Pellet and preparation method thereof

Abstract

The invention relates to pellets and a preparation method thereof, and the method comprises the following steps: grinding concentrate powder with set moisture to obtain concentrate powder with target granularity; mixing the concentrate powder with the target particle size, a flux and a binder, and controlling the addition amount of the concentrate powder with the target particle size, the flux and the binder to obtain a mixed material; and a solvent is added into the mixed material, pelletizing is conducted, and pellets are obtained. According to the content of the invention, the pelletizing rate of pellets is improved.

Description

Technical Field

[0001] The present application relates to the technical field of pellet production, and in particular to a pellet and a preparation method thereof. Background Art

[0002] In the pellet production process, the quality of raw balls is directly related to the quality of finished pellets. Conventional pellet operation technology includes batching, mixing, pelletizing and screening.

[0003] However, the proportion of pellets with a particle size of 8 to 16 mm is low, and the pelletization rate is low. Summary of the invention

[0004] The present application provides a pelletized ore and a preparation method thereof to solve the following technical problem: how to improve the pelletization rate of the pelletized ore.

[0005] In a first aspect, the present application provides a method for preparing pelletized ore, the method comprising:

[0006] Grinding the concentrate powder with a set moisture content to obtain the concentrate powder with a target particle size;

[0007] The concentrate powder with the target particle size, the flux and the binder are mixed, and the added amounts of the concentrate powder with the target particle size, the flux and the binder are controlled to obtain a mixed material;

[0008] A solvent is added to the mixed material, and then pelletization is performed to obtain pelletized ore.

[0009] Optionally, the set moisture content is 8.0% to 8.5%.

[0010] Optionally, the concentrate powder having a target particle size comprises:

[0011] The concentrate powder includes particles with a particle size of -200 mesh, and the content of the particles with a particle size of -200 mesh is more than 85 weight %.

[0012] Optionally, controlling the added amounts of the concentrate powder having the target particle size, the flux, and the binder comprises:

[0013] With respect to 100 parts by weight of the concentrate powder having the target particle size, the binder is 1.5 parts by weight to 2.0 parts by weight, and the flux is 0.5 parts by weight to 1.0 parts by weight.

[0014] Optionally, the flux includes at least one of the following: slaked lime, limestone, and magnesia flux.

[0015] Optionally, the binder includes at least one of the following: bentonite and an organic binder.

[0016] Optionally, if the binder is bentonite, the bentonite has a set water absorption rate and a set blue absorption amount.

[0017] Optionally, the set water absorption rate is greater than 360% / 2h.

[0018] Optionally, the set blue absorption amount is 30g / 100g or more.

[0019] In a second aspect, the present application provides a pellet prepared by the method described in the first aspect.

[0020] The above technical solution provided by the embodiment of the present application has the following advantages compared with the prior art:

[0021] The preparation method of the pelletized ore provided in the embodiment of the present application includes: grinding the concentrate powder with set moisture to obtain the concentrate powder with target particle size; mixing the concentrate powder with target particle size, flux and binder, and controlling the addition amount of the concentrate powder with target particle size, flux and binder to obtain a mixed material; adding a solvent to the mixed material, and then making a ball to obtain a pelletized ore. Grinding the concentrate powder with set moisture can change the particle size composition of the concentrate powder, and controlling the addition amount of the concentrate powder with target particle size, flux and binder can adjust the particle size, compressive strength and grade of the raw ball, and subsequently adding a solvent to the mixed material to make a ball, thereby increasing the interaction between the raw materials, improving the quality of the raw balls, increasing the ball formation rate of the pelletized ore, reducing the proportion of unqualified balls in the pelletized ore, and improving production efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present application and, together with the description, serve to explain the principles of the present application.

[0023] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0024] Figure 1 The present invention is a schematic flow chart of a method for preparing pelletized ore according to some embodiments of the present application. DETAILED DESCRIPTION

[0025] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application.

[0026] Various embodiments of the present application may be presented in the form of a range; it should be understood that the description in the form of a range is only for convenience and brevity, and should not be understood as a rigid limitation on the scope of the present application; therefore, the range description should be considered to have specifically disclosed all possible sub-ranges and single numerical values ​​within the range. For example, the range description from 1 to 6 should be considered to have specifically disclosed sub-ranges, such as from 1 to 3, from 1 to 4, from 1 to 5, from 2 to 4, from 2 to 6, from 3 to 6, etc., as well as single numbers within the range, such as 1, 2, 3, 4, 5 and 6, which apply regardless of the range. In addition, whenever a numerical range is indicated herein, it is meant to include any cited number (fractional or integer) within the indicated range.

[0027] In the present application, in addition, in the description of the specification of the present application, the terms "including", "comprising", etc. mean "including but not limited to". In this article, "at least one" means one or more, and "plurality" means two or more. "At least one", "at least one of the following" or similar expressions refer to any combination of these items, including any combination of single items or plural items. For example, "at least one of a, b, or c", or "at least one of a, b, and c" can all mean: a, b, c, ab (i.e., a and b), ac, bc, or abc, where a, b, and c can be single or multiple, respectively.

[0028] Unless otherwise specified, various raw materials, reagents, instruments and equipment used in this application can be purchased from the market or prepared by existing methods.

[0029] First, Figure 1 A schematic diagram of a process for preparing pelletized ore according to some embodiments of the present application; see Figure 1 The present application provides a method for preparing pelletized ore, the method comprising:

[0030] S1, grinding the concentrate powder with a set moisture content to obtain the concentrate powder with a target particle size;

[0031] In some embodiments, the set moisture content is 8.0% to 8.5%.

[0032] In the embodiments of the present application, the change of moisture affects the particle size and quality of the raw balls. If the moisture content of the concentrate powder is too high, the initial ball formation is faster, but it is easy to cause the mother balls to stick to each other and deform, resulting in uneven particle size distribution of the raw balls, poor strength of the raw balls, poor air permeability of the material layer, and at the same time affecting the drying; if the moisture content of the concentrate powder is too low, the ball formation is slow, and the moisture content is difficult to control during ball making, which can easily cause the quality of the raw balls to fail to meet the requirements. The above-mentioned grinding can be high-pressure roller milling or ball milling. Exemplarily, the above-mentioned set moisture content can be 8.0%, 8.1%, 8.2%, 8.3%, 8.4%, 8.5%, etc.

[0033] In some embodiments, the concentrate powder having a target particle size comprises:

[0034] The concentrate powder includes particles with a particle size of -200 mesh, and the content of the particles with a particle size of -200 mesh is more than 85 weight %.

[0035] In the embodiment of the present application, the particle size of the concentrate after grinding is limited to ensure the raw ball characteristics and the pellet drum index. For example, the content of the above-mentioned -200 mesh particle size particles can be 85 weight %, 86 weight %, 87 weight %, 88 weight %, 89 weight %, 90 weight %, etc.

[0036] S2, mixing the concentrate powder with the target particle size, flux and binder, and controlling the added amounts of the concentrate powder with the target particle size, flux and binder to obtain a mixed material;

[0037] In some embodiments, controlling the addition amounts of the concentrate powder having the target particle size, the flux, and the binder comprises:

[0038] With respect to 100 parts by weight of the concentrate powder having the target particle size, the binder is 1.5 parts by weight to 2.0 parts by weight, and the flux is 0.5 parts by weight to 1.0 parts by weight.

[0039] In some embodiments, the flux comprises at least one of the following: slaked lime, limestone, and magnesia flux.

[0040] In some embodiments, the binder includes at least one of the following: bentonite, an organic binder.

[0041] In the embodiment of the present application, the amount of the concentrate powder, flux and binder added to limit the target particle size is to adjust the particle size, compressive strength and grade of the green balls. Adding some flux to the pellets is beneficial to reducing the coke ratio and increasing the strength of the pellets, adjusting the alkalinity, and improving the smelting performance. It can be one or more of slaked lime, limestone, and magnesia flux. The above-mentioned binder can be one or more of bentonite and organic binder. Bentonite can increase the falling strength of the green balls, play a role in regulating moisture in the ball making process, and increase the bursting temperature of the green balls. An appropriate amount of bentonite can ensure the particle size, shape, compressive strength and grade of the green balls. Illustratively, relative to 100 parts by weight of concentrate powder having a target particle size, the binder may be 1.5 parts by weight, 1.6 parts by weight, 1.7 parts by weight, 1.8 parts by weight, 1.9 parts by weight, 2.0 parts by weight, etc., and the flux may be 0.5 parts by weight, 0.6 parts by weight, 0.7 parts by weight, 0.8 parts by weight, 0.9 parts by weight, 1.0 parts by weight, etc.

[0042] In some embodiments, if the binder is bentonite, the bentonite has a set water absorption rate and a set blue absorption amount.

[0043] In some embodiments, the set water absorption rate is greater than 360% / 2h.

[0044] In some embodiments, the set blue absorption amount is 30g / 100g or more.

[0045] In the embodiment of the present application, the water absorption rate of bentonite is the most important indicator of bentonite for metallurgy. Its function is not only to make bentonite have strong water absorption performance and adjust the moisture in the pellets, but also to increase the bursting temperature of the pellets. Generally speaking, the higher the water absorption rate, the better the performance of the pellets. Exemplarily, the above-mentioned set water absorption rate can be 360% / 2h, 365% / 2h, 375% / 2h, 370% / 2h, 363% / 2h, 368% / 2h, etc.

[0046] The blue absorption of bentonite can roughly estimate the technical index of the relative content of montmorillonite in bentonite, and the amount of montmorillonite directly affects the quality of bentonite. Blue absorption is also a characterization of the strength of adsorption and water absorption. A high blue absorption means a high montmorillonite content, strong adsorption and water absorption. Exemplary, the above-mentioned setting of blue absorption can be 30g / 100g, 32g / 100g, 34g / 100g, 36g / 100g, 38g / 100g, 40g / 100g, etc.

[0047] S3, adding a solvent to the mixed material, and then performing balling to obtain pelletized ore.

[0048] In the embodiment of the present application, the uniformly mixed raw materials are added to a disc pelletizing machine for solvent addition to obtain green balls, and the green balls are screened using a sieve with a specification of 8 to 16 mm to obtain qualified green balls. The amount of qualified green balls is divided by the total amount of green balls to calculate the green ball qualification rate. The above solvent is generally water. The strength of the above pellets after roasting can reach more than 3000N.

[0049] In a second aspect, the present application provides a pellet prepared by the method described in the first aspect.

[0050] The pelletized ore is realized based on the preparation method of the pelletized ore mentioned above. The specific steps of the preparation method of the pelletized ore can refer to the above embodiment. Since the pelletized ore adopts part or all of the technical solutions of the above embodiment, it has at least all the beneficial effects brought by the technical solutions of the above embodiment, which will not be described one by one here.

[0051] The present application will be further described below in conjunction with specific embodiments. It should be understood that these embodiments are intended only to illustrate the present application and are not intended to limit the scope of the present application. The experimental methods for which specific conditions are not specified in the following examples are usually measured according to national standards. If there is no corresponding national standard, then the conditions recommended by the manufacturer are followed.

[0052] Example 1

[0053] A method for preparing pelletized ore, comprising:

[0054] The moisture content of the concentrate powder is 8.2%.

[0055] The concentrate powder is finely ground (ball milled), and the -200 mesh particle size reaches 88% after fine grinding.

[0056] 100 parts of finely ground concentrate powder, 1.6 parts of bentonite and 0.6 parts of slaked lime are mixed in a powerful mixer; wherein the water absorption rate of the bentonite is 370% / 2h, and the blue absorption amount is 31g / 100g.

[0057] The evenly mixed raw materials are added into a disc ball making machine, and water is added to make balls to obtain raw balls.

[0058] Example 2

[0059] A method for preparing pelletized ore, comprising:

[0060] The moisture content of the concentrate powder is 8.4%.

[0061] The concentrate powder is finely ground (high pressure roller mill), and after fine grinding, the -200 mesh particle size reaches 90%.

[0062] 100 parts of finely ground concentrate powder, 1.8 parts of bentonite and 0.7 parts of slaked lime are mixed in a powerful mixer; wherein the water absorption rate of the bentonite is 380% / 2h, and the blue absorption amount is 32g / 100g.

[0063] The evenly mixed raw materials are added into a disc ball making machine, and water is added to make balls to obtain raw balls.

[0064] Example 3

[0065] A method for preparing pelletized ore, comprising:

[0066] The moisture content of the concentrate powder is 8.3%.

[0067] The concentrate powder is finely ground (ball milled), and the -200 mesh particle size reaches 87% after fine grinding.

[0068] 100 parts of finely ground concentrate powder, 1.7 parts of bentonite and 0.5 parts of slaked lime are mixed in a powerful mixer; wherein the water absorption rate of the bentonite is 360% / 2h, and the blue absorption amount is 33g / 100g.

[0069] The evenly mixed raw materials are added into a disc ball making machine, and water is added to make balls to obtain raw balls.

[0070] Example 4

[0071] A method for preparing pelletized ore, comprising:

[0072] The moisture content of the concentrate powder is 8.2%.

[0073] The concentrate powder is finely ground (high pressure roller mill), and the -200 mesh particle size reaches 92% after fine grinding.

[0074] 100 parts of finely ground concentrate powder, 1.8 parts of bentonite and 0.7 parts of slaked lime are mixed in a powerful mixer; wherein the water absorption rate of the bentonite is 382% / 2h, and the blue absorption amount is 32g / 100g.

[0075] The evenly mixed raw materials are added into a disc ball making machine, and water is added to make balls to obtain raw balls.

[0076] Comparative Example 1

[0077] A method for preparing pelletized ore, comprising:

[0078] The moisture content of the concentrate powder is 7.8%.

[0079] The concentrate powder is finely ground (ball milled), and the -200 mesh particle size reaches 87% after fine grinding.

[0080] 100 parts of finely ground concentrate powder, 1.8 parts of bentonite and 0.7 parts of slaked lime are mixed in a powerful mixer; wherein the water absorption rate of the bentonite is 375% / 2h, and the blue absorption amount is 32g / 100g.

[0081] The evenly mixed raw materials are added into a disc ball making machine, and water is added to make balls to obtain raw balls.

[0082] Comparative Example 2

[0083] A method for preparing pelletized ore, comprising:

[0084] The moisture content of the concentrate powder is 9.2%.

[0085] The concentrate powder was finely ground (high pressure roller mill), and the -200 mesh particle size reached 88% after fine grinding.

[0086] 100 parts of finely ground concentrate powder, 1.9 parts of bentonite and 0.7 parts of slaked lime were mixed in a powerful mixer; wherein the water absorption rate of the bentonite was 360% / 2h, and the blue absorption amount was 31g / 100g.

[0087] The evenly mixed raw materials are added into a disc ball making machine, and water is added to make balls to obtain raw balls.

[0088] Comparative Example 3

[0089] The moisture content of the concentrate powder is 8.3%.

[0090] The concentrate powder is finely ground (high pressure roller mill or ball mill), and after fine grinding, the -200 mesh particle size reaches 80%.

[0091] 100 parts of finely ground concentrate powder, 1.7 parts of bentonite and 0.6 parts of slaked lime are mixed in a powerful mixer; wherein the water absorption rate of the bentonite is 390% / 2h, and the blue absorption amount is 33g / 100g.

[0092] The evenly mixed raw materials are added into a disc ball making machine, and water is added to make balls to obtain raw balls.

[0093] Comparative Example 4

[0094] A method for preparing pelletized ore, comprising:

[0095] The moisture content of the concentrate powder is 8.4%.

[0096] The concentrate powder is finely ground (high pressure roller mill or ball mill), and the -200 mesh particle size reaches 87% after fine grinding.

[0097] 100 parts of finely ground concentrate powder, 1.2 parts of bentonite and 0.3 parts of slaked lime are mixed in a powerful mixer; wherein the water absorption rate of the bentonite is 370% / 2h, and the blue absorption amount is 32g / 100g.

[0098] The evenly mixed raw materials are added into a disc ball making machine, and water is added to make balls to obtain raw balls.

[0099] Comparative Example 5

[0100] The moisture content of the concentrate powder is 8.4%.

[0101] The concentrate powder is finely ground (high pressure roller mill or ball mill), and the -200 mesh particle size reaches 87% after fine grinding.

[0102] 100 parts of finely ground concentrate powder, 1.7 parts of bentonite and 0.8 parts of slaked lime are mixed in a powerful mixer; wherein the water absorption rate of the bentonite is 300% / 2h, and the blue absorption amount is 28g / 100g.

[0103] The evenly mixed raw materials are added into a disc ball making machine, and water is added to make balls to obtain raw balls.

[0104] The pellets prepared in Examples 1 to 4 and Comparative Examples 1 to 5 were screened using a sieve with a specification of 8 to 16 mm to obtain qualified green balls. The amount of qualified green balls was divided by the total amount of green balls to calculate the green ball qualified rate (ball formation rate).

[0105] The results are shown in Table 1 for the pelletization rate of the pelletized ore.

[0106] Serial number Balling rate (raw ball qualified rate) % Example 1 90.38 Example 2 89.78 Example 3 88.27 Example 4 91.36 Comparative Example 1 85.35 Comparative Example 2 84.27 Comparative Example 3 83.45 Comparative Example 4 80.28 Comparative Example 5 79.73

[0107] The qualified pellets prepared in Examples 1 to 4 and Comparative Examples 1 to 5 were subjected to performance tests, and the results are clearly shown in Table 2 for the performance of the qualified pellets.

[0108] Table 2 Performance of qualified pellets

[0109]

[0110]

[0111] From Table 1 above, the green ball qualified rate obtained by the method for preparing the pellets in the embodiment of the present application reached more than 88%, with an average of 89.95%, far exceeding the comparative examples 1-5, where the green ball qualified rate of the comparative examples 1-5 was only 82.62% on average, which was 3%-10% lower than that of the embodiment. This shows that the method for preparing the pellets in the embodiment of the present application can improve the green ball quality, increase the pelletization rate of the pellets, reduce the proportion of unqualified balls in the pellets, and improve production efficiency, thus achieving significant economic benefits.

[0112] The above description is only a specific implementation of the present application, so that those skilled in the art can understand or implement the present application. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application will not be limited to the embodiments shown herein, but will conform to the widest range consistent with the principles and novel features applied for herein.

Claims

1. A method for preparing pelletized ore, characterized in that: The method comprises: Grinding the concentrate powder with a set moisture content to obtain the concentrate powder with a target particle size; The concentrate powder with the target particle size, the flux and the binder are mixed, and the added amounts of the concentrate powder with the target particle size, the flux and the binder are controlled to obtain a mixed material; A solvent is added to the mixed material, and then pelletization is performed to obtain pelletized ore.

2. The method according to claim 1, characterized in that: The set moisture content is 8.0% to 8.5%.

3. The method according to claim 1, characterized in that: The concentrate powder having a target particle size comprises: The concentrate powder includes particles with a particle size of -200 mesh, and the content of the particles with a particle size of -200 mesh is more than 85 weight %.

4. The method according to claim 1, characterized in that: The controlling the added amounts of the concentrate powder having the target particle size, the flux and the binder comprises: With respect to 100 parts by weight of the concentrate powder having the target particle size, the binder is 1.5 parts by weight to 2.0 parts by weight, and the flux is 0.5 parts by weight to 1.0 parts by weight.

5. The method according to claim 1, characterized in that The flux includes at least one of the following: slaked lime, limestone, and magnesia flux.

6. The method according to claim 1, characterized in that The binder includes at least one of the following: bentonite and an organic binder.

7. The method according to claim 6, characterized in that If the binder is bentonite, the bentonite has a set water absorption rate and a set blue absorption amount.

8. The method according to claim 7, characterized in that The set water absorption rate is 360% / 2h or more.

9. The method according to claim 7, characterized in that: The set blue absorption amount is 30g / 100g or more.

10. A pelletized ore prepared by the method according to any one of claims 1 to 9.

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