company news about Long-Lasting Anti-Corrosion for Heavy Structural Steel in High-Salinity Mining Environments: Engineering Application of Hot-Dip Galvanizing (HDG) in Salt Lake Extraction Projects

Long-Lasting Anti-Corrosion for Heavy Structural Steel in High-Salinity Mining Environments: Engineering Application of Hot-Dip Galvanizing (HDG) in Salt Lake Extraction Projects

2.1 Corrosion Mechanisms of Multi-Tier Heavy Steel Framing in Salt Lake Regions

In salt lake extraction and mineral processing projects, multi-tier industrial steel frameworks are permanently exposed to high concentrations of chloride ions ($Cl^-$) and high humidity. According to the ISO 12944 standard, these operating conditions are typically classified under C5 (Very High Corrosivity) or CX (Extreme Corrosivity) categories.

Under such severe outdoor conditions, conventional anti-corrosion paint coatings are prone to micro-cracking. This allows salt spray to penetrate the surface and induce electrochemical corrosion of the steel. For multi-tier frames supporting heavy equipment such as large agitation tanks and separation columns, localized corrosion can rapidly reduce the cross-sectional area of structural members, compromising the structural integrity under dynamic loads.

2.2 Parameterized Corrosion Protection Mechanisms of Hot-Dip Galvanizing (HDG)

To guarantee the long-term safety of the multi-level industrial equipment support structures, Hot-Dip Galvanizing (HDG) was designated as the core anti-corrosion technology. The HDG process delivers a metallurgically bonded layer rather than a mere physical barrier.

• Standards and Material Grades: The main structural framing utilizes Q355C/Q355NE grade structural steel (optimized for high strength and low-temperature impact). The silicon (Si) and phosphorus (P) content is strictly regulated to ensure a dense, uniform zinc-iron alloy layer during the reaction.

• Galvanizing Layer Thickness Specifications: In strict compliance with the international ISO 1461 standard, an average zinc layer thickness of ≥ 85 µm is enforced for heavy H-beams and box columns with thickness exceeding 6 mm.

• Dual Protection Mechanism: The outer pure zinc layer blocks salt spray and oxygen. If the structure is scratched during on-site installation, the zinc acts as a sacrificial anode, providing continuous cathodic protection to the exposed steel matrix.

2.3 Fabrication Processes for Ensuring Structural Consistency in Multi-Tier Frames

Applying the HDG process in highly corrosive mining zones demands precision tolerance control in the fabrication workshop. To prevent thermal stress deformation when structural steel is submerged in molten zinc at approximately 450°C, parameterized controls are implemented during manufacturing:

All heavy-load connection joints for the multi-tier frames undergo complete joint penetration (CJP) welding in accordance with AWS D1.1. A 100% ultrasonic testing (UT Class 1 weld) regimen is conducted prior to galvanizing to eradicate internal porosity and cracking. Furthermore, processing vents and drainage holes (typically sized between Φ25 mm and Φ50 mm) are strategically drilled in welded box columns. This guarantees the unobstructed flow of zinc liquid across both internal and external surfaces, eliminating anti-corrosion blind spots and ensuring the absolute structural consistency and reliability of the industrial facility framework.