JP4749121B2 - Double dish granulator - Google Patents

Description

  The present invention relates to a powder granulator used in the fields of chemical industry, metallurgy, ceramics, etc., and in particular, dish-type granulation suitable for rolling and granulating a sintered raw material in an iron making process into a spherical shape. Related to the machine.

  There are various types of granulators used for granulating powder, such as rolling type, vibration type, and compression molding.

  A typical dish granulator is known as a rolling granulator. In this dish type granulator, a granulating dish having an outer peripheral side wall having a predetermined height is inclined, and the raw material has a predetermined height (raw material properties such as specific gravity and viscosity of the raw material) obliquely upward on the inclined rotating surface. , The number of rotations of the granulation dish, the angle of inclination, etc., is determined by the granulation dish specifications, and rolls downward due to the weight of the granulation product. It is possible to produce a large amount of a granulated product having a predetermined product particle diameter.

  The product particle size and strength of the granulated product are affected by the distance that can be lifted obliquely upward on the rotating surface of the granulation dish and the distance that it rolls down when rolling down.

  As an improved granulator that improves the function of the dish granulator, for example, a step type and a color granulator are known (for example, see Non-Patent Document 1).

  For example, as shown in FIG. 1, the stepped granulator includes a two-stage outer ring portion 2 outside the inner ring portion 1 of the granulation dish, and the depth gradually increases from the outermost ring portion to the inner ring portion. Has a different structure. In this granulator, as the raw material charged in the inner ring portion of the granulation dish is rolled and granulated, the granulated material sequentially flows toward the outer ring portion, and a predetermined product particle size is obtained in the outer ring portion. It becomes a granulated product.

As described above, the sizing action is improved by the multistage granulation dish, and the productivity (T / H) of the granulated product can be improved. However, since the diameter (D ₃ ) of the inner ring portion is smaller than that of a normal single-stage granulator, a sufficient rolling distance cannot be obtained during the initial granulation in the inner ring portion. The density of the final granulated product is also lowered, and there is a drawback that the product strength is lowered.

  For example, as shown in FIG. 2, the color-attached granulator has a structure in which a collar portion 3 is provided outside the inner ring portion 1. Since there is no return to the part 1, the coating operation of the second raw material in the collar part 3 becomes possible. However, since the capacity of the collar portion 3 having the function of the coating operation of the second raw material is small, it has been difficult to sufficiently improve the product strength as compared with the conventional dish-type granulator.

  Furthermore, a double dish granulator that combines the stepped mold and the color mold has also been proposed (see, for example, Patent Document 1). As shown in FIG. 3, this granulator has a structure with a collar portion 5 having a sufficient capacity outside the three-step stepped inner ring portion 4, and after granulating at the three-step stepped inner ring portion, Furthermore, the strength of the granulated product can be improved by applying a rolling compaction action at the collar portion. However, the effect of improving the strength of the granulated product by rolling compaction at the collar portion is not sufficient, and there is a technical problem in terms of improving the strength of the product.

Japanese Examined Patent Publication No. 46-5121 Granulation Handbook, edited by Japan Powder Industry Association, Ohmsha, 1975

  Although conventional dish-type granulators are excellent in terms of granulating properties and productivity (T / H), they are not always sufficient in terms of improving the strength of the granulated product. In order to improve the strength of the granulated product while maintaining it, there has been a technical problem that the granulation dish is increased in size, the load is increased, the torque is increased, and the apparatus structure is complicated.

  The present invention has a simple structure that enables partial modification of an existing single-dish granulator, and while maintaining the productivity of the granulated product compared to the conventional one, granulation compared to the conventional one. An object of the present invention is to provide a double dish type granulator capable of improving the strength of a product.

The present invention solves the above technical problem, and the gist thereof is an apparatus for granulating a sintering raw material in a steel making process into a spherical shape, and an inner ring disposed inside a granulating dish. A side wall height (H2) of the inner ring portion is lower than a side wall height (H1) of the outer ring portion and the outer ring portion of the outer ring portion is formed. The ratio (D2 / D1) of the diameter (D2) of the inner ring part to the diameter (D1) is 0.63 to 0.79, and the side wall height (H2) of the inner ring part to the diameter (D1) of the outer ring part The double dish granulator is characterized in that the ratio (H2 / D1) is 0.11 to 0.13.
Moreover, it is the manufacturing method of the sintering raw material characterized by granulating the sintering raw material in an iron-making process into a spherical shape also using the said double plate type granulator.

  ADVANTAGE OF THE INVENTION According to this invention, the dish type granulator which has the simple structure and enables manufacture of the granulated material excellent in the productivity and product strength of the granulated material can be provided. For example, by applying the present invention to a granulation step of a sintered raw material in an iron making process, it is possible to improve the product yield and productivity of the sintered ore that is the iron raw material. Is enormous.

  Hereinafter, embodiments of the present invention will be described.

  In FIG. 4, sectional drawing of the double plate type granulator of this invention is shown.

As shown in FIG. 4, the double dish type granulator of the present invention has a double structure comprising an inner ring part 1 arranged on the inner side of the granulation dish and an outer ring part 2 arranged on the outer side thereof. The side wall height (H ₂ ) of the inner ring portion is made lower than the side wall height (H ₁ ) of the outer ring portion, and the ratio of the diameter (D ₂ ) of the inner ring portion to the diameter (D ₁ ) of the outer ring portion (D ₂ / D ₁ ) and the ratio (H ₂ / D ₁ ) of the side wall height (H ₂ ) of the inner ring portion to the diameter (D ₁ ) of the outer ring portion are characteristic.

The present invention, as compared with the conventional granulator with type color, by lowering the side walls of the inner ring height (H ₂₎ to the side wall height of the outer ring portion (H _1), the outer ring 2 By circulating ungranulated particles or disintegrated particles to the inner ring portion 1 and rolling granulation at the inner ring portion, the same sizing action as a conventional stepped granulator can be promoted.

Further, the present invention determines the diameter (D ₂ ) of the inner ring portion and the side wall height (H ₂ ) of the inner ring portion by the relative ratio with respect to the diameter (D ₁ ) of the outer ring portion. Compared to the type of granulator, when rolling granulation in the outer ring portion 2, the granulated material rolls down and collides with the side wall 6 of the inner ring portion, thereby increasing the density and strength of the granulated material. It becomes possible to promote.

FIG. 5 shows the relationship between the ratio (D ₂ / D ₁ ) of the diameter (D ₂ ) of the inner ring portion to the diameter (D ₁ ) of the outer ring portion of the granulation dish, the yield of the granulated product, and the pseudo-granulation index. FIG.

In the granulation test, the diameter (D ₁ ) of the outer ring part of the granulation dish is kept constant at 1200 mm, and the diameter (D ₂ ) of the inner ring part is changed in the range of 600 mm to 1000 mm, thereby changing the diameter (D ₁ ) of the outer ring part. the ratio of the inner ring portion of diameter (D ₂₎ to (D ₂ / D ₁₎ was changed in the range of 0.5 to 0.83. As the raw material, powdered iron ore that had been sieved to 5 mm or less in advance was adjusted to a moisture content of 10% using a high-speed stirring mixer, and then charged into a double dish granulator.

The side wall height (H ₁ ) of the outer ring portion of the granulation dish and the side wall height (H ₂ ) of the inner ring portion are constant at 168 mm and 144 mm, and the side wall height of the inner ring portion with respect to the diameter (D ₁ ) of the outer ring portion. The ratio (H ₂ / D ₁ ) of thickness (H ₂ ) is 0.12.

  The yield of the granulated product is 2 minutes after the start of the feed of raw materials, and when the steady state is reached, the granulated product discharged from the granulator is collected, and the particle size of 2 to 5 mm It was defined as the ratio (mass%) of the granulated product. The yield of the granulated product is an index of productivity (T / H).

In addition, the pseudo-granulation index of the granulated product is a measured value of mass% of 1 mm or less in the raw material before granulation and mass of 1 mm or less after granulation and drying the granulated product to 3% moisture. Therefore, the index is defined by the following formula (1). This pseudo-granulation index of the granulated product is an index of the strength of the granulated product.
[Pseudo-granulation index (mass%)] = (1- [mass% of 1 mm or less after drying the granulated product] / [mass% of 1 mm or less in the raw material before granulation]) × 100 (1 )

As shown in FIG. 5, the ratio (D ₂ / D ₁ ) of the diameter (D ₂ ) of the inner ring part to the diameter (D ₁ ) of the outer ring part is in the range of 0.63 to 0.79. It was found that both the yield and the pseudo-granulation index were sufficiently high, and it was possible to produce a granulated product with excellent productivity and product strength.

Therefore, in the present invention, in the granulation dish of the double dish granulator, the ratio (D ₂ / D ₁ ) of the diameter (D ₂ ) of the inner ring part to the diameter (D ₁ ) of the outer ring part is 0.63. It was defined as a range of ˜0.79.

FIG. 6 shows the ratio (H ₂ / D ₁ ) of the side wall height (H ₂ ) of the inner ring portion to the diameter (D ₁ ) of the outer ring portion of the granulation dish, the yield of the granulated product, and the pseudo-granulation index. It is a figure which shows a relationship.

In the granulation test, the diameter (D ₁ ) of the outer ring part of the granulation dish is kept constant at 1200 mm, and the side wall height (H ₂ ) of the inner ring part is set to 120 mm to 168 mm (= the side wall height (H ₁ ) of the outer ring part). By changing the ratio, the ratio (H ₂ / D ₁ ) to the outer ring diameter (D ₁ ) was changed in the range of 0.10 to 0.14.

The diameter (D ₂ ) of the inner ring portion is constant at 800 mm and the side wall height (H ₁ ) of the outer ring portion is constant at 168 mm, and the ratio of the diameter (D ₂ ) of the inner ring portion to the diameter (D ₁ ) of the outer ring portion (D ₂ / D ₁ ) is 0.67. Other conditions and test methods are the same as those in FIG.

As shown in FIG. 6, the ratio (H ₂ / D ₁ ) of the side wall height (H ₂ ) of the inner ring part to the diameter (D ₁ ) of the outer ring part is in the range of 0.11 to 0.13. It was found that both the yield of the product and the pseudo-granulation index were sufficiently high, and it was possible to produce a granulated product excellent in the productivity and product strength of the granulated product.

Therefore, according to the present invention, in the granulation dish of the double dish granulator, the ratio (H ₂ / D ₁ ) of the side wall height (H ₂ ) of the inner ring part to the diameter (D ₁ ) of the outer ring part is 0. It was defined as 11 to 0.13.

  The present invention has a simple structure and is highly feasible that can be realized simply by attaching an inner ring to an existing single-dish granulator.

  As an example of an embodiment of the present invention, an example will be described in which the double-dish granulator of the present invention is applied to partial granulation processing of hardly granulated iron ore in a granulation step of a sintered raw material. In addition, unless it is contrary to the objective of this invention, it is not limited to the following embodiment.

  As shown in FIG. 7, the manufacturing process of sintered ore for blast furnace, which is an iron-making raw material, generally includes iron-containing raw materials such as powdered iron ore and iron-making dust, auxiliary materials such as limestone, quartzite, serpentine, and dolomite, The sintered raw material 11 made of carbon material is mixed and granulated while adding water with a drum mixer 12 to obtain pseudo particles in which fine powders of less than about 1 mm adhere around the core particles of about 1 mm or more, and then a sintering machine 13 is charged and heated and fired to produce sintered ore 14.

  In the granulation process of the sintered raw material, in order to maintain good air permeability in the sintering machine and maintain quality such as strength of the ore, product yield, and productivity, In addition to distillation and productivity, the strength of the granulated material is required to suppress collapse during charging and heating. In particular, the granulation properties of the sintered raw material are greatly influenced by the difference in properties and mineral composition depending on the brand name of the iron ore as the main raw material.

  For this reason, in the case of the iron ore as the main raw material, the iron ore with a high content of the fine powder portion or the hardly granulated iron ore 21 containing a large amount of mineral composition that inhibits the granulation property, a separate line (part In the granulation line 20), the mixture is preliminarily mixed with a mixer such as a high-speed agitation mixer 22, and is made while adding about 10% water using a dish-type granulator 23 having a higher granulation function than a drum mixer. A method (partial granulation method) is adopted in which the particles are granulated into a partially granulated product and then mixed with the remaining sintered raw material pseudo-granulated in the present granulation line 10.

  The double dish granulator of the present invention is used as a granulator when partially granulating the hardly granulated iron ore 21 in the partial granulation line 20, thereby making it a conventional dish granulator. Compared with this, it is possible to produce a granulated product that is excellent in the productivity and product strength of the granulated product, and as a result, the collapse of the sintered raw material pseudo particles during charging and heating is suppressed, It is possible to maintain good quality such as strength, product yield, and productivity.

  The effects of the present invention will be described below with reference to examples.

  An example will be described in which the present invention is applied to partial granulation treatment of hardly granulated iron ore in the iron ore sintering step.

  By using a sintering granulation line shown in FIG. 7, a sintering raw material 11 composed of various raw materials shown in Table 1 was mixed and granulated with a drum mixer 12 while adding 7% water for 2 minutes, and then the height. The sintered ore 14 was manufactured by firing at a suction negative pressure of 15 kPa using a sintering pan having a diameter of 600 mm and a diameter of 250 mm.

In this case, as the present invention method, among the iron ore, the MAC ore is pulverized and flame granulation properties ore Table 1 were mixed using a high-speed stirring mixer 2 2, further high granulation function granulation as aircraft 2 3, using a double pan granulator of the present invention, a 10% water was continuously granulated while adding water and partially granulated product, then pseudo granulated in the granulating line 10 Mixed with the rest of the granulated sintering raw material.

  As a comparative method, a method of comparatively granulating all sintered raw materials in the present granulation line 10 without performing partial granulation of the MAC ore (Comparative Example 1), an ordinary one-stage dish granulation of the MAC ore in the partial granulation line A partial granulation method (Comparative Example 2) was performed using a machine.

In addition, according to the method of the present invention, when MAC ore is partially granulated on the partial granulation line using the double-type dish granulator of the present invention, the granulation dish of the double-type dish granulator in, the ratio of the inner ring side wall height relative to the outer ring diameter _{(D 1) (H 2)} (H 2 / D 1), and the sidewall height of the inner ring relative to the outer ring diameter (D ₁₎ (H ₂ ) Partial granulation was carried out under different conditions (H ₂ / D ₁ ).

  And the yield and pseudo-granulation index | exponent of the granulated material obtained by partially granulating MAC ore with the partial granulation line were measured.

  The yield of granules is 2 minutes after the start of raw material input, when the steady state is reached, the granulated product discharged from the granulator is collected, and the particle size is 2-5 mm It was defined as the ratio of the granulated product. The yield of the granulated product is an index of productivity (T / H).

In addition, the pseudo-granulation index of the granulated product is a measured value of mass% of 1 mm or less in the raw material before granulation and mass of 1 mm or less after granulation and drying the granulated product to 3% moisture. Therefore, the index is defined by the following formula (1). This pseudo-granulation index of the granulated product is an index of the strength of the granulated product.
[Pseudo-granulation index (mass%)] = (1- [mass% of 1 mm or less after drying the granulated product] / [mass% of 1 mm or less in the raw material before granulation]) × 100 (1 )

  In addition, the product yield and the production rate when the sintered ore was produced by firing in a sintering pot were also evaluated.

  Table 2 shows test conditions and evaluation results.

  As shown in Table 2, a method of pseudo-granulating all sintered raw materials in the present granulation line without performing partial granulation of the MAC ore (Comparative Example 1), and a normal one-step process of the MAC ore in the partial granulation line Compared to the method of partial granulation using a dish granulator (Comparative Example 2), according to the method of the present invention, the MAC ore is divided into the MAC ore by the partial granulation line according to the present invention. When partial granulation is used, the yield and pseudo-granulation index of the partial granulated product of MAC ore (hard granulated iron ore) are improved. As a result, the product yield and production rate of sintered ore are improved. Both improved.

Further, according to the method of the present invention, when the MAC ore is partially granulated using the double-type dish granulator of the present invention on the partial granulation line of the MAC ore, the inner ring portion with respect to the outer ring diameter (D ₁ ) The ratio of the side wall height (H ₂ ) (H ₂ / D ₁ ) and the ratio of the inner ring side wall height (H ₂ ) to the outer ring diameter (D ₁ ) (H ₂ / D ₁ ) Inventive Example 1 to Inventive Example 3 which are within the range defined by the present invention are compared to Comparative Example 4 to Comparative Example 6 in which these conditions deviate from the range defined by the invention. The yield and pseudo-granulation index of the partially granulated stone were improved, and as a result, the product yield and production rate of the sintered ore were improved.

It is a figure which shows a step type dish type granulator. It is a figure which shows a color-type dish type granulator. It is a figure which shows the plate type granulator which combined the step type and the color type | mold. It is sectional drawing of the double plate type granulator of this invention. Is a diagram showing the relationship between the yield and pseudo-particle exponent of the ratio (D ₂ / D ₁₎ and granules of the inner ring portion with a diameter (D ₂₎ for the granulating dish of the outer ring portion with a diameter (D ₁₎ . Diagram showing the relationship between the yield and pseudo-particle exponent of granulated product and the ratio of side wall height of the inner ring portion _{(H 2) (H 2 /} D 1) for granulating dish of the outer ring portion with a diameter (D ₁₎ It is. It is a figure which shows the manufacturing process of the sintered ore for blast furnaces.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Step type plate type granulator, Color type plate type granulator, and inner ring part of Double type plate type granulator of this invention 2 Step type plate type granulator, and Double type of this invention Outer ring part of dish type granulator 3 Color part of color type dish type granulator 4 Inner ring part of double type dish type granulator 5 Outer ring part of double type dish granulator 6 Inner ring wall 10 This granulation line 11 Raw materials for sintering 12 Drum-type granulator 13 Sintering machine 14 Sintered ore 20 Partial granulation line 21 Difficult-granulating ore 22 High-speed agitation granulator 23 Conventional single-dish granulator or book Double dish granulator D ₁ , D ₂ diameter of outer ring and inner ring H ₁ , H ₂ Wall height of outer ring and inner ring

Claims (2)

An apparatus for granulating a sintered raw material in a steel making process into a spherical shape, having a double structure consisting of an inner ring portion arranged on the inner side of the granulation dish and an outer ring portion arranged on the outer side thereof, The side wall height (H2) of the inner ring part is lower than the side wall height (H1) of the outer ring part, and the ratio (D2 / D1) of the diameter (D2) of the inner ring part to the diameter (D1) of the outer ring part is 0. And the ratio (H2 / D1) of the side wall height (H2) of the inner ring portion to the diameter (D1) of the outer ring portion is 0.11 to 0.13. Heavy dish granulator. A method for producing a sintered raw material, comprising using the double dish granulator according to claim 1 to granulate a sintered raw material in an iron making process into a spherical shape.

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