Asphalt contains sulfides, organic acids and corrosive media. At high storage temperature, acid‑bitumen continuously erodes the steel inner wall of asphalt tanks, resulting in pitting corrosion, rust bulging and lining peeling. Scientific selection of anti‑corrosion lining materials and standardized construction can form a dense isolation layer on the tank wall, block corrosive medium contact with steel substrate, slow down acid‑bitumen erosion and extend the service life of asphalt tanks.

Analyze the corrosion mechanism of asphalt tanks. Sulfur‑containing components and acidic substances in asphalt decompose at high temperature, forming corrosive ions that adhere to the tank wall. Condensed water vapor inside the tank dissolves acidic substances and forms corrosive liquid film. The lining fails due to poor high‑temperature resistance, aging cracking or poor adhesion. Once local lining peels off, the steel plate is directly exposed to acid‑bitumen, and corrosion pits gradually expand. Ordinary epoxy coatings are easy to soften and lose anti‑corrosion performance under long‑term high‑temperature asphalt immersion, which cannot adapt to the working conditions of modified asphalt storage tanks.

Compare the performance of common anti‑corrosion lining materials. High temperature resistant solvent‑free epoxy lining features strong adhesion and compact structure, suitable for medium‑temperature asphalt storage, but it is prone to thermal aging under long‑term ultra‑high temperature. Modified phenolic lining possesses excellent acid resistance and thermal stability, resisting erosion from sulfur‑containing and acidic asphalt, and keeps stable performance under continuous high‑temperature soaking. Polyurethane lining has good wear resistance and flexibility, capable of coping with slight thermal deformation of steel plates, yet its service temperature range needs strict control. Flake glass lining adopts flake overlapping structure, which greatly reduces medium penetration path and effectively prevents acid‑bitumen permeation, ideal for heavily corroded working conditions.

Determine lining materials according to asphalt type and operating temperature. For base asphalt tanks with stable storage temperature, high‑temperature resistant solvent‑free epoxy lining can be selected to balance cost and anti‑corrosion effect. For modified asphalt and high‑sulfur asphalt tanks with strong corrosiveness, glass flake lining or modified phenolic lining is recommended to improve acid resistance. Avoid using ordinary low‑temperature coatings. The maximum continuous service temperature of the lining material must be higher than actual asphalt storage temperature to prevent softening and failure.

Control substrate pretreatment and lining construction quality. Remove rust, oxide scale and oil stains on the steel surface by sandblasting to reach the required roughness, ensure reliable bonding between lining and substrate. Strictly control coating thickness and uniform spraying. Avoid pinholes, sagging and local thin layers during construction. Carry out layered curing, and complete pinhole detection after each layer is formed. The lining at tank bottom, manhole, weld seams and heating pipe joints shall be thickened and reinforced, as these areas are high‑risk corrosion positions.

Formulate operation and maintenance protection specifications. Prevent excessive long‑term overheating storage, high temperature will accelerate the aging of organic lining. Regularly carry out lining inspection, detect cracking, blistering and peeling in advance. Local damaged areas shall be repaired in time to prevent corrosion diffusion. When cleaning tank sludge, avoid mechanical scratching of the anti‑corrosion lining by tools, and adopt low‑impact cleaning methods.

Carry out compatibility test before batch construction. Immerse lining samples in the stored asphalt under simulated operating temperature for long‑time aging test, observe swelling, cracking and peeling phenomena, and verify the stability of anti‑corrosion performance. Establish material selection files for different asphalt working conditions, and optimize lining schemes combined with corrosion inspection data of old tanks.