A kind of hard stone crushing system and method

Abstract

The present invention discloses a stubborn stone crushing system and method, which relates to the field of mineral processing. The stubborn stone crushing system includes a high-pressure roller mill, an autogenous mill and a double-layer screen device, wherein the double-layer screen device includes a coarse-grained-grade outlet, a fine-grained-grade outlet and an intermediate-grade outlet; wherein the intermediate-grade outlet is connected to the feed port of the high-pressure roller mill, the outlet of the high-pressure roller mill is connected and returned to the feed port of the double-layer screen device, and the coarse-grained-grade outlet of the double-layer screen device is connected to the feed port of the autogenous mill. The stubborn stone crushing system and method provided by the present invention eliminates the need for pre-crushing of stubborn stones, and the process is simpler; completely eliminates the difficult-to-grind components of stubborn stones in the autogenous mill; ensures full-grade feeding of the high-pressure roller mill, enables the high-pressure roller mill to run smoothly, and greatly improves the roller surface service life of the high-pressure roller mill; can effectively control the maximum feeding grade of the high-pressure roller mill; the entire process occupies a small area while effectively improving the output.

Description

Technical Field

[0001] The present invention relates to the field of mineral processing, and in particular to a rock crushing system and method. Background Art

[0002] The stone is the screened product of the direct discharge product of the autogenous / semi-autogenous grinding. Due to its particle size and hardness, the stone is difficult to handle in the mill, the grinding efficiency is low, and the mill capacity is suppressed. Therefore, the stone crushing system is often set up in the autogenous / semi-autogenous grinding system. The stone crushing system is an important part of the autogenous / semi-autogenous grinding process. At present, the cone crusher is used as the stone crushing equipment in the autogenous / semi-autogenous grinding process, and the crushed product is returned to the autogenous / semi-autogenous grinding mill for re-grinding. The current conventional stone crushing system has the following disadvantages: Traditional stone crushing The process is that the stubborn stone directly enters the stubborn stone crusher for crushing, and the crushed products return to the autogenous / semi-autogenous mill. Because the crushing products of the traditional cone crusher are relatively coarse, a part of the crushed products are intermediate-sized products, which are still within the range of stubborn stone and are difficult to be crushed by other media in the mill. The production capacity of the autogenous / semi-autogenous mill is still not fully released, and the grinding efficiency is low. Moreover, if there are too many intermediate-sized products in the mill, the autogenous / semi-autogenous mill will change from impact-based to grinding-based, making the product particle size too fine and resulting in over-grinding.

[0003] Chinese invention patent, publication number: CN103721823A, publication date: April 16, 2014, discloses a roadside crushing system for autogenous grinding mills. The crushing equipment used in the invention is a crusher, the crushing ratio of the crusher is relatively small, and the crushing method is mechanical crushing. The crusher simply reduces the particle size of the stubborn stone and cannot produce tiny cracks inside the stubborn stone, which is not conducive to re-grinding.

[0004] Chinese utility model patent, publication number: CN205550804U, publication date: September 7, 2016, discloses a new type of self-returning cylindrical screen for a single product. In this utility model, the hardness of the stubborn stone is high, and it is difficult to grind it even if the stubborn stone is returned to the autogenous mill for reprocessing. After a long period of accumulation, the stubborn stone will occupy a large amount of space inside the autogenous mill, resulting in a decrease in the effective volume of the autogenous mill and a decrease in the unit volume processing capacity of the autogenous mill.

[0005] China Utility Model Patent, Publication No.: CN210994673U, Publication Date: July 14, 2020, discloses a rock crushing system. The crushing equipment used in the invention is a cone crusher, which has low crushing efficiency and mechanical crushing, which is not conducive to re-grinding. It also uses eight belt transports, and the process is relatively long.

[0006] Chinese invention patent, publication number: CN110813512A, publication date: February 21, 2020, discloses a high pressure roller mill process with stone bypass for autogenous mill. The invention uses a cylindrical screen for screening, which has low screening efficiency. The high pressure roller mill feeds a single particle size feed, which makes the high pressure roller mill work inefficient and reduces the roller surface service life. Summary of the invention

[0007] The purpose of the present invention is: to address the above-mentioned problems, the present invention provides a stone crushing system and method, so that the stone does not need to be pre-crushed, and the process is simpler; the difficult-to-grind components of the stone in the autogenous mill are completely eliminated; by setting a blind plate, the full-grade feeding of the high-pressure roller mill is guaranteed, the high-pressure roller mill runs smoothly, and the service life of the roller surface of the high-pressure roller mill is greatly improved; the maximum feeding particle size of the high-pressure roller mill can be effectively controlled; the entire process occupies a small area while effectively increasing the output, and has broad application prospects.

[0008] The technical solution adopted by the present invention is as follows:

[0009] A stubborn stone crushing system comprises a high-pressure roller mill, an autogenous mill and a double-layer screen device, wherein the double-layer screen device comprises a coarse particle size outlet, a fine particle size outlet and an intermediate particle size outlet; wherein the intermediate particle size outlet is connected to the feed port of the high-pressure roller mill, the outlet of the high-pressure roller mill is connected to and returned to the feed port of the double-layer screen device, and the coarse particle size outlet of the double-layer screen device is connected to the feed port of the autogenous mill.

[0010] Due to the adoption of the above technical scheme, by connecting the intermediate particle size outlet of the double-layer screen device with the feed port of the high-pressure roller mill, the stubborn stone does not need to be pre-crushed, and can directly enter the high-pressure roller mill through the double-layer screen device for extrusion, the process is simpler, and the problem of difficult crushing of stubborn stone is solved; by connecting the coarse particle size outlet of the double-layer screen device with the feed port of the autogenous mill, only coarse particle size materials can enter the autogenous mill after being screened by the screen of the double-layer screen device, while the intermediate particle size materials cannot enter the autogenous mill, and the difficult-to-grind components of stubborn stone in the autogenous mill are completely eliminated, and the situation of excessive intermediate particle size products inside the autogenous mill, which causes the autogenous mill to change from impact-based to grinding-based, making the product particle size too fine and leading to over-grinding, is avoided. The problems of difficult crushing of stubborn stone and low crushing efficiency of the autogenous mill are solved.

[0011] Furthermore, the discharge port of the autogenous mill is connected to a single-layer screen device, the single-layer screen device comprises a coarse particle outlet and a fine particle outlet, and the coarse particle outlet is connected to and returned to the feed port of the double-layer screen device.

[0012] By adopting the above technical scheme, a part of the stubborn stones that cannot be ground by the autogenous mill are screened out by the single-layer screen device in time, and sent to the high-pressure roller mill for extrusion through the double-layer screen, thereby improving the crushing efficiency of the autogenous mill.

[0013] Furthermore, a crushing circuit is formed between the double-layer screen device and the high-pressure roller mill, and a grinding circuit is formed between the double-layer screen device, the autogenous mill and the single-layer screen device; the crushing circuit and the grinding circuit are connected through the double-layer screen device, so that the stubborn stones generated in the grinding circuit can enter the crushing circuit.

[0014] Due to the adoption of the above technical solution, by connecting the crushing circuit with the grinding circuit, the stubborn stones produced in the grinding circuit can enter the crushing circuit, ensuring that the stubborn stones are not sent into the autogenous grinding mill.

[0015] Furthermore, the double-layer screen device also includes an upper screen and a lower screen, and blind plates are arranged on both sides, in the middle or on one side of the lower screen.

[0016] Due to the adoption of the above technical solution, by setting up a blind plate, part of the material enters the high pressure roller mill directly without being screened by the lower screen, thereby ensuring full-grade feeding of the high pressure roller mill, making the high pressure roller mill run smoothly, and greatly improving the service life of the roller surface of the high pressure roller mill.

[0017] Furthermore, the coarse-grained grade outlet is arranged on the upper screen, the intermediate-grained grade outlet is arranged between the upper screen and the lower screen, the fine-grained grade outlet is arranged under the lower screen, and the grinding circuit and the crushing circuit are connected through the upper screen, so that the stubborn stone part contained in the coarse-grained material in the original ore passes through the coarse-grained grade outlet, the autogenous grinding mill, the coarse-grained grade outlet, the intermediate-grained grade outlet, the high-pressure roller mill and the fine-grained grade outlet in sequence to obtain qualified products that can enter the next stage of operation.

[0018] Due to the adoption of the above technical scheme, in the stubborn stone crushing system, the stubborn stones in the original ore will be directly screened through the upper screen and sent to the high-pressure roller mill from the intermediate particle size outlet. The stubborn stones contained in the coarse particle size materials in the original ore cannot be ground by the autogenous mill and will not return to the autogenous mill after being discharged from the autogenous mill. Qualified products that can enter the next stage of operation are obtained through the coarse particle size outlet, intermediate particle size outlet, high-pressure roller mill and fine particle size outlet on the single-layer screen equipment, thus solving the problem of low crushing efficiency of the autogenous mill.

[0019] Correspondingly, the present invention also discloses a method for crushing stubborn stones, comprising the following steps:

[0020] A. The raw ore enters the double-layer screen equipment for screening. The coarse-grained materials remain on the upper screen and are fed into the autogenous grinding mill through the transport device. The intermediate materials remain on the lower screen and are fed into the high-pressure roller mill through the intermediate particle outlet. The fine-grained materials are screened to the lower screen and enter the next stage of operation as qualified products;

[0021] B. The coarse-grained materials on the upper screen are ground by the autogenous mill and then enter the single-layer screen for screening. The coarse-grained materials remain on the single-layer screen and return to the double-layer screen through the transport device and are screened again with the new raw materials to form a grinding circuit; the fine-grained materials are screened to the bottom of the single-layer screen and enter the next stage of operation as qualified products;

[0022] C. After the intermediate material is rolled by the high-pressure roller mill, it returns to the double-layer screen equipment through the transportation device and is screened again with the new raw materials to form a crushing circuit.

[0023] Due to the adoption of the above technical scheme, the raw ore is screened by the double-layer screen in step A, so that the stubborn stone does not need to be pre-crushed, and it directly passes through the upper screen and enters the high-pressure roller mill through the intermediate particle size outlet for extrusion, the process is simpler, and the problem of difficult crushing of stubborn stone is solved; after screening by the upper screen of the double-layer screen, the intermediate particle size product cannot enter the autogenous mill, and the difficult-to-grind components of stubborn stone in the autogenous mill are completely eliminated, avoiding the situation that the autogenous mill changes from impact-based to grinding-based due to excessive intermediate particle size products inside the autogenous mill, making the product particle size too fine, resulting in over-grinding, and solving the problem of low crushing efficiency of the autogenous mill; in steps A to C, only 3 transportation devices need to be set up, the process is simple, and the entire process occupies a small area while effectively improving the output.

[0024] Furthermore, the grinding circuit in step B and the crushing circuit in step C are connected through the screening operation of the double-layer screen equipment in step A.

[0025] Due to the adoption of the above technical solution, the crushing circuit and the grinding circuit are connected through the screening operation of the double-layer screen equipment in step A, so that the stubborn stones generated in the grinding circuit can enter the crushing circuit, ensuring that the stubborn stones are not sent into the autogenous mill, thereby improving the grinding efficiency of the autogenous mill.

[0026] Furthermore, blind plates are provided on both sides, in the middle or on one side of the lower screen of the double-layer screen equipment in steps A to C, so that part of the material enters the high-pressure roller mill directly without being screened by the lower screen.

[0027] Due to the adoption of the above technical solution, by setting up a blind plate, part of the material enters the high pressure roller mill directly without being screened by the lower screen, thereby ensuring full-grade feeding of the high pressure roller mill, making the high pressure roller mill run smoothly, and greatly improving the service life of the roller surface of the high pressure roller mill.

[0028] Furthermore, in steps A to C, the mesh size of the upper sieve of the double-layer sieve device is 50 mm to 70 mm, and the mesh size of the lower sieve is 6 mm to 12 mm.

[0029] Due to the adoption of the above technical solution, the maximum feed particle size of the high pressure roller mill can be effectively controlled.

[0030] Furthermore, the single-layer sieve mesh size of the single-layer sieve device in step B is 6 mm to 12 mm.

[0031] By adopting the above technical scheme, a part of the stubborn stones that cannot be ground by the autogenous mill are screened out by the single-layer screen device in time, and sent to the high-pressure roller mill for extrusion through the double-layer screen, thereby improving the crushing efficiency of the autogenous mill.

[0032] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are:

[0033] 1. The present invention eliminates the need for pre-crushing of stubborn stones, making the process simpler.

[0034] 2. The present invention completely eliminates the difficult-to-grind component of stubborn stone in the autogenous grinding mill.

[0035] 3. The present invention ensures full-grade feeding of the high-pressure roller mill, makes the high-pressure roller mill run smoothly, and greatly improves the service life of the roller surface of the high-pressure roller mill.

[0036] 4. The present invention can effectively control the maximum feed particle size of the high pressure roller mill.

[0037] 5. The entire process of the present invention occupies a small area and effectively increases the output. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 It is a process flow chart of the stubborn stone crushing method of the present invention;

[0039] Figure 2 It is a schematic diagram of the structure in which blind plates are arranged on both sides of the lower layer of the double-layer screen of the present invention;

[0040] Figure 3 This is a schematic diagram of the structure in which a blind plate is arranged on the right side of the lower layer of the double-layer screen of the present invention;

[0041] Figure 4 It is a structural schematic diagram of a double-layer screen according to the present invention in which a blind plate is arranged on the left side of the lower layer;

[0042] Figure 5 It is a structural schematic diagram of a double-layer screen in which a blind plate is arranged in the middle of the lower layer of the screen according to the present invention. DETAILED DESCRIPTION

[0043] The present invention will be described in detail below in conjunction with the accompanying drawings.

[0044] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0045] Example 1

[0046] A rock crushing system, such as Figure 1-5 As shown, it includes a high-pressure roller mill, an autogenous mill and a double-layer screen device, wherein the double-layer screen device includes a coarse particle size outlet, a fine particle size outlet and an intermediate particle size outlet; wherein the intermediate particle size outlet is connected to the feed port of the high-pressure roller mill, the outlet of the high-pressure roller mill is connected to and returned to the feed port of the double-layer screen device, and the coarse particle size outlet of the double-layer screen device is connected to the feed port of the autogenous mill.

[0047] The discharge port of the autogenous mill is connected to a single-layer screen device, and the single-layer screen device includes a coarse particle outlet and a fine particle outlet, and the coarse particle outlet is connected to and returned to the feed port of the double-layer screen device.

[0048] A crushing circuit is formed between the double-layer screen device and the high-pressure roller mill, and a grinding circuit is formed between the double-layer screen device, the autogenous mill and the single-layer screen device; the crushing circuit and the grinding circuit are connected through the double-layer screen device, so that the stubborn stones generated in the grinding circuit can enter the crushing circuit.

[0049] The double-layer screen device also includes an upper screen and a lower screen, and blind plates are arranged on both sides of the lower screen. The blind plates include but are not limited to being arranged on both sides, in the middle or on one side of the lower layer of the double-layer screen, and any arrangement method that ensures that part of the material does not pass through the lower screen and directly enters the high-pressure roller mill should be considered to fall within the protection scope of the present invention.

[0050] The coarse-grained material outlet is arranged on the upper screen, the intermediate-grained material outlet is arranged between the upper screen and the lower screen, and the fine-grained material outlet is arranged under the lower screen. The grinding circuit and the crushing circuit are connected through the upper screen, so that the stubborn stone part contained in the coarse-grained material in the original ore passes through the coarse-grained material outlet, the autogenous mill, the coarse-grained material outlet, the intermediate-grained material outlet, the high-pressure roller mill and the fine-grained material outlet in sequence to obtain a qualified product that can enter the next stage of operation. The other part of the coarse-grained material in the original ore passes through the coarse-grained material outlet, the autogenous mill and the fine-grained material outlet in sequence to obtain a qualified product that can enter the next stage of operation. A part of the fine-grained material in the original ore directly passes through the fine-grained material outlet to obtain a qualified product that can enter the next stage of operation. The other part, due to the blind plate on the lower screen, passes through the intermediate-grained material outlet, the high-pressure roller mill and the fine-grained material outlet in sequence together with the intermediate material in the original ore to obtain a qualified product that can enter the next stage of operation.

[0051] Accordingly, this embodiment also provides a method for crushing stubborn stones, comprising the following steps:

[0052] A. The full-grade raw ore with the maximum particle size of 100mm enters the double-layer screen equipment for screening. The coarse-grade material of +70mm remains on the upper screen and is fed to the autogenous mill through the transport device. The full-grade intermediate material of -70mm remains on the lower screen and is fed to the high-pressure roller mill through the intermediate particle size outlet. The fine-grade material of -10mm is screened to the lower screen and enters the next stage of operation as a qualified product;

[0053] B. The coarse-grained materials of +70mm on the upper screen are ground by the autogenous mill and then enter the single-layer screen for screening. The coarse-grained materials of +10mm remain on the single-layer screen and return to the double-layer screen through the transport device and are screened again with the new raw materials to form a grinding circuit; the fine-grained materials of -10mm are screened to the bottom of the single-layer screen and enter the next stage of operation as qualified products;

[0054] C. After the intermediate material is rolled by the high-pressure roller mill, it returns to the double-layer screen equipment through the transportation device and is screened again with the new raw materials to form a crushing circuit.

[0055] The transport device includes but is not limited to an elevator, a belt conveyor, etc. Any device that can realize material transportation should be considered to fall within the protection scope of the present invention.

[0056] The grinding circuit in step B and the crushing circuit in step C are connected through the screening operation of the double-layer screen equipment in step A.

[0057] Blind plates are arranged on both sides of the lower screen of the double-layer screen equipment in steps A to C, so that part of the material enters the high-pressure roller mill directly without being screened by the lower screen.

[0058] In steps A to C, the upper screen of the double-layer screen equipment has a mesh size of 70 mm, and the lower screen has a mesh size of 10 mm.

[0059] The single-layer sieve mesh size of the single-layer sieve device in step B is 10 mm.

[0060] The principles and implementation methods of the present invention are described in this article using specific embodiments. The description of the above embodiments is only used to help understand the method and core ideas of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made to the present invention without departing from the principles of the present invention, and these improvements and modifications also fall within the scope of protection of the claims of the present invention.

[0061] In the description of the present invention, it should be noted that the terms "center", "up", "down", "left", "right", "vertical", "horizontal", "inside", "outside", etc. indicate directions or positional relationships based on the directions or positional relationships shown in the accompanying drawings, or are the directions or positional relationships in which the inventive product is usually placed when in use. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore should not be understood as a limitation on the present invention.

[0062] In the description of the present invention, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms "set", "install", "connect", and "connect" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

Claims

1. A rock crushing system, comprising a high pressure roller mill, an autogenous mill and a double-layer screen device, characterized in that: The double-layer screen device includes a coarse particle outlet, a fine particle outlet and an intermediate particle outlet; wherein the intermediate particle outlet is connected to the feed port of the high-pressure roller mill, the outlet of the high-pressure roller mill is connected to and returns to the feed port of the double-layer screen device, and the coarse particle outlet of the double-layer screen device is connected to the feed port of the autogenous mill; the discharge port of the autogenous mill is connected to a single-layer screen device, the single-layer screen device includes a coarse particle outlet and a fine particle outlet, and the coarse particle outlet is connected to and returns to the feed port of the double-layer screen device; the double-layer screen device also includes an upper screen and a lower screen, and the lower screen has two Blind plates are set on the side, middle or one side; part of the fine-grained materials in the original ore directly passes through the fine-grained outlet to obtain qualified products that can enter the next stage of operation; the other part, due to the blocking of the blind plate on the lower screen, passes through the intermediate grade outlet, high-pressure roller mill and fine-grained outlet in sequence together with the intermediate materials in the original ore to obtain qualified products that can enter the next stage of operation; the upper screen of the double-layer screen equipment has a mesh size of 50mm~70mm, and the lower screen has a mesh size of 6mm~12mm; the single-layer screen of the single-layer screen equipment has a mesh size of 6mm~12mm.

2. The rock crushing system according to claim 1, characterized in that: A crushing circuit is formed between the double-layer screen device and the high-pressure roller mill, and a grinding circuit is formed between the double-layer screen device, the autogenous mill and the single-layer screen device; the crushing circuit and the grinding circuit are connected through the double-layer screen device, so that the stubborn stones generated in the grinding circuit can enter the crushing circuit.

3. The rock crushing system according to claim 2, characterized in that: The coarse-grained grade outlet is arranged on the upper screen, the intermediate-grained grade outlet is arranged between the upper screen and the lower screen, the fine-grained grade outlet is arranged under the lower screen, and the grinding circuit is connected with the crushing circuit through the upper screen, so that the stubborn stone part contained in the coarse-grained material in the original ore passes through the coarse-grained grade outlet, the autogenous mill, the coarse-grained grade outlet, the intermediate-grained grade outlet, the high-pressure roller mill and the fine-grained grade outlet in sequence to obtain qualified products that can enter the next stage of operation.

4. A method for crushing stubborn stones, characterized in that: The following steps are involved: A. The raw ore enters the double-layer screen equipment for screening. The coarse-grained materials remain on the upper screen and are fed into the autogenous mill through the transport device. The intermediate materials remain on the lower screen and are fed into the high-pressure roller mill through the intermediate particle outlet. The fine-grained materials are screened to the lower screen and enter the next stage of operation as qualified products. Blind plates are set on both sides, in the middle or on one side of the lower screen of the double-layer screen equipment, so that some materials do not pass through the lower screen and directly enter the high-pressure roller mill; B. The coarse-grained materials on the upper screen are ground by the autogenous mill and then enter the single-layer screen for screening. The coarse-grained materials remain on the single-layer screen and return to the double-layer screen through the transport device and are screened again with the new raw materials to form a grinding circuit; the fine-grained materials are screened to the bottom of the single-layer screen and enter the next stage of operation as qualified products; C. After the intermediate material is rolled by the high-pressure roller mill, it returns to the double-layer screen equipment through the transportation device and is screened again with the new raw materials to form a crushing circuit.

5. The method for crushing stubborn stones according to claim 4, characterized in that: The grinding circuit in step B and the crushing circuit in step C are connected through the screening operation of the double-layer screen equipment in step A.

6. The method for crushing stubborn stones according to claim 4 or 5, characterized in that: In steps A to C, the mesh size of the upper screen of the double-layer screen equipment is 50 mm to 70 mm, and the mesh size of the lower screen is 6 mm to 12 mm.

7. The method for crushing stubborn stones according to claim 4, characterized in that: The single-layer sieve mesh size of the single-layer sieve equipment in step B is 6 mm to 12 mm.

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