CN1328358C - Coal agglomerate for smelting reduction process and its manufacturing method - Google Patents

Abstract

Disclosed herein are a coal briquette for a smelting reduction process, in which coal and iron ore are charged into a smelting furnace to produce molten iron, and a method of manufacturing the same. The coal briquette comprises, as main components, not more than 50% by weight of at least one of sludge and dust, and the balance of pulverized coal, the sludge and dust comprising iron (Fe) or an iron compound, carbon (C), a calcium compound and a magnesium compound, and 5 to 20 parts by weight of a binder based on 100 parts by weight of the main raw materials.

Description

Coal agglomerate for smelting reduction process and its manufacturing method

technical field

The present invention relates to coal agglomerates for a smelting reduction process in which coal and iron ore are fed into a melting furnace to produce molten iron. More specifically, the present invention relates to a coal briquette comprising sludge and ash powder as raw materials, having sufficient drop strength and thermal burst performance required by a smelting reduction process, and a manufacturing method thereof.

Background technique

As is well known, since the new FINEX and COREX processes of the smelting reduction process (a process for producing molten iron from coal) use coal instead of coke as a fuel for a melting furnace, they have advantages in availability of fuel. The particle size of coal available for the smelting reduction process is limited to not less than 8 mm. When the particle size of the coal is less than 8mm, they cannot be completely burned in the melting furnace and are collected by the dust collector. In addition, when the pulverized coal having a particle size of less than 8 mm is added in an excessively large amount, an undesired imbalance occurs which causes various problems in the process, such as fuel shortage due to capture in the dust collector. Therefore, the application of such pulverized coal in the iron-making process is limited. However, most of the coal currently used in the iron-making process consists of fine particles with a particle size not larger than 8 mm.

Since pulverized coal is limited in its use in the smelting reduction process, it is primarily used for pulverized coal injection (PCI), or fuel for coke production. However, coal has been shown to be capable of being used in smelting reduction processes in terms of its properties, and there are limitations to the use of coal fines in processes other than smelting reduction processes. Therefore, there is a need to develop methods capable of combining coal fines into coal briquettes in an appropriate manner for use in smelting reduction processes.

PCT Publication WO 02/50219 proposes a method of producing coal briquettes from pulverized coal that can be used in the smelting reduction ironmaking process. The coal briquettes provided in this gazette are produced by mixing molasses as a binder and quicklime as a hardening agent with pulverized coal. Because the smelting reduction process is different from the blast furnace ironmaking process, the properties required for coal briquettes are also different. In the blast furnace process, since the temperature of the upper part of the blast furnace is as low as 200-300° C., thermal cracking is not particularly considered. At this time, coal lumps and sintered ore are sequentially fed into the blast furnace, and then slowly descend to the lower part of the blast furnace. Therefore, coal briquettes for blast furnace processes are required to have high compressive strength. On the contrary, in the smelting reduction process, since the temperature in the upper part of the melting furnace is as high as 1000° C., the volatile components of the coal lumps are volatilized and exploded upon being charged into the melting furnace. Therefore, thermal and thermal explosive properties and drop strength are important factors in the requirements of coal briquettes for smelting reduction processes. Although coal briquettes of the prior art satisfy various properties required by the smelting reduction process, such as not less than 70% of drop strength, not less than 70% of thermal burstability, they only use coal powder as a raw material.

Various by-products are produced from ironworks. There are economic advantages to recycling these by-products from the ironmaking process. These by-products generally fall into the following four categories: dust, sludge, slag and spent refractories. Among them, dust and sludge are recycled as raw materials in ironworks and cement industries because they contain a large amount of iron or iron compounds, carbon (C), calcium compounds, and magnesium compounds. The iron compound mainly includes iron oxide. However, a large amount of dust and sludge is buried without recycling through solidification or calcination. Therefore, the disposal and recycling of these by-products is becoming an important environmental issue.

Dust and sludge are generated from each process in ironworks. They contain carbon that can be used as a heat source and reducing agent, iron compounds that can be used as an iron source, and calcium and magnesium compounds that can be used as additives. Most of the dust and sludge particle size is not larger than 1 mm. The moisture content in them mainly depends on the nature of the various processes, or dusts and sludges. Since the dust and sludge contain a large amount of valuable components, a part of them is recycled. In consideration of the components contained in the dust and sludge and their properties and secondary pollution, etc., a new method capable of recycling dust and sludge in the pig iron manufacturing process is required. Sludge is rarely recycled due to its higher moisture content and the extra drying step. Therefore, it is important to recycle sludge.

Contents of the invention

Therefore, the present invention has been developed in view of the above-mentioned problems, and an object of the present invention is to provide coal briquettes having sufficient drop strength, thermal burst performance and thermal dynamic burst performance required for the smelting reduction process, using by-products produced from iron works as raw materials.

Another object of the present invention is to provide a method of manufacturing said coal briquettes.

In order to achieve the above object, a coal lump for smelting reduction process is provided, which comprises:

sludge comprising iron (Fe) or iron compounds, carbon (C), calcium compounds and magnesium compounds as a main component not more than 50% by weight and the balance coal fines; and

The main component is 100 parts, and the weight is 5-20 parts of binder, and the binder includes petroleum hard asphalt, petroleum asphalt, syrup, thermosetting resin, starch and cement. one or more.

According to another aspect of the present invention, there is provided a coal briquette for smelting reduction process, which comprises:

Dust comprising iron (Fe) or iron compounds, carbon (C), calcium compounds and magnesium compounds as a major component not more than 50% by weight and the balance coal dust; and

100 parts of the important components, the weight is 5-20 parts of binder, the binder is selected from the group consisting of petroleum hard asphalt, petroleum asphalt, syrup, thermosetting resin, starch and cement one or more of .

According to another aspect of the present invention, there is provided a coal briquette for smelting reduction process, which comprises:

A mixture of sludge and dust including iron (Fe) or iron compounds, carbon (C), calcium compounds, and magnesium, as the main components, and the balance coal powder by weight not more than 50% compounds; and

Taking the important component as 100 parts, the weight is 5-20 parts of binder, and the binder includes petroleum hard asphalt, petroleum asphalt, syrup, thermosetting resin, starch and cement. one or more.

According to another aspect of the present invention, there is provided a method of manufacturing a coal briquette for a smelting reduction process, comprising the steps of:

Mixing as main components not more than 50% by weight of at least one of sludge and dust including iron (Fe) or iron compounds, carbon (C), calcium compounds and magnesium with the balance of coal powder compounds; and

Adding 5-20 parts by weight of binder based on 100 parts of said important components, and stirring; and shaping the obtained mixture.

If necessary, before adding the binder, quicklime with a weight of not more than 5 parts per 100 parts of the main component can be added as a hardening agent, and then aged.

The present inventors have found that, as a result of the implementation of the present invention, coal briquettes produced from sludge or dust and coal dust as by-products of ironworks production can be used in the smelting reduction process (FINEX or COREX). The coal agglomerate according to the present invention satisfies the requirements of the drop strength, thermal burst performance and thermal burst performance of the smelting reduction process. In particular, the sludge used as raw material for coal briquettes according to the present invention may be dried or not.

Description of drawings

The above-mentioned and other objects, features and other advantages of the present invention are described in detail below in conjunction with the accompanying drawings, wherein:

Fig. 1 is a flow diagram schematically showing a method for producing coal lumps using sludge and dust according to the present invention.

Detailed ways

The present invention will be described below with respect to coal briquettes and their manufacturing method.

[coal lump]

The coal briquette of the present invention includes at least one of sludge and dust and coal powder as main components; and a binder. The coal briquettes of the present invention also include a hardening agent, if desired.

[coal powder]

The coal powder used in the present invention is coal that does not meet the grain size requirements of the pig iron production process (COREX process). That is, it is generally recommended to use coal with particles not smaller than 8 mm in the COREX process. Therefore, the particle size of the pulverized coal used in the present invention is less than 8 mm, preferably less than 4 mm. When the pulverized coal particles are not smaller than 8 mm, a high compaction force is required in the forming step, and thus may cause breakage of the resulting coal briquette. Therefore, it is preferred to grind the coal powder to a particle size below 4 mm.

[Sludge and Dust]

The sludge and dust used in the present invention include valuable components such as iron (Fe) or iron compounds, carbon (C), calcium compounds and magnesium compounds. The iron compound mainly includes iron oxide.

Sludge and dust produced by ironworks (pig iron smelting process, steelmaking process, etc.) include the above-mentioned valuable components. The physical properties of sludge are similar to those of dust except for the moisture content. Therefore, if the sludge is dried, the physical properties of the sludge are almost the same as those of the dust.

Sludge can be used in dry form, but is characterized in its undried form. That is, undried sludge can be used as a raw material of coal lumps for the smelting reduction process of the present invention. Undried sludge preferably contains no more than 50% moisture. When the moisture content of the undried sludge exceeds 50%, the undried sludge cannot be evenly distributed into the coal powder, and finally coalesces in the form of clumps. That is, the segregated undried sludge reduces the drop strength and thermal burstability of the resulting coal briquettes.

In another aspect, dried sludge that can be used in the present invention contains no more than 5% water.

Considering the recycling of sludge and dust as raw material for coal briquettes in pig iron smelting process, the higher the content of valuable components, the better. Preferably, the content of valuable components is not less than 30% by dry weight of sludge or dust. Sludge or dust may contain impurities such as Zn, alkali metals, Al ₂ O ₃ , S, P, Cl, etc. The content of these impurities is preferably limited as follows: not more than 2.0% of Zn, not more than 2.0% of the total weight of alkali metals, not more than 1.0% of S, not more than 1.0% _of P, not more than 6.0% of _Al2O3 , and not more than 1.0% Cl. Since Zn and alkali metals form precipitates in the gasification melting furnace, negatively affect the flow of gas and hinder the descending of charge, etc., their contents are preferably limited to not more than 2.0%, respectively. Since S and P are limited components in pig iron water, their contents are preferably limited to not more than 1.0%, respectively. Since Al ₂ O ₃ is a problematic component affecting slag fluidity, it is required to add a large amount of auxiliary raw materials to prevent slag flow. Therefore, the Al ₂ O ₃ content is limited to not more than 6.0%, preferably not more than 3.0%. Cl can concentrate in water treatment equipment and thus corrode these equipment. Therefore, the content of Cl is preferably limited to not more than 1.0%.

Preferably, the total weight of valuable components and the content of impurities meet the above requirements. When the total weight of valuable components and the content of impurities exceed the above-mentioned preferred range, the sludge or dust within the above-mentioned preferred range can be mixed with the sludge or dust beyond the above-mentioned range, so that the total weight of valuable components and impurity content satisfying these preferred ranges.

Representative examples of the sludge satisfying the preferred range include sludge from a blast furnace of an iron factory, sludge from a molten iron manufacturing process using coal, sludge from a water treatment facility of a steel factory, and sludge from a sewage treatment facility. On the other hand, as the dust, dust from wire equipment in ironworks is mainly used. Because the dust from the sintering equipment of the iron works exceeds the allowable content range of alkali metals and Cl, it is not desirable to use them as a raw material for the coal briquette of the present invention. Table 1 shows the composition of sludge and dust generated from iron works.

Table 1

Sludge/dust Composition (weight percent) T.Fe CaO MgO C S P Zn Na ₂ O K ₂ O Al ₂ O ₃ Cl A 30-60 1-5 0.5-1 10-30 □1.0 □1.0 □1.0 □1.0 □1.0 2-3 □1.0 B 20-40 5-10 1-2 20-30 □1.0 □1.0 □0.5 □1.0 □1.0 2-3 □0.5 C 10-20 5-10 1-3 20-50 □1.0 □1.0 □2.0 □0.5 □0.5 3-6 □0.1 D. 10-25 2-10 1-3 20-50 □1.0 □1.0 □2.0 □0.5 □0.5 3-6 □0.1 E. 70-80 □0.5 □0.1 □2 □1.0 □1.0 □0.01 □0.1 □0.1 □1 □0.5 f 40-50 5-15 □2.0 5-10 □1.5 □1.5 □0.1 □0.3 1.0-7.0 1-2 □5.0 A: blast furnace sludge B: sludge from the process of producing molten iron from coal, C: sludge from water treatment equipment in steel plants, D: sludge from sewage treatment equipment, E: dust from wire rod equipment, F: Dust from sintering equipment.

Preferably, the main components of the coal briquette of the present invention include not more than 50% by weight of at least one of sludge and dust and the balance of coal powder. When the content of sludge and dust is above 50%, the physical properties of the produced coal agglomerates may be reduced. Since the physical properties of sludge are similar to those of dust, the mixing ratio of sludge and dust can be appropriately determined.

[binder]

The binder that can be used in the present invention includes petroleum pitch (petroleum pitch), petroleum pitch (petroleum bitumen), syrup, thermosetting resin, starch and cement etc., preferably syrup. The syrup solids content is preferably 70-80% by weight. When the solids content is less than 70%, the sugar content is too low to exhibit the inherent properties of the binder. When the solids content is higher than 80%, it is impossible to mix uniformly with other ingredients due to the high viscosity of the syrup.

Based on 100 parts by weight of the main component, the binder is added in an amount of 5-20 parts, wherein the main component is composed of at least one of sludge and dust with a content not greater than 50% and the rest of coal powder. When the weight of the added binder is less than 5 parts, the forming strength of the coal agglomerate is too low. When the added weight of the binder is higher than 20 parts, it is not preferred because of uneconomical.

[hardener]

The coal briquettes of the present invention also include a hardening agent, if desired. As the hardening agent, inorganic materials such as quicklime (CaO), limestone, iron ore, bauxite, etc. can be used, and quicklime is most preferable. Quicklime (CaO) is converted to slaked lime by an exothermic reaction with moisture contained in coal dust or sludge. Quicklime can remove moisture from coal dust or sludge by exothermic reaction. The quicklime preferably has a particle size of not greater than 1 mm. The smaller the quicklime particles, the larger the specific surface area. Therefore, quicklime is easily transformed into slaked lime by reacting with moisture in coal dust.

Based on 100 parts by weight of the main components composed of coal powder, sludge and dust, it is preferable to add 5 parts by weight of hardener. When the weight of the added hardener exceeds 5 parts, the physical properties of the resulting coal lumps are reduced.

[production of coal lump]

The coal briquettes of the present invention are manufactured by adding a binder to the main components consisting of coal fines, sludge and/or dust and, where necessary, a hardening agent. The mixing order of these raw materials and process variables affect the physical properties of the coal briquette. In the present invention, syrup is used as binding agent and quicklime is used as hardening agent. Figure 1 shows the most preferred method of making coal briquettes.

First, 50% by weight of at least one of sludge and dust is added to pulverized coal.

Vary the mixing time depending on whether the sludge is dry or not. When the sludge is dry, the mixing time is no more than 3 minutes. When the sludge is dry, the mixing time is within 3-10 minutes.

When the dried sludge was mixed for a time longer than 3 minutes, the increased time did not contribute to an improvement in performance. When the mixing time of the undried sludge is less than 3 minutes, the mixing of the pulverized coal and the undried sludge is not complete, and agglomeration may occur. When the undried sludge mixing time was greater than 10 minutes, the increased time did not help to improve performance.

When the weight of the main components composed of coal powder, sludge and dust is 100 parts, the added weight of quicklime is 5 parts. Mixing is carried out in a mixer to obtain a homogeneous mixture. The mixing time is preferably in the range of 1-3 minutes.

Then, the quicklime is aged to convert to slaked lime. This aging takes place partly in the mixer, but this is limited due to the relatively short residence times in the mixer. Therefore, aging is best performed in a reservoir such as a funnel for a long period of time. Preferably aging is performed for about 2 minutes to 2 hours.

The aged mixture is mixed with 5-20 parts by weight of binder syrup. Mix in a mixer. In the mixing step, the unreacted quicklime reacts with the moisture in the syrup, as a result of which sucrose-calcium bonds are formed between them, so that the quicklime turns into slaked lime. This transition is limited due to the short residence time in the mixer.

Therefore, preferably, the mixture of quicklime and molasses is agitated for a long residence time to mature the coal briquette through the formation of calcium sucrose salt bonds, increasing the strength of the final coal briquette. This mixing is done in a kneader, a type of mixing mill, rather than in a mixer. The kneader has a vertical cylindrical central shaft mounted with blades. This kneader is used to stir the mixture of quicklime and syrup.

This mixing is preferably performed within the range of 2-50 minutes. When the stirring time is less than 2 minutes, the strength of the final coal lump is not good. When the stirring time is more than 50 minutes, the mixture is relatively dry, so the strength of the formed coal briquettes is not good.

Shaping is performed after stirring. Coal briquettes are produced by forming them in a roller press under constant pressure.

When the coal briquette of the present invention has a moisture content of not less than 30%, it is poor in drop strength and thermal burstability. Therefore, it is preferred to keep the moisture content not higher than 30% throughout the process.

Next, the present invention will be described in detail with reference to the following examples.

[example 1]

10% by weight of dry sludge and/or dust having the composition listed in Table 2, and pulverized coal having a particle size not greater than 4 mm were mixed for 3 minutes or less. The dried sludge and dust used met the impurity content ranges shown in Table 1 above. A dry sludge is obtained by drying in a rotary kiln.

Table 2

Dry sludge and dust composition (weight percent) Sludge/dust Total amount of Fe C CaO MgO Total A1 42.37 25.00 2.78 0.58 70.73 C1 17.46 37.20 5.45 0.99 61.10 D1 12.13 46.80 6.00 2.30 67.23 E1 71.96 1.46 - - 73.42 F1 40.33 5.89 7.97 1.01 55.20 A1: Blast furnace sludge C1: Sludge from water treatment equipment in steel mills, D1: Sludge from sewage treatment equipment, E1: Dust from wire rod production equipment, F1: Dust from sintering equipment.

Based on 100 parts by weight of the mixture (main component), 3 parts by weight of quicklime was added as a hardening agent. The resulting mixture was aged for 2 minutes to 2 hours. Add 8% by weight of syrup binder to 100 parts by weight of the aging mixture, and then stir at room temperature for 2-50 minutes to make coal briquettes. Measures drop strength, thermal burst and dynamic thermal burst. The results are shown in Table 3.

The drop strength was measured by dropping the coal briquettes thus manufactured 4 times at a height of 5 meters and expressed as a fraction of coarse and fine particles (particle size ≤ 6.3 mm) based on the total weight of the broken particles. The percentage of coarse particles is calculated by the following formula:

Granules with a particle size greater than 20 mm (weight percent)+{particles with a particle size of 10-20 mm (weight percent)×(1/2)}

Coal was obtained by placing the thus-produced coal briquettes in a reaction furnace at 1000° C. to measure thermal explosiveness and expressed as the percentage of coarse and fine particles (particle size ≤ 2.0 mm) based on the weight of the obtained coal. Calculate the percentage of coarse particles by the following formula:

Granules with a particle size greater than 20 mm (weight percent)+{particles with a particle size greater than 16 mm (weight percent)×(3/4)}+{particles with a particle size greater than 13 mm (weight percent)×(2/ 4)}+{with particles larger than 10 mm (weight percent) × (1/4)}

Coal measurements were obtained by placing the coal briquettes thus produced in a rotary furnace at 900° C. and expressed as a percentage of coarse particles based on the weight of the coal obtained. The percentage of coarse particles is calculated by the following formula:

Particles with a particle size greater than 20 mm (weight percent) + {dry particles with a particle size of 10 mm (weight percent) × (1/2)}

The greater the percentage of coarse particles and the smaller the percentage of fine particles, the better these properties are.

table 3

Coal lump raw material Drop strength (coarse particle percentage) Drop strength (percentage of fine particles)   Thermal Explosiveness (Coarse Particle Percentage)   Thermal Explosiveness (Percentage of Fine Particles) Thermal Explosiveness (Coarse Particle Percentage) A1 87.4 7.4 60.5 1.6 50.5 C1 76.4 13.8 61.3 1.2 51.2 D1 91.4 5.0 54.2 1.3 48.6 E1 88.7 5.7 67.3 1.8 56.3 F1 82.6 8.5 63.5 2.1 47.5 A1+F1 79.4 10.3 62.8 2.0 52.8 C1+E1 83.1 4.7 59.6 1.8 51.1 lump coal 78.7 10.4 60.2 4.6 50.2 As described in Table 1, A1, C1, D1, E1 and F1 are sludge and dust, respectively.

As shown in Table 3, the performance of the coal briquettes of the present invention is equal to or higher than that of lump coal. Therefore, the coal briquette of the present invention can be used in a molten iron production process using coal.

In the present invention, the dust (E1) from the sintering plant can be used in the form of being mixed with coal, however, it contains a large amount of harmful components (S, alkali metals, C1) which cause process problems. Therefore, it is recommended to mix the dust from the sinter plant with other sludges or dusts in order to dilute the content of harmful components. At this time, the amount of sludge or dust to be mixed can be limited by the content of harmful components.

[Example 2]

Undried sludge and dust having the ingredients listed in Table 4 were mixed with each other for 3-10 minutes to obtain the mixture shown in Table 5. The use of the undried sludge shown in Table 4 complies with the impurity content ranges shown in Table 1 above. At this time, 10% by weight of sludge and dust is mixed with 90% by weight of pulverized coal having a particle size not larger than 4mm.

Table 4

Undried sludge and dust components (weight percent) sludge T.Fe C CaO MgO Total Moisture A2 35.94 30.4 3.81 0.56 70.71 15.7 A3 40.40 22.4 3.90 0.57 67.27 16.3 B1 29.81 28.4 5.17 1.54 64.92 42.4 A2: blast furnace sludge (undried), A3: blast furnace sludge (undried), B1: sludge of molten iron production process using coal (undried).

3 parts by weight of hardener are added to 100 parts by weight of the mixture (main component), followed by aging for 2 minutes to 2 hours. To 100 parts by weight of the aged mixture was added 8 parts by weight of syrup. The resulting mixture is stirred for 2-50 minutes to create coal briquettes. On the other hand, coal briquettes were manufactured in the same manner as in Example 1 except that the undried sludge shown in Table 4 was dried. The drop strength and thermal burstability of the thus produced coal briquettes were measured.

table 5

Coal lump raw material Sludge (dry) Sludge (undried) drop strength   Thermal burst drop strength   Thermal burst A2 93.3 56.8 83.7 85.2 A3 86.3 82.3 88.9 77.9 B1 70.2 79.2 92.9 75.1 A2+F1 84.5 69.7 89.4 77.4 A3+E1 91.5 80.2 84.5 81.2 A1+A2 76.4 77.3 80.5 83.2 A1+A2+F1 88.4 83.2 90.5 81.8 lump coal 78.7 60.2 - - As shown in Table 1, A1, E1 and F1 are dry sludge and dust, respectively. A2, A3 and B1 are the sludges shown in Table 4 above.

As shown in Table 5, coal briquettes made using undried sludge performed equal to or better than lump coal. Therefore, the coal briquette of the present invention can be used in a molten iron production process using coal.

[Example 3]

The undried sludge B1 shown in Table 4 was dried so that the moisture content in the undried sludge became not more than 3%. Undried sludge is mixed with pulverized coal with particle size not greater than 4mm for not more than 3 minutes. In this step, the mixing ratio of dried sludge and pulverized coal is shown in Table 6 below. To 100 parts by weight of a mixture of sludge and pulverized coal (main component) was added 3 parts by weight of quicklime. The resulting mixture is then aged for 2 minutes to 2 hours. To 100 parts by weight of the aged mixture was added 8 parts by weight of syrup as a binder. The resulting mixture is stirred at room temperature for 2 minutes to 50 minutes to create a coal briquette. The drop strength and thermal burstability of the thus produced coal briquettes were measured. The results are shown in Table 6 below.

Table 6

Content of sludge in coal lump (%) B1 sludge (dry) Drop strength (coarse particle percentage)   Thermal burst (coarse particle percentage) 5 86.33 74.76 10 70.09 79.16 15 78.87 82.71 20 72.38 89.72

From the results in Table 6, it can be seen that although the amount of sludge mixed was changed, the properties of the coal briquette did not change greatly, and the coal briquette of the present invention can be used in the molten iron production process using coal.

Industrial applicability

As described above, according to the present invention, dust and sludge, especially undried sludge, can be recycled as a raw material of coal briquettes in ironmaking process. In addition, the coal briquette according to the present invention has superior drop strength and thermal burst performance than conventional coal briquettes made from coal.

Although the preferred embodiment of the present invention has been disclosed for purposes of illustration, it will be appreciated by those skilled in the art that various modifications may be made without departing from the spirit and scope of the invention as claimed.

Claims (15)

1. coal agglomerate that smelting reduction process is used, it comprises:

As the weight of main ingredient is 50% or still less the sludge and the coal dust of its surplus, and described sludge comprises iron or iron cpd, carbon, calcium cpd and magnesium compound; With

With main ingredient weight is 100 parts of notes, and weight is the binding agent of 5-20 part, and described tackiness agent comprises and is selected from the group that is made of petroleum pitch, petroleum, petroleum pitch, syrup, thermosetting resin, starch and cement one or more.

2. coal agglomerate that smelting reduction process is used, it comprises:

As the weight of main ingredient is 50% or still less the dust and the coal dust of its surplus, and described dust comprises iron or iron cpd, carbon, calcium cpd and magnesium compound; With

With main ingredient weight is 100 parts of notes, and weight is the binding agent of 5-20 part, and described tackiness agent comprises and is selected from the group that is made of petroleum pitch, petroleum, petroleum pitch, syrup, thermosetting resin, starch and cement one or more.

3. coal agglomerate that smelting reduction process is used, it comprises:

As the weight of main ingredient is 50% or still less the sludge and the coal dust of dust mixture and its surplus, and described sludge and dust comprise iron or iron cpd, carbon, calcium cpd and magnesium compound; With

With main ingredient weight is 100 parts of notes, and weight is the binding agent of 5-20 part, and described tackiness agent comprises and is selected from the group that is made of petroleum pitch, petroleum, petroleum pitch, syrup, thermosetting resin, starch and cement one or more.

4. the coal agglomerate of using according to the smelting reduction process of claim 1 or 3, wherein sludge is to contain the 50wt% or the not dried forms of moisture still less.

5. the coal agglomerate of using according to any one smelting reduction process of claim 1-3, wherein sludge or dust contain following impurity: 2.0wt% or Zn still less, 2.0wt% or basic metal still less, 1.0wt% or S still less, 1.0wt% or P still less, 6.0wt% or Al still less ₂O ₃And 1.0wt% or Cl still less.

6. the coal agglomerate of using according to the smelting reduction process of claim 5, wherein said sludge are from from the sludge of ironworks blast furnace, from the sludge of the molten iron manufacturing process of using coal, at least a from what select the sludge of the water treating equipment of Steel Plant and the sludge from sewage disposal device.

7. the coal agglomerate of using according to the smelting reduction process of claim 5, wherein said dust comprises the dust from wire production equipment.

8. the coal agglomerate of using according to any one smelting reduction process of claim 1-3, wherein the weight total content of iron or iron cpd, carbon, calcium cpd and magnesium compound be sludge or dust dry weight 30% or more.

9. according to any one melting and reducing coal agglomerate of claim 1-3, wherein said binding agent is a syrup.

10. according to any one melting and reducing coal agglomerate of claim 1-3, also comprising, is 100 parts in main ingredient weight, weight be 5 parts or still less be selected from stiffening agent in unslaked lime, Wingdale, iron ore, the bauxite group.

11. according to the melting and reducing of claim 10 coal agglomerate, wherein said stiffening agent is a unslaked lime.

12. a method of making the coal agglomerate that smelting reduction process uses may further comprise the steps:

Mixing as main ingredient, weight be 50% or still less sludge and dust in the coal dust of at least a and its surplus, sludge and dust comprise iron or iron cpd, carbon, calcium cpd and magnesium compound;

With main ingredient weight is 100 parts of notes, and the syrup that adds weight and be 5-20 part is as binding agent, and stirs; With

The mixture that shaping obtains.

13. the method for the coal agglomerate of using according to the manufacturing smelting reduction process of claim 12 is to contain 5wt% or still less during the dried forms of moisture, carried out 3 minutes or less time with mixing of coal dust at sludge wherein.

14. the method for the coal agglomerate of using according to the manufacturing smelting reduction process of claim 12 is when containing the not dried forms of 5-50wt% moisture at sludge wherein, carries out 3-10 branch clock time with mixing of coal dust.

15. the method for the coal agglomerate of using according to the manufacturing smelting reduction process of claim 12, also be included in add binding agent before, to the main ingredient of 100 parts of weight add weight be 5 parts or still less unslaked lime as stiffening agent, and wear out.

Images