Anti-corrosion process for in-situ leaching uranium mine solution conveying pipeline

Abstract

The invention belongs to an anti-corrosion process, and particularly relates to an anti-corrosion process for an in-situ leaching uranium mine solution conveying pipeline. The invention relates to an in-situ leaching uranium mine solution conveying pipeline anti-corrosion process which comprises the following steps: step 1, pretreatment; the method comprises the following steps: 1, pre-treating a pipeline to be subjected to anti-corrosion treatment; preheating a to-be-treated pipeline; 3, forming an anti-corrosion layer; forming an anti-corrosion layer on the surface of the pipeline by using PO powder; 4, surface layer treatment; and the surface of the formed anti-corrosion layer is treated. The corrosion-resistant coating has the remarkable effects that the use temperature is-70 DEG C to + 150 DEG C, and the corrosion-resistant coating has excellent heat resistance, electric energy property and cohesiveness and can meet the corrosion-resistant requirement of the in-situ leaching uranium mine solution conveying pipeline.

Description

Technical Field

[0001] This invention pertains to corrosion protection technology, specifically a corrosion protection technology for pipelines transporting uranium ore leaching solutions. Background Technology

[0002] In-situ leaching mining is one of the main mining methods in my country. The leaching solution is corrosive, and due to limitations imposed by the geological and hydrogeological conditions of the ore deposit, the injection pressure is controlled between 1.1 and 1.3 MPa. The injection pipes are made of carbon steel, stainless steel, and pressure-resistant PE. The Cl- in the groundwater of the ore deposit... - It has a high content, reaching 2.8–3.4 g / L, and is highly corrosive to both carbon steel and stainless steel pipes. During operation, corrosion points frequently occur, causing leaks and subsequently affecting the normal operation of in-situ leaching uranium mines.

[0003] Existing technologies all involve remedial measures after corrosion and leakage occur, without any pre-existing anti-corrosion process steps. Summary of the Invention

[0004] This invention addresses the shortcomings of existing technologies by providing a corrosion protection process for pipelines transporting uranium ore leaching solutions.

[0005] This invention is implemented as follows: a corrosion protection process for pipelines transporting uranium ore leaching solutions, comprising the following steps:

[0006] Step 1: Preprocessing

[0007] Pre-treatment is performed on pipelines that require corrosion protection.

[0008] Step 2: Preheating

[0009] Preheat the pipeline to be treated;

[0010] Step 3: Forming an anti-corrosion layer

[0011] PO powder is used to form an anti-corrosion layer on the pipe surface;

[0012] Step 4: Surface treatment

[0013] The surface of the formed anti-corrosion layer is treated.

[0014] The corrosion protection process for a pipeline transporting uranium ore leaching solution, as described above, includes a pretreatment process in step one where the pipeline surface is free of slag or burrs, the weld is smooth, and there are no undercuts, weld beads, cracks, arc craters, surface pores, or spatter. The above standards are based on visual inspection.

[0015] In the corrosion protection process for a uranium ore leaching solution transport pipeline described above, in step one, after the weld inspection is qualified, the oxide scale and impurities inside the pipe are wiped clean with a large cloth or cotton cloth.

[0016] In the above-described anti-corrosion process for a pipeline transporting uranium ore leaching solution, in step two, the pipeline is heated and the anti-corrosion components are slowly rotated to ensure uniform heating of the components, with the temperature controlled between 180°C and 200°C.

[0017] In the corrosion protection process for a pipeline transporting uranium ore leaching solution described above, in step three, PO powder is sprinkled into the corrosion-resistant components. The components rotate slowly on a roller to ensure uniform flow and cooling of the PO powder, forming a lining. The PO powder is evenly spread on the inner wall of the pipe fittings, flanges, and the interface between the flanges and pipe fittings. The PO powder thickness is controlled between 0.6 and 1.0 mm.

[0018] In the corrosion protection process for a uranium ore leaching solution transport pipeline described above, in step four, an electric spark detector is used for inspection. If the inspection is qualified, the subsequent steps are performed. If the inspection is unqualified, step four is repeated until the inspection is qualified.

[0019] In the above-described anti-corrosion process for a pipeline transporting uranium ore leaching solution, in step four, after the pipeline passes inspection with an electric spark tester, it is painted after cooling to room temperature. The painted pipeline is the product after the anti-corrosion process is completed.

[0020] The significant advantages of this invention are: it has an operating temperature range of -70℃ to +150℃, excellent heat resistance, electrical properties, and adhesion, and can meet the corrosion protection requirements of pipelines transporting uranium ore leaching solutions. Detailed Implementation

[0021] A corrosion protection process for pipelines transporting uranium leaching solutions is disclosed. This process targets pipelines transporting uranium leaching solutions with high mineralization, high chloride, and high sulfate content, requiring a certain pressure resistance. The PO lining corrosion protection process involves firmly bonding PO powder (pipe-grade HQ001 modified polyethylene powder produced by Dongguan Huaqing Plastics Co., Ltd.) to the surface of a metal structure (steel mesh is required for DN≥200mm) through rotary heating, creating a steel-plastic integrated composite corrosion protection process. The technical solution of this invention includes the following steps:

[0022] Step 1: Cut the steel pipe to the designed dimensions. After cutting, clean the slag or burrs from the cut.

[0023] Step 2: Weld by manual arc welding. The weld must not have undercut, weld beads, cracks, arc craters, surface porosity, or spatter.

[0024] Step 3: The weld seams inside the pipe should be ground smooth and not concave. Repair welding may be necessary if required. After grinding, wipe the inside of the pipe clean with a large cloth or cotton cloth to remove oxide scale and impurities. Sandblasting can be performed if available.

[0025] Step 4: Burn the component to be anti-corrosive with the flame ejected by a gas gun. Slowly rotate the anti-corrosive component to make the pipe fitting evenly heated, and control the temperature at 180°C to 200°C, which can be measured by an infrared thermometer.

[0026] Step 5: Sprinkle PO powder onto the anti-corrosive component. The anti-corrosive component rotates slowly on the roller rack to make the PO powder flow evenly and cool to form a lining. The PO powder is evenly spread on the inner wall of the pipe fitting, the flange, and the interface between the flange and the pipe fitting. The thickness of the lined PO is generally controlled at 0.6 - 1.0 mm. When the PO powder in the flange hole has not completely solidified, remove the PO block in the flange hole with a screw or iron rod slightly smaller than the flange hole.

[0027] Step 6: After the PO anti-corrosion is completed, the inner lining of the pipe fitting should be flat, smooth, and without obvious unevenness. The corners should have a smooth transition. The pipe fitting after anti-corrosion treatment is strictly inspected with an electric spark detector. During the inspection, the probe should touch the PO and move slowly. If no electric spark appears or no alarm sound is heard during the movement, it is considered that the inspection of the pinholes in the hot rotational molding layer is qualified; otherwise, secondary anti-corrosion should be carried out on the alarm points.

[0028] Step 7: Paint the surface of the anti-corrosive component after it cools, and make marks on the anti-corrosive component according to production needs.

[0029] The features of the present invention are as follows: In the working pressure range of 1.10 - 1.30 MPa, the pH range of 5.0 - 7.5, and the chloride ion concentration of 2.8 - 3.4 g / L working condition environment, ordinary stainless steel valves and pipe fittings have all shown corrosion phenomena. The solution conveying pipelines, distributors, and each branch pipe after being lined with PO for anti-corrosion are all in good operating conditions.

[0030] The PO lining process for steel has simple operation, wide application range, good anti-corrosion effect, can be put into production use in a timely manner, and has strong economic benefits.

[0031] An anti-corrosion process for the solution conveying pipelines in in-situ leaching uranium mines is also described in detail in the embodiments of the present invention. The above embodiments are the optimal examples of the anti-corrosion process for the solution conveying pipelines in in-situ leaching uranium mines. However, under the anti-corrosion treatment conditions of different types of leaching solutions, the control parameters can vary without departing from the purpose of the present invention. Any modifications, equivalent replacements, and improvements made within the spirit and principle of the invention shall fall within the protection scope of the present invention patent.

Claims

1. A corrosion protection process for pipelines transporting uranium ore leaching solutions, characterized in that, Includes the following steps: Step 1: Preprocessing Pre-treatment is performed on pipelines that require corrosion protection. Step 2: Preheating Preheat the pipeline to be treated; Step 3: Forming an anti-corrosion layer PO powder is used to form an anti-corrosion layer on the pipe surface; Step 4: Surface treatment The surface of the formed anti-corrosion layer is treated.

2. The corrosion protection process for a pipeline transporting uranium ore leaching solution as described in claim 1, characterized in that: In step one, the pretreatment is based on the premise that the pipe surface is free of slag or burrs, the weld is smooth, and there are no undercuts, weld beads, cracks, arc craters, surface pores, or spatter. The above standards are subject to visual inspection.

3. The corrosion protection process for a pipeline transporting uranium ore leaching solution as described in claim 2, characterized in that: In step one, after the weld inspection is qualified, the oxide scale and impurities inside the pipe are wiped clean with a large cloth or cotton cloth.

4. The corrosion protection process for a pipeline transporting uranium ore leaching solution as described in claim 3, characterized in that: In step two, the pipe is heated and the anti-corrosion parts are slowly rotated to ensure that the pipe is heated evenly, with the temperature controlled between 180℃ and 200℃.

5. The corrosion protection process for a pipeline transporting uranium ore leaching solution as described in claim 4, characterized in that: In step three, PO powder is sprinkled into the anti-corrosion parts, which then rotate slowly on a roller to ensure uniform flow and cooling of the PO powder, forming a lining. The PO powder is evenly spread on the inner wall of the pipe fittings, flanges, and the interface between the flanges and pipe fittings. The PO powder thickness is controlled between 0.6 and 1.0 mm.

6. The corrosion protection process for a pipeline transporting uranium ore leaching solution as described in claim 5, characterized in that: In step four, an electric spark detector is used for inspection. If the inspection is qualified, the subsequent steps are performed. If the inspection is unqualified, step four is repeated until the inspection is qualified.

7. The corrosion protection process for a pipeline transporting uranium ore leaching solution as described in claim 6, characterized in that: In step four, after the pipeline passes the inspection with an electric spark tester, it is painted after cooling to room temperature. The painted pipeline is the product after the anti-corrosion process is completed.