JP2006225682A - Method and apparatus for manufacturing sintered ore - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method and apparatus for manufacturing a sintered ore in which the yield of the sintered ore in both width-directional end portions of a sintering pallet for the sintered ore can be improved without reducing productivity and the yield of the overall sintered ore can be improved. <P>SOLUTION: In this manufacturing method, when manufacturing the sintered ore by sintering a sintering raw material bed 5 prepared by packing raw materials for sintering on the sintering pallet, heating is applied, after igniting the surface of the sintering raw material bed, the region in the vicinity of the pallet wall, within 700 mm from the end of the sintering pallet of surface of the sintering raw material bed is heated using combustion gas. Moreover, a sintering machine used in this method has: an ignition furnace 2 having an ignition line burner 3 for igniting the surface of the sintering raw material bed; and at least one or more sets of gas combustion auxiliary burners 1a, 1b and 1c which heat, the region in the vicinity of the pallet wall, within 700 mm from the end of the sintering pallet of surface of the sintering raw material bed using combustion gas, and the gas combustion auxiliary burners are located on the downstream side of the ignition line burner. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a method and an apparatus for producing sintered ore using a downward suction dwelloid type sintering machine.

  Sinter ore, which is the main raw material of a blast furnace, is generally manufactured as follows. First, a sintered raw material blended with fine iron ore, carbonaceous material, CaO-containing auxiliary raw materials, etc., is filled to a predetermined thickness on a sintering pallet of a Dwightroid type sintering machine, and this filled sintered raw material layer After igniting the surface carbon material, the carbon material in the sintered raw material layer is burned while sucking air downward, and the sintered raw material is sintered by the combustion heat to obtain a sintered cake. And this sintered cake is grind | pulverized and sized, and the sintered ore whose particle size is several mm or more is obtained.

  The upper layer portion of the sintered raw material layer has a low yield because the firing temperature and firing time are short due to cooling of the suction air from above, and the strength of the sintered ore is lowered. Further, in the vicinity of the sidewalls (hereinafter referred to as sidewalls) located at both ends in the width direction of the sintered pallet, the gas flow rate is high because the filling property of the sintering raw material is low, and the cooling rate in the firing process is high. Faster than the center in the width direction. For this reason, in the vicinity of the side wall, the firing yield of the sintered ore is drastically decreased as compared with the central portion, which causes the productivity to decrease.

  In order to solve the above problems and improve the strength and yield of the fragile portion, (a) increasing the coke (carbon material) as a heat source in the upper layer portion of the sintering raw material layer or in the vicinity of the sidewall, (b) Controlling ignition furnace combustion has been devised.

  (A) About increasing coke to the upper layer part of a sintering raw material layer, and side wall vicinity, (a-1) Coke is spread over the whole surface of a sintering raw material layer (for example, refer patent document 1, patent document 2). ), (A-2) From the carbonaceous material addition device installed separately from the sintering raw material hopper, the carbonaceous material (coke in the vicinity of the side wall (in the region of 150 to 500 mm from the side wall, 5 to 10 kg / t · s)) (See, for example, Patent Document 3), (a-3) Grooves are formed on the surface of the sintering raw material layer, and carbonaceous materials are charged into the grooves (see, for example, Patent Document 4). ) Etc.

(B) For controlling the combustion of the ignition furnace, (b-1) measuring the surface temperature of the sintering raw material layer and adjusting the flow rate of the ignition furnace fuel so that the surface temperature in the vicinity of the pallet side wall becomes higher than the central portion. (For example, refer to Patent Document 5), (b-2) A method in which two or more rows of burners are installed in the traveling direction of the sintering pallet so that at least one line can be moved (for example, refer to Patent Document 6). It has been known.
Japanese Patent Laid-Open No. 10-330854 JP 2000-256757 A JP-A 64-52029 JP-A-2-301525 Japanese Patent Laid-Open No. 2-153027 JP-A-3-031431

  However, in the technique (a-1) in which coke is charged over the entire surface of the sintering raw material layer, the thickness of the coke combustion zone is increased over the entire width of the sintering pallet, so that the ventilation resistance when the gas passes is increased. Thereby, air permeability deteriorates and baking is delayed. In addition, since the basic unit of air necessary for completing the combustion of coke is increased, the time for sucking the required amount of air into the sintering raw material layer becomes longer, and the sintering time becomes longer. Therefore, the productivity of sinter production decreases. In the technique (a-2) in which coke is applied to the surface of the sintering raw material layer end portion, since the coke is charged only in the both ends in the width direction near the side wall of the sintering raw material layer, deterioration of air permeability is suppressed to some extent. it can. However, since the amount of coke is large and the ratio of coke that does not contribute effectively to the temperature rise of the sintered iron ore as a raw material for sintering is high, the productivity of sinter ore production as a whole decreases. (A-3) inserts carbonaceous material into the groove formed on the surface of the sintering raw material layer, so that uneven burning occurs between the part where the groove is formed and the part where the groove is not formed, thereby forming the groove. The yield is hardly improved in the parts that were not present.

  Also, in the method (b-1) of adjusting the flow rate of the ignition furnace fuel so that the surface temperature in the vicinity of the side wall of the sintering pallet is higher than that in the center, the ignition area of the sintering raw material layer is constant. The effect of improving the deterioration of the sintering reaction is small. When the method (b-2) is used, the ventilation resistance is increased when the high temperature gas passes over the entire width of the sintering pallet. For this reason, aeration of the sintering raw material layer is deteriorated and firing is delayed. Therefore, there is a limit to firing at a high production rate.

  Therefore, the object of the present invention is to solve such problems of the prior art and improve the yield of sintered ore at both ends in the width direction of the sintered pallet without reducing the productivity. An object of the present invention is to provide a method and an apparatus for producing sintered ore that can improve the yield of the entire ore.

The features of the present invention for solving such problems are as follows.
(1) When producing a sintered ore by firing a sintered material layer filled with a sintered material on a sintering pallet, the surface of the sintered material layer is ignited after ignition on the surface of the sintered material layer. A method for producing a sintered ore characterized by heating a region near a pallet wall within 700 mm from an end of a pallet with combustion gas.
(2) The method for producing a sintered ore according to (1), wherein heating is performed with combustion gas immediately after ignition.
(3) In an apparatus for producing a sintered ore by firing a sintered raw material layer filled with a sintered raw material on a sintering pallet, an ignition furnace having an ignition line burner for igniting the surface of the sintered raw material layer; At least one set of gas combustion auxiliary burners for heating a pallet wall region within 700 mm from the end of the sintering pallet on the surface of the sintering raw material layer with combustion gas, the gas combustion auxiliary burner for the ignition An apparatus for producing sintered ore, which is installed downstream of a line burner.
(4) One or more sets of gas combustion auxiliary burners are installed within 3 m downstream from the line burner position for ignition. The apparatus for producing a sintered ore according to (3),
(5) The apparatus for producing a sintered ore according to (3), wherein a gas combustion auxiliary burner is installed in the ignition furnace.

  According to the present invention, it becomes possible to produce a sintered ore with improved yield without reducing the productivity without reducing the sintering speed, and the production amount of the sintered ore can be increased. .

  In the present invention, the pallet wall area near the side wall of the sintered pallet has the same cooling rate as the sintering raw material firing at the center of the pallet width direction, thereby deteriorating the firing yield of the pallet wall area. To prevent the decline in productivity. Specifically, the sintering yield is prevented from deteriorating in the pallet wall region by sintering while heating the surface of the sintering raw material layer in the pallet wall region within 700 mm from the pallet side wall with the combustion gas.

  By heating the surface of the sintering raw material layer in the region near the pallet wall with combustion gas, the combustion zone becomes hot and thick, the ventilation resistance increases, the firing temperature is high, and the firing time is prolonged, so the strength of the sintered ore Can improve the yield.

  On the other hand, since there is no influence on the center part of the sintering pallet balanced at an appropriate gas speed, there is no change in the time until the end of firing, and a high production rate can be maintained.

  The reason for heating the surface of the sintering raw material layer in the vicinity of the side wall within 700 mm from the side wall of the pallet with the combustion gas is that, as a result of examining the distribution of the yield of sintered ore, the yield from the side wall to 700 mm is substantially reduced. This is because the maximum width of the region, when heated to a range exceeding 700 mm from the side wall, the ratio of the sintered raw material layer to the surface increases beyond 30%, and the ventilation resistance increases, resulting in a decrease in productivity. Therefore, in the present invention, the surface of the sintering raw material layer within 700 mm from the side wall where the yield decreases is heated to achieve the yield improvement of the manufactured sintered ore. It is effective if at least a part of the surface of the sintering raw material layer within 700 mm from the side wall is heated. On the other hand, if heating is performed only within a range of less than 200 mm from the side wall, the effect of heating the surface of the sintering raw material layer is achieved. Is small, and the yield improvement effect is also small.

  The heating with the combustion gas is preferably high-temperature combustion gas heating. If a high temperature gas of 500 ° C. or higher is used, the effect is high, but if it is 1500 ° C. or higher, there is a problem with the heat resistance of the auxiliary burner, so about 1500 ° C. or less, more preferably 1300 ° C. or less is appropriate.

  Further, in order to improve the thermal history during sintering raw material firing on the upper part of the sintering pallet, it is desirable to supply a heating gas (high temperature combustion gas) from the surface while the upper layer coke is burning as much as possible. It is desirable to perform heating with the combustion gas immediately after ignition of the surface of the binder layer.

  Next, an apparatus for producing sintered ore suitable for carrying out the method of the present invention will be described.

  In order to carry out the above method, an ignition line for igniting the surface of the sintered raw material layer in an apparatus for producing a sintered ore by firing a sintered raw material layer filled with a sintered raw material on a sintering pallet An ignition furnace having a burner, and at least one set of gas combustion auxiliary burners for heating a pallet wall region within 700 mm from the end of the sintering pallet on the surface of the sintering raw material layer with combustion gas, It is desirable to use a sintered ore production apparatus in which a combustion auxiliary burner is installed on the downstream side of the ignition line burner. By installing the gas combustion auxiliary burner on the downstream side of the ignition line burner, the sintering raw material in the area near the pallet wall during firing is heated. In addition, it is desirable that two gas combustion auxiliary burners are used as a set, and the pallet wall regions on both sides of the sintering pallet corresponding to the same position in the line direction are heated simultaneously.

  As the gas combustion auxiliary burner, an ordinary gas burner may be used. For example, an ironworks generated gas or the like can be used as fuel.

  It is desirable to install one or more gas combustion auxiliary burners within 3 m downstream of the ignition line burner position. In order to improve the thermal history during sintering raw material firing at the upper part of the sintering pallet, it is desirable to supply the combustion gas from the surface while the upper layer coke is burning as much as possible. It is desirable to install at a downstream position within 3 m from the ignition position of the ignition line burner. If the gas heating area on the surface is longer than 3m in the downstream position, the improvement effect increases as the traveling direction becomes longer. However, even if only one burner is installed per pallet wall area on one side of the line, the improvement effect is great. The number of gas combustion auxiliary burners can be appropriately selected from the viewpoint of economy with respect to the amount.

  In addition, when using a gas combustion auxiliary burner, it is desirable to prevent the heated gas from the gas combustion auxiliary burner from being diluted with cold air in order to make the sintering raw material layer surface higher temperature. It is preferable to cover the periphery of the jet outlet or install a gas combustion auxiliary burner in an ignition furnace whose inner surface is covered with a refractory. In the case where the gas combustion auxiliary burner is installed in the ignition furnace, it is particularly preferable because it has an effect of heating the surface layer of the sintered raw material immediately after ignition.

  FIG. 1 shows a schematic diagram of an embodiment of the sintered ore production apparatus of the present invention. 1A is a side view in the line direction, and FIG. 1B is a plan view. The gas combustion auxiliary burner 1 is downstream of the ignition line burner 3 installed in the ignition furnace 2, the gas combustion auxiliary burner 1 a installed in the ignition furnace 2, and the gas combustion installed outside the ignition furnace 2. This is a case in which three gas combustion auxiliary burners 1 are arranged, each consisting of auxiliary burners 1b and 1c, three per pallet wall area on one side of the line, and a total of six on both sides. Each gas combustion auxiliary burner 1 is installed so as to heat the inside area of the pallet wall within 700 mm from the pallet side wall 4. With such an arrangement, the surface of the sintering raw material layer 5 can be heated by the ignition line burner 3 immediately after being ignited and ignited, and the surface of the sintering raw material layer 5 can be heated further downstream. A set of gas combustion auxiliary burners 1b and 1c are sequentially installed.

  Sintered ore was produced using a droidoid sinter ore manufacturing apparatus with gas combustion auxiliary burners on both sides of the sintering pallet, similar to FIG. The gas combustion auxiliary burner can be moved, and the number, arrangement interval, and arrangement position from the side wall can be changed. M gas was used as the combustion gas of the gas combustion auxiliary burner, and the width of the sintering pallet was 4.0 m.

  A raw material ore having a chemical composition shown in Table 1 and an auxiliary raw material were blended at a blending ratio shown in Table 2 to constitute a sintered raw material.

  The raw material layer thickness on the sintering pallet was set to 600 mm, and the sintering operation was performed at a standard pallet speed of 2.5 m / min. The pallet speed was appropriately adjusted according to the firing time. The operating conditions were changed in the following (A) to (C) to produce sintered ore, and the yield, sintering time, and productivity were measured. Yield is the ratio of product sinter obtained from raw materials, sintering time is the time required for sintering to complete sintering in the manufacturing equipment, productivity is product per unit time, unit firing area In the amount of sintered ore produced, the relative value is defined with the condition of no heating by the gas combustion auxiliary burner being 100.

(A) Gas combustion auxiliary burners are installed 300 mm inside from the side wall, on both sides of the sintering pallet downstream from the ignition line burner, and the gas combustion auxiliary burners are sequentially increased from the ignition line burner to the downstream side at intervals of 1 m. Comparison was made. The amount of combustion M gas per gas combustion auxiliary burner was 0.8 Nm ³ / min. The gas combustion auxiliary burner was changed on one to five on one side. The results are shown in FIGS.

(B) A gas combustion auxiliary burner is installed 300 mm inside from the side wall and on both sides of the sintering pallet downstream from the ignition line burner, and the distance from the ignition line burner to the gas combustion auxiliary burner is changed for comparison. I did it. The number of gas combustion auxiliary burners was 3 on one side (6 on each side), and the amount of combustion M gas per gas combustion auxiliary burner was 0.8 Nm ³ / min. The results are shown in FIGS.

(C) Three sets of gas combustion auxiliary burners, one on each side (6 on each side), are installed at intervals of 1 mm from the 1 m position downstream from the ignition line burner. Comparison was made by changing at 110 cm. The amount of combustion M gas per gas combustion auxiliary burner was 0.8 Nm ³ / min. The results are shown in FIGS.

  In the case of changing the number of gas combustion auxiliary burners in (A), the yield of the conventional method without using the gas combustion auxiliary burner is 75%, whereas the method of the present invention using the gas combustion auxiliary burner was used. In some cases, the yield was improved to 76.4% or more. There was no significant change in sintering time, and productivity was improved.

  When the interval from the ignition line burner to the gas combustion auxiliary burner in (B) is changed, a sufficient yield improvement can be obtained within 3 m, but when the distance from the ignition line burner exceeds 3 m, As the sintering time increased, productivity decreased. Therefore, it is desirable to install one or more gas combustion auxiliary burners within 3 m downstream of the ignition line burner position.

  In the case where the position of the gas combustion auxiliary burner from the side wall of (C) is changed, a sufficient yield improvement is obtained in a region within 700 mm, but if it exceeds 700 mm, the sintering time is extended and productivity is lowered. did.

Schematic of one Embodiment of the sintered ore manufacturing apparatus of this invention. (A) Side view of line direction, (b) Plan view. The graph which shows the relationship between the number of one-side gas combustion auxiliary burners, and a yield. The graph which shows the relationship between the number of one-side gas combustion auxiliary burners, and sintering time. The graph which shows the relationship between the number of one-side gas combustion auxiliary burners, and productivity. The graph which shows the space | interval from the line burner for ignition to a gas combustion auxiliary burner, and the yield. The graph which shows the relationship between the space | interval from the line burner for ignition to a gas combustion auxiliary burner, and sintering time. The graph which shows the relationship between the space | interval from the line burner for ignition to a gas combustion auxiliary burner, and productivity. The graph which shows the relationship between the gas combustion auxiliary burner position from a side wall, and a yield. The graph which shows the relationship between the gas combustion auxiliary burner position from a side wall, and sintering time. The graph which shows the relationship between the gas combustion auxiliary burner position from a side wall, and productivity.

Explanation of symbols

1 (1a, 1b, 1c) Gas combustion auxiliary burner 2 Ignition furnace 3 Ignition line burner 4 Pallet side wall 5 Sintering raw material layer

Claims (5)

  When the sintered raw material layer filled with the sintered raw material on the sintering pallet is fired to produce a sintered ore, the surface of the sintered raw material layer is ignited and then the sintered pallet on the surface of the sintered raw material layer is ignited. A method for producing a sintered ore characterized by heating a region near a pallet wall within 700 mm from an end by a combustion gas.   2. The method for producing a sintered ore according to claim 1, wherein heating is performed with combustion gas immediately after ignition.   In an apparatus for producing a sintered ore by firing a sintering material layer filled with a sintering material on a sintering pallet, an ignition furnace having an ignition line burner for igniting the surface of the sintering material layer, and the sintering At least one set of gas combustion auxiliary burners for heating a pallet wall edge region within 700 mm from the end of the sintered pallet on the surface of the raw material layer with combustion gas, and the gas combustion auxiliary burner is the ignition line burner An apparatus for producing sintered ore, which is installed on the downstream side.   4. The sintered ore manufacturing apparatus according to claim 3, wherein at least one set of gas combustion auxiliary burners is installed within 3 m downstream from the ignition line burner position.   The apparatus for producing sintered ore according to claim 3, wherein the gas combustion auxiliary burner is installed in an ignition furnace.

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