A rod mill, a rolling sand preparation system and method

Abstract

The present invention belongs to the technical field of preparing rolled sand in construction, and particularly relates to a rod mill, a rolled sand preparation system and a method. Through the improved rod mill and the rolled sand preparation system composed of a raw material washing and screening unit, a first semi-finished product storage bin, a second semi-finished product storage bin, a finished product configuration unit and a finished product storage bin, the preparation of qualified rolled sand is completed through four steps: washing and screening of natural sand materials, operation of the rod mill, finished product configuration and finished product transportation. The present invention simplifies the process flow, saves the production cost of stone powder, and avoids problems such as the generation of production wastewater during the adjustment of the particle size distribution of natural sand and the dust in the process of stone powder processing.

Description

Technical Field

[0001] The present invention belongs to the technical field of preparing rolled sand in construction, and particularly relates to a rod mill, a rolled sand preparation system and a method. Background Art

[0002] Generally, the particle size distribution of natural sand shows that the content of particles with a particle size above 3.0 mm is relatively large, which does not meet the requirements of the fineness modulus of sand for concrete. In engineering, usually, after washing the natural sand to remove mud, wet sand making is carried out with a rod mill, and the particle size of the feed particles is 3.0 - 20.0 mm.

[0003] After being processed by the rod mill, the stone powder generated during the sand making process is removed by the subsequent water washing unit, and the processed sand is then added with stone powder or fly ash and other rolled concrete. The stone powder required in the concrete preparation process is mainly prepared by a powder mill, and the blasting materials during the surrounding rock excavation are often selected and powdered after drying.

[0004] During the wet rod mill sand making process, there are problems such as difficult recovery of stone powder and generation of a large amount of production sewage; while in the stone powder preparation process, there are deficiencies such as serious dust emission and high energy consumption. Summary of the Invention

[0005] The present invention provides a rod mill, a rolled sand preparation system and a method. One of the purposes is to provide a rod mill, a rolled sand preparation system and a method with low energy consumption, low production cost, high production efficiency and environmental protection.

[0006] To achieve the above purpose, the technical solution adopted by the present invention is:

[0007] A rod mill includes at least two pairs of fixed brackets, two pairs of cylinder rotating devices and a rolling cylinder; the two pairs of cylinder rotating devices are respectively connected to the two pairs of fixed brackets, the rolling cylinder is connected to the two pairs of cylinder rotating devices, a cylinder wear-resistant lining is arranged in the rolling cylinder, and further includes a first screw feeder and a second screw feeder for feeding; the first screw feeder and the second screw feeder are respectively connected to both sides of the rolling cylinder, and a rod mill discharge port is arranged at the bottom of the rolling cylinder.

[0008] The first screw feeder and the second screw feeder have exactly the same structure; the first screw feeder includes a feeder cylinder body, an inlet funnel, a screw propelling rod and a screw feeder driving motor; the screw feeder driving motor is connected to one side of the feeder cylinder body, the output end of the screw feeder driving motor is connected to the screw propelling rod through a transmission shaft, and the screw propelling rod is arranged on the central axis in the feeder cylinder body; the inlet funnel is connected to the upper part of the feeder cylinder body, and the other side of the cylinder body of the screw feeder is connected to the input end of the rolling cylinder.

[0009] The discharge port of the rod mill is set at the middle position of the bottom.

[0010] A rolling sand preparation system includes at least one rod mill and also includes

[0011] A raw material washing and screening unit, and the raw material washing and screening unit is connected to two inlets of the rod mill through a conveyor belt;

[0012] A first semi-finished product storage bin, and the first semi-finished product storage bin is connected to the raw material washing and screening unit through a conveyor belt;

[0013] A second semi-finished product storage bin, and the second semi-finished product storage bin is connected to the rod mill discharge port at the lower part of the rod mill

[0014] A finished product configuration unit, and the inlet of the finished product configuration unit is respectively connected to the outlets of the first semi-finished product storage bin and the second semi-finished product storage bin through conveyor belts;

[0015] A finished product storage bin, and the finished product storage bin is connected to the finished product configuration unit through a conveyor belt.

[0016] The described raw material washing and screening unit includes a feeding conveyor belt, a sand washer, a primary vibrating screen and a secondary vibrating screen; the sand washer is connected to the primary vibrating screen through the feeding conveyor belt; the primary vibrating screen is respectively connected to the secondary vibrating screen and the first semi-finished product storage bin through the feeding conveyor belt; the secondary vibrating screen is respectively connected to the first semi-finished product storage bin and the rod mill through the feeding conveyor belt.

[0017] The described finished product configuration unit is a mixing tank and a feeding conveyor belt; the inlet of the mixing tank is respectively connected to the outlets of the first semi-finished product storage bin and the second semi-finished product storage bin through the feeding conveyor belt, and the outlet of the mixing tank is connected to the finished product storage bin through the feeding conveyor belt.

[0018] A method for preparing rolling sand includes the following steps

[0019] Step 1: Washing and screening of natural sand

[0020] Put the natural sand into the raw material washing and screening unit for washing the natural sand. After washing away the soil in the sand, it enters the primary vibrating screen. The screen hole diameter of the primary vibrating screen is 5 mm. A part of the sand with a particle size less than 5 mm enters the first semi-finished product storage bin, and another part of the sand with a particle size less than 5 mm enters the secondary vibrating screen with a screen hole diameter of 3 mm. The remaining part of the secondary vibrating screen with a particle size of 3.0 - 5.0 mm enters the rod mill, and the part with a pore diameter less than 3 mm enters the first semi-finished product storage bin;

[0021] Step 2: Operation of the rod mill

[0022] The rod mill processes the particles conveyed in Step 1. After the incoming particles are processed, they freely fall from the rod mill discharge port to the conveyor belt and are transported to the second semi-finished product storage bin;

[0023] Step 3: Finished product configuration

[0024] Mix the materials in the first semi-finished product storage bin and the second semi-finished product storage bin in the finished product configuration unit;

[0025] Step 4: Finished product transportation

[0026] Transport the finished product configured in Step 3 to the finished product storage bin to complete the preparation of the rolled sand.

[0027] The material fed into the rod mill (3) in Step 2 is controlled at 25 - 30 t / h.

[0028] The mixing ratio of the materials in the first semi-finished product storage bin and the second semi-finished product storage bin in the finished product configuration unit in Step 3 is 1:1 - 1.6.

[0029] Beneficial effects:

[0030] (1) The present invention integrates the production of stone powder and the process of adjusting the particle size distribution of sand for concrete, reducing the production cost of concrete, simplifying the work process, and improving the environmental friendliness of production activities.

[0031] (2) The present invention removes the water washing to remove stone powder, stone powder recovery, vibrating screen separation, and sewage treatment devices at the rear end of the conventional rod mill process, simplifies the process flow, and avoids the generation of production sewage in this process section;

[0032] (3) After the natural sand is washed and screened by the washing and screening unit to remove the soil in the sand, the particles with a particle size less than 5.0 mm are transported to the semi-finished product storage bin unit through the conveyor belt, and some particles with a particle size of 3.0 - 5.0 mm are transported to the processing unit through the conveyor belt, and the adjustment of the sand particle size distribution and the production of stone powder are carried out synchronously in the processing unit;

[0033] (4) The present invention changes the feeding method to screw feeding, without adding water during the feeding process, avoiding the generation of production sewage in this unit and removing the subsequent sewage treatment unit; the stone powder content in the rod mill discharge is stable at 25% - 28%, the water content is 5% - 9%, there is no dust emission at the rod mill discharge port, and the fine particles do not agglomerate into blocks, and the discharge is smooth, avoiding the occurrence of dust emission.

[0034] The above description is only an overview of the technical solution of the present invention. In order to understand the technical means of the present invention more clearly and implement it according to the content of the specification, the following is a detailed description of the preferred embodiment of the present invention in conjunction with the accompanying drawings. Description of the drawings

[0035] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0036] Figure 1 is a schematic structural diagram of the preparation system of the present invention;

[0037] Figure 2 is a schematic structural diagram of the rod mill of the present invention.

[0038] In the figure: 1 - raw material washing and screening unit; 2 - first screw feeder; 3 - rod mill; 4 - rod mill discharge port; 5 - first semi-finished product storage bin; 6 - second screw feeder; 7 - second semi-finished product storage bin; 8 - finished product configuration unit; 9 - finished product storage bin; 10 - fixed support; 11 - cylinder rotating device; 12 - rolling cylinder; 13 - cylinder wear-resistant lining; 14 - screw propulsion rod; 15 - screw feeder drive motor; 16 - feeder cylinder; 17 - inlet funnel. Specific embodiments

[0039] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, rather than all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present invention.

[0040] Embodiment 1:

[0041] According to Figure 1 and Figure 2 A rod mill shown, at least including two pairs of fixed supports 10, two pairs of cylinder rotating devices 11 and a rolling cylinder 12; the two pairs of cylinder rotating devices 11 are respectively connected to the two pairs of fixed supports 10, the rolling cylinder 12 is connected to the two pairs of cylinder rotating devices 11, a cylinder wear-resistant lining 13 is arranged inside the rolling cylinder 12, and it also includes a first screw feeder 2 and a second screw feeder 6 for feeding; the first screw feeder 2 and the second screw feeder 6 are respectively connected to both sides of the rolling cylinder 12, and a rod mill discharge port 4 is arranged at the bottom of the rolling cylinder 12.

[0042] During actual use, the feeding of the rod mill 3 is carried out through the first spiral feeder 2 and the second spiral feeder 6 connected to both sides of the rolling cylinder 12. The first spiral feeder 2 and the second spiral feeder 6 transport the materials conveyed by the conveyor belt from both ends of the rolling cylinder 12 to the inside of the cylinder; the rolling cylinder 12 is mainly responsible for adjusting the particle size distribution of the fed materials; the particles after the adjustment are discharged from the rod mill discharge port 4 located at the bottom of the rolling cylinder 12.

[0043] The fixed bracket 10, the cylinder rotating device 11 and the rolling cylinder 12 of the rod mill 3 are all prior arts. The rolling cylinder 12 is filled with steel rods. After the materials are conveyed into the rod mill through the first spiral feeder 2 and the second spiral feeder 6, the rolling cylinder 12 will lift the steel rods to a certain height and then drop them during the rotation process, generating an impact crushing effect on the material particles, and the grinding effect of the steel rods and the cylinder wear-resistant lining 13 in the rolling cylinder 12 on the materials during the rotation of the cylinder, grinding the materials into finer sand grains or stone powder. The sand materials entering the rod mill 3 carry a certain amount of moisture during the flushing process, and part of the moisture is lost during the conveyor belt transportation process, and finally the surface of the materials entering the rod mill is moist. During the processing process, due to the action of this part of the moisture, the temperature inside the cylinder will not rise rapidly, and the stone powder will not generate dust during the disturbance process, and the discharge is smooth and environmentally friendly.

[0044] The rod mill is respectively provided with the first spiral feeder 2 and the second spiral feeder 6 on both sides of the rolling cylinder 12, which not only makes the feeding smoother, but also has a higher efficiency in further adjusting the particle size distribution of the added materials.

[0045] Embodiment 2:

[0046] According to Figure 1 A rod mill shown in the figure, the difference from Embodiment 1 is that: the first spiral feeder 2 and the second spiral feeder 6 have exactly the same structure; the first spiral feeder 2 includes a feeder cylinder 16, an inlet funnel 17, a spiral propelling rod 14 and a spiral feeder drive motor 15; the spiral feeder drive motor 15 is connected to one side of the feeder cylinder 16, and the output end of the spiral feeder drive motor 15 is connected to the spiral propelling rod 14 through a transmission shaft, and the spiral propelling rod 14 is arranged on the central axis inside the feeder cylinder 16; the inlet funnel 17 is connected to the upper part of the feeder cylinder 16, and the other side of the cylinder 16 of the spiral feeder is connected to the input end of the rolling cylinder 12.

[0047] During actual use, the spiral propelling rod 14, under the drive of the spiral feeder drive motor 15, will push the material particles entering the feeder cylinder 16 from the inlet funnel 17 into the rolling cylinder 12 in a spiral manner for further adjustment of the particle size distribution of the material particles.

[0048] Due to the use of the spiral pushing method, the feeder has a uniform feeding rate and a smooth feeding process, and can efficiently complete the feeding task under the condition of no water flow providing power.

[0049] Embodiment 3:

[0050] According to Figure 1 A rod mill as shown, which is different from Embodiment 1 in that: the discharge port 4 of the rod mill is arranged at the middle position of the bottom.

[0051] During actual use, the discharge port 4 of the rod mill is arranged at the middle position of the bottom, so that the material particles in the rod mill 3 can be fully graded before being discharged, and the discharged material particles can meet the requirements.

[0052] Embodiment 4:

[0053] According to Figure 2 A roller sand preparation system as shown, which at least includes a rod mill, and also includes

[0054] A raw material washing and screening unit 1, and the raw material washing and screening unit 1 is connected to two inlets of the rod mill 3 through a conveyor belt;

[0055] A first semi-finished product storage bin 5, and the first semi-finished product storage bin 5 is connected to the raw material washing and screening unit 1 through a conveyor belt;

[0056] A second semi-finished product storage bin 7, and the second semi-finished product storage bin 7 is connected to the rod mill discharge port 4 at the lower part of the rod mill 3

[0057] A finished product configuration unit 8, and the inlet of the finished product configuration unit 8 is respectively connected to the outlets of the first semi-finished product storage bin 5 and the second semi-finished product storage bin 7 through conveyor belts;

[0058] A finished product storage bin 9, and the finished product storage bin 9 is connected to the finished product configuration unit 8 through a conveyor belt.

[0059] During actual use, the main function of the rod mill is to simultaneously adjust the grading of the incoming material particles and produce stone powder; the feeding method of the rod mill 3 is changed to spiral feeding at both ends, and no water is added during the feeding process, avoiding the generation of production sewage in this unit and removing the subsequent sewage treatment unit; the particle size of the feeding particles of the rod mill 3 in the present invention is changed from the conventional 3.0 - 20.0 mm to 3.0 - 5.0 mm, and the stone powder recovery unit at the discharge port of the rod mill 3 is removed, and the discharge is directly transported to the second semi-finished product storage bin 7; in the present invention, the material in the second semi-finished product storage bin 7 with adjusted particle size and the material in the first semi-finished product 5 after sorting are mixed in the finished product configuration unit 8 according to a preset ratio to produce roller sand that meets the requirements of the stone powder content and sand particle fineness modulus of roller compacted concrete.

[0060] The present invention integrates the production of stone powder with the process of adjusting the particle size distribution of sand for concrete, reducing the production cost of concrete, simplifying the work process, and improving the environmental friendliness of production activities. The present invention removes the water washing and stone powder removal, stone powder recovery, vibrating screen separation, and sewage treatment devices at the rear end of the conventional process rod mill, simplifies the process flow, and avoids the generation of production sewage in this process section; after the natural sand is washed and screened by the raw material washing and screening unit 1 to remove the soil in the sand, the particles with a particle size less than 5.0 mm are transported to the first semi-finished product storage bin 5 through a conveyor belt, and some particles with a particle size of 3.0 - 5.0 mm are transported to the rod mill 3 through a conveyor belt, and the adjustment of sand particle size distribution and the production of stone powder are carried out synchronously in the rod mill 3; the present invention changes the feeding method to screw feeding, without adding water during the feeding process, avoiding the generation of production sewage in this unit and removing the subsequent sewage treatment unit; the stone powder content in the discharge of the rod mill 3 is stable at 25% - 28%, and the water content is 5% - 9%. There is no dust emission at the discharge port 4 of the rod mill, and the fine particles will not agglomerate into blocks, and the discharge is smooth, avoiding the occurrence of dust emission.

[0061] Example Five:

[0062] According to Figure 2 A rolling sand preparation system as shown, which is different from Example Two in that: the raw material washing and screening unit 1 includes a feeding conveyor belt, a sand washer, a first-stage vibrating screen, and a second-stage vibrating screen; the sand washer is connected to the first-stage vibrating screen through the feeding conveyor belt; the first-stage vibrating screen is respectively connected to the second-stage vibrating screen and the first semi-finished product storage bin 5 through the feeding conveyor belt; the second-stage vibrating screen is respectively connected to the first semi-finished product storage bin 5 and the rod mill 3 through the feeding conveyor belt.

[0063] During actual use, the natural sand is washed by the sand washer in the washing and screening unit 1 to remove the soil in the sand and then enters the first-stage vibrating screen. The screen hole diameter of the first-stage vibrating screen is 5 mm. Part of the sand with a particle size less than 5 mm enters the first semi-finished product storage bin 5, and the other part of the sand with a particle size less than 5 mm enters the second-stage vibrating screen with a screen hole diameter of 3 mm. The remaining particles with a particle size of 3.0 - 5.0 mm after screening by the second-stage vibrating screen enter the rod mill 3, and those with a pore diameter less than 3 mm enter the first semi-finished product storage bin 5.

[0064] After the washing and screening by the raw material washing and screening unit 1, not only does the natural sand have a certain moisture content, but also it lays a foundation for the subsequent processing and distribution of materials.

[0065] Example Six:

[0066] According to Figure 2A rolled sand preparation system as shown, which is different from the second embodiment in that: the finished product configuration unit 8 is a mixing tank and a feeding conveyor belt; the inlet of the mixing tank is connected to the outlets of the first semi-finished product storage bin 5 and the second semi-finished product storage bin 7 through the feeding conveyor belt respectively, and the outlet of the mixing tank is connected to the finished product storage bin 9 through the feeding conveyor belt.

[0067] During actual use, the mixing tank mixes the semi-finished materials from the first semi-finished product storage bin 5 and the second semi-finished product storage bin 7 evenly. After homogenization, the finished product is conveyed to the finished product storage bin 9 through the conveyor belt. In specific applications, according to the material quantities in the first semi-finished product storage bin 5 and the second semi-finished product storage bin 7, as well as parameters such as the particle gradation and stone powder content of the finished material, after theoretical calculation by the prior art, the mixing ratio of the materials in the first semi-finished product storage bin 5 and the second semi-finished product storage bin 7 can be flexibly determined to configure the finished material that meets the usage requirements.

[0068] Embodiment Seven:

[0069] A method for preparing rolled sand, comprising the following steps

[0070] Step 1: Washing and screening of natural sand

[0071] Put the natural sand into the raw material washing and screening unit 1 for washing the natural sand. After washing away the mud in the sand, it enters the first-stage vibrating screen. The aperture of the sieve holes of the first-stage vibrating screen is 5 mm. A part of the sand with a particle size less than 5 mm enters the first semi-finished product storage bin 5, and another part of the sand with a particle size less than 5 mm enters the second-stage vibrating screen with a sieve hole aperture of 3 mm. The part with a particle size of 3.0 - 5.0 mm in the residue of the second-stage vibrating screen enters the rod mill 3, and the part with an aperture less than 3 mm enters the first semi-finished product storage bin 5;

[0072] Step 2: Operation of the rod mill 3

[0073] The rod mill 3 processes the particles conveyed in Step 1. After the incoming particles are processed, they freely fall from the discharge port 4 of the rod mill to the conveyor belt and are conveyed to the second semi-finished product storage bin 7;

[0074] Step 3: Finished product configuration

[0075] Mix and homogenize the materials in the first semi-finished product storage bin 5 and the second semi-finished product storage bin 7 in the finished product configuration unit 8;

[0076] Step 4: Finished product conveyance

[0077] Convey the finished product configured in Step 3 to the finished product storage bin 9 to complete the preparation of the rolled sand.

[0078] In actual use, after the natural sand is washed and screened by the washing and screening unit 1 to remove the soil in the sand, it enters the first-stage vibrating screen. The aperture of the sieve holes of the first-stage vibrating screen is 5 mm. A part of the sand with particle size less than 5 mm enters the first semi-finished product storage bin 5, and another part of the sand with particle size less than 5 mm enters the second-stage vibrating screen with a sieve hole aperture of 3 mm. The screened part with particle size of 3.0 - 5.0 mm enters the rod mill 3, and the part with aperture less than 3 mm enters the first semi-finished product storage bin 5. Inside the rolling cylinder 12 of the rod mill 3, the steel rods are lifted to a certain height and then dropped, which has an impact crushing effect on the material particles, and the grinding effect of the steel rods and the cylinder wear-resistant lining 13 inside the rolling cylinder 12 on the material during the rotation of the rolling cylinder 12, grinding the material into finer sand grains or stone powder; the part less than 3.0 mm enters the first semi-finished product storage bin 5. The sand material entering the rod mill 3 has a certain moisture content during the washing process, and part of the moisture is lost during the conveyor belt transportation process, and finally the surface of the material entering the rod mill 3 is wet. Entering the rod mill 3 from the first screw feeder 2 and the second screw feeder 6, the incoming material moisture content is 5% - 9%, the steel rod addition amount of the rod mill 3 is 25% - 35% of the net volume of the rod mill 3. During the startup process of the rod mill 3, the steel rods repeatedly roll the material to change the particle size of the material. After the feed stays in the rod mill 3, it freely falls from the discharge port 4 of the rod mill to the conveyor belt and is transported to the second semi-finished product storage bin 7; when the feed rate is controlled at 25 - 30 t / h, the stone powder content of the rod mill 3 discharge is stable at 25% - 28%, the water content is 5% - 9%, there is no dust emission at the discharge port 4 of the rod mill, and the fine particles will not agglomerate into blocks, and the discharge is smooth; the materials in the first semi-finished product storage bin 5 and the second semi-finished product storage bin 7 are mixed in the finished product configuration unit 8 according to a ratio of 1:1.0 - 1.6 to configure a mixed sand with a stone powder content of 12.5% - 17.2% and a fineness modulus of 2.2 - 2.9, meeting the requirements of roller-compacted concrete.

[0079] Example VIII:

[0080] A method for preparing roller-compacted sand, which is different from Example VII in that: in step two, the material entering the rod mill 3 is controlled at 25 - 30 t / h.

[0081] In actual use, when the feeding rate of the rod mill 3 is controlled at 25 - 30 t / h, the residence time of the particles in the rolling cylinder 12 is 4 - 6 min, the stone powder content of the discharge is 25% - 28%, and the particle fineness modulus is 1.7 - 2.2; while the fineness modulus of the sand grains in the first semi-finished product storage bin 5 is 3.5 - 3.8; it is very easy to mix the materials in the first semi-finished product storage bin 5 with the materials in the second semi-finished product storage bin 7 to configure a roller-compacted sand that meets the requirements of roller-compacted concrete materials.

[0082] Example IX:

[0083] A method for preparing rolled sand, which is different from Example 5 in that: the mixing ratio of the materials in the first semi-finished product storage bin 5 and the second semi-finished product storage bin 7 in the third step in the finished product configuration unit 8 is 1:1 to 1.6.

[0084] During actual use, when the feeding rate of the rod mill 3 is controlled at 25 - 30 t / h, the stone powder content of the discharged material is 25% - 28%, and the particle fineness modulus is 1.7 - 2.2; the fineness modulus of the sand grains in the first semi-finished product storage bin 5 is 3.5 - 3.8. After mixing according to the ratio of the material in the first semi-finished product storage bin 5 to the material in the second semi-finished product storage bin 7 of 1.0:1.0 to 1.6, the stone powder content of the finished product material is 12.5% - 17.2%, and the particle fineness modulus is 2.2 - 2.9, meeting the requirements for sand used in roller-compacted concrete. When producing roller-compacted concrete, no additional admixtures such as stone powder or fly ash are required.

[0085] Example 10:

[0086] This example deals with natural sand from a certain stockyard. After being washed and screened, some 3.0 - 5.0 mm particles enter the rod mill 3 through the first spiral feeder 2 and the second spiral feeder 6; the average moisture content of the sand grains at the first spiral feeder 2 is measured to be 7.4%; after being processed by the rod mill 3, there is no dust at the discharge port 4 of the rod mill and the discharge is smooth; the measured stone powder content of the discharged material is 25.4%; after mixing the semi-finished materials in the first semi-finished product storage bin 5 and the second semi-finished product storage bin 7 in the finished product configuration unit 8 according to a ratio of 1:1, rolled sand with a stone powder content of 12.7% and a fineness modulus of 2.5 is obtained.

[0087] Example 11:

[0088] This example deals with natural sand from a certain stockyard. After being washed and screened, some 3.0 - 5.0 mm particles enter the rod mill 3 through the first spiral feeder 2 and the second spiral feeder 6; the average moisture content of the sand grains at the first spiral feeder 2 is measured to be 6.8%; after being processed by the rod mill 3, there is no dust at the discharge port 4 of the rod mill and the discharge is smooth; the measured stone powder content of the discharged material is 26.1%; after mixing the semi-finished materials in the first semi-finished product storage bin 5 and the second semi-finished product storage bin 7 in the finished product configuration unit 8 according to a ratio of 1:1.1, rolled sand with a stone powder content of 12.4% and a fineness modulus of 2.8 is obtained.

[0089] Example 12:

[0090] This embodiment deals with natural sand from a sand yard. After being washed and screened, some particles with a size of 3.0 - 5.0 mm enter the rod mill 3 through the first screw feeder 2 and the second screw feeder 6. After measurement, the average moisture content of the sand grains at the first screw feeder 2 is 6.9%. After being processed by the rod mill 3, there is no dust emission at the discharge port 4 of the rod mill, and the discharge is smooth. After measurement, the stone powder content of the discharge is 25.5%. In the finished product configuration unit 8, the semi-finished materials in the first semi-finished product storage bin 5 and the second semi-finished product storage bin 7 are mixed and configured in a ratio of 1:1.2 to obtain rolled sand with a stone powder content of 11.6% and a fineness modulus of 2.6.

[0091] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention shall be included within the protection scope of the present invention.

[0092] Without conflict, those skilled in the art can combine the relevant technical features in the above examples according to the actual situation to achieve the corresponding technical effects. The specific combination situations are not elaborated herein one by one.

[0093] It should be noted that all the directional indications (such as up, down, left, right, front, back...) in the embodiments of the present invention are only used to explain the relative position relationship and movement conditions between components in a specific posture (as shown in the drawings). If this specific posture changes, the directional indications will also change accordingly.

[0094] In addition, the descriptions involving "first", "second", etc. in the present invention are only for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include at least one such feature.

[0095] As mentioned above, these are only the preferred embodiments of the present invention. The present invention will not be limited to these embodiments shown herein, but rather to the broadest scope consistent with the principles and novel features disclosed herein. Any simple modifications, equivalent changes, and decorations made to the above embodiments based on the technical essence of the present invention still fall within the scope of the technical solutions of the present invention.

Claims

1. A method for preparing rolled sand, characterized in that, A rolling sand preparation system is adopted, which includes a rod mill; the rod mill at least includes two pairs of fixed brackets (10), two pairs of cylinder rotating devices (11) and a rolling cylinder (12); the two pairs of cylinder rotating devices (11) are respectively connected to the two pairs of fixed brackets (10), the rolling cylinder (12) is connected to the two pairs of cylinder rotating devices (11), a cylinder wear-resistant lining (13) is arranged in the rolling cylinder (12), and a first screw feeder (2) and a second screw feeder (6) for feeding are further included; the first screw feeder (2) and the second screw feeder (6) are respectively connected to both sides of the rolling cylinder (12), a rod mill discharge port (4) is arranged at the middle position of the bottom of the rolling cylinder (12); the first screw feeder (2) and the second screw feeder (6) have exactly the same structure; the first screw feeder (2) includes a feeder cylinder (16), an inlet funnel (17), a screw propelling rod (14) and a screw feeder driving motor (15); the screw feeder driving motor (15) is connected to one side of the feeder cylinder (16), the output end of the screw feeder driving motor (15) is connected to the screw propelling rod (14) through a transmission shaft, and the screw propelling rod (14) is arranged on the central axis in the feeder cylinder (16); the inlet funnel (17) is connected to the upper part of the feeder cylinder (16), and the other side of the cylinder (16) of the screw feeder is connected to the input end of the rolling cylinder (12); a raw material washing and screening unit (1), a first semi-finished product storage bin (5), a second semi-finished product storage bin (7), a finished product configuration unit (8) and a finished product storage bin (9) are further included; the raw material washing and screening unit (1) is connected to two inlets of the rod mill (3) through a conveyor belt; the first semi-finished product storage bin (5) is connected to the raw material washing and screening unit (1) through a conveyor belt; the second semi-finished product storage bin (7) is connected to the rod mill discharge port (4) at the lower part of the rod mill (3) through a conveyor belt; the inlet of the finished product configuration unit (8) is respectively connected to the outlets of the first semi-finished product storage bin (5) and the second semi-finished product storage bin (7) through a conveyor belt; the finished product storage bin (9) is connected to the finished product configuration unit (8) through a conveyor belt; It includes the following steps: Step 1: Washing and screening of natural sand materials Put the natural sand materials into the raw material washing and screening unit (1) for washing the natural sand materials. After washing away the soil in the sand materials, it enters the first-stage vibrating screen. The screen hole diameter of the first-stage vibrating screen is 5 mm. A part of the sand with a particle size less than 5 mm enters the first semi-finished product storage bin (5), and another part of the sand with a particle size less than 5 mm enters the second-stage vibrating screen with a screen hole diameter of 3 mm. The remaining part of the second-stage vibrating screen with a particle size of 3.0 - 5.0 mm enters the rod mill (3), and the part with a pore diameter less than 3 mm enters the first semi-finished product storage bin (5); Step 2: Operation of the rod mill (3) The rod mill (3) processes the particles conveyed in Step 1. After the incoming particles are processed, they freely fall to the conveyor belt from the rod mill discharge port (4) and are conveyed to the second semi-finished product storage bin (7); the materials entering the rod mill (3) are controlled at 25 - 30 t / h; Step 3: Finished product configuration Mix and homogenize the materials in the first semi-finished product storage bin (5) and the second semi-finished product storage bin (7) in the finished product configuration unit (8). Step 4: Finished product transportation Transport the finished product configured in Step 3 to the finished product storage bin (9) to complete the preparation of rolled sand. Realize the synchronous adjustment of sand particle gradation and the production of stone powder in the rod mill (3); no water is added during the spiral feeding process. In the Step 3, the mixing ratio of the materials in the first semi-finished product storage bin (5) and the second semi-finished product storage bin (7) in the finished product configuration unit (8) is 1:1 - 1.6; the stone powder content of the finished product is 12.5% - 17.2%, the particle fineness modulus is 2.2 - 2.9, the stone powder content of the rod mill discharge is 25% - 28%, and the water content is 5% - 9%. When producing roller-compacted concrete, no additional stone powder or fly ash as an admixture is required.

2. The method for preparing rolled sand according to claim 1, characterized in that: The raw material washing and screening unit (1) includes a feeding conveyor belt, a sand washer, a primary vibrating screen, and a secondary vibrating screen; the sand washer is connected to the primary vibrating screen through the feeding conveyor belt; the primary vibrating screen is respectively connected to the secondary vibrating screen and the first semi-finished product storage bin (5) through the feeding conveyor belt; the secondary vibrating screen is respectively connected to the first semi-finished product storage bin (5) and the rod mill (3) through the feeding conveyor belt.

3. The method for preparing rolled sand according to claim 1, characterized in that: The finished product configuration unit (8) is a mixing tank and a feeding conveyor belt; the inlet of the mixing tank is respectively connected to the outlets of the first semi-finished product storage bin (5) and the second semi-finished product storage bin (7) through the feeding conveyor belt, and the outlet of the mixing tank is connected to the finished product storage bin (9) through the feeding conveyor belt.

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