Stainless Steel Coil Tube for In-Situ Leaching (ISL) Uranium Mining Systems
Product Overview
The Stainless Steel Coil Tube (Product No. 612) manufactured by Wenzhou Jixing Metal Materials Co., Ltd. is a precision-engineered coiled tubular product specifically designed for deployment in In-Situ Leaching (ISL) uranium extraction systems. Unlike conventional straight-pipe configurations, the coil tube geometry enables compact, high-density installation within underground injection and recovery wells, facilitating the automated deployment and retrieval of leaching agent delivery and fluid recovery apparatus in uranium-bearing aquifers.
This product represents a specialized application of stainless steel tubing technology in the nuclear fuel cycle, where corrosion resistance, mechanical integrity, and long-term in-situ durability are paramount. The coil tube is integral to the automatic coil tube device (自动盘管装置) used in modern ISL uranium mining operations, enabling continuous, remotely controlled operation of leaching circuits deep within geological formations.
Material & Properties
The coil tube is fabricated from high-grade austenitic stainless steel, selected for its exceptional resistance to the aggressive chemical environments encountered during uranium in-situ leaching operations. The leaching solutions typically include sulfuric acid (H₂SO₄), hydrogen peroxide (H₂O₂) as an oxidant, and sometimes sodium sulfite (Na₂SO₃) as a reductant, creating a highly corrosive environment that demands superior material performance.
- Primary Material Grades: AISI 316L (UNS S31603), AISI 304L (UNS S30403), and duplex stainless steel (2205/UNS S31803) depending on specific application requirements
- Corrosion Resistance: Superior resistance to pitting and crevice corrosion in acidic, oxidizing environments containing dissolved sulfates, chlorides, and uranium species (UO₂²⁺)
- Mechanical Properties: High tensile strength (≥515 MPa for 316L), elongation ≥40%, providing resistance to mechanical deformation under geological stress and handling loads
- Temperature Range: Operational stability from cryogenic temperatures to +200°C, accommodating thermal gradients within subsurface formations
- Chemical Composition: Carbon ≤0.03% (L-grade), Chromium 16–18%, Nickel 10–14%, Molybdenum 2–3% (for 316L variant), ensuring maximum corrosion resistance and weldability
- Surface Finish: Electropolished or passivated inner surface with Ra ≤0.4 μm to minimize biofouling and facilitate fluid flow
Specifications
| Parameter | Specification | Standard / Reference |
|---|---|---|
| Product Type | Stainless Steel Coil Tube (盘管 / Coiltube) | — |
| Product Number | 612 | — |
| Material Grade | AISI 316L / 304L / 2205 Duplex | ASTM A269 / ASTM A312 |
| Outer Diameter (OD) | 19.05 mm – 88.9 mm (3/4" – 3.5") | ASME B36.19M |
| Wall Thickness | 1.0 mm – 3.0 mm | ASTM A213 |
| Coil Diameter | 500 mm – 2000 mm (customizable) | — |
| Tube Length per Coil | 100 m – 1500 m | — |
| Surface Treatment | Electropolished / Passivated / Pickled | ASTM A967 |
| End Condition | Plain, Beveled, or Threaded (BSPP/BSPT/NPT) | ISO 7 / BS EN 10226 |
| Pressure Rating | Up to 6.0 MPa (operating) | ASME B31.3 |
| Tolerance (OD) | ±0.10 mm – ±0.25 mm | ASTM A213 |
| Straightness | ≤1.5 mm per meter | — |
| Application Environment | ISL Uranium Leaching (H₂SO₄/H₂O₂ systems) | — |
| Manufacturer | Wenzhou Jixing Metal Materials Co., Ltd. | — |
Manufacturing Process
The production of high-performance stainless steel coil tubes for ISL uranium applications follows a rigorous, multi-stage manufacturing process designed to ensure dimensional accuracy, metallurgical integrity, and corrosion resistance:
- Raw Material Selection: Certified stainless steel billets or wire rod from approved mills, with mill test certificates (MTC) verifying chemical composition and mechanical properties conforming to ASTM/AISI specifications.
- Hot Rolling / Extrusion: Initial formation of seamless tube blanks through hot extrusion or hot rolling processes, achieving the required wall thickness and outer diameter with controlled microstructure.
- Pickling & Descaling: Removal of oxide scale formed during hot working through controlled acid pickling (HNO₃/HF blend), restoring the passive chromium oxide layer essential for corrosion resistance.
- Cold Drawing / Cold Drawing & Sizing: Precision reduction of tube dimensions through multi-pass cold drawing over tungsten carbide dies, achieving tight dimensional tolerances and enhanced mechanical properties through strain hardening.
- Intermediate Annealing: Solution annealing at 1050–1150°C followed by controlled water quenching to restore ductility, relieve cold-work stresses, and ensure full solution of carbides (particularly critical for L-grade and duplex steels).
- Coil Winding: Precision winding of the tube into specified coil configurations using automated coiling equipment, maintaining consistent coil diameter, inter-coil spacing, and avoiding kinks or deformation.
- Electropolishing / Passivation: Electrochemical removal of surface contamination and enrichment of the chromium oxide passive film, achieving surface roughness Ra ≤0.4 μm and maximum corrosion resistance.
- Non-Destructive Testing (NDT):strong> 100% eddy current testing for wall thickness verification and surface defect detection; hydrostatic pressure testing per ASTM A269/A312 requirements.
- Packaging & Shipping: Protective wrapping, moisture barriers, and secure bundling to prevent mechanical damage and atmospheric exposure during transit.
Applications
The stainless steel coil tube from Wenzhou Jixing Metal Materials Co., Ltd. finds primary application in the following domains:
- In-Situ Leaching (ISL) Uranium Mining: The primary application involves deployment as the core tubing element in automatic coil tube devices for underground injection and recovery wells. The coiled configuration allows for compact storage and controlled, automated deployment of tubing into uranium-bearing aquifers, where leaching solutions are injected to dissolve uranium minerals (primarily uraninite, UO₂) into solution for subsequent recovery.
- Automated Well Intervention Systems: The coil tube serves as the conduit for delivering leaching reagents (sulfuric acid, hydrogen peroxide) to the ore body and recovering uranium-laden pregnant leach solution (PLS) to the surface, enabling continuous, remotely operated mining without the need for extensive underground infrastructure.
- Groundwater Remediation Systems: Due to its corrosion resistance and deployable coil configuration, the tubing is also suitable for environmental remediation applications requiring subsurface fluid injection and recovery.
- Hydrothermal and Geothermal Applications: The material properties and coil geometry make the product suitable for heat exchange and fluid transport in geothermal energy systems operating under elevated temperature and pressure conditions.
- Chemical Processing Piping: In industrial chemical plants requiring coiled piping for compact heat exchangers, reactor internals, and process loops handling aggressive media.
Quality Certifications
Wenzhou Jixing Metal Materials Co., Ltd. maintains a comprehensive quality management system ensuring product conformity to international standards:
- ISO 9001:2015 — Quality Management System certification covering all manufacturing operations
- ISO 14001:2015 — Environmental Management System certification for sustainable manufacturing practices
- ISO 45001:2018 — Occupational Health and Safety Management System
- Product Standards Compliance: ASTM A269 (Welded Austenitic Stainless Steel Tubing), ASTM A312 (Welded Austenitic Stainless Steel Seamless Tubing), ASTM A213 (Boiler, Heat Exchanger, and Condenser Tubes), ASME B36.19M (Welded and Seamless Wrought Stainless Steel Pipe)
- Nuclear Industry Compliance: Products available with applicable documentation for nuclear fuel cycle applications, including material traceability and radiation resistance verification
- Testing & Inspection: Third-party inspection available per buyer requirements; 100% hydrostatic testing, eddy current testing, and dimensional verification included as standard
- Mill Test Certificates (MTC): Full EN 10204 Type 3.1 certificates provided with each shipment, documenting chemical analysis, mechanical testing, and heat treatment records
Unique Selling Points
- Specialized ISL Application Expertise: Products specifically engineered for the unique demands of in-situ leaching uranium mining, with proven performance in aggressive acidic leachant environments
- Automated Deployment Compatibility: Coil tube geometry optimized for integration with automatic coil tube deployment and retrieval devices, enabling rapid, remote subsurface intervention
- Long-Term In-Situ Durability: L-grade and duplex material options providing extended service life in corrosive subsurface environments, reducing well intervention frequency and operational costs
- Custom Coil Configuration: Flexible manufacturing capability for custom coil diameters, tube lengths, and configurations tailored to specific well geometry and operational requirements
- Complete Traceability: Full material and manufacturing traceability from raw material to finished product, supporting regulatory compliance in the nuclear industry