Ferrous metal casting; Steel rolling processing; Manufacturing of specialized environmental protection equipment; Technology import and export; Metal structure manufacturing; Sales of specialized equipment for oil refining and chemical production; Goods import and export; Installation services for general mechanical equipment; Sales of specialized environmental protection equipment; Manufacturing of specialized equipment for oil refining and chemical production; Manufacturing of non-metallic mineral products. Licensed items: Production of steel bars for construction; Manufacturing of special equipment; Design of special equipment; Construction engineering design; Installation, modification, and repair of special equipment.