Process and system for producing solid agglomerates - Patents.com

Abstract

The present invention relates to a system and a process for producing a solid agglomerate. In this scenario, the present invention relates to a process for producing a solid agglomerate (5) by means of a roller press (10) comprising two rollers (10a, 10b) provided with a cavity (11) that can be filled with a granular composition, comprising the steps of (i) feeding a first composition from above into a first upper angular portion (12a) of each of the rollers (10a, 10b) of the roller press (10) and (ii) feeding a second composition onto a second upper angular portion (12b) of each of the rollers (10a, 10b) of the roller press (10). (iii) pressing the material fed onto the rollers (10a, 10b) to form a solid agglomerate (5) comprising a core (5n) formed by the second composition and a cladding (5r) formed by the first composition. The present invention also provides a system related to the above method.

Description

[Technical field]

[0001] The present invention relates to solid aggregates, and more particularly to processes and systems for producing solid aggregates. [Background technology]

[0002] One of the main elements of the installation in which the iron reduction process takes place is called the blast furnace. Its function is to separate the iron Fe from its Fe2O3 ore. This separation is carried out by chemical reduction, which involves separating the metal from its oxide, and is carried out using a reducing agent. This reducing agent is a material that, under the operating conditions, must attract more oxygen than the metal to be reduced. The main reducing agent used in the iron and steel industry is coke, which is derived from mined coal.

[0003] The steel industry is heavily dependent on metallurgical coal, which represents a large portion of the final cost of the steel produced. The mining coal for integrated coking steelmaking is known as caking coal, which is essential in the reduction of iron ore to metallic iron, as it combines with oxygen to produce carbon dioxide, iron, and slag.

[0004] The type of coal commonly used in steelmaking is bituminous coal (soft coal), which forms a solid mass (caking coal) when heated, whereas if it does not soften or clump when heated, it is called non-caking coal.

[0005] Nowadays, the use of agglomerates in the steel industry is gradually increasing. The agglomeration process consists of bundling fine-grained materials together using a binder to obtain a larger product. This process can, for example, produce high-quality metal agglomerates or briquettes while utilizing small pieces that would normally be discarded. In some cases, coal agglomerates may replace caking coal and metal agglomerates may replace iron ore.

[0006] Among the various agglomeration processes, the briquetting technique is gaining ground in the industry. This technique, which can be used for both mineral coal and wood charcoal, generally involves the following steps: (i) granulometric balancing of the charcoal or biomass particles, (ii) mixing of a binder (agglomerant), (iii) physical compaction, and (iv) drying of the briquettes. This document below describes examples of briquettes and their respective production processes.

[0007] For example, US Pat. No. 5,399,633 describes a method and system for briquetting a solid fuel, such as charcoal, in which the solid fuel is conveyed through a continuous feed solid fuel processing plant, treated with electromagnetic energy, and briquettered after treatment.

[0008] Patent Document 2 describes charcoal briquettes and a method for producing the briquettes. The method for producing the briquettes includes the steps of (i) providing low-grade coal, (ii) producing a mixture by mixing between 1 and 5 parts by weight of a hardener and between 5 and 15 parts by weight of a binder with respect to 100 parts by weight of the low-grade coal, and (iii) casting the mixture. In the step of providing the low-grade coal, the low-grade coal includes (i) more than 0% and not more than 50% by weight of low-grade coal, and (ii) the balance of lime coal. The low-grade coal has a volatile fraction (on an anhydrous basis) of 25% to 40% by weight and a crucible expansion number of more than 0 and less than 3.

[0009] US Patent No. 5,399,633 describes a process for making charcoal-containing briquettes, in which charcoal, together with a binder system, is subjected to mixing with steam introduction and the resulting mixture is subjected to pressing to form briquettes, where at least one of the steps of (i) drying the carbon support before mixing, (ii) setting the temperature of the carbon support to be mixed with the binder system before mixing within a predetermined temperature range, and (iii) heat treating the briquettes after pressing is performed by direct or indirect interaction with superheated steam. The resulting residual steam is used as at least a portion of the steam introduced during mixing.

[0010] US Patent No. 5,399,633 describes a process for forming briquettes composed of low-rank coal and aggregate material, the process including drying a feedstock of low-rank coal to produce dried coal having a moisture content of between 8% and 16% by weight, mixing the dried coal with the aggregate material, and compressing the dried coal and aggregate material into briquettes.

[0011] However, the current state of the art lacks techniques that allow for the production of briquettes containing two or more different compositions, each composition being located within a specific region of the briquette.

[0012] The proposed invention solves the above problems in a simple and effective manner. [Prior art documents] [Patent documents]

[0013] [Patent Document 1] U.S. Pat. No. 8,585,786 [Patent Document 2] International Publication No. 2014098413 [Patent Document 3] International Publication No. 2013152959 [Patent Document 4] Australian Patent No. 2008203855 Summary of the Invention [Problem to be solved by the invention]

[0014] It is a primary object of the present invention to provide a system and process for manufacturing a solid agglomerate to contain within its structure two or more separate compositions, each composition being located within a specific region of the solid agglomerate. [Means for solving the problem]

[0015] In order to achieve the above object, the present invention provides a process for producing a solid agglomerate by means of a roller press comprising two rollers provided with cavities that can be filled with a granular composition, the process comprising the steps of: (i) providing a first composition from above into a first upper angular portion of each of the rollers of the roller press; (ii) providing a second composition from above onto a second upper angular portion of each of the rollers of the roller press, the second upper angular portion being positioned downstream of the first upper angular portion for the same rollers in relation to the direction of rotation of each roller; and (iii) pressing the material provided on the rollers to form a solid agglomerate comprising a core formed by the second composition and a cladding formed by the first composition.

[0016] The present invention further provides a system for producing a solid agglomerate comprising a roller press having two rollers provided with cavities that can be filled with a granular composition, the system comprising: (i) means for feeding a first composition from above into a first upper angular portion of each of the rollers of the roller press; (ii) means for feeding a second composition from above onto a second upper angular portion of each of the rollers of the roller press, the second upper angular portion being positioned downstream of the first upper angular portion for the same roller with respect to the direction of rotation of each roller; and (iii) means for pressing the material fed onto the rollers to form a solid agglomerate comprising a core formed by the second composition and a cladding formed by the first composition.

[0017] The following detailed description refers to the accompanying drawings and their respective reference numerals. [Brief description of the drawings]

[0018] [Figure 1] FIG. 1 is a schematic cross-sectional view of a roller press system according to the prior art. [Diagram 2] 1 is a schematic cross-sectional view of a preferred embodiment of the system of the present invention; [Diagram 3] FIG. 2 is a schematic diagram of a roller press according to a preferred embodiment of the system of the present invention. [Figure 4] FIG. 1 is a schematic diagram of a solid agglomerate produced using the process and system of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0019] It should be noted in advance that the following description is based on a preferred embodiment of the present invention. However, as will be apparent to those skilled in the art, the present invention is not limited to this specific embodiment.

[0020] The present invention provides a system for producing solid agglomerates 5 comprising a roller press 10 having two rollers 10a, 10b rotating in opposite directions and provided with cavities 11 which can be filled with a granular composition, as shown in Figure 1. The aforementioned technique, already known from the prior art, comprises a central feeder provided with a dosing screw 42 for feeding and pressing the granular composition between the rollers 10a, 10b to form the solid agglomerates 5.

[0021] In the present invention, unlike the technique in FIG. 1, two different compositions are fed to rollers 10a, 10b at different locations to form a solid agglomerate 5 with a core formed by one composition and a cladding formed by the other composition.

[0022] 2 and 3, which show a preferred embodiment of the system of the present invention, means are provided for feeding a first composition from above into the first upper inclined portion 12a of each of the rollers 10a, 10b of the roller press 10. The feeding of the first composition is indicated by the green arrows in FIGS.

[0023] The means for supplying the first composition onto the first upper angular portion 12a of each of the rollers 10a, 10b of the roller press 10 may comprise, for example, (i) at least one side silo 30 adapted to store the first composition, (ii) at least one side dosing screw 32 for the first composition, and / or (iii) at least one passage silo 34 adapted to guide the first composition onto the first upper angular portion 12a of each of the rollers 10a, 10b of the roller press 10.

[0024] Furthermore, the present invention further comprises means for providing a second composition from above onto the second upper inclined portion 12b of each of the rollers 10a, 10b of the roller press 10. The supply of the second composition is indicated by the red arrows in Figures 2 and 3.

[0025] The means for supplying the second composition to the second upper angular portion 12b of each of the rollers 10a, 10b of the roller press 10 may, for example, comprise (i) at least one central silo 40 for storing the second composition, (ii) at least one central dosing screw 42 of the second composition, driven by a motor 44. The central dosing screw 42 also preferably pre-compresses the second composition prior to the step of supplying the second composition to the roller press 10.

[0026] It is defined in this description that the first upper angle portion 12a and the second upper angle portion 12b of each roller 10a, 10b correspond to complementary upper angles of the cylinder (roller) that add up to 180°. In Figure 3, the first upper angle portion 12a is represented on each roller by a green quadrant and the second upper angle portion 12b is represented on each roller by a red quadrant.

[0027] Although each of the angular portions is represented in Fig. 3 by an opening angle of 90° (a quarter of a circle), these portions are not limited to this particular angle and can vary as required. What is important is to ensure that for the same rollers 10a, 10b, the second upper angular portion 12b is located downstream of the first upper angular portion 12a with respect to the direction of rotation of each roller 10a, 10b.

[0028] Thus, for a given solid agglomerate produced by the system of the present invention, its cladding material (first composition) is first deposited on the rollers in a first upper angular portion 12a. This material partially or completely fills the cavities 11 of the rollers 10a, 10b. The core material of the solid agglomerate (second composition) is then provided on the rollers 10a, 10b in a second upper angular portion 12b near the point of minimum distance between the rollers 10a, 10b where pressure is applied. Thus, when pressure is applied, an agglomerate 5 is formed that contains the first composition in its cladding 5r and the second composition in its core 5n, as shown in FIG. 4.

[0029] The ratio of the amount of material in the core of the solid agglomerate 5 to the amount of material in the cladding is adjusted by the feed rate of each material in the press 10. For example, by increasing the feed rate of the second composition and leaving the feed rate of the first composition unchanged, a solid agglomerate with a larger and / or denser core is obtained.

[0030] The invention further relates to a process for producing a solid agglomerate 5 by means of a roller press 10 comprising two rollers 10a, 10b provided with a cavity 11 which can be filled with a granular composition, comprising a) providing a first composition from above onto a first upper angular portion 12a of each of the rollers 10a, 10b of the roller press 10; b) providing a second composition from above onto the second upper angular portion 12b of each of the rollers 10a, 10b of the roller press 10, the second upper angular portion 12b being arranged downstream of the first upper angular portion 12a with respect to the direction of rotation of each of the rollers 10a, 10b for the same rollers 10a, 10b; c) pressing the material provided on the rollers 10a, 10b to form a solid agglomerate 5 with a core 5n formed by the second composition and a cladding 5r formed by the first composition; The present invention provides a process including:

[0031] The step of providing the first composition on the first upper angular portion 12a is preferably performed simultaneously and separately for each roller 10a, 10b, as shown in FIGS.

[0032] The step of providing the second composition on the second upper inclined portion 12b is preferably performed at the same location for both rollers 10a, 10b, and more preferably between the rollers 10a, 10b.

[0033] The process of the present invention preferably further comprises the step of pre-compressing the second composition prior to the step of feeding the second composition into the second upper inclined portion 12b of each of the rollers 10a, 10b of the roller press 10. As already mentioned, this step is preferably performed by the central dosing screw 42.

[0034] The solid agglomerate 5 formed by the above process and system is shown in Figure 4 and comprises a core 5n formed by the second composition and a cladding 5r formed by the first composition. The solid agglomerate 5 of the present invention may be, for example, a combustible briquette or metal agglomerate, such as a pellet or ferrous briquette.

[0035] In the case of fuel briquettes, the second composition forming the core 5n preferably comprises at least one type of caking coal and at least one type of binder. The core material 5n is therefore a coking material commonly used in fuel briquettes. More preferably, the second composition forming the core 5n comprises 60% to 70% by weight of caking coal and 6% to 10% by weight of binder.

[0036] The first composition forming the cladding 5r preferably comprises non-caking coal or its residues and at least one binder. The coal in the cladding composition 5r may be, for example, coke dregs, or coal litter, which is generally a low-rank coal, etc. It is worth noting here that any inert coal litter (non-coking) may be used in the composition of the cladding 5r. In this way, when heated inside the reduction furnace, the cladding material 5r does not coke, which prevents the surfaces of the aggregates from sticking to each other and thus prevents the formation of curls.

[0037] Most preferably, the first composition forming the cladding 5r comprises 70% to 95% by weight of non-coking coal, coke waste, coal ash, or any combination thereof, and 5% to 15% by weight of a binder.

[0038] In a second embodiment of the invention, the solid agglomerate 5 is a metal agglomerate, such as an iron pellet or briquette. In this case, an inert material, preferably containing a metal, is used in the cladding 5r of the agglomerate to act as a sacrificial material. The core 5n is formed by the material of interest.

[0039] The solid aggregate 5 of the present invention can be manufactured in any existing geometric shape, and therefore the scope of protection of the present invention is not limited to the elliptical shape depicted in FIG.

[0040] Thus, as discussed above, the present invention provides systems and methods for manufacturing solid aggregates such that the solid aggregate comprises two or more separate compositions in its structure, with each composition located in specific regions (cladding and core) of the solid aggregate.

[0041] Numerous variations are permitted which affect the scope of protection of this application, which reinforces the fact that the present invention is not limited to the specific configurations / embodiments described above. [Explanation of symbols]

[0042] 5 Solid aggregates 5n Core 5r Cladding 10 Roller press 10a Lola 10b Lola 12a First upper angle part 12b Second upper angle part 11 Cavity 30 Side Silo 32 Side injection screw 34 Aisle Silo 42 Dosing screw 44 Motor

Claims

1. A process for producing a solid agglomerate (5) by means of a roller press (10) comprising two rollers (10a, 10b) provided with a cavity (11) which can be filled with a granular composition, comprising: providing a first composition from above onto a first upper inclined portion (12a) of each of said rollers (10a, 10b) of said roller press (10); providing a second composition from above into a second upper inclined portion (12b) of each of the rollers (10a, 10b) of the roller press (10), the second upper angular portion (12b) being arranged downstream of the first upper angular portion (12a) with respect to the direction of rotation of each roller (10a, 10b) for the same roller (10a, 10b); pressing said material fed onto said rollers (10a, 10b) to form a solid agglomerate (5) comprising a core (5n) formed by said second composition and a cladding (5r) formed by said first composition; A process comprising:

2. 2. The process according to claim 1, characterized in that the step of providing the first composition in the first upper angular portion (12a) is carried out simultaneously and separately for each roll (10a, 10b).

3. 3. The process according to claim 1 or 2, characterized in that the step of providing the second composition in the second upper angular portion (12b) is performed at the same location for both rollers (10a, 10b).

4. 4. The process according to claim 3, characterized in that the step of providing the second composition in the second upper angular portion (12b) is carried out between the rollers (10a, 10b).

5. 5. The process according to claim 1, further comprising a step of pre-compressing the second composition prior to the step of feeding the second composition into the second upper angular portion (12b) of each of the rollers (10a, 10b) of the roller press (10).

6. A system for producing solid agglomerates (5), comprising a roller press (10) having two rollers (10a, 10b) provided with a cavity (11) which can be filled with a granular composition, a means for providing a first composition from above onto a first upper inclined portion (12a) of each of said rollers (10a, 10b) of said roller press (10); means for feeding a second composition from above onto a second upper inclined portion (12b) of each of the rollers (10a, 10b) of the roller press (10), the second upper angular portion (12b) being arranged downstream of the first upper angular portion (12a) with respect to the direction of rotation of each roller (10a, 10b) for the same roller (10a, 10b); means for pressing said material fed onto said rollers (10a, 10b) so as to form a solid agglomerate (5) comprising a core (5n) formed by said second composition and a cladding (5r) formed by said first composition; A system comprising:

7. The means for providing the first composition in the first upper angular portion (12a) comprises: at least one side silo (30) adapted to store said first composition; At least one side injection screw (32) for the first composition; and at least one passage silo (34) adapted to direct the first composition onto the first upper angular portion (12a) of each of the rollers (10a, 10b) of the roller press (10); 7. The system of claim 6, characterized in that it is at least one of:

8. The means for providing the second composition in the second upper angular portion (12b) comprises: At least one central silo (40) adapted to store said second composition; and At least one central dosing screw (42) for said second composition, driven by a motor (44); 8. The system according to claim 6 or 7, characterized in that it is at least one of the following:

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