Case Study: Emergency Repair of Carbonation Resistance and Structural Reinforcement of the Sulfur Pit at Sinopec Shanghai Petrochemical Co., Ltd., Refining Division
Project Name: Structural Repair and Anti-Corrosion Project for the No. 4 Refining Sulfur Pit, Sinopec Shanghai Petrochemical Co., Ltd.
Project Date: 2021
Service Environment: Highly acidic sulfur environment, alternating temperatures, high humidity (Extreme chemical corrosion environment).
01 Site Diagnosis: The Threat of Structural "Cancer"
During inspections in 2021, the sulfur pit exhibited typical symptoms of chemical attack:
Deep Carbonation & Neutralization: Infiltration of hydrogen sulfide and acidic media led to a loss of concrete alkalinity, rendering the protective layer for the reinforcement completely ineffective.
Severe Reinforcement Corrosion: Traditional rust removal methods proved insufficient to completely eliminate rust from micropores, leading to a vicious cycle of "repair & re-corrosion".
Structural Spalling: Extensive areas of concrete became friable, loose, and experienced detachment, posing a serious threat to the operational safety of the Refining Division.
02 Core Technology Application: Safeguarding Structural Integrity with Advanced Science
To address the harsh, highly acidic and alkaline environment of the chemical pit, we implemented two core proprietary technologies:
Technology 1: Acid-Free Rust Conversion Technology (Precision Treatment of Corroded Reinforcement)
Challenge Addressed: Traditional acid pickling or mechanical rust removal is difficult to perform in the confined space of a sulfur pit and carries the risk of residual acid ions.
Technical Advantage: We employed an acid-free rust conversion process. This technology directly transforms loose rust on the steel reinforcement surface into a dense, passivating organic chelated protective film. This method not only eliminates pollution from acid pickling but also fundamentally blocks secondary chemical attack on the reinforcement.
Technology 2: Hyperbranched Nano Concrete Repair Technology (Structural Matrix Restoration)
Challenge Addressed: Ordinary mortars exhibit high permeability, are prone to cracking, and offer poor chemical resistance in aggressive chemical environments.
Technical Advantage: Leveraging the nanoscale permeability of hyperbranched polymers, the repair material deeply fills micro-pores within the concrete, forming a cross-linked network structure.
Superior Impermeability: Significantly increases the matrix density, leaving "no gaps" for aggressive acidic or alkaline media to penetrate.
High Strength & Toughness: Effectively manages thermal stress during sulfur pit operation, preventing repair layer cracking and delamination.
Products Used:
KB-0651 Water-based Rust-resistant & Converting Primer
KB-0652 Water-based Anti-carbonation Penetrating Sealer
KB-0654 Flexible Polyurethane Mastic
KB-0653 Water-based Reactive Anti-carbonation Filler Mastic (Two-component)
03 Construction Process & Demonstration
Thorough Substrate Preparation: Removal of carbonated concrete layer to expose a sound, healthy base.
Acid-Free Rust Conversion Treatment: Application of rust converter to exposed reinforcement, establishing the primary defense layer.
Nano-Repair & Reinforcement: Structural restoration using hyperbranched nano repair materials.
Specialized Anti-Corrosion Topcoat: Application of a high-performance anti-carbonation coating to create a comprehensive composite protection system.
04 Client Value
Extended Lifecycle: Compared to traditional repair methods, the service life of the structure enhanced by this technology is increased by 2-3 times, significantly reducing the enterprise's operational and maintenance costs.
Green & Safe Construction: The acid-free rust conversion technology eliminates the environmental and safety risks associated with using strong acids during construction.
Production Assurance: The efficient execution of this emergency repair ensured the production continuity of Sinopec Shanghai Petrochemical Co., Ltd.'s Refining Division, earning high recognition from the client.
