Suzhou CMT Completes Full-Scope Sulfuric Acid Plant Engineering

Suzhou CMT Engineering Co., Ltd has announced the completion of a full-scope sulfuric acid plant turnkey engineering project at its facility in Suzhou, China. This project, which spans process design to handover, is a significant milestone for the company and underscores its commitment to delivering high-efficiency industrial chemical production facilities.

The sulfuric acid plant is designed to produce between 100 and 3,000 tons per day, utilizing a 3+1 or 3+2 Double Contact Double Absorption (DCDA) production train. This setup ensures that the plant can meet the varying demands of its clients, from small-scale operations to large industrial applications. The plant's design incorporates state-of-the-art technology, including the use of refractory-lined combustion furnaces at temperatures between 1,050°C and 1,150°C, which produce clean furnace gases containing 10 to 12 percent sulfur dioxide.

For the pyrite ore processing, the plant employs fluidized-bed roasters operating at temperatures between 850°C and 950°C. This process generates sulfur dioxide gas and high-value iron oxide cinders, providing a dual benefit of sulfuric acid production and iron oxide recovery. The gas from these processes undergoes a rigorous cleaning process, passing through venturi scrubbers, gas cooling towers, and wet electrostatic precipitators. This ensures that the gas is free from dust, arsenic, and acid mist before entering drying towers.

The sulfuric acid production process is further optimized through the use of specialized catalysts and efficient heat recovery systems. Multi-bed converter vessels house four or five catalyst beds packed with vanadium pentoxide (V2O5) and cesium-promoted low-temperature catalysts. Inter-bed gas heat exchangers regulate process gas temperatures between 410°C and 440°C, ensuring that the gas maintains optimal conditions for catalytic conversion. The intermediate absorption stage removes sulfur trioxide gas before the remaining sulfur dioxide returns to the final catalyst pass.

The absorption towers, packed with ceramic saddles, contact process gases counter-currently with 98 percent sulfuric acid, achieving a 99.9 percent absorption efficiency. Specialized silicon alloy metallurgy is used for piping and tower components, ensuring resistance to hot concentrated acid corrosion. The heat recovery system operates at elevated temperatures up to 200°C, generating low-pressure saturated steam directly from the exothermic acid absorption reaction. High-efficiency candle-type fiber bed mist eliminators installed at the absorption tower tops capture sub-micron acid mist droplets with 99.5 percent collection efficiency, protecting downstream ductwork and the ambient atmosphere from acid fallout.

Suzhou CMT Engineering Co., Ltd has partnered with a proven contractor to deliver the project, ensuring compliance with international ASME Section VIII, CE PED pressure equipment directives, and ISO 9001 standards. The company's engineering governance spans hazardous chemical piping, refractory boiler fabrication, and automated plant safety systems. The project is executed under strict welding inspection protocols, with comprehensive factory acceptance testing verifying boiler tube non-destructive ultrasonic examinations, hydraulic seal tests, and emergency shutdown logic before maritime shipment.

Field installation crews manage high-alloy piping spool welding, refractory masonry brick installation, and main blower motor alignment. Standardized quality hold points guarantee that all pressure vessel welds and acid circulation lines pass non-destructive examinations prior to preheating. The phased commissioning governance ensures safe converter catalyst heat-up and continuous 72-hour commercial production runs to verify daily acid output tonnage, overall SO2 conversion efficiency, steam generation per ton of acid, and stack emission compliance.