sub lance holes around it.
- Gaseous oxygen is supplied from the sub lance hole, and gaseous oxygen or It is particularly preferable to supply a CaO source to the hot metal bath surface by using a gas other than the above-described gaseous oxygen as a carrier gas.
- the blowing of gaseous oxygen and the blowing of a CaO source using gaseous oxygen or a gas other than the gaseous oxygen described above as a carrier gas may be performed using different upper blowing lances.
- the carrier gas of the CaO source is gaseous oxygen in order to most effectively slag the CaO source.
- a converter type vessel is most preferable in that a sufficient free board can be secured, but other than this, a Ca ⁇ source may be sprayed on the hot metal bath surface.
- a container having a function of being able to remove water There is no particular limitation as long as it is a container having a function of being able to remove water.
- FIG. 10 shows one embodiment of the method of the present invention using a converter type vessel
- 1 is a converter type vessel
- 2 is an upper blowing lance
- 3 is a bottom blowing nozzle provided at the bottom of the furnace.
- the CaO source is blown from the top blow lance 2 to the hot metal bath surface using gaseous oxygen as a carrier gas, and the stirring gas is blown into the hot metal from the bottom blow nozzle 3.
- the effect of the present invention differs depending on the Si concentration in the hot metal before the dephosphorization reaction, and the present invention is applied to the hot metal whose Si concentration in the hot metal before the dephosphorization reaction is 0.1 O ma SS % or less. Particularly remarkable dephosphorization efficiency is obtained when the method is carried out.
- the concentration of Si in the hot metal before the dephosphorization reaction is high, the amount of generated Si 0 2 increases, the amount of CaO for adjusting the basicity increases, and the amount of generated slag increases. It is desirable to reduce it. In general, it S i 0 2 Many of producing hot metal in S i concentration before dephosphorization reaction treatment is high, the result, not only the amount of slag is increased, C a O amount for the basicity adjustment many become.
- molten pig iron in the S i concentration before dephosphorization reaction process in terms are preferably low, S i O 2 of the one hand, and molten pig iron in S i concentration before dephosphorization reaction treatment is lower slag Since the concentration is reduced, the melting property of CaO is further deteriorated, and the efficiency of the dephosphorization reaction is reduced. Nevertheless, in the case of the method of the present invention, the lower the Si concentration in the hot metal prior to the dephosphorization reaction treatment (preferably 0.10 ma SS % or less), the more the efficiency of the deaeration reaction is remarkably improved. .
- C for blowing in a O source powder bath surface of the C a O source is, S i 0 2 melt of C a O by F e O even in the absence of is promoted in the present invention method This is considered to be because as a result, the efficiency of contributing to the dephosphorization reaction of CaO is improved.
- the amount of slag generated can be reduced for the same reason as described in the first production method.
- the production method of the present invention is particularly effective when applied to hot metal having a Si concentration of 0.1 Omass% or less, and therefore, is applicable to hot metal having a Si concentration of 0.155% or less.
- the Si concentration of hot metal produced in a blast furnace or the like is 0.1 Omass% or less, the hot metal may be subjected to a dephosphorization reaction without performing the following desiliconization.
- the Si concentration of hot metal produced in a blast furnace, etc. exceeds 0.1 Omass%, desiliconization is performed in a blast furnace, a slab, a hot metal pot, etc.
- the dephosphorization reaction is performed after the Si concentration in the hot metal before treatment is reduced to 0.1 Oraass% or less.
- the details of the desiliconization process are as described above.
- the hot metal temperature is lower.
- the treatment can be carried out efficiently at a treatment end temperature of usually about 1280 to 1360 ° C. If the temperature of the hot metal is low, problems will arise in terms of the heat allowance in the next process.
- high dephosphorization reaction efficiency can be obtained even when the dephosphorization reaction temperature is high, so that the hot metal temperature at the end of the dephosphorization treatment should be 1 360 ° C or more, which was difficult with the conventional technology. Can be.
- the hot metal temperature at the end of the treatment is not only in the above-mentioned temperature range of 1280 1 360 ° C, but also in the higher temperature range of 1360 1450 ° C. Processing can be performed with high dephosphorization reaction efficiency.
- the dephosphorization reaction is an oxidation reaction of P, it is conventionally advantageous to use a lower hot metal temperature. It is a common sense that this is the case, and in the past it was thought that treating at a high hot metal temperature would restore slag to metal. For this reason, conventionally, it has been considered that it is difficult to perform the treatment in a high-temperature region exceeding 136 ° C.
- the present inventors have made the slag basicity lower by reducing the Si concentration in the hot metal subjected to the dephosphorization reaction.
- S i concentration 0. Relative to 1 O mass% or less of molten iron, not substantially added C a amount of F 2 below 1 kg / molten pig iron ton or C a F 2 Perform processing under conditions. Thereby, even when the temperature of the hot metal at the end of the treatment is set to 1360 ° C to 1450 ° C, a high delacitation effect can be obtained.
- Figure 1 1 is a converter-type vessel in (3 0 0 t 0 n) perform dephosphorization reaction treatment of molten iron under the condition of adding no C a F 2, molten iron temperature on removal ⁇ rate (dephosphorization lime efficiency) ( The effects of the hot metal temperature at the end of the dephosphorization treatment) and the Si concentration in the hot metal before the dephosphorization reaction were investigated.
- dephosphorization lime efficiency shown in FIG. 1 the fraction of lime contributed to the dephosphorization reaction to the total lime added as C a O source (burnt lime), phosphorus oxide is 3 C a O ⁇ P 2 0 assuming that it is fixed as 5 those derived from the stoichiometric ratio.
- the blast furnace hot metal was desiliconized in a hot metal bed and a hot metal pot as needed, then desulfurized in the hot metal pot, and the hot metal was transferred to a converter-type vessel for dephosphorization.
- the Si concentration of the hot metal subjected to the dephosphorization reaction and the hot metal temperature after the treatment were varied.
- Oxygen gas was mainly used as the oxygen source, and this was added by spraying it onto the hot metal bath surface from the top blowing lance, and for some, the addition of a solid acid source (iron ore) was also used. Desiliconization out oxygen content was controlled in the range of between 1:10 LNM 3 Z hot metal ton.
- the time for the dephosphorization reaction was set to 10 to 11 minutes, and the temperature of the hot metal after the dephosphorization reaction was controlled by adjusting the hot metal temperature and the amount of scrap added before the dephosphorization reaction.
- ⁇ represents a test example in which a CaO source was added by overhead charging and the hot metal temperature at the end of the dephosphorization reaction was set at 1280 to 1350 ° C.
- the hot metal temperature at the end of the phosphorus reaction treatment was 1360 to 1450 ° C (CaO source addition: spraying onto the hot metal bath surface)
- the temperature was set to 1280 to 1360 ° C (adding a CaO source: spraying onto the hot metal bath surface).
- the addition amount of the CaO source was varied in the range of 5-30 kg / hot metal ton according to the Si concentration in the hot metal.
- the dephosphorization lime efficiency when the treatment end temperature is set to the high temperature side in the method of the present invention is almost the same as the case where the treatment end temperature is set to 1280 to 1360 ° C in the method of the present invention. It can be seen that high dephosphorization efficiency can be obtained even by high-temperature treatment in the invention method. At low temperatures, the dephosphorization reaction is more advantageous on average, but the results in Fig. 11 show that in the method of the present invention, the dephosphorization rate depends on the slag melting property and the immobilization of the dephosphorized product. It is considered that this was due to a decrease in.
- the amount of C a F 2 is improved dephosphorization stone ash efficiency becomes less than 1 kg / molten pig iron ton.
- C a F 2 has a function of accelerating the melting of C a ⁇ , and the addition of C a F 2 increases the liquid phase ratio of the slag.
- the treatment temperature hot metal temperature
- the rate of rephosphorization from slag to metal increases and the equilibrium value increases. It is thought that the efficiency of dephosphorized lime deteriorates because it is easily approached. Therefore, in order to improve the dephosphorization efficiency treatment temperature (hot metal temperature) as 1 3 60 ° C or higher minimizes (LKG / hot metal ton or less or substantially no addition) the amount of C a F 2 Is preferred.
- the hot metal temperature at the end of the dephosphorization reaction must be 1450 ° C or lower.
- the phosphoric acid concentration of the slag is increased.
- the Si content in the hot metal before the dephosphorization reaction is low, the S i 0 2 amount is small, moreover the addition amount of C a O amount for the basicity adjustment more to less amount of slag is extremely small to be generated.
- a very small amount of C a F 2 is added because high dephosphorization efficiency is obtained, or it is possible to perform processing without substantially adding a F 2.
- a raw material (slag) for phosphorous fertilizer having a very low fluorine content and a high phosphoric acid concentration can be produced.
- the temperature of the hot metal before the dephosphorization reaction is about 125 ° C to 135 ° C, but the method of adjusting the hot metal temperature at the end of the dephosphorization reaction is usually a method in which scrap is melted.
- a method of suppressing the amount of scrap input may be mentioned.
- a method of adjusting the amount of a solid oxygen source such as sintering powder may be used. Therefore, the hot metal temperature at the end of the treatment may be adjusted in the range of 1360 ° C to 1450 ° C by such a method.
- the hot metal temperature during the dephosphorization reaction is calculated from the gas composition analysis value of the exhaust gas generated by the defaying reaction and the exhaust gas temperature. Is the easiest to control based on That is, in this method, the exhaust gas is analyzed for gas composition to obtain CO and CO 2 concentrations, and the amount of generated gas is calculated from the exhaust gas temperature. The calorific value in the furnace is calculated from these, and the hot metal temperature can be calculated based on the calorific value.
- gaseous oxygen is blown onto the hot metal bath surface through the top blowing lance, but according to such a supply form of gaseous oxygen and a Ca ⁇ source, the above-mentioned restoration rate can be further reduced.
- the invention can be implemented particularly advantageously. That is, in this supply mode, powder is used as the CaO source, and the CaO source is supplied to the hot metal bath surface region where a large amount of FeO is generated by gas oxygen colliding with the bath surface as described above. Since it is supplied directly, the area where CaO (CaO source) comes into contact with FeO is greatly increased as compared with the method of placing lump lime on top. Therefore, P oxidized by F e O.
- a CaO source and an oxygen source are added to a pot-type or torpedo-car-type container holding hot metal to cause a dephosphorization reaction of the hot metal, and the phosphoric acid
- gas oxygen and at least a portion of the CaO source are sprayed onto the hot metal bath surface through the top blowing lance, and powder is contained through the immersion lance or Z and the blowing nozzle. Gas is blown into the hot metal.
- the phosphoric acid concentration in the slag generated during the above dephosphorization reaction of hot metal depends on the P concentration in the hot metal before and after the treatment, the amount of slag generated, etc. (Usually about 7 to 10 raass%), and a treatment under particularly favorable conditions can obtain a phosphoric acid concentration of 10 niass% or more (usually about 10 to 15 mass%).
- gaseous oxygen is blown onto the hot metal bath surface through the top blowing lance, a large amount of FeO is generated by the gaseous oxygen that collides with the bath surface, which is a very advantageous condition for promoting the slagging of the CaO source.
- the amount of gaseous oxygen (acid supply amount) blown from the top blowing lance to the hot metal bath surface is 0.7 ⁇ ⁇ 3 / min / hot metal ton or less. If the amount of acid sent from the upper blowing lance is excessive, slag forming may cause slag to be blown out of the processing vessel. By controlling the amount of acid sent from the top blowing lance to 0.7 Nm 3 Zmin / hot metal ton or less, slag forming can be suppressed and stable operation can be achieved. '
- CaO sources such as lime powder, dust generated in steelworks such as converter dust, coke powder, etc. carbonaceous material, iron oxide, such as sintered powder and mill scale can be used C a C0 3, C a ( OH) 2, C aMg (C0 3) 1 or more kinds of powder, such as 2 .
- C a C0 3, C a (OH) 2, powder such as C a M g (CO 3) 2 is thermally decomposed to generate a gas (C0 2, H 2 0) in the hot metal, This gas contributes to strengthening the stirring of the bath, and Ca 0 generated by thermal decomposition functions as a CaO source.
- C aMg (C0 3) 2 is, M g to migrate to the slag is an effective component of fertilizer among them.
- the iron oxide powder becomes a part of the oxygen source in the bath.
- gaseous oxygen pure oxygen gas or oxygen-containing gas
- inert gas such as N 2 or Ar, etc.
- the type of gas to be used may be selected in consideration of the total cost including the life of the lance and the nozzle.
- an immersion lance As a means for blowing the CaO source into the hot metal, an immersion lance, a blowing nozzle provided in a hot metal holding container, or both can be used.
- a blowing nozzle any type such as a bottom blowing nozzle and a side blowing nozzle can be used.
- the addition rate X (kg / min) of the CaO source and the addition rate Y ( ⁇ mmin) of the gaseous oxygen through the top blowing lance are as follows ( By spraying the CaO source and gaseous oxygen onto the hot metal bath surface so as to satisfy equation 5), the dephosphorization efficiency can be further improved.
- the addition amount of the CaO source through the blowing lance is preferably 20 to 80 mass% of the total addition amount of the CaO source. If the ratio of the CaO source blown to the hot metal bath surface through the top blowing lance exceeds 80 mass% of the total amount of the Ca source, the stirring effect of the hot metal by blowing the Ca The small size makes it difficult to obtain the stirring power required for the dephosphorization reaction. On the other hand, if it is less than 20 mass %, the above-mentioned effect of promoting slag formation by spraying the Ca0 source onto the hot metal bath surface cannot be sufficiently obtained.
- Fig. 14 shows the case where the entire amount of Ca ⁇ source is added by spraying onto the hot metal bath surface through the top blowing lance and blowing into the hot metal through the immersion lance or / and the blowing nozzle.
- C a through top blowing lance based on test results performed by the inventors This shows the relationship between the ratio of the added amount of the O source to the total amount of the added Ca O source and the dephosphorization efficiency.
- concentration of P retained in a pot-shaped vessel (150 ton): 0.10 ⁇ 0.1 lmass%, Si concentration: 0.02 ⁇ 0.09mass% hot metal (hot metal temperature: 1300 ⁇ 1320 ° C), oxygen gas (4.5-5.
- Lime powder (0 to 6 kg / hot metal ton) is sprayed onto the hot metal bath from the top blowing lance while the remaining lime content (0 to 61 ⁇ ⁇ hot metal 1 on)
- treatment time 15 minutes.
- the ratio A / B between the addition rate A (kg / min) of the CaO source through the top blowing lance and the addition rate B (NmVmin) of gaseous oxygen was set to 0.5.
- the ratio of the amount of CaO source added through the top blowing lance to the total amount of CaO source added is less than 20 niass%, and the dephosphorization efficiency is significantly reduced in the region over 80 mass%. I have.
- the Si concentration in the hot metal subjected to the dephosphorization reaction is preferably set to 0.10 mass% or less.
- the hot metal in the S i concentration before dephosphorization is low, the melting of the C a O is worsened because the S i O 2 concentration is decreased in the slag, dephosphorization efficiency is lowered.
- the lower the Si concentration in the hot metal before the dephosphorization treatment (0.10 mass% or less), the higher the dephosphorization efficiency.
- FIG. 15 shows an example of the relationship between the Si concentration in the hot metal and the amount of lime required for the dephosphorization reaction treatment before the dephosphorylation treatment according to the present invention.
- the case where the CaO source was supplied only by in-bath injection without blowing upward onto the hot metal bath surface is also shown.
- oxygen gas 4.5 to 5 Nm 3 / hot metal ton
- an amount of C corresponding to the Si concentration in the hot metal is determined.
- An aO source (lime powder: 4 to 10 kg g hot metal ton) was sprayed onto the hot metal bath from the top blowing lance.
- the lime ratio of this top blow was set to 0.5, and the remaining required lime (2 to 5 kgZ hot metal ton) was injected from the immersion lance into the hot metal.
- all of the CaO source (lime powder) was injected into the hot metal from the immersion lance.
- the treatment time was 15 minutes, and C a F 2 was not added.
- FIG. 15 shows the amount of lime required for the P concentration after treatment to be 0.02 mass% or less.
- the hot metal may be subjected to a dephosphorization reaction without performing the following desiliconization.
- desiliconization treatment is performed in a blast furnace cryon bed or hot metal ladle prior to the dephosphorization reaction treatment, and It is desirable to carry out the dephosphorization reaction after the concentration of Si in the hot metal before the phosphorus reaction is reduced to 0.10 mass% or less.
- the details of the desiliconization treatment are as described above.
- the hot metal temperature at the start of the dephosphorization reaction treatment be set to 1280 ° C or higher.
- Fig. 16 shows an example in which the present invention is applied when performing hot metal dephosphorization in a blast furnace pot type dephosphorization facility.
- desiliconization such as bed desiliconization is performed before dephosphorization.
- hot metal is put into a blast furnace pot 4 and lime powder (refining agent) is injected from a lance 5 immersed in the hot metal, and at the same time, lime powder (purifying agent) is mixed with gaseous oxygen from a top blowing lance 6 in a hot metal bath. Blowing on the face Squeak.
- the supply speed of the lime powder to be injected should be such that the molten iron is sufficiently stirred.
- the gaseous oxygen used in these production methods may be either pure oxygen gas or oxygen-containing gas.
- a solid oxygen source such as iron oxide (for example, sintered powder or mill scale) can be used in addition to gaseous oxygen. It can be added by an arbitrary method such as induction.
- 50% or more of the oxygen source added to the hot metal holding vessel preferably It is desirable that 70% or more (gas oxygen equivalent amount) be gas oxygen supplied to the hot metal bath surface through the top blowing lance.
- Lime is usually used as the CaO source. Powder is used as the CaO source to be sprayed onto the hot metal bath surface through the top blowing lance.
- the C a O source may be partially added to the hot metal bath surface by means of overhead charging or injection into the bath, instead of spraying onto the hot metal bath surface by the top blowing lance.
- the amount of the CaO source added by the method described in (1) is preferably not more than 70 1 ⁇ 53%, more preferably not more than 20 mass% of the entire Ca0 source. If the proportion of the Ca source added by a method other than spraying onto the hot metal bath by the top blowing lance exceeds 70 nmss% of the total, the Ca O source is blown onto the hot metal bath with gaseous oxygen. The effect of accelerating the dephosphorization reaction tends to decrease.
- the hot metal in order to further improve the dephosphorization reaction efficiency, it is preferable to agitate the hot metal with gas.
- This gas stirring is performed by blowing an inert gas such as a nitrogen gas or an argon gas into the hot metal through, for example, an injection lance or a bottom blowing nozzle.
- the supply amount of such stirring gas is 0.02 Nm 3 / min / hot metal ton or more, and too strong stirring of the bath will reduce the rate of C reduction in the hot metal to the generated FeO, which is 0.3 NmVm in / hot metal. It is preferable to set it to ton or less.
- the melting point of the slag increases, and the initial slagging of the CaO source may be insufficient.
- it is effective to increase the temperature of the hot metal at the start of the dephosphorization reaction to promote the initial slagging and to generate molten Fe at an early stage.
- the hot metal temperature at the start of the dephosphorization reaction be 1280 ° C or higher.
- Temperature conditions are important for the dephosphorization reaction, and a lower hot metal temperature is more advantageous for dephosphorization.However, as described above, since the oxidation reaction is promoted and Ca O When gaseous oxygen is supplied to the hot metal bath surface, the temperature of the hot metal rises in the hot metal bath surface region to which the gaseous oxygen has been supplied, and this is a factor inhibiting the dephosphorization reaction.
- the present inventor has studied a method of setting the hot metal bath surface area to which gaseous oxygen is supplied to a temperature condition advantageous for the dephosphorization reaction, and as a result, the hot metal to which gaseous oxygen is supplied bath
- gaseous oxygen is supplied without impeding the slagging promotion of CaO source by gaseous oxygen. It has been found that the temperature rise in the hot metal bath surface region is appropriately suppressed and high dephosphorization reaction efficiency can be obtained.
- the hot metal bath surface region to which the gaseous oxygen is supplied is subjected to a chemical reaction and / or a thermal decomposition reaction. It is preferable to supply a substance that absorbs the heat of the heat (hereinafter referred to as “endothermic substance”).
- the endothermic substance is supplied to a so-called "fire point" generated by the acid supply by the top blowing acid lance in the hot metal bath surface area to which gaseous oxygen is supplied.
- the hot metal bath surface region to which gaseous oxygen is supplied (particularly preferably, the above-mentioned “fire point” region) a
- the method of spraying (projecting) the 0 source using gaseous oxygen or another carrier gas is a collision field of the gaseous oxygen gas jet on the hot metal bath surface, that is, the oxidation reaction by gaseous oxygen is concentrated and gaseous oxygen gas
- the CaO source By directly supplying the CaO source to the region where the jet is strongly agitated (the main product of FeO), slagging of CaO is effectively promoted, and CaO
- the contact efficiency of FeO increases, and the conditions for contact between CaO and FeO are optimized, whereby the dephosphorization reaction can be particularly remarkably promoted.
- the endothermic substance is directly supplied to the above-mentioned region where the oxidation reaction due to gaseous oxygen is concentrated and strongly stirred by the gaseous oxygen gas jet, and the rise of the hot metal temperature in that region is suppressed, whereby degassing is performed.
- the phosphorus reaction can be further effectively promoted.
- the endothermic substance a special substance is used as long as it is a substance that removes heat from the hot metal by a chemical reaction, a pyrolysis reaction, or both reactions when added to the hot metal. No restrictions. Therefore, this endothermic substance may be either gas or solid.
- Examples of the gas that can be used as the endothermic substance include carbon dioxide, water vapor, and nitrogen oxide (NOx), and one or more of these can be used.
- These gases endothermic compound reacts mainly F e by being supplied to the hot metal bath surface (e.g., C0 2 + F e ⁇ F e 0 + CO, H 2 O + F e ⁇ F e O + H 2) At that time, the hot metal absorbs heat.
- F e oxidation with gaseous oxygen (F e + 1/20 2 ⁇ F e O) or or the heat generation amount becomes endothermic total is significantly reduced.
- Examples of the solid that can be used as the endothermic substance include metal carbonates and metal hydroxides, particularly preferably alkali metal and alkaline earth metal carbonates and hydroxides. Can be used. These solid endothermic compound mainly cause thermal decomposition reaction by being supplied to the hot metal bath surface, performs an endothermic hot metal At that time, by the thermal decomposition to produce a C0 2 or H 2 0, the CO 2 or Since H 20 further functions as an endothermic substance as described above, a particularly high endothermic effect is obtained.
- Such metal carbonates C a C_ ⁇ 3, C aMg (C0 3) 2, Mg C0 3, Na C0 3, F e C0 3, Mn C0 3, N a HC 0 3 ( bicarbonate Na thorium), and the like, and as the hydroxide of the metal is C a (OH) 2, Mg (OH) 2, B a (OH) 2, a 1 (OH) 3 F e (OH) 2, Mn ( OH) n, Ni (OH) n and the like, and one or more of these can be used.
- C a C0 3 Among these solid endothermic compound, C a (OH) 2, C aMg (C o 3) 2 is not only readily available, C a O is produced by the thermal decomposition , this. It is particularly preferred because aO has the great advantage of functioning as a CaO source. When CaMg (CO 3) 2 is used, Mg transferred to the slag becomes an effective ingredient of the fertilizer. Usually, these solid endothermic substances are added in the form of unfired or semi-fired limestone or dolomite.
- the solid endothermic substance is preferably a powder having an average particle diameter of 5 mm or less, because if the particle size is too large, thermal decomposition or the like does not proceed rapidly.
- gas endothermic substance and the solid endothermic substance as described above may be used in combination, and the gas endothermic substance may be used as part or all of the carrier gas when the solid endothermic substance is supplied to the hot metal bath surface.
- Top-blowing lance spraying onto the hot metal bath surface by another lance, charging on top (using a solid endothermic substance, etc.
- the endothermic substance can be reliably supplied to the hot metal bath surface region (particularly preferably, "fire point") to which gaseous oxygen has been supplied, and the effect described above can be obtained.
- C a C O 3 , C a (OH) 2 , C aMg (C 0 3 ) 2 generate C a O by thermal decomposition, and this C a O is used as a C a O source. Therefore, the solid endothermic substance is supplied in place of part or all of the CaO source, and the CaO generated from this substance is converted into a substantial CaO source. Dephosphorization may be performed partially or entirely. That is, in this case, instead of part or all of the CaO source, a CaO source-generating substance and a chemical reaction or thermal decomposition reaction are applied to the hot metal bath surface area to which gaseous oxygen is supplied.
- C a O source generation. endothermic compound the hot metal of the heat as a substance which absorbs heat, C a C 0 3, C a (OH) 2, C aMg (C0 3) 1 or more selected from among 2 (hereinafter referred to as "C a O source generation. endothermic compound” ).
- the heat of the hot metal is absorbed by thermal decomposition of the C a O source generation / endothermic substance supplied to the hot metal bath surface, and the C a O And ⁇ 2 or 11 20 which is an endothermic substance is generated.
- the method of adding the C a O generating / endothermic substance may be the same as that of the above-mentioned endothermic substance. Also, in this case, for the same reason as described above, the above-mentioned C a O source generation-endothermic substance is generated in the hot metal bath surface area to which gaseous oxygen is supplied, particularly by the acid supply by the top blowing lance. It is preferred to supply to an area called "".
- a single dephosphorization reaction treatment is performed on a hot metal having a P concentration of 0.2 mass S % or less to obtain a fluorine-containing material. It is possible to efficiently and inexpensively produce a raw material (slag) for a phosphate fertilizer having an extremely small amount and containing a high concentration of phosphoric acid.
- hot metal with high P concentration obtained from high phosphate iron ore having a P content of 0.06 mass% or more can be subjected to dephosphorization reaction with high dephosphorization reaction efficiency.
- a raw material (slag) for phosphate fertilizer having a particularly high phosphoric acid concentration can be produced.
- the raw material for phosphate fertilizer of the present invention is not limited to the slag obtained by the above-described production method.
- a supply form of the CaO source a immersion nozzle or a bottom blowing nozzle may be used.
- a slag obtained by a method of blowing a source into hot metal may be used.
- Dephosphorization of hot metal from blast furnace was carried out using a 300 t converter.
- a specified amount of CaO source was added after the hot metal was charged into the converter, and oxygen was blown from the top blowing lance. Note that the dephosphorization reaction was performed in the same processing time in both the present invention example and the comparative example.
- the dephosphorization reaction was carried out without desiliconizing the hot metal that had been tapped.
- the hot metal that had been tapped was de-siliconized or de-siliconized + ladle de-siliconization.
- a defatting reaction treatment was performed.
- C a F 2 was not added.
- Table 2 shows the conditions for the dephosphorization reaction and the composition of the produced slag.
- the dephosphorization treatment was performed after reducing the Si content in the hot metal to 0.07 mass% or less (particularly, 0.03 mass./. Or less).
- the phosphorus removal efficiency was dramatically improved as compared with the comparative example, and the amount of slag produced was small, so that a raw material for phosphate fertilizer having a high phosphoric acid concentration was obtained.
- C a F 2 is not added, the fluorine content (the contained fluorine is an impurity) is small.
- Hot metal from the blast furnace is desiliconized in the hot metal ladle and, if necessary, in the hot metal ladle, then desulfurized in the hot metal ladle using mechanical stirring, and then dephosphorized in a 250 ton converter.
- the reaction was processed.
- the hot metal temperature before and after this dephosphorization reaction treatment was set to 125 0 150 ° C, and the CaO source was calcined lime mainly composed of CaO, which was sieved with a particle size of 200 mesh or less.
- the basic unit of CaO was set to 5 15 kg / hot metal ton according to the Si concentration in the hot metal.
- a CaO source was The source of C a O and the source of oxygen were supplied (blowing time: 10 minutes) by blowing hydrogen onto the bath surface as carrier gas. At that time, the oxygen supply rate A (NmVm in hot metal ton) and C a The operation was carried out under various conditions where the ratio A ZB to the supply rate B (kgin hot metal ton) of the O source was different. Note that C a F 2 was not added. Nitrogen gas was blown into the hot metal from the bottom blow nozzle at the flow rate of 0.05 to 0.15 NmVmin / hot metal ton from the bottom blowing nozzle at the furnace bottom.
- the Si concentration in the hot metal subjected to the dephosphorization reaction was tr. To 0.3 mass%.
- the P concentration in the hot metal after the dephosphorization reaction is 0.015 mass% or less, which is the target [P] concentration, in all cases where the A / B is less than 0.3 and more than 7 Has not been reached.
- Table 3 shows typical compositions of the slag obtained in the examples of the present invention.
- Table 3 Slag composition (mass%) Phosphoric acid solubility
- Hot metal from the blast furnace is desiliconized in the hot metal ladle and, if necessary, in the hot metal ladle, then desulfurized in the hot metal ladle using mechanical stirring, and then dephosphorized in a 250 ton converter. I understood.
- the hot metal temperature at the end of this dephosphorization reaction was in the range of 1360 to 1450 ° C.
- the CaO source calcined lime mainly composed of CaO and sieved with a particle size of 200 mesh or less was used. .
- a CaO source was blown through the top blowing lance with oxygen as a carrier gas to the bath surface, and the oxygen supply rate A (NmVmin / hot metal ton) and the CaO source
- the CaO and oxygen sources were supplied (blowing time: 10 minutes) under the condition that the ratio A / B to the supply rate B (kgin hot metal ton) satisfied 0.3 to 7. Note that C a F 2 was not added.
- Nitrogen gas was blown into the hot metal from the bottom blowing nozzle at the flow rate of 0.05 to 0.15 NmVmin / hot metal ton from the bottom blowing nozzle at the furnace bottom.
- Table 4 shows the composition of the slag obtained in this example.
- hot metal from the blast furnace After hot metal from the blast furnace is desiliconized on a hot bed, it is received in a hot metal ladle, desiliconized in the hot metal ladle, discharged, and then subjected to a 300 ton conversion for dephosphorization reaction. Hot metal was charged into the furnace. In the dephosphorization reaction, oxygen gas is blown to the hot metal bath surface through the top blowing lance.
- lime powder with a particle size of 3 mm or less is sprayed onto the hot metal bath surface, and the oxygen supply rate A (Nn ⁇ / min / hot metal ton) and the supply rate of the CaO source B (k).
- the gaseous oxygen and Ca ⁇ sources were added under the condition that the ratio A / B to gZm in / hot metal ton) satisfied 0.3 to 7. Further, the temperature of the processing end Ryoji In this process in the range of 1 360 ⁇ 1450 ° C, C a F 2 was not added.
- Nitrogen gas was blown in from the bottom of the converter at a supply rate of 0.1 Nm 3 / min / hot metal ton, and the hot metal was agitated to perform a defatting reaction for 10 to 11 minutes.
- the hot metal temperature at the end of the dephosphorization reaction was controlled by adjusting the hot metal temperature before the dephosphorization reaction and the amount of scrap added.
- Table 5 shows the composition of the slag obtained in this example.
- Hot metal from the blast furnace is desiliconized on a cymbal bed, it is received in a hot metal ladle, desiliconized in the hot metal ladle, discharged, and then subjected to 300 ton conversion for dephosphorization reaction. Hot metal was charged into the furnace.
- the oxygen gas through the top lance with attached can blow the hot metal bath surface
- the C a C0 3 is a particle size less than 1 mm of lime powder and the endothermic material the oxygen gas as Kiyariagasu the molten iron bath surface spraying, oxygen supply rate a of (Nm 3 / in i nZ hot metal ton) and C a O source feed rate B (kg / min hot metal ton) gas under the condition that the ratio AZB satisfies 0.3 to 7 with oxygen And a C a O source were added. Further, the molten iron temperature during processing is completed in this process was in the range of 1360 ⁇ 1450 ° C, C a F 2 was not added.
- Nitrogen gas was blown from the bottom of the converter at a supply rate of 0.1 Nm 3 / in in / hot metal ton, and the hot metal was stirred and dephosphorized for 10 to 11 minutes.
- the hot metal temperature at the end of the dephosphorization reaction was controlled by adjusting the hot metal temperature and the amount of scrap added before the dephosphorization reaction.
- Table 6 shows the composition of the slag obtained in this example.
- the hot metal discharged from the blast furnace is desiliconized on the hotbed, it is received in a hot metal ladle, desiliconized in the hot metal ladle, discharged, and then transferred to the dephosphorization station. Then, a dephosphorization reaction treatment was performed.
- Phosphoric acid fertilizer raw materials which consist of slag containing phosphoric acid generated by the hot metal depolymerization reaction, were ground to a particle size of 1 mm or less.
- the pulverized product was weighed in a predetermined amount, and various binders shown in Table 8 were added and mixed to adjust the water content, and then granulated with a rotary dish granulator for testing.
- the granulated product was dehydrated and dried at 100 ° C. in a small box drier, and then sieved to obtain a sample having a particle size of 1 to 5 mm and a No. 1 to 0.5. These samples were evaluated for granulation properties, hardness, and underwater breakability.
- the raw material for phosphate fertilizer of the present invention has a high concentration of phosphoric acid and a required concentration of soluble phosphoric acid, it is useful for producing a phosphate fertilizer having excellent fertilizer characteristics.
- the method for producing a raw material for phosphate fertilizer of the present invention is useful as a method for producing a raw material for fertilizer fertilizer having excellent fertilizer characteristics, since slag having a high phosphoric acid concentration and extremely low fluorine content can be produced. It is something.
Landscapes
- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Inorganic Chemistry (AREA)
- Fertilizers (AREA)
- Refinement Of Pig-Iron, Manufacture Of Cast Iron, And Steel Manufacture Other Than In Revolving Furnaces (AREA)
Description
Claims
Priority Applications (6)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
KR10-2003-7014925A KR20040010645A (ko) | 2001-05-17 | 2002-05-17 | 인산비료용 원료 및 그 제조방법 |
JP2002589425A JP4211396B2 (ja) | 2001-05-17 | 2002-05-17 | 燐酸肥料用原料 |
BR0209829-6A BR0209829A (pt) | 2001-05-17 | 2002-05-17 | Matéria-prima para fertilizante de fosfato e método para a fabricação do mesmo |
EP02728078A EP1391445A1 (en) | 2001-05-17 | 2002-05-17 | Material for phosphate fertilizer and method for production thereof |
CA002447411A CA2447411A1 (en) | 2001-05-17 | 2002-05-17 | Raw material for phosphate fertilizer and method for manufacturing same |
US10/476,783 US20040163435A1 (en) | 2001-05-17 | 2002-05-17 | Material for phosphate fertilizer and method for production thereof |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2001-147811 | 2001-05-17 | ||
JP2001147811 | 2001-05-17 |
Publications (1)
Publication Number | Publication Date |
---|---|
WO2002092537A1 true WO2002092537A1 (fr) | 2002-11-21 |
Family
ID=18993234
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/JP2002/004785 WO2002092537A1 (fr) | 2001-05-17 | 2002-05-17 | Materiau pour engrais phosphate et procede de production associe |
Country Status (8)
Country | Link |
---|---|
US (1) | US20040163435A1 (ja) |
EP (1) | EP1391445A1 (ja) |
JP (1) | JP4211396B2 (ja) |
KR (1) | KR20040010645A (ja) |
CN (1) | CN1509261A (ja) |
BR (1) | BR0209829A (ja) |
CA (1) | CA2447411A1 (ja) |
WO (1) | WO2002092537A1 (ja) |
Cited By (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2009132544A (ja) * | 2007-11-28 | 2009-06-18 | Nippon Steel Corp | スラグの製造方法 |
JP2012007189A (ja) * | 2010-06-22 | 2012-01-12 | Jfe Steel Corp | 製鋼スラグからの鉄及び燐の回収方法並びに高炉スラグ微粉末または高炉スラグセメント及び燐酸資源原料 |
JP2015140294A (ja) * | 2014-01-30 | 2015-08-03 | Jfeスチール株式会社 | リン酸質肥料原料、リン酸質肥料およびその製造方法 |
JP2016074940A (ja) * | 2014-10-06 | 2016-05-12 | 新日鐵住金株式会社 | 脱リンスラグ及びリン酸肥料原料の製造方法 |
JP2016088757A (ja) * | 2014-10-29 | 2016-05-23 | 新日鐵住金株式会社 | リン酸肥料原料及びその製造方法 |
JP2017031013A (ja) * | 2015-08-03 | 2017-02-09 | 新日鐵住金株式会社 | リン酸肥料原料及びその製造方法 |
Families Citing this family (10)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP5332651B2 (ja) * | 2008-12-26 | 2013-11-06 | Jfeスチール株式会社 | 製鋼スラグからの鉄及び燐の回収方法 |
KR101108336B1 (ko) * | 2009-06-18 | 2012-01-25 | 주식회사 효석 | 페로니켈 슬래그를 이용한 토양개량비료 제조방법 |
CN102363580A (zh) * | 2011-10-20 | 2012-02-29 | 瓮福(集团)有限责任公司 | 一种利用磷肥厂污水渣制备磷肥的方法 |
KR101321849B1 (ko) * | 2011-12-12 | 2013-10-22 | 주식회사 포스코 | 매용제 및 이를 이용한 생석회의 재화 촉진 방법 |
KR101321850B1 (ko) * | 2011-12-12 | 2013-10-22 | 주식회사 포스코 | 용강 제조 방법 |
KR101353208B1 (ko) * | 2011-12-15 | 2014-01-20 | 주식회사 포스코 | 용강에 대한 탈린 및 탈황 방법 |
CN109641810A (zh) * | 2017-06-28 | 2019-04-16 | 新日铁住金株式会社 | 肥料原料用炼钢炉渣、肥料原料用炼钢炉渣的制造方法、肥料的制造方法及施肥方法 |
AU2018282388B2 (en) * | 2017-06-28 | 2019-09-19 | Nippon Steel Corporation | Steelmaking slag for fertilizer raw material, method for producing steelmaking slag for fertilizer raw material, method for producing fertilizer, and fertilizer application method |
CA3078912A1 (en) * | 2017-10-20 | 2019-04-25 | Nippon Steel Corporation | Method of dechromizing molten iron and method of manufacturing phosphate fertilizer raw material |
WO2020189647A1 (ja) * | 2019-03-15 | 2020-09-24 | 日本製鉄株式会社 | リン酸肥料原料の製造方法 |
Citations (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS56127717A (en) * | 1980-03-11 | 1981-10-06 | Nippon Steel Corp | Steel making process discharging slag suited as phosphatic fertilizer |
US4525197A (en) * | 1974-02-13 | 1985-06-25 | Schering Aktiengesellschaft | Fertilizer |
JPH02172883A (ja) * | 1988-12-26 | 1990-07-04 | Oji Kenzai Kogyo Kk | 肥料用造粒剤 |
JPH02277709A (ja) * | 1989-04-19 | 1990-11-14 | Kawasaki Steel Corp | 溶銑予備処理スラグからの燐酸質肥料用原料回収法 |
JPH11158526A (ja) * | 1997-11-28 | 1999-06-15 | Sumitomo Metal Ind Ltd | 高pスラグの製造方法 |
Family Cites Families (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4804401A (en) * | 1985-04-17 | 1989-02-14 | Wahlberg Arvo | Method of producing a phosphorus fertilizer soil conditioner |
FI73192C (fi) * | 1985-04-17 | 1987-09-10 | Arvo Wahlberg | Foerfarande foer framstaellning av kombinerat fosforgoedselmedel och jordfoerbaettringsmedel. |
-
2002
- 2002-05-17 CN CNA028100794A patent/CN1509261A/zh active Pending
- 2002-05-17 CA CA002447411A patent/CA2447411A1/en not_active Abandoned
- 2002-05-17 KR KR10-2003-7014925A patent/KR20040010645A/ko active IP Right Grant
- 2002-05-17 EP EP02728078A patent/EP1391445A1/en not_active Withdrawn
- 2002-05-17 US US10/476,783 patent/US20040163435A1/en not_active Abandoned
- 2002-05-17 WO PCT/JP2002/004785 patent/WO2002092537A1/ja not_active Application Discontinuation
- 2002-05-17 JP JP2002589425A patent/JP4211396B2/ja not_active Expired - Lifetime
- 2002-05-17 BR BR0209829-6A patent/BR0209829A/pt not_active IP Right Cessation
Patent Citations (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4525197A (en) * | 1974-02-13 | 1985-06-25 | Schering Aktiengesellschaft | Fertilizer |
JPS56127717A (en) * | 1980-03-11 | 1981-10-06 | Nippon Steel Corp | Steel making process discharging slag suited as phosphatic fertilizer |
JPH02172883A (ja) * | 1988-12-26 | 1990-07-04 | Oji Kenzai Kogyo Kk | 肥料用造粒剤 |
JPH02277709A (ja) * | 1989-04-19 | 1990-11-14 | Kawasaki Steel Corp | 溶銑予備処理スラグからの燐酸質肥料用原料回収法 |
JPH11158526A (ja) * | 1997-11-28 | 1999-06-15 | Sumitomo Metal Ind Ltd | 高pスラグの製造方法 |
Cited By (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2009132544A (ja) * | 2007-11-28 | 2009-06-18 | Nippon Steel Corp | スラグの製造方法 |
JP2012007189A (ja) * | 2010-06-22 | 2012-01-12 | Jfe Steel Corp | 製鋼スラグからの鉄及び燐の回収方法並びに高炉スラグ微粉末または高炉スラグセメント及び燐酸資源原料 |
JP2015140294A (ja) * | 2014-01-30 | 2015-08-03 | Jfeスチール株式会社 | リン酸質肥料原料、リン酸質肥料およびその製造方法 |
JP2016074940A (ja) * | 2014-10-06 | 2016-05-12 | 新日鐵住金株式会社 | 脱リンスラグ及びリン酸肥料原料の製造方法 |
JP2016088757A (ja) * | 2014-10-29 | 2016-05-23 | 新日鐵住金株式会社 | リン酸肥料原料及びその製造方法 |
JP2017031013A (ja) * | 2015-08-03 | 2017-02-09 | 新日鐵住金株式会社 | リン酸肥料原料及びその製造方法 |
Also Published As
Publication number | Publication date |
---|---|
CN1509261A (zh) | 2004-06-30 |
KR20040010645A (ko) | 2004-01-31 |
US20040163435A1 (en) | 2004-08-26 |
CA2447411A1 (en) | 2002-11-21 |
JPWO2002092537A1 (ja) | 2004-08-26 |
BR0209829A (pt) | 2004-06-15 |
JP4211396B2 (ja) | 2009-01-21 |
EP1391445A1 (en) | 2004-02-25 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
WO2002092537A1 (fr) | Materiau pour engrais phosphate et procede de production associe | |
JP5560947B2 (ja) | 製鋼スラグからの鉄及び燐の回収方法並びに高炉スラグ微粉末または高炉スラグセメント及び燐酸資源原料 | |
JP5935770B2 (ja) | 燐酸資源原料の製造方法及び燐酸質肥料 | |
JP5320680B2 (ja) | 高燐スラグの製造方法 | |
JP3557910B2 (ja) | 溶銑脱燐方法と低硫・低燐鋼の溶製方法 | |
JP4781813B2 (ja) | 溶鉄の製造方法 | |
JP2004137136A (ja) | 珪酸燐酸肥料用原料及びその製造方法 | |
JP3750589B2 (ja) | 脱炭炉スラグの製造方法及び製鋼方法 | |
JP3500975B2 (ja) | ク溶性カリ肥料の製造方法 | |
JP3525766B2 (ja) | 溶銑の脱りん方法 | |
JPH11116364A (ja) | ク溶性カリ肥料の製造方法 | |
JP3288208B2 (ja) | 溶銑の脱りん方法 | |
JP3912176B2 (ja) | 低燐溶銑の製造方法 | |
JP4639943B2 (ja) | 溶銑の脱硫方法 | |
JP2000226284A (ja) | ク溶性カリ肥料の製造方法 | |
JP2003048793A (ja) | 緩効性カリ肥料の製造方法 | |
RU2103377C1 (ru) | Шихта для приготовления материала для металлургического производства и способ его приготовления | |
JP2001279316A (ja) | 溶銑の予備処理方法 | |
JP2005060846A (ja) | 肥料用原料の製造方法 | |
JP4178569B2 (ja) | 溶銑の脱硫方法および溶銑の脱硫剤 | |
JP3644420B2 (ja) | 肥料用原料の製造方法 | |
JPH1171611A (ja) | 金属精錬用石灰系フラックス | |
KR101863916B1 (ko) | 마그네슘 제련공정 부산물과 알루미늄 제련공정 폐부산물을 이용한 탈황 및 탈산용 제강플럭스 조성물 | |
JP3316270B2 (ja) | 金属精錬用石灰系フラックスの製造法 | |
WO2004020677A1 (ja) | 低燐溶銑の製造方法 |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
AK | Designated states |
Kind code of ref document: A1 Designated state(s): BR CA CN JP KR US |
|
AL | Designated countries for regional patents |
Kind code of ref document: A1 Designated state(s): AT BE CH CY DE DK ES FI FR GB GR IE IT LU MC NL PT SE TR |
|
121 | Ep: the epo has been informed by wipo that ep was designated in this application | ||
WWE | Wipo information: entry into national phase |
Ref document number: 2002589425 Country of ref document: JP |
|
DFPE | Request for preliminary examination filed prior to expiration of 19th month from priority date (pct application filed before 20040101) | ||
WWE | Wipo information: entry into national phase |
Ref document number: 2447411 Country of ref document: CA |
|
WWE | Wipo information: entry into national phase |
Ref document number: 2002728078 Country of ref document: EP |
|
WWE | Wipo information: entry into national phase |
Ref document number: 028100794 Country of ref document: CN Ref document number: 1020037014925 Country of ref document: KR |
|
WWP | Wipo information: published in national office |
Ref document number: 2002728078 Country of ref document: EP |
|
WWE | Wipo information: entry into national phase |
Ref document number: 10476783 Country of ref document: US |
|
WWW | Wipo information: withdrawn in national office |
Ref document number: 2002728078 Country of ref document: EP |