A method for preparing a new type of ultra-high hardness grinding ball for molybdenum ore

Abstract

The invention relates to the technical field of novel ultra-high hardness grinding balls and discloses a preparation method of a novel ultra-high hardness grinding ball for molybdenum ore. The method comprises batching, smelting, deoxidation, pouring, quenching and tempering. The batching comprises the following elements in mass percentage: C: 3.3-3.6%, Si: ≤1.2%, Mn: 0.9-1.2%, Cr: 13-14%, S: ≤0.06%, P: ≤0.1%, Ni: 0.05-0.1%, Mo: 0.05-1.0%, and V: 0.05-1.0%. The preparation method of the new ultra-high hardness grinding ball for molybdenum ore significantly improves the hardness of the grinding ball by optimizing the chemical composition, especially increasing the C content to 3.3-3.6%, and adding alloy elements such as Ni, Mo, and V. The hardness of the final product reaches HRC 65-66, which is much higher than the HRC 58-60 of ordinary high-chromium balls. Through multi-stage quenching and tempering treatment, the stability of the internal structure of the grinding ball and the consistency of the surface hardness are ensured. The optimized smelting and heat treatment process not only improves the performance of the product, but also shortens the production cycle, improves production efficiency, and reduces production costs.

Description

Technical Field

[0001] The invention relates to the technical field of novel ultra-high hardness grinding balls, in particular to a method for preparing novel ultra-high hardness grinding balls for molybdenum ore. Background Art

[0002] The new ultra-high hardness grinding ball is a high-performance grinding ball specially designed for high-wear environments. By optimizing the chemical composition and heat treatment process, its hardness, wear resistance, tensile strength, elongation, impact toughness and service life are significantly improved. However, in the prior art, the hardness of ordinary high-chromium balls is relatively weak. In a high-intensity wear environment, the hardness level easily causes the grinding balls to wear quickly, shortening their service life, increasing maintenance costs and the risk of production interruptions. In addition, the tensile strength of ordinary high-chromium balls is insufficient, making the grinding balls easy to break when subjected to high loads, affecting their reliability and safety under complex working conditions. At the same time, the existing high-chromium balls have poor impact toughness, making the grinding balls easy to be damaged when subjected to strong impacts, affecting their reliability and service life in high-impact environments. Summary of the invention

[0003] The purpose of this section is to summarize some aspects of embodiments of the present invention and briefly introduce some preferred embodiments. Some simplifications or omissions may be made in this section and the specification abstract and the invention title of this application to avoid blurring the purpose of this section, the specification abstract and the invention title, and such simplifications or omissions cannot be used to limit the scope of the present invention.

[0004] To achieve the above object, the present invention provides the following technical solutions:

[0005] A method for preparing a new type of ultra-high hardness grinding ball for molybdenum ore, the method comprising:

[0006] Batching, smelting, deoxidation, pouring, quenching and tempering.

[0007] As a further solution of the present invention: the ingredients include the following elements in percentage by mass:

[0008] C: 3.3-3.6%, Si: ≤1.2%, Mn: 0.9-1.2%, Cr: 13-14%, S: ≤0.06%, P: ≤0.1%, Ni: 0.05-0.1%, Mo: 0.05-1.0%, V: 0.05-1.0%.

[0009] As a further solution of the present invention: in the smelting step, the above materials need to be smelted to a temperature above 1550°C.

[0010] As a further solution of the present invention: in the deoxidation step, it is necessary to add 0.3-0.5 kg of aluminum ingots per ton of molten metal for deoxidation treatment two minutes before the molten metal is taken out of the furnace.

[0011] As a further solution of the present invention: in the pouring step, the deoxidized liquid is transferred to a transfer ladle for slagging and poured into a pouring ladle, the pouring temperature is controlled between 1480°C and 1520°C, and the pouring time is 10-20 minutes.

[0012] As a further solution of the present invention: in the quenching step, the semi-finished product is placed on a quenching line and heated in four stages, 520-550°C, 750-780°C, 840-880°C and 880-920°C, with each stage being maintained for 2.5 hours.

[0013] As a further solution of the present invention: the quenching step also includes, finally, at 150°C

[0014] Quench in -190℃ high temperature special quenching oil for 15 minutes. The quenching oil replacement cycle is every 1000 quenching operations.

[0015] As a further solution of the present invention: in the tempering step, a tempering treatment at 120°C-150°C is required for 8 hours to ensure the internal structural stability and surface hardness of the grinding ball, and the product after the tempering treatment needs to be naturally cooled to room temperature.

[0016] As a further solution of the present invention: during the smelting process, the C content is 3.3-3.6%, and the addition amounts of alloying elements such as Ni, Mo, and V are 0.05-0.1%, 0.05-1.0%, and 0.05-1.0%, respectively.

[0017] As a further solution of the present invention: the pouring step also includes preheating the pouring ladle at a temperature of 800-900°C.

[0018] As a further solution of the present invention: by optimizing the element ratio and heat treatment process parameters during the smelting process, the hardness of the final product reaches HRC 65-66, and the wear is reduced by at least 15% compared with the traditional high chromium ball.

[0019] As a further solution of the present invention: by precisely controlling the pouring temperature and time, internal defects of the casting can be effectively reduced and product quality can be improved.

[0020] Compared with the prior art, the present invention has the following beneficial effects:

[0021] By optimizing the chemical composition, especially increasing the C content to 3.3-3.6%, and adding alloying elements such as Ni, Mo, and V, the hardness of the grinding balls is significantly improved. The hardness of the final product reaches HRC 65-66, which is much higher than the HRC 58-60 of ordinary high chromium balls. Through multi-stage quenching and tempering treatment, the stability of the internal structure of the grinding balls and the consistency of the surface hardness are ensured. The optimized smelting and heat treatment process not only improves the performance of the products, but also shortens the production cycle, improves production efficiency, and reduces production costs. By accurately controlling the pouring temperature and time, as well as the preheating treatment of the casting ladle, the defects such as pores and cracks inside the castings are effectively reduced, and the overall quality of the products is improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 The present invention is a schematic diagram of a method flow of a preparation method of a new type of ultra-high hardness grinding ball for molybdenum ore. DETAILED DESCRIPTION

[0023] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and understandable, the specific implementation modes of the present invention are described in detail below in conjunction with the accompanying drawings.

[0024] In the following description, many specific details are set forth to facilitate a full understanding of the present invention, but the present invention may also be implemented in other ways different from those described herein, and those skilled in the art may make similar generalizations without violating the connotation of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0025] Secondly, the term "one embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The term "in one embodiment" that appears in different places in this specification does not necessarily refer to the same embodiment, nor does it refer to a separate or selective embodiment that is mutually exclusive with other embodiments.

[0026] Example

[0027] See also Figure 1 , is an embodiment of the present invention, which provides a method for preparing a new type of ultra-high hardness grinding ball for molybdenum ore, verifies the effectiveness and superiority of the method for preparing a new type of ultra-high hardness grinding ball for molybdenum ore, and conducts detailed experimental research;

[0028] The experiment was divided into two parts: the prior art group and the invention group. Each group prepared 10 grinding ball samples, including:

[0029] Ingredients:

[0030] The existing technology group: adopts the chemical composition of conventional high chromium balls, specifically C: 2.8-3.2%, Si: ≤1.0%, Mn: 0.5-0.8%, Cr: 12-13%, S: ≤0.05%, P: ≤0.08%, and does not contain alloy elements such as Ni, Mo, and V.

[0031] The group of the present invention adopts the optimized chemical composition, specifically C: 3.3-3.6%, Si: ≤1.2%, Mn: 0.9-1.2%, Cr: 13-14%, S: ≤0.06%, P: ≤0.1%, Ni: 0.05-0.1%, Mo: 0.05-1.0%, V: 0.05-1.0%.

[0032] Smelting:

[0033] Prior art group: putting the above materials into a medium frequency induction furnace and melting them until the temperature reaches 1500°C.

[0034] The present invention group: puts the above materials into a medium frequency induction furnace, smelts them until the temperature reaches above 1550°C, and performs a furnace front chemical composition test to ensure that the proportion of each element meets the requirements.

[0035] deoxidation:

[0036] Existing technology group: Two minutes before the furnace is taken out, 0.2-0.3 kg of aluminum ingots are added for deoxidation treatment per ton of molten metal.

[0037] The group of the present invention: two minutes before the furnace is taken out, 0.3-0.5 kg of aluminum ingots are added per ton of molten metal for deoxidation treatment.

[0038] pouring:

[0039] Existing technology group: the deoxidized liquid is transferred to the transfer ladle for slagging and poured into the pouring ladle, the pouring temperature is controlled between 1450°C and 1470°C, and the pouring time is 10-15 minutes.

[0040] The present invention group: the deoxidized liquid is transferred to the transfer bag to remove the slag, and then poured into the pouring bag, the pouring temperature is controlled between 1480℃-1520℃, the pouring time is 10-20 minutes. The pouring bag is preheated at a temperature of 800-900℃.

[0041] Quenching:

[0042] Prior art group: The semi-finished product is placed on a quenching line and heated in three stages, 500-530°C, 720-750°C and 820-850°C, each stage is maintained for 2 hours, and finally quenched in quenching oil at 140°C-160°C for 10 minutes.

[0043] The present invention group: the semi-finished product is placed on the quenching line, and is heated in four stages in sequence at 520-550℃, 750-780℃, 840-880℃, and 880-920℃, each stage is maintained for 2.5 hours, and finally quenched in a high-temperature special quenching oil at 150℃-190℃ for 15 minutes. The quenching oil is replaced every 1000 quenching operations.

[0044] Tempering:

[0045] Existing technology group: Perform tempering treatment at 110℃-130℃ for 6 hours to ensure the internal structure stability and surface hardness of the grinding ball.

[0046] The group of the present invention: the tempering treatment is carried out at 120°C-150°C for 8 hours to ensure the internal structural stability and surface hardness of the grinding balls. The products after the tempering treatment need to be naturally cooled to room temperature.

[0047] Table: Performance comparison of grinding balls for molybdenum ore:

[0048]

[0049] Tabular data analysis:

[0050] By comparing the data in the above tables, it can be clearly seen that the present invention has significant advantages over the prior art in multiple key performance indicators.

[0051] hardness:

[0052] The hardness of the grinding balls of the present invention reaches HRC 65-66, while the hardness of the grinding balls of the prior art is only HRC 58-60, an increase of 12.5%, indicating that by optimizing the chemical composition and heat treatment process, the present invention significantly improves the hardness of the grinding balls, making them have stronger wear resistance in high-wear environments such as molybdenum mines.

[0053] Wear rate:

[0054] The grinding ball of the present invention has an abrasion rate of 0.0425 g / t, while the grinding ball of the prior art has an abrasion rate of 0.05 g / t, and the abrasion rate is reduced by 15%, which means that the grinding ball of the present invention has less loss during use, longer service life and higher economic benefits.

[0055] tensile strength:

[0056] The tensile strength of the grinding balls of the present invention is 1800 MPa, while the tensile strength of the grinding balls of the prior art is 1600 MPa, an increase of 12.5%. Higher tensile strength means that the grinding balls are less likely to break when subjected to high loads, thereby improving their reliability under complex working conditions.

[0057] In summary, the present invention significantly improves the hardness, wear resistance, tensile strength, elongation, impact toughness and service life of grinding balls for molybdenum mines by optimizing the chemical composition and heat treatment process, while effectively reducing internal defects. It not only solves the problems existing in the prior art, but also demonstrates the great potential and economic value of the present invention in practical applications.

[0058] Importantly, it should be noted that the construction and arrangement of the present application shown in a plurality of different exemplary embodiments are only exemplary. Although only a few embodiments are described in detail in this disclosure, it should be readily understood by those who refer to this disclosure that many modifications are possible (e.g., the size, scale, structure, shape and proportion of various elements, and parameter values ​​(e.g., temperature, pressure, etc.), installation arrangement, use of materials, color, directional changes, etc.) without substantially departing from the novel teachings and advantages of the subject matter described in the application. For example, the element shown as integrally formed can be composed of multiple parts or elements, the position of the element can be inverted or otherwise changed, and the nature or number or position of the discrete element can be changed or changed. Therefore, all such modifications are intended to be included in the scope of the present invention. The order or sequence of any process or method steps can be changed or reordered according to alternative embodiments. In the claims, any "device plus function" clause is intended to cover the structure of performing the function described herein, and is not only structurally equivalent but also equivalent structure. Without departing from the scope of the present invention, other replacements, modifications, changes and omissions can be made in the design, operating conditions and arrangement of the exemplary embodiments. Therefore, the invention is not limited to a specific embodiment, but extends to numerous modifications still falling within the scope of the appended claims.

[0059] Additionally, in order to provide a concise description of exemplary embodiments, all features of an actual embodiment (ie, those features that are not relevant to the best mode presently contemplated for carrying out the invention or those that are not relevant to implementing the invention) may not be described.

[0060] It will be appreciated that in the development of any actual implementation, as in any engineering or design project, numerous implementation-specific decisions may be made. Such a development effort may be complex and time-consuming, but will be a routine task of design, fabrication, and production for those of ordinary skill having the benefit of this disclosure without undue experimentation.

[0061] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention, which should all be included in the scope of the claims of the present invention.

Claims

1. A method for preparing a new type of ultra-high hardness grinding ball for molybdenum ore, characterized in that: The method comprises, Batching, smelting, deoxidation, pouring, quenching and tempering.

2. The method for preparing a new type of ultra-high hardness grinding ball for molybdenum ore according to claim 1, characterized in that: The ingredients include the following elements in percentage by mass: C: 3.3-3.6%, Si: ≤1.2%, Mn: 0.9-1.2%, Cr: 13-14%, S: ≤0.06%, P: ≤0.1%, Ni: 0.05-0.1%, Mo: 0.05-1.0%, V: 0.05-1.0%.

3. The method for preparing a new type of ultra-high hardness grinding ball for molybdenum ore according to claim 1, characterized in that: In the smelting step, the above materials need to be smelted to a temperature above 1550°C.

4. The method for preparing a new type of ultra-high hardness grinding ball for molybdenum ore according to claim 1, characterized in that: In the deoxidation step, 0.3-0.5 kg of aluminum ingots are added per ton of molten metal for deoxidation two minutes before the molten metal is taken out of the furnace.

5. The method for preparing a new type of ultra-high hardness grinding ball for molybdenum ore according to claim 1, characterized in that: In the pouring step, the deoxidized liquid is transferred to a transfer ladle to remove slag and poured into a pouring ladle. The pouring temperature is controlled between 1480° C. and 1520° C., and the pouring time is 10 to 20 minutes.

6. The method for preparing a new type of ultra-high hardness grinding ball for molybdenum ore according to claim 1, characterized in that: In the quenching step, the semi-finished product is placed on a quenching line and heated in four stages, 520-550°C, 750-780°C, 840-880°C and 880-920°C, with each stage being maintained for 2.5 hours.

7. The method for preparing a new type of ultra-high hardness grinding ball for molybdenum ore according to claim 1, characterized in that: The quenching step also includes a final quenching in a high-temperature special quenching oil at 150° C.-190° C. for 15 minutes, and the quenching oil is replaced every 1,000 quenching operations.

8. The method for preparing a new type of ultra-high hardness grinding ball for molybdenum ore according to claim 1, characterized in that: In the tempering step, a tempering treatment at 120° C.-150° C. is required for 8 hours to ensure the internal structural stability and surface hardness of the grinding ball. The product after the tempering treatment needs to be naturally cooled to room temperature.

9. The method for preparing a new type of ultra-high hardness grinding ball for molybdenum ore according to claim 1, characterized in that: During the smelting process, the C content is 3.3-3.6%, and the addition amounts of alloy elements such as Ni, Mo, and V are 0.05-0.1%, 0.05-1.0%, and 0.05-1.0%, respectively.

10. The method for preparing a new type of ultra-high hardness grinding ball for molybdenum ore according to claim 1, characterized in that: The pouring step also includes preheating the pouring ladle at a temperature of 800-900°C.

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