A number of unique technologies in blast furnace longevity, blast furnace intelligence, high-efficiency hot blast furnace, energy conservation, and environmental protection have reached leading level nationwide and worldwide.
Tackling "persistent problems" to ensure safe and stable production
In November 2021, the hard work of all staff of the Ironmaking Division was finally recognized when the "comprehensive safety and longevity technology of the bottom of the anti-rising and anti-leakage blast furnace" was appraised by Metallurgical Corporation of China as "leading in China".
The sealing of the blast furnace bottom directly affects the life of the blast furnace. Once problems occur, they are not only difficult to deal with, but also cause major safety hazards and economic losses. To overcome the "persistent problem," based on decades of experiences accumulated in the overall design and engineering practice of blast furnaces, MCC Huatian took the lead in proposing a new idea based on the double-layer sealing plate structure at the bottom of the furnace to realize the purpose of rising and leakage prevention for BF bottom and hearth. After continuous research and testing, the "anti-rising and anti-leakage BF hearth and bottom comprehensive safety and long-life technology" stood out and was granted an invention patent. The technology alleviates the structural damage of the BF bottom and hearth caused by the rise of the blast furnace and the resulting leakage of gas from the bottom of the BF, and to a certain extent improves the adaptability of the BF to coke, coal and various ores, and promotes the BF long life, safe production and environmental protection.
The intelligent monitoring system for BF bottom and hearth erosion developed independently by MCC Huatian put into operation
At present, the technology has been applied to more than ten BFes, including Hebei Anfeng, Fujian SISCO, Luoyuan Minguang, Yongfeng Lingang, Hebei Huaxin and Ji'nan Wenfeng. Among them, the No. 2 blast furnace of Hebei Anfeng Iron and Steel has been put into operation since then. Temperature of the BF bottom and hearth has been found normal; hearth and bottom are in good conditions; no curving is found with the BF bottom plate. The application effect is as expected.
New technology to achieve zero emission of bled gas and dust removal ash
The gas bled during the BF production process is a toxic and combustible mixture containing a large amount of carbon monoxide and dust, and the noise and dust generated during its bleeding not only directly pollute the atmosphere but also waste gas energy. Hence, recovery and utilization of gas bled from the material hopper at BF top has become an urgent problem in the industry.
To tackle the problems, MCC Huatian designed a new equalized pressure gas recovery and purification system to solve the problems such as the large pressure difference & instability between the material hopper and the gas pipe network, and pressure impact on the pipe network. Through the application test, the "Blast Furnace Top Equal Pressure Gas Purification and Recycling Technology" can achieve zero emission of bled gas and dust removal ash, and the recycling rate of bled gas can reach 80%–100%, which can efficiently solve the air pollution problem caused by the direct emission of equalized pressure gas and gas ash to the air at the top of the BF.
The PCI shop of Guangxi Fangchenggang Iron and Steel Base undertaken by MCC Huatian in EPC mode
The technology has been authorized for one invention patent and five utility model patents and has been applied to projects of Zibo Iron and Steel, Anshan Baode Iron and Steel, Baowu Ma Steel, Hebei Huaxin, Ji'nan Wenfeng, Fujian Sankang, and Luoyuan Minguang. Compared with the traditional process of bleeding gas directly from the top of the furnace, it can recover millions of cubic meters of gas per year and bring about several million yuan benefits for clients.
Independent research and development to help green development
The traditional PCI process system has shortcomings such as large fluctuations in instantaneous delivery volume and high production costs. MCC Huatian has independently developed a new type of down discharging, uniform dense phase automatic PCI technology to realize one-touch automatic uniform PCI through a unique process design, which solves the problems of low automation, large fluctuation of delivery volume and high delivery cost.
Today, this technology, which has been appraised as "internationally leading" by MCC, has been successfully applied in engineering design projects such as Fangchenggang Steel, Liu Steel, Chang Steel, Hebei Huaxin and Jinnan Steel. The four blast furnaces of Baowu Ma Steel Second Iron General Plant can replace about 1.3 million tons of pulverised coal per year, which can replace about 1.04 million tons of coke and save more than 400 million yuan in iron production costs; the use of concentrated phase conveying can save 50 million standard cubic meters of nitrogen consumption, which can save about 1 million yuan in pulverised coal blowing costs; the use of automatic blowing reduces the number of employees by three-quarters, saving 1.2 million yuan in annual labour costs, and the work intensity is reduced, reducing the secondary pollution of the environment and flue gas emission, with significant economic and environmental benefits.
The main control room of PCI EPC project in Guangxi Fangchenggang Iron and Steel Base