Currently, there is much debate regarding the choice of technology for steel refining. In practice, both the closed-loop blast furnace technology, which processes iron ore into finished steel, and the electric arc furnace (EAF) continuous casting technology have their pros and cons. These factors impact the environment and are also related to efficient energy use and savings.
The steel manufacturing plants in Vietnam are currently employing which technology?
In Vietnam, the majority of steel is produced using the electric arc furnace continuous casting technology. The steel industry in Vietnam initially started with two 50-ton batch Mactanh furnaces at Thai Nguyen Iron and Steel Company and two 5-ton batch BOF furnaces at Gia Sang Steel Rolling Mill. After several years of operation, the company transitioned to electric arc furnaces. Currently, the steel industry in Vietnam exclusively uses electric arc furnace technology, a decision influenced by the limited availability of liquid iron in the country. Recently, several steel billet production plants have been constructed and become operational, such as Hoa Phat, Dinh Vu, Luong Tai, and Van Loi. The electric furnaces in Vietnam are relatively small, except for the Phu My Steel Plant equipped with a new DANARC 70-ton batch electric arc furnace. These furnaces have adopted some advanced techniques such as oxygen and coal injection to create foamy slag, high-capacity power transformers, the use of highly durable refractory materials, and off-center steel tappin
At present, in Vietnam, Hoa Phat is the sole enterprise utilizing the closed-loop blast furnace technology, processing iron ore into finished steel, commonly known as steel production from raw materials
How does the blast furnace technology for steel production from raw materials operate?
A simplified understanding of the steel production process from raw materials involves four steps: Firstly, raw iron ore of various types is taken to a processing plant to remove impurities, increase the iron content, and pelletize it into round-shaped pellets. These iron ore pellets, along with coke (coking coal), limestone, and other additives, are then fed into a blast furnace to be melted into molten iron. The molten iron from the blast furnace is transferred to the refining furnaces of the steel mill to produce billets that meet the required standards. Lastly, the freshly produced billets are immediately sent to the rolling mill to manufacture finished construction steel, completing the closed-loop production cycle.
The most modern steel manufacturing plant in Vietnam?
Built on an area of 132 hectares, the Hoa Phat Steel Complex in Kinh Mon, Hai Duong encompasses an integrated complex, including a raw material processing plant, a coke and thermal power production plant, a steel refining plant, a steel manufacturing plant, and various supporting facilities. The plants within the complex form a closed and synchronized production line, where the output of one plant serves as the input for another. The project is constructed systematically to optimize the value chain in the stages of the metallurgical process. It is considered a comprehensive, synchronized, modern, and the largest-scale investment in Vietnam at present.
In terms of technology, the advantages of the oxygen blast furnace (BOF) technology used by Hoa Phat include its lower electricity consumption compared to the electric arc furnace (EAF) technology commonly employed by the majority of steel enterprises in Vietnam. It is estimated that the electricity consumption per ton of steel produced using BOF technology is 10-15% lower than that of EAF technology. Moreover, in the specific processes of the high furnace and oxygen blast furnace technologies, a significant amount of CO gas is generated. All of this CO gas is meticulously recovered and stored in two tanks with a capacity of 80,000m3 for later use as a combustion fuel, replacing the need for LPG or FO oil in other production stages such as lime calcination for slag conditioning or the production of iron ore pellets. Another improvement is that while most reheating furnaces are typically fueled by FO oil, Hoa Phat utilizes a system of 10 coal gasification furnaces to produce CO gas from anthracite coal as fuel for reheating furnaces in steel rolling mills, resulting in up to a 50% reduction in fuel costs for the steel rolling process.
Trong tương lai, công nghệ luyện thép nào phù hợp với xu thế phát triển trên thế giới?
Tuy nhiên, thế giới hiện đã chuyển sang khuyến khích phát triển năng lượng sạch, sử dụng nguồn nguyên liệu tái tạo với công nghệ tiên tiến và từ đó, xu hướng chuyển dịch ngành luyện thép từ quặng, luyện than cốc… sang các nước đang phát triển có công nghệ luyện thép và cách xử lý môi trường rất hiện đại. Nói cách khác, đã có những thay đổi trong nhận thức khi không còn tối ưu hóa công nghệ luyện thép từ quặng, luyện bằng than cốc.
In the future, which steel refining technology aligns with global development trends? However, the world has now shifted towards promoting the development of clean energy, utilizing renewable resources with advanced technology. Consequently, there is a trend in transitioning the steel industry from ore and coke-based refining to countries with steel refining technologies and environmentally friendly practices that are highly advanced. In other words, there has been a shift in perception away from optimizing steel refining technology based on ore and coke. Additionally, there is an opinion suggesting that it is unnecessary to relentlessly pursue every technology to produce everything from A to Z. The concept of a self-sufficient industry, integrated from sources such as ore extraction to in-depth processing into final products, is no longer suitable. In a world where specialization in production is extremely high, breaking down production into small links and each country relying on its strengths to participate in a portion of that chain, the choice of steel refining technology is no longer overly imperative.
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