A standard sand manufacturing method based on a granule lamination crushing technique

Abstract

The application provides a standard sand manufacturing method based on a particle laminating crushing technology, which comprises the following steps: S1, raw material preparation, crushing mineral rocks into large particle materials with a particle size less than 25 mm; S2, using a straight pressure inclined type roller mill, continuously conveying the large particle materials from the horizontal direction to the gap between the roller working surfaces, the pressure between the roller working surfaces is F: 1.5Mp~3.5Mp, and the conveying speed of the large particle materials is less than or equal to the fixed roller linear speed; S3, during the pressing process, the large particle materials are pressed into machine-made standard sand particles by timely controlling the pressure F between the roller working surfaces. The application adopts zero-pressure feeding and particle laminating crushing technology, and the materials form a dispersed small particle layer between the fixed roller and the movable roller, so that the falling dispersed product is less in powder material, close to the average particle size and particle size composition of the standard sand, and suitable for the manufacturing of machine-made standard sand.

Description

Technical Field

[0001] This invention relates to standard sand manufacturing technology, specifically a standard sand production method based on particle lamination and crushing technology. Background Technology

[0002] As is widely known, Xiamen ISO standard sand is the national benchmark material for determining cement strength. China's standard sand source is Pingtan, Fujian, commonly known as Pingtan standard sand. It is natural quartz sea sand with SiO2 > 96%, and is processed from this type of sea sand through washing and screening. However, with the depletion of natural sand, machine-made standard sand produced from sandstone ore has gradually come into focus.

[0003] Standard sand is generally classified into single-grade and multi-grade categories, with each grade having specific particle size requirements. The standard sand proposed by the International Organization for Standardization (ISO R679-68) consists of three grades: coarse, medium, and fine. The particle size distribution of Chinese standard sand is as follows: 1% residue on a sieve for particles larger than 2 mm, 32.23% residue on a sieve for particles larger than 1 mm, 99.8% residue on a sieve for particles larger than 0.08 mm, and 98% SiO2 content in sandstone ore.

[0004] Considering the particle size requirements of standard sand, the crushing and shaping process of manufactured standard sand should be as close as possible to the average particle size and particle size distribution of standard sand for subsequent processing. However, currently, there is a lack of suitable technology and equipment for crushing and shaping of manufactured sand from existing sandstone mines. Some companies use roller press grinding technology to produce standard sand. However, roller press grinding operates under conditions of high pressure on the rollers, low roller speed, and full feed under pressure. The roller press has a high crushing pressure and low roller linear speed, and the material is fed under pressure. During crushing, the material is crushed under high pressure under positive pressure, resulting in a large amount of fine powder in the resulting cake. Other companies use double-roll mills for crushing and sand production. Double-roll mills operate under conditions of low pressure on the rollers, high roller speed, and loose feed, producing a product with less fine powder but a larger particle size. Both of these manufactured standard sand technologies result in material products with average particle size and particle size distribution that differ significantly from the average particle size and particle size distribution of standard sand. Summary of the Invention

[0005] In response to the problems raised in the background technology, the purpose of this invention is to propose a standard sand preparation method based on particle lamination and crushing technology, which solves the problem that the average particle size and particle size composition of the material products obtained during the crushing and shaping of existing mechanical standard sand differ significantly from the average particle size and particle size composition of standard sand.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] A standard sand preparation method based on particle lamination and crushing technology includes the following steps:

[0008] S1. Raw material preparation: crushing the ore into large particles with a particle size of less than 25mm.

[0009] S2. A direct-pressure inclined roller mill is used to continuously convey large particles of material from the horizontal direction to the gap between the working surfaces of the rollers. The pressure between the working surfaces of the rollers is F: 1.5Mp~3.5Mp; the conveying speed of large particles of material is less than or equal to the linear speed of the fixed rollers.

[0010] S3. During the pressing process, the pressure F between the working surfaces of the rollers is controlled in a timely manner to press large particles into standard machine-made sand particles.

[0011] The direct-pressure inclined roller press includes a movable roller and a fixed roller mounted on the frame. The movable roller is located obliquely above the fixed roller, and the axis of the movable roller is parallel to the fixed roller. The movable roller is controlled by a drive cylinder to move its axis along the center line connecting the movable roller and the fixed roller. The fixed roller is matched with a drive motor to drive the rotation of the fixed roller.

[0012] The drive cylinder is a hydraulic cylinder, with one end connected to the roller shaft of the movable roller and the other end fixedly connected to the frame.

[0013] A speed sensor is installed on the shaft of the fixed roller to measure the speed of the fixed roller; a pressure sensor is installed on the shaft of the movable roller to measure the pressure F between the movable roller and the fixed roller.

[0014] In step S2, the linear speed of the fixed roller of the direct-pressure inclined double roller mill is 0.3-0.38 m / s.

[0015] In step S2, the conveying of large particles is carried out by a screw feeder. The screw feeder is set horizontally, and the discharge port of its screw cylinder is provided with a feed trough. The feed trough is a rectangular trough with openings at both ends. One end of the feed trough is connected to the discharge port of the screw cylinder, and the other end is located above the fixed roller. The distance from the bottom surface of the feed trough to the surface of the fixed roller is no more than 20 mm.

[0016] In step S3, the real-time control method for the pressure F between the working surfaces of the rollers is as follows: when F exceeds the threshold range set in step S2, the rotation speed of the fixed roller and the conveying speed of the large particles are adjusted synchronously so that F is always within the threshold range set in step S2.

[0017] The principle of this invention is as follows: ① Zero-pressure feeding of materials to achieve particle layering and crushing. The feeding point is basically at the highest point of the fixed roller. The material falling from the feeder enters the pressure zone of the fixed roller and the movable roller under the drive of the fixed roller. At the same time, the linear speed of the fixed roller is not less than the conveying speed of the feeder. This prevents the material from agglomerating and forming pressure, and facilitates the control of the pressure between the rollers; ② The particle layer is formed under medium pressure, which is between the high pressure of roller press grinding and the low pressure of double roller crushing. After particle layering and crushing, the crushed sandstone mineral material forms a dispersed small particle layer. The crushed material product is close to the average particle size and particle size composition of standard sand, with less powder, achieving the particle size composition required by standard sand.

[0018] The beneficial effects of the present invention are as follows: The present invention adopts zero-pressure feeding and particle layering crushing technology, in which the material forms a dispersed small particle layer between the fixed roller and the moving roller. The product after falling and dispersing has less powdery material and is close to the average particle size and particle size composition of standard sand, which is suitable for the manufacture of machine-made standard sand. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the structure of the device of the present invention.

[0020] Figure 2 for Figure 1 A diagram showing the rotation from a top-down view.

[0021] In the diagram: 1. Fixed roller, 2. Fixed roller support bearing seat, 3. Movable roller, 4. Frame, 5. Movable roller support bearing seat, 7. Material layer, 8. Speed ​​sensor, 9. Drive motor, 10. Pressure sensor, 11. Hydraulic cylinder, 12. Screw feeder, 13. Feed trough. Detailed Implementation

[0022] The technical solution of the present invention will be clearly and completely described below with reference to the accompanying drawings. It should be noted that the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0023] like Figure 1-2 As shown, this invention proposes a standard sand preparation method based on particle lamination and crushing technology, comprising the following steps:

[0024] S1. Raw material preparation: crushing the ore into large particles with a particle size of less than 25mm.

[0025] S2. A direct-pressure inclined roller mill is used to continuously convey large particles of material from the horizontal direction to the gap between the working surfaces of the rollers. The pressure between the working surfaces of the rollers is F: 1.5Mp~3.5Mp; the conveying speed of large particles of material is less than or equal to the linear speed of the fixed rollers.

[0026] S3. During the pressing process, the pressure F between the working surfaces of the rollers is controlled in a timely manner to press large particles into standard machine-made sand particles.

[0027] The direct-pressure inclined double roller machine includes a movable roller 3 and a fixed roller 1 mounted on the frame 4. The movable roller 3 is located obliquely above the fixed roller 1, and the axis of the movable roller 3 is parallel to the fixed roller 1. The movable roller 3 is controlled by a drive cylinder to move its axis along the center line connecting the movable roller 3 and the fixed roller 1. The fixed roller 1 is matched with a drive motor 9 for driving the rotation of the fixed roller 1.

[0028] The drive cylinder is a hydraulic cylinder 11, with one end connected to the roller shaft of the movable roller 3 and the other end fixedly connected to the frame 4.

[0029] A speed sensor 8 is installed on the roller shaft of the fixed roller 1 to measure the speed of the fixed roller 1; a pressure sensor 10 is installed on the roller shaft of the movable roller 3 to measure the pressure F between the movable roller 3 and the fixed roller 1.

[0030] In step S2, the linear speed of the fixed roller 1 of the direct-pressure inclined roller mill is 0.3-0.38 m / s.

[0031] In one embodiment of the present invention, in step S2, the conveying of large particles is carried out by a screw feeder 12. The screw feeder 12 is set horizontally, and its screw cylinder outlet is provided with a feed trough 13 with a horizontal bottom surface. The feed trough 13 is a rectangular trough with openings at both ends. One end of the feed trough is connected to the outlet of the screw cylinder, and the other end is located above the fixed roller 1. The distance from the bottom surface of the feed trough 13 to the roller surface of the fixed roller 1 is not greater than 20 mm.

[0032] In step S3, the real-time control method for the pressure F between the working surfaces of the rollers is as follows: when F exceeds the threshold range set in step S2, the rotation speed of the fixed roller and the conveying speed of the large particles are adjusted synchronously so that F is always within the threshold range set in step S2.

[0033] In one embodiment of the present invention, the direct-pressure inclined roller press includes a fixed roller 1 and a movable roller 3. The fixed roller 1 is mounted on the frame 4, and the roller shaft of the fixed roller 1 is mounted in the fixed roller support bearing seat 2. The fixed roller 1 is connected to the drive motor 9 and rotates under the drive of the drive motor 9. The movable roller 3 is mounted in the movable roller support bearing seat 5 and rotates under the drive of the material particle layer 7 and the fixed roller 1. The movable roller support bearing seat 5 is connected to the frame 4 through a hydraulic cylinder 11. Under the action of the hydraulic cylinder 11, the movable roller support bearing seat 5 drives the movable roller 3 to move inclined along the axis connecting the center of the movable roller 3 and the fixed roller 1 on the slide provided on the frame 4, thereby realizing direct-pressure inclined roller pressing.

[0034] After practical verification, the particle size distribution of the product obtained after pulverization using the particle lamination technology proposed in this patent is shown in Table 1 below:

[0035]

[0036] It is evident that the product obtained by this invention is very close to the particle size distribution of standard sand in existing national standards.

[0037] In summary, the method provided by this invention is suitable for the manufacture of machine-made standard sand.

[0038] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

[0039] The parts of this invention not described in detail are prior art.

Claims

1. A standard sand preparation method based on particle lamination and crushing technology, characterized in that: Includes the following steps: S1. Raw material preparation: crushing the ore into large particles with a particle size of less than 25mm. S2. A direct-pressure inclined roller mill is used to continuously convey large particles of material from the horizontal direction to the gap between the working surfaces of the rollers. The pressure between the working surfaces of the rollers is F: 1.5Mp~3.5Mp. The direct-pressure inclined roller mill includes a movable roller and a fixed roller mounted on the frame. The movable roller is located obliquely above the fixed roller, and the conveying speed of the large particles is less than or equal to the linear speed of the fixed roller. S3. During the pressing process, the pressure F between the working surfaces of the rollers is controlled in a timely manner to press large particles into standard machine-made sand particles. The timely control method of the pressure F between the working surfaces of the rollers is as follows: when F exceeds the threshold range set in step S2, the rotation speed of the fixed roller and the conveying speed of the large particles are adjusted synchronously so that F is always within the threshold range set in step S2. In step S2, the conveying of large particles is carried out by a screw feeder. The screw feeder is set horizontally, and its screw cylinder outlet is provided with a feed trough with a horizontal bottom surface. The feed trough is a rectangular trough with openings at both ends. One end of the feed trough is connected to the outlet of the screw cylinder, and the other end is located above the highest point of the fixed roller. The material falling from the feed trough enters the pressure zone of the fixed roller and the movable roller under the drive of the fixed roller, and the distance from the bottom surface of the feed trough to the surface of the fixed roller is not greater than 20 mm. In step S2, the linear speed of the fixed roller of the direct-pressure inclined double roller mill is 0.3-0.38 m / s.

2. The standard sand preparation method based on particle lamination and crushing technology according to claim 1, characterized in that: The axis of the movable roller is parallel to that of the fixed roller; the movable roller is controlled by a drive cylinder to move its axis along the center line connecting the movable roller and the fixed roller, and the fixed roller is matched with a drive motor to drive the rotation of the fixed roller.

3. The standard sand preparation method based on particle lamination and crushing technology according to claim 2, characterized in that: The drive cylinder is a hydraulic cylinder, with one end connected to the roller shaft of the movable roller and the other end fixedly connected to the frame.

4. The standard sand preparation method based on particle lamination and crushing technology according to claim 2, characterized in that: A speed sensor is installed on the shaft of the fixed roller to measure the speed of the fixed roller; a pressure sensor is installed on the shaft of the movable roller to measure the pressure F between the movable roller and the fixed roller.

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