Recently, Shougang Jingtang’s60,000 Nm³/h low-cost oxygen production projectsuccessfully commissioned itsUnit 4with a one-time startup. The oxygen product is delivered as blast-furnace enrichment air through the blower, marking a new milestone in the industry by pioneering ahybrid oxygen supply model (pre-blast and post-blast mixing) for large-scale blast furnaces.

According to reports, the low-cost oxygen production project of Shougang Jingtang Company commenced construction in early 2022. As one of the comprehensive energy-saving andconsumption-reducing initiatives within the ironmaking system, this project holds significant importance for furtherincreasing the oxygen enrichment rate in blast furnaces, reducing the coke ratio, and cutting carbon emissions.The project includes four sets of the largest domestic 15,000 m3/h (80% oxygen concentration) pressure swing adsorption (PSA) units. For the first time worldwide,permanent magnet motorsandvariable-frequency controlled centrifugal blowers and vacuum pumpshave been applied in a PSA system. Compared with conventional motors and controls, this configuration significantly reduces energy consumption. At the same time, large hydraulic control valves are deployed to improve system stability and reduce the additional cost of blast furnace oxygen enrichment by40%.

At the design stage, Shougang Jingtang carefully compared the operating cost and efficiency differences betweencryogenic and PSA technologies, focusing precisely on the blast furnace’s requirement forlow-purity oxygen enrichment. The PSA process was chosen to avoid the unnecessary high-purity enrichment produced by cryogenic systems. The company also innovatively proposed thepre-and post-blast furnace hybrid oxygen supply concept, leveraging the blast furnace blower to pressurize low-pressure oxygen directly into the furnace. This eliminated the need for downstream oxygen compressors, reduced energy consumption, and avoided cold-air venting caused by post-compression.

The PSA process separates oxygen from air by exploiting the different adsorption selectivity of oxygen and nitrogen on the adsorbent. By cycling between high-pressure adsorption and low-pressure desorption, oxygen is obtained. Compared with cryogenic separation, PSA offers the advantages oflower investment, lower energy consumption, and greater flexibility. The system can start up or shut down within 30 minutes, ensuring synchronized operation during short furnace maintenance periods. In addition, load adjustment is fast and precise, better meeting variable oxygen demand and solving the issue of untimely oxygen supply common in cryogenic processes.

During the project construction, the Energy and Environment Department, responding to leadership directives and proactively intensifying efforts amid a challenging steel market and the company's cost-reduction initiatives, overcame COVID-19-related staff shortages and equipment delays. Through innovative approaches and problem-solving, they resolved industry challenges including thesimultaneous loading of two molecular sieve typesandthe commissioning of the nation's first high-speed permanent magnet synchronous motor with frequency conversion control system—a pioneering endeavor without prior domestic experience. These efforts compressed the schedule, enabling a two-month early commissioning of one unit.

Shougang Jingtang Company announced that it will proceed tooptimize the coordinated operation of pre- and post-blower oxygen enrichment units, tailored to varying oxygen demands under different blast furnace enrichment conditions. The company will simultaneously enhance refined management and risk control during system operation, while exploringstable, efficient, and synergistic operational models.The ultimate goal is tominimize operating costs, achieve peak energy efficiency, and further reduce blast furnace smelting costs, making a positive contribution to sustainable steel production.