On July 11th, the EPC general contracting project for the chemical production renovation of Jiuquan Hongxiang Energy's No. 3 and No. 4 coke ovens, undertaken by Shandong Province Metallurgical Engineering Co., Ltd. (hereinafter referred to as "SDM Design"), successfully completed the full line connection between the old and new systems. All process units were successfully connected and officially put into operation, eight months ahead of the original contract schedule. The overall construction quality, safety control, and renovation effectiveness of the project were highly recognized by the client, Jiuquan Iron and Steel Group, setting multiple optimal records for similar chemical production renovation projects in China.

This project is the first comprehensive gas purification general contracting project designed by SDM, integrating the demolition of old equipment, utilization and renovation of existing equipment, and construction of brand-new units. It covers the construction of drum cooling, benzene elution, oil depot, and supporting utility facilities. As a rare full-scale renovation project of an operational coke oven gas purification plant in China, there is no mature construction experience to draw from. Moreover, the construction area is adjacent to the production plant, with intensive cross-operation and extremely high safety and environmental risks. Coupled with multiple challenges such as the presence of a large amount of flammable and toxic residues from equipment over 20 years old, construction in the extremely cold winter at minus 20 degrees Celsius, and urgent adjustments to the client's ultra-low emission acceptance schedule, the project faces severe challenges throughout its construction process.

Facing numerous challenges and difficulties, the SDM Design Project Department fully leveraged the leading role of party building, established a party member pioneer team, with party members taking the lead in the charge and all members working day and night, taking multiple measures to break through construction bottlenecks. In response to the difficult problem of disposing of high-risk hazardous waste from old equipment, the team formulated a special closed-loop management plan. After five months of hard work, they disposed of more than 5,000 tons of hazardous waste in a standardized manner, completely eliminating safety and environmental hazards at the site. In response to the significant reduction in the construction period, the technical team repeatedly optimized the construction plan, innovatively broke the traditional mode of "demolition before construction", and implemented a parallel construction mode where demolition and construction are carried out simultaneously and procedures are interspersed, successfully overcoming key challenges such as the stagnation of core equipment installation and civil construction.

During the winter construction period, the project department precisely implemented the low-temperature anti-freezing curing process, adopting special measures of "external covering and internal steam insulation". They maintained 24-hour on-site supervision to strictly control construction details, successfully completing the pouring of 6,000 cubic meters of concrete with a 100% pass rate, ensuring zero quality defects in the main structure construction. In response to the issues of limited construction space in the factory area and complex underground pipelines, the team optimized the construction process, promoting a factory prefabrication and on-site assembly model. This efficiently accomplished the construction of over 600 tons of steel structure for the pipeline gallery and over 500 meters of buried pipelines, significantly reducing the construction period and operational risks.

The greatest technological breakthrough of this project lies in the process of connecting old and new systems with pressure sealing without production halt, marking the company's first application of negative pressure system pressure sealing technology. Under the stringent conditions of continuous operation and only load reduction of the coke oven, the project successfully completed the connection of high-risk medium pipelines, including the largest DN2200 crude gas, coke oven gas, and return gas pipelines in China, achieving a safe, environmentally friendly, and efficient seamless switch. This has established a benchmark project for chemical production transformation in the industry, which is the most thorough in transformation, shortest in time, and highest in intrinsic safety level.

The successful commissioning of this project not only lays a solid equipment foundation for the ultra-low emission upgrade and green, low-carbon development of Jiuquan Hongxiang Energy, but also accumulates valuable engineering experience in non-stop production system transformation, high-risk pipeline connection, and complex working condition construction. This has laid a solid foundation for SDM to expand the metallurgical coking transformation market and establish a distinctive general contracting engineering brand.