WO2018170767A1 - Ore pellet, preparation method therefor, and preparation equipment - Google Patents

Abstract

An ore pellet, a preparation method therefor, and preparation equipment. The mass percent content of components in the ore pellet are: TFe 62.1%-65.82%, FeO 0.2%-0.58%, SiO₂ 1.9%-6.13%, CaO 0.19%-3.23%, MgO 0.18%-0.52%, and Al₂O₃ 0.58%-2.66%. The preparation method comprises: a sintered ore powder is finely milled to produce a finely milled sintered powder; a pelletized powder and/or a boron-containing pelletized powder and the finely milled sintered powder are blended to produce a fine ore powder; a binding agent is added to the fine ore powder to produce an intermediate mixture; and the intermediate mixture sequentially undergoes pelletizing and roasting to produce the ore pellet. The preparation equipment comprises a miller, a container, a pelletizer, and a roasting system. The sintered ore powder of poorer quality and higher environmental costs is utilized in the preparation to produce the ore pellet of better quality and lower environmental costs, thus creating a simple and favorable approach for the green development of the metallurgical industry.

Description

Pellet ore, preparation method thereof and preparation device Technical field

The invention relates to the technical field of sintered ore powder, in particular to a pellet, a preparation method thereof and a preparation device.

Background technique

Pellet ore and sinter are the main charge for blast furnace ironmaking. The sinter ore is prepared by mixing various powdery iron-containing raw materials into a certain proportion of fuel and flux as required, and uniformly granulating and sintering on the sintering machine. The iron ore fine powder for sintering is relatively coarse in particle size, and the particle size requirement is relatively low, and a plurality of mineral powders can be used. Pellet ore production requires relatively high raw materials, requiring pellets with a certain particle size and particle size composition, suitable moisture and uniform chemical composition. Compared with the sintered powder, the general pellet powder is finely ground and selected ore powder, which has high grade, fine particle size and low content of harmful components. Therefore, the pellets have relatively few types of raw materials, relatively low yields, and relatively high prices.

Compared with sinter, the cold quality of pellets and the environmental performance of the production process are better than sintering. The sinter has low strength, high returning rate, large amount of exhaust gas in the production process, high dust concentration, large amount of dust, and generation of pollutants such as dioxins. In addition, the energy consumption of the sintering process is twice that of the pellet process. the above. The amount of exhaust gas in the pellet production process is relatively low, and there are very few pollutants such as dioxins in the production process, low energy consumption in the process, and low dust content. With the increasingly severe global environmental requirements, the development of pellet technology, the production and use of pellets is a trend. To develop pellets, first of all, there must be sufficient and cost-effective mineral resources. However, the current global pellets are still limited and the price is relatively high, which has made it difficult for steel companies worldwide to develop pellets. Process.

Summary of the invention

In view of the above, the present invention provides a pellet, a preparation method thereof and a preparation apparatus which are capable of using a sintered ore powder to prepare a pellet, thereby being more suitable for practical use.

In order to achieve the above first object, the technical scheme of the pellets provided by the present invention is as follows:

The mass percentage of each component of the pellets provided by the present invention includes: TFe: 62.1% to 65.82%, FeO: 0.2% to 0.58%, SiO ₂ : 1.90% to 5.97%, and CaO: 0.17% to 3.23. %, MgO: 0.18% to 0.52%, Al ₂ O ₃ : 0.58% to 2.66%, mass ratio of CaO to SiO ₂ : 0.035 to 1.31;

among them,

When the mass percentage of SiO ₂ is <3.0%, the mass ratio of CaO to SiO ₂ is ≥1.0. In order to achieve the above second object, the technical solution of the method for preparing pellets provided by the present invention is as follows:

The preparation method of the pellets provided by the invention comprises the following steps:

Finely grinding the sintered ore powder to obtain a finely ground sintered powder having set parameters;

Pellet powder and/or boron-containing pellet powder, the fine grinding sintered powder is ore-matched to obtain concentrate powder;

Adding a binder to the concentrate powder to obtain an intermediate mixture;

The intermediate mixture is passed through a pelletizing and calcining process in sequence to produce the pellet.

In order to achieve the above third object, the technical solution of the pelletizing apparatus provided by the present invention is as follows:

The preparation device of the pellet ore provided by the invention comprises a grinding device, a container, a pelletizing device, a roasting system,

The grinding device is used for fine grinding the sintered ore powder to obtain a fine grinding sintered powder having set parameters;

The container is used for accommodating pellets and/or boron-containing ore powder, finely ground powder obtained by ore blending of the finely ground sintered powder; and an intermediate mixture obtained by adding a binder to the concentrate powder;

The pelletizing device is configured to pellet the intermediate product to obtain a spherical intermediate product;

The calcination system is used in a calcination process of the spherical intermediate product, and the pellet is obtained through the calcination process.

The pellets provided by the invention are prepared by sintering ore powder, that is, the pellets with good quality and relatively low environmental cost can be prepared by using the ore fine powder with poor quality and relatively high environmental cost, The green development of the metallurgical industry has opened up a simple and beneficial approach.

The pellet ore provided by the present invention can be obtained by the preparation method and preparation device of the pellet ore provided by the present invention, that is, the sintered ore powder with poor quality and relatively high environmental cost can be prepared to obtain better quality and environment. The relatively low cost pellets have created a simple and beneficial way for the green development of the metallurgical industry.

DRAWINGS

Various other advantages and benefits will become apparent to those skilled in the art from a The drawings are only for the purpose of illustrating the preferred embodiments and are not to be construed as limiting. Throughout the drawings, the same reference numerals are used to refer to the same parts. In the drawing:

1 is a flow chart showing the steps of a method for preparing a pellet ore according to an embodiment of the present invention;

2 is a flow chart of material changes in a process for preparing a pellet ore according to an embodiment of the present invention;

3 is a flow chart showing the steps of a roasting process involved in a method for preparing a pellet ore according to an embodiment of the present invention;

4 is a schematic diagram showing a connection relationship between devices in a pelletizing apparatus according to an embodiment of the present invention;

Figure 5 is a physical photograph of the sinter;

FIG. 6 is a photo photograph of a pellet of a pellet obtained by the preparation method and the preparation apparatus provided by the embodiment of the present invention.

detailed description

In order to solve the problems existing in the prior art, the present invention provides a pellet, a preparation method thereof and a preparation device, which are capable of applying a sinter powder to prepare a pellet, thereby being more suitable for practical use.

In order to further illustrate the technical means and efficacy of the present invention in order to achieve the intended purpose of the invention, the specific embodiments of the pellets, the preparation method and the preparation apparatus thereof according to the present invention are described below with reference to the accompanying drawings and preferred embodiments. , structure, characteristics and efficacy, as detailed below. In the following description, different "an embodiment" or "an embodiment" does not necessarily mean the same embodiment. Furthermore, the particular features, structures, or characteristics of one or more embodiments can be combined in any suitable form.

The term “and/or” in this context is merely an association that describes an associated object, indicating that there may be three relationships, for example, A and/or B. The specific understanding is that A and B can be included at the same time, and can be separate. If A exists, B may exist alone, and any of the above three cases may be provided.

Example 1

Fine-grinding the Baca mineral powder to obtain fine-ground Baca mineral powder, wherein the fine-grained Baca mineral powder has a mass percentage of particles of ≤74 μm ≥80%, and the quality of particles with particle size ≤44 μm The percentage is >60%. Weigh 99.0kg of concentrate powder of fine grinding Baka mineral powder, add 0.6kg bentonite as binder, 3.3kg slaked lime as calcium-containing flux, water as liquid medium, and mix to obtain intermediate product. In the intermediate product, the moisture content was 7.0% by weight. Place the intermediate product on the disc The ball is formed in the pelletizer, and the peening time lasts for 10 minutes. The green ball with the particle size of 9 mm to 16 mm is sieved, and the roasting process is completed in the baking cup to obtain the pellet. The roasting process comprises: the raw ball is first subjected to blast drying, the temperature is 320 ° C, the duration is 3 minutes, and then the air is dried, the temperature is 450 ° C, the duration is 5 minutes, and then preheated, the temperature is 1000 ° C, and the duration is After 6 minutes, the calcination was carried out at a temperature of 1290 ° C for a duration of 10 minutes, followed by soaking at a temperature of 1150 ° C for a duration of 3 minutes; the pellet after soaking was cooled to 150 ° C with air.

The mass percentages of the components in the pellet are: TFe: 63.46%, FeO: 0.56%, SiO ₂ : 2.32%, CaO: 2.76%, MgO: 0.27%, Al ₂ O ₃ : 2.01%, CaO The mass ratio to SiO ₂ was 1.19.

The compressive strength of the pellet was 2879 N/P, the drum index was 93.2%, the reduction expansion ratio was 17.2%, and the reduction degree was 73.5%.

Table 1 Example 1-18 provides the mass percentage of each component in the pellets and other indicators

Among them, the requirements for the pellet quality of the qualified quality are: compressive strength > 2400 N, reduction expansion ratio < 20%; considering the above-mentioned Examples 1 to 18 of the present invention, it is understood that the above-described Embodiments 1 to 18 of the present invention are satisfied. The above indicators require that, therefore, the quality of the pellets obtained by using Examples 1 to 18 of the present invention is acceptable.

Table 2 Operating parameters of the preparation method of the pellets provided in Examples 1 to 18

Continued Table 2

Among them, hematite (chemical formula: Fe ₂ O ₃ ) sintered powder can be used alone or with different proportions of magnetite (chemical formula: Fe ₃ O ₄ ) pellet powder, if it contains limonite (chemical formula is Fe ₂ O) ₃ · H ₂ O) Sintered powder is formulated with 50 to 90% of magnetite pellet powder or hematite (chemical formula of Fe ₂ O ₃ ) sintered powder or 5 to 10% of boron-containing pellet powder.

Referring to Figure 5 and Figure 6, wherein Figure 5 shows a sintered ore, as can be seen from Figure 5, the appearance of the sintered ore is irregularly porous; Figure 6 shows the pellets, from As can be seen from Figure 6, the appearance of the pellets is a regular circular structure.

Example 19

Referring to Figure 4, a pelletizing apparatus provided in Embodiment 19 of the present invention includes a grinding apparatus, a container, a pelletizing apparatus, and a baking system. The grinding device is used for finely grinding the sintered ore powder to obtain a fine grinding sintered powder having set parameters; the container is used for accommodating the concentrate of the pellet ore and/or the boron-containing ore powder and the finely ground sintered powder through the ore blending. Powder; an intermediate mixture obtained by adding a binder to the concentrate powder; a pelletizing device for granulating the intermediate product to obtain a spherical intermediate product; and a calcination system for the calcination process of the spherical intermediate product, after the calcination process, Get the pellets. In this case, since the calcium-containing flux is not added to the intermediate mixture, the obtained pellets are acidic pellets. In general, the pellets having a mass ratio of CaO to SiO ₂ of ≤ 0.6 are acidic balls. Mission mine.

Among them, the intermediate mixture also includes a calcium-containing flux. In this case, the calcium-containing flux is usually slaked lime (Ca(OH) ₂ ) or limestone (CaCO ₃ ), and the obtained pellet is obtained as a flux pellet or a self-fluxing pellet. In general, a pellet having a mass ratio of CaO to SiO ₂ of >0.6 is a flux pellet, wherein a pellet having a mass ratio of CaO to SiO ₂ of 0.8 to 1.2 is a self-fluxing pellet.

The apparatus for preparing pellets provided in Embodiment 13 of the present invention further includes a first screen and a second screen. The screen diameter of the first screen was 74 μm, and the diameter of the screen of the second screen was 44 μm. In this case, the particles trapped on the first screen are judged to have a particle size of >74 μm, and the particles capable of passing through the first screen are judged to have a particle diameter of ≤74 μm; further, they are trapped in the second sieve. The particles above the web were judged to have a particle size of > 44 μm, and the particles capable of passing through the second screen were judged to have a particle diameter of ≤ 44 μm. At this time, in order to ensure that the particles having a particle diameter smaller than the pore diameter can smoothly pass through the first screen and/or the second screen, a shaker apparatus can also be provided, which is used for the first screen and/or the second screen. The web is shaken in a horizontal direction such that the various angles of the particles above the first screen and/or the second screen are likely to contact the screen openings, avoiding the particles and the first screen and/or the second screen Mistakes caused by misalignment of the contact angle of the net. In addition, in order to avoid the clogging of the screen hole due to the distribution of the particles on the surface of the screen which are close to the pore size of the sieve hole, a first stirring mechanism and/or a second stirring mechanism may be provided, the first stirring mechanism For agitating the upper surface of the first screen, the second stirring mechanism is for stirring the upper surface of the second screen so as to directly cover the surface of the first screen and/or the surface of the second screen The particles are in an active state, further enhancing the screening efficiency of the first screen and/or the second screen.

Wherein, the second screen is arranged below the first screen. In this case, due to the mesh aperture of the first screen > the aperture of the mesh of the second screen, the particle size leaked from the first screen ≤ the aperture of the first screen The particles can fall directly on the surface of the second screen, so that it is no longer necessary to transfer to the surface of the second screen by means of the transfer container, so that the technical solution is simpler and the operation is more convenient.

The apparatus for preparing pellets according to the thirteenth embodiment of the present invention further includes a third screen, wherein the diameter of the third screen is in the range of 9 mm to 16 mm, and the third screen is used for screening the range of the particle diameter. It is a raw ball of 9mm to 16mm.

The apparatus for preparing pellets provided in Embodiment 19 of the present invention further includes a clock for measuring time intervals of the pelletizing and/or firing process. In this case, the time control of the pelletizing and/or firing process can be made more precise. In addition, in order to make the ball making time easier to control, an alarm can also be set. When the peening time reaches a preset time, the alarm automatically issues an alarm, and the alarm can be selected from a buzzer, a signal light, a short message, a qq message. Any one or several of voice messages and WeChat messages.

In order to enable the green ball sieved through the third screen to be automatically fed into the roasting system, a conveying mechanism can be provided to automatically feed the raw ball into the roasting system through the conveying mechanism, thereby making the operation more convenient and quick.

The apparatus for preparing pellets provided in Embodiment 19 of the present invention further includes a temperature control device for adjusting the temperature of the baking system. In this case, the temperature of each stage of the baking process can be more accurately controlled, and the test result is more accurate.

While the preferred embodiment of the invention has been described, it will be understood that Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and the modifications and

It is apparent that those skilled in the art can make various modifications and variations to the invention without departing from the spirit and scope of the invention. Thus, if such modifications and variations of the invention are within the scope of the invention The invention is also intended to cover such modifications and variations within the scope of the equivalents.

Claims (20)

A pellet, characterized in that the mass percentage of each component includes: TFe: 62.1% to 65.82%, FeO: 0.2% to 0.58%, SiO ₂ : 1.90% to 5.97%, and CaO: 0.17%. 3.23%, MgO: 0.18% to 0.52%, Al ₂ O ₃ : 0.58% to 2.66%, mass ratio of CaO to SiO ₂ : 0.035 to 1.251; among them, When the mass percentage of SiO ₂ is <3.0%, the mass ratio of CaO to SiO ₂ is ≥1.0. The method for preparing a pellet of claim 1, comprising the steps of: Finely grinding the sintered ore powder to obtain a finely ground sintered powder having set parameters; Pellet powder and/or boron-containing pellet powder, the fine grinding sintered powder is ore-matched to obtain concentrate powder; Adding a binder to the concentrate powder to obtain an intermediate mixture; The intermediate mixture is passed through a pelletizing and calcining process in sequence to produce the pellet. The method of preparing a pellet of claim 2, wherein the pellet is an acidic pellet. The method for preparing a pellet ore according to claim 2, wherein the step of adding a binder to the concentrate powder to obtain an intermediate product further comprises the step of adding a calcium-containing flux to the concentrate powder. . The method for preparing a pellet ore according to claim 4, wherein the pellet is a flux pellet and a self-fluxing pellet. The method for preparing a pellet ore according to claim 2 or 4, wherein the sintered ore powder is selected from the group consisting of baca powder, PB powder, macadam powder, Newman powder, poplar powder, FMG powder, and Brazilian sinter powder. Any one or a mixture of a mixture of South African powder and Indian powder. The method for producing a pellet ore according to claim 2 or 4, wherein in the finely ground sintered powder, The mass percentage of particles having a particle size of ≤74 μm is >80%; The mass percentage of particles having a particle size of ≤ 44 μm is > 60%. The method for preparing a pellet ore according to claim 4, wherein a binder and a calcium-containing flux are added to the concentrate powder to obtain an intermediate mixture. The mass ratio between the concentrate powder, the binder, and the calcium-containing flux ranges from (99.5 to 92.5): (0 to 1.5): (0 to 6). The method of producing a pellet according to claim 8, further comprising the step of mixing said concentrate powder, a binder, and a calcium-containing flux. The method for preparing a pellet ore according to claim 9, wherein the process of mixing the concentrate powder, the binder, and the flux is performed by means of a liquid medium; Wherein the liquid medium is water. The method for preparing a pellet ore according to claim 2, wherein the duration of the pelletizing is in the range of 8 min to 11 min. The method for preparing a pellet ore according to claim 2, further comprising the step of selecting a green ball having a particle diameter ranging from 9 mm to 16 mm between the pelletizing and calcining processes. The method for preparing a pellet ore according to claim 2, wherein the process conditions of the roasting process comprise: The blast is dry, wherein the temperature ranges from 250 ° C to 350 ° C, and the duration ranges from 2 min to 3 min; Exhaust air drying, wherein the temperature range is from 400 ° C to 550 ° C, the duration of the value range The circumference is 4min ~ 5min; Preheating, wherein the temperature ranges from 800 ° C to 1000 ° C, and the duration ranges from 6 min to 10 min; Calcination, wherein the temperature ranges from 1260 ° C to 1300 ° C, and the duration ranges from 7 min to 12 min; Homogenization, wherein the temperature ranges from 1100 ° C to 1150 ° C, and the duration ranges from 2 min to 3 min; Cooling, wherein after the cooling, the range of temperature is reduced to ≤150 °C. The apparatus for preparing a pellet ore according to claim 1, comprising a grinding device, a container, a pelletizing device, a baking system, The grinding device is used for fine grinding the sintered ore powder to obtain a fine grinding sintered powder having set parameters; The container is used for accommodating pellets and/or boron-containing ore powder, finely ground powder obtained by ore blending of the finely ground sintered powder; and an intermediate mixture obtained by adding a binder to the concentrate powder; The pelletizing device is configured to pellet the intermediate product to obtain a spherical intermediate product; The calcination system is used in a calcination process of the spherical intermediate product, and the pellet is obtained through the calcination process. The apparatus for producing pellets according to claim 14, wherein said intermediate mixture further comprises a calcium-containing flux. The apparatus for preparing a pellet ore according to claim 14, further comprising a first screen and a second screen. The sieve diameter of the first screen is 74 μm, The mesh size of the second screen was 44 μm. The apparatus for preparing a pellet ore according to claim 16, wherein the second screen is disposed below the first screen. The apparatus for preparing a pellet ore according to claim 14, further comprising a third screen, wherein the aperture of the third screen has a value ranging from 9 mm to 16 mm, and the third screen is used for The green balls with a particle size ranging from 9 mm to 16 mm are sieved. The apparatus for preparing pellets according to claim 14, further comprising a clock for measuring each time interval of the pelletizing and/or firing process. The apparatus for preparing a pellet ore according to claim 14, further comprising temperature control means for adjusting a temperature of the calcination system.

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