JP2002105542A - Method for producing sintered ore for blast furnace - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a production technique of sintered ore by which the excellent quality can be maintained while securing the high productivity and the high yield though a large quantity of high crystallized water-containing ore is used. SOLUTION: The high crystallized water-containing ore 10 having >=4% crystallized water is used at >=25% blending ratio, and the high crystallized water-containing ores of two or more kinds or two or more brands are classified into two or more grain size divisions, and a suitable pre-treatment is selected based on one or more kinds among water-absorbability, water retentivity and wettability of each classified part ore. Or, the above each ore is classified into two or more without crushing and separated into plural groups based on the above physical property levels and compared with the physical property levels of each grain size division of usual ore and two or more groups are selected and one or more kinds of the following treatments are applied; (a): The ore is stirred and mixed with added moisture by using a high speed stirring mixer 15. (b): The ore is blended with other raw materials by using a bedding method 2. (c): After crushing, the grain size thereof is made to fine grain, or further, the pulverized fine portion is classified, but the fine grain portion in the initial classification is untreated as it is, and it is unnecessary to perform pre-treatment. (d): The moisture is added by water-spraying 16.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a method for producing a raw material for sinter used in a blast furnace iron making method, which uses a large amount of high-crystal water ore, and ensures high productivity and a high yield while maintaining excellent productivity. The present invention relates to a technique for producing sinter which enables the maintenance of high quality.

[0002]

2. Description of the Related Art A sintered ore used as a raw material for a blast furnace is generally produced by the following method. Iron ore stocked for each brand in the ore stock yard is bedding to the ore yard. In bedding, various brands of iron ore fines, containing CaO auxiliary material, containing SiO ₂ auxiliary material, mixed by bedding method at a rate that is set in advance dust and carbonaceous material such as, a blending powder (B powder). This blending powder, limestone and / or quicklime, quartzite and / or serpentine, coke breeze and / or anthracite, and return ore, and in some cases, raw materials such as plain ore, are put into separate compounding tanks. A predetermined amount of each raw material is continuously cut out from each mixing tank. Then, an appropriate amount of water is added to the cut out raw materials, mixed, and granulated. Here, the moisture functions as a granulation binder.

[0003] The sintering raw material in the form of quasi-particles thus granulated is continuously supplied from a hopper onto a pallet of an endless moving grate type sintering machine (Dwyroid type sintering machine) to have a layer thickness of 500 to 500 mm. The sintering raw material layer is formed in the form of a packed layer having a height of about 700 mm. Next, in the sintering machine ignition furnace, the carbon material in the sintering material layer is ignited, air is sucked from the upper part to the lower part of the sintering material layer, and the carbon material mixed in the sintering material layer is ignited. Is burned, and the sintering material in the form of quasi-particles constituting the sintering material layer is fired by a melting reaction and a sintering reaction by the combustion heat generated here to agglomerate.
After cooling the sintered cake thus baked, it is crushed and sized, and particles having a size of 3 to 5 mm or more are charged into a blast furnace as "product sinter". Fine powder ore having a size of 3 to 5 mm or less generated in the crushing and sizing process is used again as a raw material for sinter ore. In the production of sintered ore using this Dwyroid type sintering machine, in the sintering process, the raw material layer charged on a pallet by mixing the sintering raw material and the coke breeze as a carbon material,
The basic operation is to provide heat transfer by gas flow and to provide necessary and sufficient heat, and it is necessary to maintain good air permeability in the packed bed of sintering raw materials in order to improve the productivity and quality of sinter. It is.

[0004] The quality of the sintered ore produced in this way has a great influence on the stability of the unloading state in the furnace, gas permeability and liquid permeability, reduction efficiency, high-temperature properties, etc. in the blast furnace operation. Therefore, in the production of sintered ore, high quality of sintered ore is required, strict quality control is performed, and in order to reduce the production cost, improvement of the product yield of sintered ore is required. Therefore, the efficiency of the sinter production line is required, and the productivity is required to be improved. Here, the product yield of the sintered ore is represented by the ratio of the “product sintered ore” weight to the weight of the sintered cake, ie, product sintered ore / sinter cake.

On the other hand, in terms of iron ore supply, hematite (Fe ₂ O ₃ , hematite) and magnetite (Fe ₃ O ₄ ,
High-quality iron ore such as magnetite) is reduced, and a high crystal water content such as a pisolite ore or maramamba ore containing a large amount of goethite (Fe ₂ O ₃ .nH ₂ O) is generated. Ore ”is increasing. The content of water of crystallization in ore reaches as high as about 10% by mass. There has been a strong demand for a technique for using such a highly crystalline water ore in a large amount and advantageously as a sinter for a blast furnace.

However, the above-mentioned highly crystalline water ore generally has the following problems when used as a raw material for producing sinter. 1. Heat compensation is required for the thermal decomposition reaction at the time of elimination of water of crystallization that occurs when the temperature of the sintering raw material rises, and accordingly, more coke breeze is required. 2. Due to the porosity resulting from the elimination of water of crystallization, a local overmelting reaction is caused by the melt generated during the melting reaction of the sintering raw material. For this reason, the sintering productivity and yield are reduced. 3. Since the crystallinity is low and the powder is easily powdered, the ratio of fine particles or fine powder is large. For this reason, the sintering material is inferior in granulation properties,
The air permeability in the sintering material layer in the sintering machine bed is inferior, and as a result, the sintering production rate and yield are reduced. In particular, in order to establish a technology for increasing the production of sinter that is necessary when increasing the amount of hot metal produced in a blast furnace, the productivity and yield of sinter should be maintained while maintaining the quality of sinter products. It is important to improve. However, when the use ratio of the high-crystal water ore is increased, the granulating capacity of the raw material of the sinter becomes remarkable, and therefore, the unburned portion increases due to deterioration of the air permeability in the bed, and This leads to a decrease in yield and product strength.

Conventionally, the ratio of high-crystalline water ore containing 4 mass% or more of crystallization water to the mixed raw material is 25 mass%.
It has been found that when the amount is increased to about s% or more, the above-described problems of the first to third items become significant. In view of the above, the present invention has been made to solve the above-mentioned problem (3), particularly in order to ensure high productivity and yield of sintered ore even when such a large amount of high-crystal water ore is used in such a large amount. It tries to solve the point.

[0008] Despite the heavy use of highly crystalline water ore,
There has been proposed a technique for maintaining good granulation of a sintering raw material to be charged into a sintering machine, securing productivity and yield of a sinter, and maintaining the quality of the product. For example, in the pre-processing step of the sintering raw material, the sintering raw material is divided into “two lines” before the final mixing and granulation processing, and the pre-processing line of the high crystal water ore is used as a granulation binder. A technique has been proposed in which the amount of quick lime added is increased to improve the granulation of the highly crystalline water ore and to maintain the productivity and yield of the entire sintered ore (Japanese Patent Laid-Open No. Hei 5-9601). Gazette, hereinafter referred to as “prior art 1”).

According to the prior art 1, the same effect as the increase in the capacity of the mixer can be obtained by optimizing the distribution of the amount of quicklime added in the "two-series granulation method". However, the complexity of the process and the necessity of improving the cost associated with the execution of the "two-series granulation method" remain as problems.

Therefore, in view of the above circumstances, the present inventors,
Among the physical properties of high-crystal water ore, the level and level characteristics between species or brands of high-crystal water ore, regarding physical properties related to granulation that can maintain good pseudo-particle morphology and properties as a sintering raw material Focusing on the differences between the high-crystalline water ores, by taking advantage of these differences, it is suitable for achieving the intended objectives of improving the productivity, yield and product quality of sinter. The pre-processing flow of the sintering raw materials was reviewed, and attention was paid to performing pre-processing according to each brand of high-crystal water ore and its particle size classification. In addition, the sintering raw material having good granulation properties can solve the problems in the above-described prior arts and can secure the gas permeability of the raw material layer in the sintering machine bed even when a large amount of high-crystal water ore is used. The purpose of this study was to develop a pre-processing method.

Thus, an object of the present invention is to provide a raw material having no particular limitation on the raw material grade, such as using a raw material having a low content of SiO ₂ or Al ₂ O _{3 in} iron ore. Even if a large amount of high-crystal water ore, which is rapidly increasing, is used, the granulation properties can be maintained in the same manner as when using ordinary iron ore without specially increasing the granulator equipment for sintering raw materials. It is another object of the present invention to provide a method for producing a sintered ore for a blast furnace, which can ensure the productivity and the yield of the sintered ore well and maintain the quality of the product.

[0012]

Means for Solving the Problems The present inventors have conducted tests and studies on the above problems and obtained the following findings.

The high crystal water ore having a water content of crystallization of about 4 mass% or more greatly varies in its particle size distribution depending on the place of production and, therefore, its brand. Further, it depends on the combination of the brand of the high crystal water ore and its particle size. The physical properties of the ore that govern the granulation of the pseudo particles of the sintering raw material often differ. That is, the water absorption in the iron ore particles, that is, the water absorption capacity and the water absorption rate, the water retention between the iron ore particles, and the wettability of the iron ore particle surface with water, that is, the interfacial tension and the wetting rate (however, in this specification, The level of wettability is always different for water). In view of such a particle size of the high crystal water ore and the above-mentioned physical property level, attention was paid to the influence of the combination of the particle size and the physical property level on the granulation property of the sintering raw material. As a result, it has been found that there is a method suitable for pretreatment of highly crystalline water ore as a sintering raw material depending on the characteristics of the physical property level determined by the combination of the particle size and the physical property level. Prior art includes:
When using multiple highly crystalline water ores as raw materials for sintering,
For each combination of the high-crystal water ore with the particle size classification and the brand of the high-crystal water ore belonging to the classification, there are differences in the above-mentioned physical properties, and the pre-processing method of the sintering raw material is changed according to this difference. There is no idea of doing it.
However, if the present inventors appropriately select the pretreatment method of the sintering raw material for each combination of the particle size and physical properties of each brand, the sintering raw material thus pretreated is mixed and granulated. By doing so, it has been found that the granulation property is remarkably improved.

[0014] In this specification, the expression "good granulation of the sintering raw material" means that the quasi-granulated particle diameter grows large and the quasi-particles are dense and function as a binder. It means that the moisture is hardly desorbed and released, and therefore the pseudo particles are hardly broken in the subsequent step. Thus, due to the excellent granulation properties, it is not only difficult for the pseudo particles to be finely divided or disintegrated in the transportation process until the pseudo particles are charged into the sintering machine, but also in the sintering machine bed. In the process of increasing the temperature of the sintering material, the sintering material layer hardly collapses, and as a result, the sintering material layer has good air permeability. Thus, high levels of productivity and yield and quality of the sinter are assured.

The present invention has been made based on the above findings, and the gist thereof is as follows. In the method for producing a sintered ore for a blast furnace according to claim 1, in the step of producing a sintered ore that is a raw material to be charged into the blast furnace, 25% of the mixed raw material is used.
In a method for producing the sintered ore using a high-crystal water ore containing 4 mass% or more of crystallization water in mass% or more,
This is a method for producing a sintered ore by blending two or more high-crystalline water ores or two or more brands of high-crystalline water ore as the high-crystalline water ore. Then, the two or more high-crystal water ores, or the two or more high-crystal water ores,
Classified into two or more particle size classes for each of the high crystalline water ores, and for each classified partial ore of each obtained high crystalline water ore, from the water absorption, water retention and wettability of the classified partial ore An appropriate pretreatment method is selected based on at least one physical property level selected from the physical property group. The pre-treatment selected in this way is characterized in that it is applied to the respective classified partial ores. However, when there is no characteristic in the above physical properties level of the classified partial ore,
It is not always necessary to perform pre-treatment on all of the classified partial ores, and some of the classified partial ores may not be subjected to special pre-treatment.

According to a second aspect of the present invention, there is provided a method for producing a sintered ore for a blast furnace, wherein in the step of producing a sintered ore which is a raw material to be charged into the blast furnace, 4 mass% or more of crystallization water is added to 25 mass% or more of the mixed raw material. In the method for producing a sintered ore using the high-crystal water ore containing above, the high-crystal water ore is mixed with two or more kinds of high-crystal water ore or two or more brands of high-crystal water ore and sintered. This is a method for producing a sintered ore for producing an ore.
Then, the high crystal water ore of two or more types or the high crystal water ore of two brands or more are classified as they are without being crushed into two or more particle size classifications for each of the high crystal water ores. Based on the level of at least one physical property selected from the group of physical properties consisting of water absorption, water retention and wettability of each classified partial ore of each of the obtained high crystalline water ores, the classified partial ores are classified into Classify all into multiple groups. At the same time, the level of the selected physical properties of each of the groups is changed to a size corresponding to the particle size classification of the high crystalline water ore of the ordinary ore (ore having a water content of crystallization of less than 4 mass%) used in the production of the sintered ore. By comparing with the same physical property level as the above-mentioned selected physical property of the classified partial ore, at least two groups of the highly crystalline water ore having a characteristic with respect to the physical property level are selected. Appropriate pre-processing is performed on the at least two groups thus selected in consideration of the characteristics of the physical property levels of the respective groups, and the following steps (a) to (d)
Select at least one from among the above. The pre-processing selected in this way is performed on the selected group. However, when there is no feature in the physical property level of the group, it is not always necessary to perform pre-processing on all of the groups, and there may be a group that does not perform special pre-processing. The mixed raw material thus obtained is granulated in the form of pseudo-particles, and the granulated pseudo-particles are charged into the pallet of the sintering machine while being layered and charged. is there.

Here, the above pre-processing steps (a) to (d)
The following steps are performed while each of the high crystalline water ores flows through the line from the ore stockyard to the sintering machine: (a) a step of stirring and mixing with added water by a high-speed stirring mixer; (b) another step by a bedding method. A step of blending with the raw material, (c) a step of pulverizing the particle size by performing a crushing process, or a step of further classifying the fine powder portion after the crushing process, or as a special case, classifying into the initial two or more particle size classes. In the case where the fine ore obtained as a result is in the state of the ore and is not particularly subjected to the pretreatment, it refers to (d) a step of adding water by watering.

According to a third aspect of the present invention, in the method for producing a blast furnace sintered ore according to the second aspect of the present invention, the number of ore species or the number of brands of the high crystalline water ore used as a raw material of the sinter ore is total. 2, the classification number of the high-crystal water ore according to the particle size classification is 2, and the classification number of the group according to the physical property level of the classified partial ore is 4, and the classification standard of each group is 4. The characteristic of the certain physical property level and the pre-processing step for the classified partial ore belonging to each group selected based on the characteristic level are characterized as follows.

Group 1: Fine ore classified partial ore, which has a high water retention between particles but a low wettability, is charged at least with quicklime and then charged into a high-speed stirring mixer and added. Stir and mix with water.

Group 2: Classified ores in the coarse-grained portion where the physical properties of water absorption, water retention and wettability are substantially the same as those of the classified ores of ordinary ores. After blending with other raw materials by a bedding method, the mixture is charged into a raw material mixing hopper of a sintering machine.

Group 3: A fine-grain classified ore having high water absorption and wettability is subjected to crushing treatment and then charged into a raw material mixing hopper of a sintering machine. Alternatively, it is mixed with the mixed raw material on the mixed raw material route upstream of the mixing / granulating step.

Group 4: Classified ores in the coarse-grained portion, which have a high water absorption into the particles but a low water absorption speed into the particles, belong to the ore stockyard from the sintering machine material mixing hopper. The water spray treatment is performed until the ore particles are absorbed into the ore particles. It is important that the water sprinkled here is sufficiently absorbed into the ore particles, and sufficient time is taken to be absorbed into the particles.

According to a fourth aspect of the present invention, there is provided the method for producing a sintered ore for a blast furnace according to the third aspect.
The high crystalline water ore of Group 4 is characterized by the following cases. Group 1: Maramanba ore or one brand of high-crystal water ore belonging thereto, wherein the ratio of particles having a particle size of 0.25 mm or less accounts for 30 mass% or more Group 2: Maramanba ore or one member thereof High-grade water ore of a brand, having a ratio of 0.7 mm or more in particle size occupying 50 mass% or less Group 3: Pisolite ore or one type of high-crystal water ore belonging thereto, having a particle size of 0.25 mm Group 4: Pisolite ore or one kind of high-grade water ore belonging to the same group, the ratio of which is 0.7 mm or more occupies 50 mass% or more.

According to a fifth aspect of the present invention, there is provided a method for producing a sintered ore for a blast furnace, wherein in the step of producing a sintered ore which is a raw material to be charged to the blast furnace, 4 mass% or more of crystallization water is added to 25 mass% or more of the mixed raw material. In the method for producing a blast furnace sintered ore using the high crystalline water ore containing above, as the high crystalline water ore,
At least two or more or two or more grades of highly crystalline water ore are used. Among them, at least one ore or one grade of highly crystalline water ore, the water retention between particles in the fine-grained portion is as follows. It is classified into a group of high-crystal water ores having a high but low wetting rate (referred to as group (A)), and as at least one other or one brand of high-crystal water ore, in the grains of the coarse-grained portion. A highly crystalline water ore classified into a group of highly crystalline water ores having high water absorption into the particles but having a low water absorption rate into the particles (referred to as group (B)) is used. Then, it is classified into two or more particle sizes for each type or each brand. The fine-grained portion of the highly crystalline water ore classified into the group (A) is subjected to mixing and granulation after mixing and stirring with water using at least a high-speed stirring mixer. on the other hand,
The coarse-grained portion of the highly crystalline water ore classified into the group (B) is characterized in that the mixing and granulation is performed after at least watering is performed to sufficiently absorb the water. .

According to a sixth aspect of the present invention, in the method for producing a blast furnace sintered ore according to the fifth aspect of the present invention, the high crystal water ore classified in the group (A) is a brand belonging to the Maramamba ore. Of high crystal water ore, and among the high crystal water ores classified into the group (B), high grade water ore of the brand belonging to the pisolite ore is characterized. Things.

According to a seventh aspect of the present invention, in the method of manufacturing a sintered ore for a blast furnace, in the step of manufacturing a sintered ore which is a raw material to be charged into the blast furnace, at least 25 mass% of the mixed raw material and at least two ore types are mixed. Alternatively, in a method for producing a blast furnace sintered ore using two or more brands of high-crystal water ore containing 4 mass% or more of crystallization water, at least one of the two or more or two or more brands of high-crystal water ore, As a highly crystalline water ore (hereinafter referred to as “highly crystalline water ore (A)”), fine-grained ore has a higher level of water retention between particles than a normal ore, but has a lower level of wettability. For coarse-grained ores, highly crystalline water ore having the same physical level as that of ordinary ore is used. Further, as at least one other highly crystalline water ore (hereinafter referred to as “highly crystalline water ore”), coarse partial ore has a higher level of water absorption ability into the inside of the particles than ordinary ore, A high crystalline water ore having a low water absorption rate and a physical property level similar to that of ordinary ore is used for fine-grained ore. The fine-grain ore of the high-crystal water ore (A) is subjected to at least a pre-treatment of mixing and stirring with water using a high-speed stirring mixer, and the coarse-grain portion of the high-crystal water ore (B) is The ore is subjected to at least a pre-treatment for sufficiently absorbing water by performing a water spray treatment, and then granulating, and charging the pseudo-particles thus granulated in the pallet of the sintering machine in a layered manner. It is characterized by the following.

In order to solve the above-mentioned problems when the present inventors have made the present invention, the obtained hints and experimental results which led to the above-mentioned findings will be described below.

First, since the high crystal water ore has a low crystallinity and is easily powdered, it is expected that the ratio of fine particles or fine powder is large. Therefore, when using the supplied high-crystal water ore as a sintering raw material, in order to obtain an index for obtaining good granulation properties by adding moisture without using a special binder in the mixing and granulation steps. In addition, the ore's particle size distribution is grasped by type or brand, and depending on the size of the ore, the ore absorption, water retention and wettability as the physical properties of the ore that governs the granulation properties are determined. A basic test to evaluate the level was performed. The types and methods of the tests are as follows, and some useful findings were obtained in consideration of the test results. These are described below.

[Test Procedures and Measurement Results] ○ The iron ores to be tested are new maramamba ores (brand designations: M and W) and pisolite ores (brand: Robe River (ROB)), which are high crystal water ores. Yandi (Y
AN)), as well as the common ore, Calajas (CA
J), Hamasley (HAM) and Romeral (ROM). The types of tests are chemical composition analysis, particle size distribution and measurement,
Rolling limit water content measurement, saturated water content measurement, and wettability test, and the test procedures and measurement results for each were shown, and then considered. As a result, some useful findings were obtained.

○ Chemical composition analysis: Table 1 shows examples of the analysis results. The analysis results of OB-29 as a brand belonging to the conventional Maramamba ore are also described. The new Maramamba ore has a high water content of crystallization of about 5 mass% or more, similar to the conventional Maramamba ore and pisolite ore.

[0031]

[Table 1]

○ Particle size distribution test:-
0.045mm, -0.063mm, -0.125m
m, -0.25 mm, -0.5 mm, -1 mm, -2.
The particles were classified into 10 particle sizes of 8 mm, -4.75 mm, -8.0 and +8.0 mm, and the weight of each particle size was measured. The results are summarized in FIG. (a) M, W of new Maramamba ore, which is a highly crystalline water ore
In any case, the ratio of passage of 0.125 mm is 20 to 30 m
It is as large as ass%. This is because, for example, similarly to OB-29 of Maramamba ore, which is a conventional high crystalline water ore, the degree of crystallinity is low and powdering is easy.

Rolling limit moisture content test: 400 mmφ × 100 mm using 1.5 kg of a completely dried particle size sample
A granulation test was performed on a drum of length. Predetermined amount of water 3
After the addition in 0 seconds, the average particle size after rotation at a rotation speed of 15 rpm for 3 minutes was measured. The upper limit value of the added water (rolling limit water amount) at which the rolling during granulation is possible was defined as the water amount when the pseudo particles start slipping in the drum. FIG. 3 shows the measurement results.

Observation of macrostructure of ore: FIG. 4 shows a typical example of a macrostructure of ore particles at a low magnification using a mineral microscope. In the figure, the black part of the matrix is the part of the gangue. (b) Carrajas (C
AJ) and Hamassley (HAM)
It is in agreement with the value of 8 to 9 mass%, which is a value close to the amount of water added during granulation in the current operation, which the present inventors have grasped. It is about 15 to 15% by mass, about 1.5 to 2 times as high as that of the ordinary ore, and it can be seen that the water absorption is high [Knowledge-1].

(C) On the other hand, the rolling limit water content of the lobe river (ROB) of a pisolite-based ore, which has been conventionally known to have high water absorption, is about 9 mass%, It is much lower than ore. The roriver (ROB) has a fish egg-like structure (FIG. 4,
(C)), despite the inherently high water absorption into the ore particles, the lobe river (RO)
As shown in FIG. 2, the low rolling limit moisture content of B) was obtained because the particle size distribution of the lobe river (ROB) was coarse and the conditions of the rolling limit moisture content test of this time were obtained. It is presumed that water penetration into the ore particles was not sufficiently performed below. Therefore, as for the lobe river (ROB), in the ordinary watering and granulating method in which the contact and permeation time with water is short, the water has not yet sufficiently penetrated into the ore particles. During the elapse of time before being charged into the pallet, the water that has been serving as a binder between the ore particles permeates into the ore particles. For this reason, the binder action of the particles due to moisture is weakened before the particles are charged into the sintering machine, the moisture between the particles in the pseudo particles formed in the granulation step is reduced, and the pseudo particles are easily broken. Further, in the process of raising the temperature of the raw material in the sintering machine pallet, the water content between the particles is further reduced. In this way, the disintegration of the pseudo particles proceeds further. On the other hand, the length of the elapsed time from the granulation step to charging to the pallet is unique to the sintering operation in each factory. Therefore, in this case, before entering the mixing / granulation step, it is necessary to set a time allowance for the added water to sufficiently penetrate into the ore particles. Otherwise, the permeability of the raw material layer is deteriorated due to the disintegration of the pseudo particles, the productivity of the sintered ore is reduced, and the product yield is reduced. Therefore, like Lobe River (ROB),
In the high crystalline water ore, despite the high water absorption into the ore particles, in the method of adding water to those having a low water absorption rate, especially for the ore of the coarse particle size,
It is necessary to perform the watering operation on the ore at an early stage of the pretreatment process [Knowledge-2].

○ Saturated water content measurement test: The immersion sample was immersed in water for 24 hours with the sample placed on a sieve having a sieve mesh of 0.045 mm in diameter. Was calculated. The result is shown in FIG. (d) The ores of Karajas (CAJ) and Romeral (R)
OM) has a high degree of crystallinity and is dense, and therefore has a relatively low saturated water absorption as compared with other ores. On the other hand, Lobe River (RO) made of pisolite ore, which is a highly crystalline water ore
B) and M and W of the new Maramamba ore all have a high saturated water absorption of about 17 to 20 mass% [Kind 3]. (e) Pisolite ore lobe river (ROB) is coarse (see FIG. 2) but porous (FIG. 4, (c)
See)), so the saturated water absorption is high. Therefore, if the immersion time in water is sufficiently long, it is considered that the water has sufficiently penetrated into the ore particles and a higher saturated water absorption than the measurement result in FIG. This suggests that if watering is performed in advance in a storage place such as a yard or a hopper where the raw material residence time is relatively long, an improvement in granulation properties can be expected [Knowledge-4]. (f) On the other hand, the coarse-grained portion of M of the new Maramamba-based ore is relatively dense (see (d) in FIG. 4), and it is considered that the penetration of moisture into the ore particles is small. Therefore, this may be a pre-treatment method according to the above-mentioned ordinary ore [Kind -5].

○ Wettability test: Two kinds of samples were tested: (a) -1 mm particles classified from flake fine ore, and (b) 75-44 μm particles after crushing fine ore. As a test device, a powder wetting device (manufactured by Kyowa Kagaku Co., Ltd.) was used to measure the water absorption height with respect to the elapsed time.
Expressed as a power. (A) Fig. 6 shows the measurement results for the -1mm particles of the ore.
FIG. 7 shows the measurement results of the 75-44 μm classified particles after pulverization. It is considered that the relationship between the wettability of the ore particle surface and the water retention capacity between the ore particles appears more remarkably when the particles are crushed and sized to the fine particle portion as in the sample (b). The following matters can be understood from FIGS. (g) Hamasley (HAM), Karajas (C
AJ) and romeral (ROM) have a small amount of fine particles (see FIG. 2) and a low saturated water absorption (see FIG. 5). , The wetting speed (the slope of the straight line in FIG. 6) is high. On the other hand, M and W of the new Maramamba ore, which is one of the highly crystalline water ores, have many fine particles (see FIG. 2), and the fine particles have a high water retention ability but a low wetting rate. Considering also the above findings -1 and -3,
The ore particle surface has a large water retention capacity, but its wetting speed is low and its water absorption is high. As a treatment method, a sufficient amount of water is added to forcibly accelerate the wetting rate on the ore particle surface, and at that time, an appropriate ore such that the crushing action of the ore particle can be suppressed and the fineness can be prevented can be prevented. It is effective to mix the ore particles and water using a high-speed stirring mixer device [Knowledge-6]. (h) Robe River (ROB), another high crystalline water ore
And the fine-grained portion of Yandi (YAN) has a large water retention capacity and a high wetting rate. Therefore, the lobe river (RO)
In the case of B) and Yandi (YAN), fine granulation is performed, or finely divided portions are classified without performing fine pulverization, and are used as adhered particles in the granulation process to obtain granulation properties. It can be seen that an improvement effect can be expected [Knowledge-7]. The present inventors have accomplished the present invention based on the above-mentioned various findings and operating experience in the production of sinter.

[0038]

Next, the present invention will be described with reference to the drawings. FIG. 1 shows a schematic flow chart during sinter production according to the present invention. First, the flow of charging the ordinary ore 1 into the sintering machine 9 is as follows. Ore 1 placed in ore stock yard, bedding 2 in ore yard
I do. Iron ore various brands by the normal ore 1 bedding method (fine ore), containing CaO auxiliary material, containing SiO ₂ auxiliary materials,
Blending powder (B powder) 3 is mixed with dust, carbonaceous material, and the like at a predetermined ratio as appropriate, and charged into a predetermined raw material mixing layer 4. B powder 3 is cut out in a predetermined mixture with other raw materials such as limestone 5 in the raw material mixing tank 4 and the slag-making material,
After charging into a mixing / granulating machine 6 and pseudo-granulation, a coke breeze 7 is attached to the surface of the particles by a coating mixer 8 and packaged, and then charged into a sintering machine 9 as a sintering raw material.

On the other hand, the flow up to charging of the highly crystalline water ore 10 into the sintering machine 9 is as follows. The highly crystalline water ore is classified by a sieve 11 'for each seed or brand. The ore obtained by classification by the sieving apparatus 11 'is referred to as "classified partial ore" in this specification. In the present invention, the pretreatment method of the highly crystalline water ore, which is suitable for improving the mixing and granulating properties, is determined by the water absorption, water retention and wettability among various physical properties of the ore. That
It is a technically important feature. Therefore, an appropriate pretreatment method for improving the granulation property of the high-crystal water ore is selected by evaluating the level of the physical properties of the high-crystal water ore. At that time, from the viewpoint of selecting a pretreatment method that is more suitable for improving the granulation property, the highly crystalline water ore is classified in order to more appropriately determine the level of the physical properties of the highly crystalline water ore. Then, the level of the physical properties was evaluated for each "classified partial ore", and the focus was placed on characterizing the physical properties of the ores. Thus, in the present invention, the classification treatment of the high-crystal water ore is performed by classifying the high-crystal water ore based on the water absorption, water retention and wettability of the high-crystal water ore by granulating it. This step is necessary to select a more appropriate pretreatment method for improvement. On the other hand, it is also important to aim for cost minimum without lowering the productivity in the manufacturing flow shown in FIG. 1, so that a method that efficiently satisfies the purpose of the classification process is desirable. From this point of view, this classification processing may be sufficient if rough classification processing can be performed by a simple method. This is referred to as “simple classification” in this specification.

Here, the supply of high-crystal water ore to an ironworks is usually received for each high-crystal water ore mined from a predetermined ore deposit, or is divided according to the brand of the high-crystal water ore. Although it arrives, the present inventors further assumed that highly crystalline water ore species of different or different ore deposits, or different brands of highly crystalline water ore may arrive in a mixed state. Therefore, in the present specification, the division form of supply or receipt of high-crystal water ore is defined as a state in which seeds or deposits of high-crystal water ore are mixed or different brands in the same kind of high-crystal water ore are mixed. Even if they are received or received, they were used as raw materials for sintering so that they could be used without any particular problem in sintering technology.
Further, in the present specification, the high crystal water ore generally refers to an ore having a crystal water content of 4 mass% or more, and the ordinary ore refers to an ore having a crystal water of less than 4 mass%. Conventionally, when an ore containing 4 mass% or more of crystallization water is blended in a proportion exceeding 25 mass% in the mixed raw material, the granulation property of the sintering raw material becomes insufficient and the productivity of the sinter is reduced. This is because it is known that the reduction in yield is a problem.

In FIG. 1, the pre-treatment according to the following flow is performed on the classified ore of the highly crystalline water ore that has been simply classified 11 by the sieving device 11 '. Here, a description will be given of what kind of pre-processing is performed in accordance with a flow on the classified ore obtained by the simple classification.

First, the high-crystal water ore 10 is classified into a fine-grained or fine-grained ore and a coarse-grained ore, and each of the classified ores has the above-mentioned physical properties (water absorption, water retention and wettability). Characterization is performed based on According to the “physical characteristics” assigned to each classified partial ore, a “pretreatment pattern” consisting of a combination of a pretreatment method and a flow route of the classified partial ore is selected. A mixed raw material obtained by mixing the classified ore of the crystal water ore with the ordinary ore 1 and other raw materials is charged into a mixing / granulating machine 6 and quasi-granulated.
A coke breeze 7 is attached to the surface of the particles with a coating mixer 8 and is then charged into a sintering machine 9 as a sintering raw material.

The following (I) to (IV) are set as the pre-treatment patterns for the classified ore of the highly crystalline water ore.

Pretreatment pattern (I): The classified partial ore corresponding to this is a fine-grained portion of highly crystalline water ore, and its physical properties are characterized by a high water retention between particles but a low wetting rate. Can be For example, the fine-grained portion of the Mara Mamba ore corresponds to this. Such a partially classified ore is subjected to stirring and mixing with the added water by using a high-speed stirring mixer 15 in a downstream step of the simple classification 11.
At that time, it is desirable to perform the treatment after blending with the quicklime 13 and the ore return 14. Since the treatment is for promoting the absorption of moisture to the ore with a low wetting rate, quicklime that reacts with moisture is blended in advance,
This is because it is desirable to operate the lime so that the lime easily adheres to the surface of the ore particles or to mix the returned mineral in advance in order to promote the granulating action of the ore particle and the returned mineral. . The raw material subjected to the pretreatment in this way is combined with other raw materials before the mixing / granulating machine 6 in FIG. There is no need to limit the method of merging, and for example, raw materials may be merged by entering the conveyor belt. Further, as the high-speed stirring mixer 15, a device that functions to help water to quickly enter between the particles without further reducing the ore particles is desirable. For example, a commercially available Eirich mixer, Loedige mixer or these may be used. Use the same equipment.

Pre-treatment pattern (II): The physical properties of the classified partial ore correspond to the coarse-grained portion of the highly crystalline water ore, and its physical properties are as follows: water absorption, water retention and wettability. The ore 1 is characterized by being in the same level as the physical properties of the classified ore substantially corresponding to the coarse-grained portion of the ore 1. For example, the coarse-grained portion of the Mara Mamba ore corresponds to this. In the downstream process of the simplified classification 11, the classified ore is subjected to a process of blending 2 with the ordinary ore 1 or the like by a bedding method, and after the blending 2, is charged into the raw material mixing tank 4 as B powder 3. I do. The reason why such a raw material flow is adopted in the pretreatment pattern (II) is that the behavior of the ore 1 is similar to that of the coarse part of the ordinary ore 1 and is treated as a core particle in the mixing and granulating operation. It is desirable.

Pretreatment pattern (III): The classified partial ore corresponds to the fine-grained portion of highly crystalline water ore, and its physical properties are characterized by high water absorption and high wettability. For example, a fine-grain portion of a pisolite ore corresponds to this. For such fine or fine classified partial ores, the following two cases are adopted. First, after simple classification 11, the special ore fines are not subjected to any special pretreatment, and are combined with other raw materials by route (III) -1 or route (III) -2 shown in FIG. The second method is a method in which the fine-grained ore after the simple classification is further pulverized, and this is combined with other raw materials by the above-mentioned route (III) -1 or (III) -2. Regarding the mixing ratio and mixing / granulation operation of the fine or fine ore corresponding to the pre-treatment pattern (III), it is desirable to treat them as adhered particles.

Pretreatment pattern (IV): The classified partial ore corresponding to this is a coarse-grained portion of high-crystal water ore, and its physical properties are such that water absorption into ore particles is high, but It is characterized by a low water absorption rate. For example, a coarse-grained portion of a pisolite ore corresponds to this. Since the water absorption rate is slow for the coarse-grained partial ore, in the mixing and granulating operation, firstly, there is sufficient time for the added water to be sufficiently absorbed into the ore particles. Since it is necessary and has high water absorption into the particles, it is necessary to add a sufficient amount of water. Therefore, the coarse ore corresponding to the pretreatment pattern (IV) is subjected to simple classification 11 and then subjected to sprinkling treatment 16 using a yard, a conveyor belt being transported, or a bedding yard.
And then bedding 2 (route (IV) in FIG. 1)
-1) Here, after being mixed with other ordinary raw materials 1 and the like, they are transported and loaded into the raw material mixing tank 4, or after being subjected to simple classification 11, they are transported and loaded into the dedicated raw material mixing tank 17 capable of spraying water. Enter
Here, it is desirable to perform a sprinkling treatment, take a long time to sufficiently absorb the water, and then cut out the raw material mixing tank 17 into a mixing line (route (IV) -2).

The above-mentioned pre-processing patterns (I) to (IV)
The fine grain, fine grain and coarse grain boundary grain size, and the fine grain, fine grain and coarse grain quantitative ratio are determined by the grain size distribution of the highly crystalline water ore used as the sintering raw material. It is desirable to determine according to the specific mixing / granulation operation conditions which depend on the target, or the target pseudo particle characteristics such as the target particle size and strength of the pseudo particle to be prepared. From this viewpoint, the classified partial ores corresponding to each of the pre-treatment patterns (I) to (IV) are fine particles of the Maramamba ore when the pre-treatment pattern (I), as exemplified above, In the case of the treatment pattern (II), it is a coarse-grained portion of the Maramamba ore, in the case of the pretreatment pattern (III), it is a fine portion of the pisolite ore, and in the case of the pretreatment pattern (IV), it is the pisolite ore In the case of the coarse-grained portion, the combination of each boundary grain size and its quantitative ratio is as follows: Pre-processing pattern (I)
, The ratio of the particle size of 0.25 mm or less is 30mas
s% or more, in the pre-processing pattern (II), the ratio of the particle size of 0.7 mm or more is 50 mass% or less, and in the pre-processing pattern (III), the ratio of the particle size of 0.25 mm or less is 20 mass% or less. In pattern (IV), the ratio of particles having a particle size of 0.7 mm or more is 50 m.
It is desirable to limit the amount to at least ass%.

The reasons for these limitations are derived from the above-mentioned findings 1 to 7 derived from the measurement results regarding various physical properties of the highly crystalline water ore shown in FIGS. The reasons for these limitations are the above-mentioned findings 1 to 7 derived from the measurement results regarding various physical properties of the highly crystalline water ore shown in FIGS.
It is derived from consideration of the sinter pot test results.

[0050]

As described above, according to the present invention,
Even if a large amount of high-crystal water ore is used, it is possible to secure the permeability of the raw material layer in the bed of the sintering machine without specially increasing the granulator equipment for the sintering raw material, and to provide a simulated material with good granulation properties. It is possible to prepare particulate sintering raw material, secure it in the same way as when using ordinary iron ore, secure good productivity and yield of sintered ore, and maintain good product quality can do. A method for producing such a blast furnace sintered ore can be provided, and an industrially useful effect is provided.

[Brief description of the drawings]

FIG. 1 is a schematic flow chart when producing a sintered ore by the method of the present invention.

FIG. 2 is a measurement example of a particle size distribution of various brand ores.

FIG. 3 is a measurement example of the rolling limit water content of various brand ores.

FIG. 4 is a diagram for explaining characteristics of various brand ores by macrostructure observation.

FIG. 5 is a measurement example of the saturated water absorption of various brand ores.

FIG. 6 is a measurement example of wettability of various brand ores.

FIG. 7 is another measurement example of the wettability of various brand ores.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 ordinary ore 2 bedding 3 B powder 4 raw material mixing tank 5 limestone 6 mixing / granulating machine 7 coke breeze 8 coating mixer 9 sintering machine 10 high crystal water ore 11 simple classification 11 ′ sieving device 12 fine ore (high crystal water) Ore) 13 quicklime 14 returned ore 15 high-speed stirring mixer 16 water sprinkling 17 classification ore of high-crystal water ore 17 'dedicated raw material mixing tank 18 other raw materials

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Satoshi Machida 1-2-1, Marunouchi, Chiyoda-ku, Tokyo Nihon Kokan Co., Ltd. (72) Inventor Noboru Sakamoto 1-2-1, Marunouchi, Chiyoda-ku, Tokyo Sun (72) Inventor Hideaki Sato 1-2-1, Marunouchi, Chiyoda-ku, Tokyo Japan 1-2.Inventor Yoshinori Watanabe 1-2-1, Marunouchi, Chiyoda-ku, Tokyo Japan 1-2 Co., Ltd. F term (reference) 4K001 AA10 BA02 CA10 CA33 CA38 CA39

Claims (7)

[Claims] In the step of producing a sintered ore, which is a raw material charged to a blast furnace, 25 mass% or more of the mixed raw material is
In the method for producing the sintered ore using the high crystalline water ore containing 4 mass% or more of crystallization water, as the high crystalline water ore, two or more kinds of high crystalline water ore or two or more brands of high crystalline water ore are used. A method for producing a sintered ore by blending to produce a sintered ore, wherein the two or more high-crystal water ores, or the two or more high-crystal water ores are mixed for each of the high-crystal water ores. Classified into two or more particle size classes, and for each classified partial ore of each of the obtained highly crystalline water ores, at least selected from a group of physical properties consisting of water absorption, water retention and wettability of the classified partial ore. A method for producing a sintered ore for a blast furnace, characterized in that an appropriate pretreatment method is selected based on one kind of physical property level and the selected pretreatment is applied to each of the classified partial ores. 2. A process for producing a sinter which is a raw material to be charged into a blast furnace, wherein at least 25 mass% of the mixed raw material is
In the method for producing the sintered ore using the high crystalline water ore containing 4 mass% or more of crystallization water, as the high crystalline water ore, two or more kinds of high crystalline water ore or two or more brands of high crystalline water ore are used. A method for producing a sintered ore by blending to produce a sintered ore, wherein the high crystal water ore of at least two ore species or the high crystal water ore of at least two brands are not crushed, and Classified into two or more particle sizes for each crystal water ore, and at least one selected from the group of physical properties consisting of water absorption, water retention and wettability of each classified partial ore of each of the obtained high crystal water ores. Based on the level of physical properties, each of the classified partial ores is classified into multiple groups for all of them, and the selected level of physical properties of each group is used for the ordinary ore used in the production of the sinter. Classified partial ore corresponding to the above particle size classification Compared to the selected physical property level and the same physical property level, and at least two groups having characteristics for the physical property level are selected. Based on the characteristics of the physical property levels, at least one of the following pre-processes of the following processes (a) to (d) is selected, and the pre-process selected in this way is applied to the selected group. Then, the mixed raw material thus obtained is granulated in the form of pseudo particles, and the granulated pseudo particles are charged into the pallet of the sintering machine while being layered and charged, Production method of sinter for ore. Here, the pretreatment steps (a) to (d) include the following steps while each of the high crystalline water ores flows through the line from the ore stock yard to the sintering machine: (a) water added by a high-speed stirring mixer (B) a step of blending with other raw materials by a bedding method, (c) a step of pulverizing to reduce the particle size, or a step of further classifying a fine powder portion after the crushing processing, or And, as a special case, when the fine ore obtained by classifying into the initial two or more particle size classifications is not subjected to any special pretreatment, (d) a step of adding water by water spraying, Point to. 3. The number of ore types or brands of the highly crystalline water ore used as a raw material of the sintered ore is 2 in total, and the classification number of each of the highly crystalline water ores by the particle size classification is 2. And the classification number of the group according to the physical property level of the classified partial ore is 4, and the characteristics of the physical property level which is the classification standard of each group and the classified partial ore belonging to each group selected based on the characteristic are The method for producing a sintered ore for a blast furnace according to claim 2, wherein the pretreatment step is as follows. Group 1: A fine-grained classified ore, which has a high water retention between particles but a low wetting rate, is mixed at least with quick lime, and then charged into a high-speed stirring mixer to remove added water and Stir and mix. Group 2: Classified ores in the coarse-grained portion, in which the properties of water absorption, water retention and wettability are almost the same as those of the classified ores of ordinary ores, are classified into the bedding method. After blending with other raw materials, the sintering machine is charged into a raw material mixing hopper. Group 3: Fine ore-classified partial ores having high water absorption and wettability are subjected to crushing treatment and then charged into a raw material mixing hopper of a sintering machine or mixed. Either blending with the mixed raw material on the mixed raw material route upstream of the granulation process. Group 4: Classified ore in the coarse-grained portion, which has a high water absorption into the particles but has a low water absorption rate into the particles, a group from the ore stockyard to the raw material mixing hopper of the sintering machine In the above, water sprinkling treatment is performed to absorb the water sprinkled into the ore particles. 4. The method for producing a sintered ore for a blast furnace according to claim 3, wherein the high-crystal water ores in Groups 1 to 4 are as follows. Group 1: Maramanba ore or one kind of high-crystal water ore belonging thereto, wherein the ratio of particles having a particle size of 0.25 mm or less occupies 30 mass% or more Group 2: Maramanba ore or one part of the same High crystalline water ore having a particle size of 0.7 mm or more occupying 50 mass% or less Group 3: Pisolite ore or one brand of high crystal water ore having a particle size of 0.25 mm or less Group 4: Pisolite ore or one kind of high-crystal water ore belonging to the group, with a ratio of 0.7 mm or more occupying 50 mass% or more. 5. A process for producing a sinter which is a raw material to be charged into a blast furnace, wherein at least 25 mass% of the mixed raw material is
In a method for producing a blast furnace sinter using a high-crystal water ore containing 4 mass% or more of crystallization water, as the high-crystal water ore, at least two ore species, or two or more brands,
A group of highly crystalline water ores, of which at least one ore or one brand of highly crystalline water ore, has high water retention between particles in the fine-grained portion but a low wetting rate. (Group A) and at least one other or one brand of high crystalline water ore, the coarse part has high water absorption into the particles, but the water absorption rate into the particles. Using high-crystal water ore classified into a group of high-crystal water ore (hereinafter referred to as group B), which is classified into two or more particle sizes for each type or each brand, and The fine-grained portion of the water ore is subjected to mixing and granulation after mixing and stirring with water at least using a high-speed stirring mixer, and the coarse-grained portion of the highly crystalline water ore classified into the group B About at least watering A method for producing a sintered ore for a blast furnace, wherein the mixing and granulating treatment is performed after the water is sufficiently absorbed by the treatment. 6. The high crystalline water ore classified into the group (A) includes a high crystalline water ore of a brand belonging to the Maramamba ore, and the high crystal water ore classified into the group (B) is included. It is characterized in that the crystalline water ore contains a high crystalline water ore of a brand belonging to the pisolite ore,
A method for producing a blast furnace sintered ore according to claim 5. 7. A process for producing a sinter which is a raw material to be charged into a blast furnace, wherein at least 25 mass% of the mixed raw material is
2 mass or more or 2 brands or more, crystallization water 4 mass%
In the method for producing a blast furnace sintered ore using the high-crystal water ore containing above, of the two or more or two or more brands of high-crystal water ore,
At least one highly crystalline water ore (hereinafter, highly crystalline water ore shell)
As a result, the fine ore has a higher level of interparticle water retention than the normal ore, but has a lower level of wettability, and the coarse partial ore has the same physical level as the normal ore. High-crystal water ore is used, and as at least one other high-crystal water ore (hereinafter referred to as high-crystal water ore B), coarse-grained partial ore is more than ordinary ore,
The water absorption capacity inside the particles is at a high level, but the water absorption rate is at a low level, and for fine-grained partial ores, a highly crystalline water ore having a physical property level similar to that of ordinary ores is used; The fine-grained ore of the crystallized water ore shell is subjected to at least a pretreatment of mixing and stirring with water using a high-speed stirring mixer, and the coarse-grained ore of the high-crystallized water ore B is subjected to at least watering treatment. Sintering is carried out by pre-treating the sintering machine to sufficiently absorb moisture, and then granulating, and the quasi-particles thus granulated are charged into the pallet of the sintering machine while being layered and charged. The method of producing condensate.