High-frequency screen mesh repairing method

Abstract

The invention relates to the technical field of repairing and reusing of a high-frequency fine screen in preparation equipment, in particular to a high-frequency screen repairing method which comprises the following steps: (a) pretreatment: flushing a replaced high-frequency screen by using a high-pressure water gun, removing surface mineral residues, and then naturally air-drying for more than or equal to 24 hours; (b) damage treatment: flattening the screen mesh, fixing the screen mesh on a tension frame, applying a tensile force greater than or equal to 50N, and trimming the damaged edge until no burr or warped edge exists; (c) gluing and repairing: attaching a polytetrafluoroethylene gasket to the back surface of the damaged area, uniformly coating polyurethane-based transparent flexible glue, and controlling the coating thickness to be 80%-100% of the thickness of the screen; (d) performing permeation treatment: slightly brushing colloid for 20-30 times along the sieve pore direction by using a nylon brush, and promoting permeation under the assistance of 0.2-0.5 MPa compressed airflow. And economical efficiency: the repair cost is less than 50 yuan / piece, and the annual fund is saved by more than 20%.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of high-frequency fine screen mesh repair and reuse in beneficiation equipment, and in particular to a high-frequency screen mesh repair method. BACKGROUND

[0002] A high-frequency fine screen is an important beneficiation equipment in mineral processing engineering, and its main function is to separate minerals of a target particle size from coarse particles to provide a basis for subsequent operations. The material and aperture of a high-frequency screen mesh directly affect the screening effect, and therefore regular inspection and replacement of the screen mesh is an important task, which determines the effect of subsequent beneficiation operations. Due to the material, mineral properties and other factors, the degree of wear and tear of the high-frequency screen mesh is different. Under normal circumstances, the replacement cycle of the high-frequency fine screen mesh is three months. The replaced screen mesh will be damaged to some extent, and some areas may have large holes that cannot be used. In the case where the beneficiation fineness cannot be guaranteed, the screen mesh will be discarded, and the number of replacement will be relatively large. Some screen meshes are damaged to some extent and cannot be used, which is a waste. The high-frequency screen mesh is expensive, with a value of 4-5 thousand yuan per screen mesh. The high-frequency screen mesh cannot be reused, which does not conform to the concept of green mine and energy saving and consumption reduction.

[0003] Therefore, a high-frequency screen mesh repair method is provided. SUMMARY

[0004] The present application aims to provide a high-frequency screen mesh repair method to solve the problems in the background. To achieve the above purpose, the present application provides the following technical solution: a high-frequency screen mesh repair method, comprising the following steps:

[0005] (a) Pretreatment: use a high-pressure water gun to flush the replaced high-frequency screen mesh, and then naturally air dry for ≥24 hours after removing the surface mineral residues;

[0006] (b) Damage treatment: flatten and fix the screen mesh on a tension frame, apply ≥50N tension, and trim the damaged edges to be free of burrs and warping;

[0007] (c) Glue repair: paste a polytetrafluoroethylene gasket on the back of the damaged area, and evenly coat a polyurethane-based transparent soft glue with a thickness of 80%-100% of the thickness of the screen mesh;

[0008] (d) Penetration treatment: lightly brush the glue with a nylon brush along the direction of the screen holes for 20-30 times, and supplement with 0.2MPa-0.5MPa compressed air flow to promote penetration;

[0009] (e) Curing: after initial setting for 10 minutes, remove the gasket and horizontally air dry for ≥4 hours;

[0010] The single point repair area is less than or equal to 50 cm 2 The single screen cumulative repair area is less than or equal to 150 cm 2 .

[0011] Preferably, the viscosity of the polyurethane-based transparent soft glue is 50 cps-70 cps, the main component is a polyurethane prepolymer with an isocyanate group content of 30%-35%, and the hardness after curing is greater than or equal to 80 Shore A.

[0012] Preferably, the thickness of the gasket in step (c) is 1 mm-3 mm, the area is greater than 20%-30% of the maximum repair area allowed by a single point, and the edge is chamfered.

[0013] Preferably, the temperature of the compressed air flow in step (d) is 40°C-50°C, and the angle between the air flow direction and the screen hole axis is 15°-30°.

[0014] An application method for repairing a screen, the repaired screen is used in a ratio of 1:9 to 2:8 with a new screen, if multiple repaired screens are used at one time, the repaired screens should be used separately, and at most 2 repaired screens can be used for one high-frequency screen.

[0015] Preferably, the repaired screen needs to pass through double-stage quality detection before being put into use:

[0016] Primary detection: aperture deviation is less than or equal to 3.5%, laser scanning method is adopted;

[0017] Secondary detection: adhesive bonding strength is greater than or equal to 5 MPa, a tensile testing machine is adopted for testing.

[0018] Preferably, a multi-point tension calibration system is adopted in step (b) to ensure that the flatness error of the screen surface is less than or equal to 0.5 mm / m 2 .

[0019] A high-frequency screen repair system, comprising:

[0020] A tension frame with a force value display and a locking device;

[0021] A glue coating tool set, including a polytetrafluoroethylene gasket, a nylon brush and a constant-temperature air gun;

[0022] A polyurethane soft glue quantitative supply device with an error of ±1 ml;

[0023] An air-drying rack with a horizontal adjustment instrument and a temperature and humidity sensor.

[0024] Preferably, the constant-temperature air gun integrates a PID temperature control module, and the air flow temperature is stably controlled at 40-50°C±2°C.

[0025] Compared with the prior art, the present application has the following beneficial effects:

[0026] 1. Economy: repair cost < 50 yuan per screen, annual savings > 20%;

[0027] 2. Reliability: repair screen life up to 96% of new screen (average 98 days vs 100 days);

[0028] 3. Environmental protection: certified by ISO 14067, carbon emission reduction 8.6 tons / year. BRIEF DESCRIPTION OF DRAWINGS

[0029] In order to more clearly illustrate the specific embodiments of the present application or the technical solutions in the prior art, the drawings needed in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present application, and those skilled in the art can also obtain other drawings according to these drawings without creative labor.

[0030] Figure 1 Flow chart of the high-frequency screen repair method of the present application. DETAILED DESCRIPTION

[0031] The technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, not all. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the present application.

[0032] Please refer to Figure 1 , the present application provides a technical solution:

[0033] A high-frequency screen repair method, comprising the following steps:

[0034] (a) Pretreatment: washing the replaced high-frequency screen with a high-pressure water gun, removing surface mineral residues, and naturally air-drying for ≥24 hours;

[0035] (b) Damage treatment: flattening and fixing the screen on a tension frame, applying ≥50N tension, and trimming the damaged edges to be free of burrs and warping;

[0036] (c) Glue repair: attaching a polytetrafluoroethylene gasket on the back of the damaged area, uniformly applying polyurethane-based transparent soft glue, and controlling the coating thickness to be 80%-100% of the screen thickness;

[0037] (d) Penetration treatment: brushing the glue 20-30 times along the screen hole direction with a nylon brush, and assisting with 0.2MPa-0.5MPa compressed air flow to promote penetration;

[0038] (e) Curing: remove the shim after 10 minutes of initial setting, and air dry horizontally for ≥4 hours;

[0039] wherein the single point repair area is ≤50 cm 2 , and the cumulative repair area of the single screen is ≤150 cm 2 .

[0040] Specifically, the viscosity of the polyurethane-based transparent soft glue is 50-70 cps, and the main component is a polyurethane prepolymer with an isocyanate group content of 30-35%, and the hardness after curing is ≥80 Shore A.

[0041] Specifically, the thickness of the shim in step (c) is 1-3 mm, and the area is greater than 20-30% of the maximum repair area allowed by a single point, and the edges are rounded.

[0042] Specifically, the compressed air temperature in step (d) is 40-50°C, and the angle between the air flow direction and the screen hole axis is 15-30°.

[0043] An application method for repairing screen, the repaired screen is used in a ratio of 1:9 to 2:8 with a new screen, if multiple repaired screens are used at one time, the repaired screens should be used separately, and at most 2 repaired screens can be used for one high-frequency screen.

[0044] Specifically, the repaired screen needs to pass through double-stage quality detection before being put into use:

[0045] Primary detection: aperture deviation ≤3.5%, using laser scanning method;

[0046] Secondary detection: adhesive bonding strength ≥5 MPa, tested by a tensile testing machine.

[0047] Specifically, in step (b), a multi-point tension calibration system is used to ensure that the flatness error of the screen surface is ≤0.5 mm / m 2 .

[0048] A high-frequency screen repair system, comprising:

[0049] A tension frame with a force value display and a locking device;

[0050] A glue coating tool set, including a polytetrafluoroethylene shim, a nylon brush, and a constant temperature air gun;

[0051] A polyurethane soft glue quantitative supply device with an error of ±1 ml;

[0052] An air drying rack with a horizontal adjustment instrument and a temperature and humidity sensor.

[0053] Specifically, the constant temperature air gun integrates a PID temperature control module, and the air flow temperature is stabilized at 40-50°C ±2°C.

[0054] Example 1: Repair process parameter optimization

[0055] Glue layer thickness comparison experiment:

[0056]

[0057]

[0058] Example 2: Industrial application case

[0059] Magnetite concentrator (10 groups of screen machines, annual processing capacity of 3 million tons) implementation data:

[0060] Index Before repair After repair Tons of screen cost 0.158 yuan / ton 0.126 yuan / ton Fineness qualified rate 98.3％ 99.0％ Carbon emission reduction - 8.6 tons / year

[0061] Finally, it should be noted that the above examples are only used to illustrate the technical solutions of the present application, and are not limited thereto; although the present application has been described in detail with reference to the foregoing examples, those skilled in the art should understand that the technical solutions described in the foregoing examples can still be modified, or some or all of the technical features can be replaced by equivalents; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A method for repairing high-frequency screens, characterized in that, Includes the following steps: (a) Pretreatment: The replaced high-frequency screen is rinsed with a high-pressure water gun to remove surface mineral residues and then air-dried for ≥24 hours. (b) Damage handling: Pull the screen flat and fix it on the tension frame, apply a tension of ≥50N, and trim the damaged edges until there are no burrs or curled edges; (c) Adhesive repair: Attach a polytetrafluoroethylene gasket to the back of the damaged area and evenly coat it with polyurethane-based transparent soft adhesive. The coating thickness is controlled at 80%-100% of the screen thickness. (d) Infiltration treatment: Use a nylon brush to gently brush the colloid along the direction of the sieve holes 20-30 times, and supplement with compressed air flow of 0.2MPa-0.5MPa to promote infiltration; (e) Curing: After standing for 10 minutes for initial setting, remove the gasket and air dry horizontally for ≥4 hours; Among them, the single-point repair area is ≤50cm² 2 The cumulative repair area of ​​a single screen is ≤150cm². 2 .

2. The high-frequency screen repair method according to claim 1, characterized in that: The viscosity of the polyurethane-based transparent soft adhesive is 50cps-70cps, and its main component is a polyurethane prepolymer with an isocyanate group content of 30%-35%. After curing, its hardness is ≥80 Shore A.

3. The high-frequency screen repair method according to claim 1, characterized in that: In step (c), the shim thickness is 1mm-3mm, the area is 20%-30% larger than the maximum allowable repair area for a single point, and the edges are rounded.

4. The high-frequency screen repair method according to claim 1, characterized in that: In step (d), the temperature of the compressed airflow is 40℃-50℃, and the airflow direction forms an angle of 15°-30° with the axis of the sieve holes.

5. A method for repairing screens, characterized in that: Repaired screens and new screens should be used in a ratio of 1:9 to 2:

8. If multiple repaired screens are used at once, they should be used separately. A maximum of two repaired screens can be used on the same high-frequency screen.

6. The application method for repairing a screen according to claim 5, characterized in that: The repaired screen must undergo dual-level quality testing before being put into use. Preliminary inspection: Aperture deviation ≤3.5%, using laser scanning method; Secondary testing: Adhesive layer adhesion strength ≥ 5MPa, tested using a tensile testing machine.

7. The high-frequency screen repair method according to claim 1, characterized in that: In step (b), a multi-point tension calibration system is used to ensure that the surface flatness error of the screen is ≤0.5mm / m. 2 .

8. A high-frequency screen repair system, characterized in that, include: Tension frame, with force value display and locking device; Glue application tool set, including PTFE gasket, nylon brush and thermostatic air gun; Polyurethane soft gel metering device, error ±1ml; Drying rack with leveling device and temperature and humidity sensor.

9. A high-frequency screen repair system according to claim 8, characterized in that: The constant temperature air gun integrates a PID temperature control module, and the airflow temperature is kept stable at 40-50℃±2℃.

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