Text/Xiang Zhongyong
September 18 this year marks the 30th anniversary of Cai Bo's death, and his life is worth commemorating. In particular, his technical ideas for strengthening blast furnace production are in line with the requirements of the current national carbon peaking and carbon neutrality major strategic decisions. As early as 1955, at the National Blast Furnace Production Technology Conference, Cai Bo proposed in the report "On Strengthening the Production of Angang Blast Furnace": "Reducing the coke ratio is the main way to strengthen the blast furnace production, but this does not mean that the strength can be ignored." This simply means that the intensity should be increased without raising the focal ratio ... It should be the future task of ANGANG Steel. "The steel industry accounts for about 17% of the country's total carbon emissions, while ironmaking accounts for about 90% of the steel industry's total carbon emissions. In 2019, China's pig iron production accounted for about 63% of the world's pig iron production. According to this estimate, the carbon emissions of China's ironmaking industry exceed half of the total carbon emissions of the world's steel industry. Therefore, it is of special significance to commemorate Cai Bo today, when carbon emissions are valued.
Cai Bo was the son of revolutionary martyr Cai Hesen and Xiang Jingyu, who went to the Soviet Union at the age of 15 to study, graduated from the Moscow Iron and Steel Institute, and came to Angang Steel after returning to China with Liu Shaoqi in 1949, serving as the director of the Angang Iron and Steel Works, which had more than half of the country's iron production at that time, and was the youngest factory and mine director in New China. At that time, angang steel raw material conditions are poor, backward equipment, Cai Bo adhere to everything from the reality, seeking truth from facts of the scientific attitude, to maximize the wisdom of people, learn from foreign experience, and combined with the specific reality of our country, so that the blast furnace production in adverse conditions to reach the best level, and the formation of China's characteristics of the blast furnace operation technology, especially he put forward the "comprehensive strengthening of blast furnace operation" thesis, has a profound impact on the sustainable development of China's steel industry.
learn and create advanced technologies,
Create "Angang Mode"
◀ Group photo of some employees of the former Anshan Black Metallurgical Design Institute. (Photographed in 1955)
While absorbing a large number of foreign advanced technologies, Cai Bo has created his own new technologies through continuous improvement.
Angang attaches great importance to raw material work. Angang Began to produce sinters in 1950, changing the mode of producing clumps from the tunnel kilns left over from Japan and The Use of Simple Gantry Cranes to Mix Iron Ore from 1952 onwards. Over the years, ANSCO has been working hard to improve the grade of concentrate and improve the quality of sinter.
Before the founding of New China, Angang Steel could not smelt iron for steelmaking, and the blast furnace molten iron was first pre-refined in the steelmaking plant. Under the leadership of Cai Bo, in 1951, Angang Steel successfully smelted 0.6% to 0.9% of the steel water containing silicon, and since then, the steel output has increased by about 50%.
In 1951, Angang Steel put forward the technical requirements of attaching importance to blowing speed and blowing kinetic energy, and after 10 years of efforts, developed into a systematic "lower adjustment" operating method, and established a set of guiding "lower adjustment procedures", which played an important role in the long-term stable and anterograde of the blast furnace. Today, the lower adjustment method generally followed by the blast furnace production of various steel enterprises in China is mostly evolved and developed by the angang steel regulations.
In 1954, Angang Steel changed the slagging system of traditional smelting cast iron, the slag changed from alkaline slag to acid slag, and the blast furnace smelting technology reached a new height.
From 1956 to 1957, when the national steel industry prevailed in the "only Soviet expert theory", Cai Bo carefully and strictly weighed and went against the tide and implemented measures to increase the temperature of dry air.
In 1956, Angang Steel implemented high-pressure operation on the tank loading equipment of the No. 9 blast furnace. These important blast furnace operation technologies have been rapidly promoted throughout the country and are a model for China to absorb foreign technologies and improve them. This experience has become a successful precedent for us to introduce foreign technology in the future and integrate foreign technology into domestic technology.
Strengthen the operation of the blast furnace and ensure the forward flow of the blast furnace,
The One-Tree "Angang School"
◀ Angang Steel's three major projects are an angang steel rolling mill. (File photo)
Cai Bo is constantly seeking to comprehensively strengthen the operation of the blast furnace, and he not only pays attention to improving the smelting intensity, but also emphasizes reducing consumption. His "medium smelting strength" ironmaking production policy was once understood and even criticized. Anyone who has read pavlov's discussion on the residence time of the furnace in the blast furnace by pavlov, an academician of the former Soviet Academy of Sciences, knows that excessively reinforced blast furnace smelting, the charge and gas do not have enough residence time or contact time in the furnace, and the reduction reaction stays at a low level, which inevitably leads to an increase in the coke ratio or fuel ratio. However, Angang Attaches great importance to the problem of smelting cycle, emphasizing the improvement of smelting intensity on the basis of adapting to the conditions of raw materials; under the principle of not improving the coke ratio, strive to improve the comprehensive benefits of output and prolong life, which is the essence of medium smelting strength ironmaking technology. This is also the reason why some developed countries still adhere to medium-intensity smelting operations despite good raw material conditions.
In 1958, China's annual output of steel was 5.35 million tons, the country urgently needed steel, under the guidance of the policy of "giving priority to the development of heavy industry", put forward the "big steel", requiring that steel production be doubled in 1959 to 10.7 million tons. In order to achieve immediate results and disregard objective conditions, some people put forward the ironmaking production policy of "taking the wind as the guideline", shouted out the slogan of "if there is wind, there is iron", disregarded the mature crops in the field, mobilized all the staff to go up to the mountain to smelt iron, smash pots, cut down trees, and carry out predatory development.
The Angang blast furnace under the leadership of Cai Bo operates in accordance with daily norms, minimizes changes, and adheres to long-term stable and downward movement. Angang steel correctly pointed out: "Anterograde is not the goal, it is the premise. The blast furnace has no anterograde and gets nothing. "The stable production emphasized by Cai Bo has formed a fine tradition of angang blast furnace operation. Angang blast furnace production is not vigorous, like an old cattle, steadily pulling a plough in the field to cultivate, although it does not have the majesty of galloping horses in the racecourse, it can not get too much cheering, but it can provide "food".
During my studies at Northeastern University, I interned at an Iron Works in Angang Iron works in 1955, and after graduating in 1957, I was assigned to work at the Anshan Black Design Institute, where I worked for half a year in front of the Blast Furnace No. 4 of Angang Steel. There, every day, a medium-sized, thin-faced young man speaking Mandarin with a Hunan accent can be seen, and the workers proudly say, "This is our factory director Cai Bo." Cai Bo went to the factory at about 5 o'clock every morning, walked through 9 blast furnaces before the next night shift, understood the situation of each blast furnace the day before, analyzed the furnace condition to the foreman and the furnace director during the shift handover, and proposed the operation policy of each blast furnace. When the day shift is off, he also organizes a summary meeting to summarize the situation of the day. If any blast furnace was not in good condition, he would stay in the factory until late at night. His conscientious and responsible, in-depth and meticulous style of work has deeply affected everyone. He made the deepest impression on me that he paid great attention to stabilizing the furnace condition, emphasizing the "unification of the three shifts", the reasonable distribution of the gas flow, the bimodal gas distribution, and the high utilization rate of the gas.
The essence of blast furnace ironmaking is high temperature reduction reaction and melting and separation of slag iron. This is in stark contrast to the ironmaking community's emphasis on how to make the gas smooth, a large number of "down-the-line" through the material column, the use of over-blown "center coke" technology, and the release of excess furnace gas to strengthen the smelting. Therefore, Cai Bo's blast furnace anterograde thought is still of great significance to this day.
Attach importance to scientific research support,
Cultivate ironmaking talents for the country
◀ Angang Iron and Steel Co., Ltd. no. 7 blast furnace of Angang Iron and Steel Factory. (File photo)
Cai Bo implemented a number of new technologies at the Angang Iron Works. He is not only a practitioner, but also attaches great importance to the study of ironmaking theory, scientific research and the collection and collation of advanced technical information to improve the technical level.
In the early days of the founding of New China, China's iron-making scientific and technological strength was relatively weak, and the various technological innovations of Angang Ironmaking needed the support of scientific research. At that time, the Central Laboratory of Angang Steel played a great role, and the ironmaking researchers represented by Zhuang Zhenxian did a lot of research work.
Old China did not have systematic ironmaking theory books, nor did it introduce the experience of large blast furnace operations. In order to improve the level of ironmaking technology, Cai Bo on the one hand, he taught by example, and at the same time took time out of his busy work to personally write and translate a large number of technical materials and related papers. His translation of the book "Lamb Blast Furnace Ingredient Joint Calculation Method" written by Professor Lamb, an expert of the former Soviet Union based on the law of immortality of matter and conservation of energy, is still widely used in the ironmaking industry. His translation of "How to Master the Operation of the Blast Furnace" was originally the fourth chapter of a book co-authored by former Soviet experts Ostrovov and Krasavtsev. After the translation of this article was completed, it was handed over to the Ministry of Heavy Industry for printing as a pamphlet, which was a practical and specific blast furnace operation textbook with pictures and texts, and it was also the only monograph on the specific operation of blast furnace in China at that time. At that time, Angang Iron and Steel Factory also often translated scientific and technological papers in foreign magazines, mimeographed and distributed to everyone. We broadened our horizons, inspired innovative thinking, and some put it into practice.
Cai Bo's style is rigorous, informal, and pragmatic. His laughter is not much, but it is very special, generally "only smell laughter, not smile". As the head of a factory, he was able to accommodate different technical perspectives and create the conditions for experimentation. In the blast furnace duty room, in addition to the handover records and logs, because the foremen cannot often gather together, there is also a record book for exchanging blast furnace conditions, different views and academic opinions. These have played a great role in further raising awareness among foremen, unifying the operation of the three shifts, and improving the technical level.
Cai Bo has strict requirements for technical personnel and careful guidance, and has trained a large number of outstanding ironmaking experts for the country. These people were later distributed to various steel enterprises across the country and became the technical backbone of each factory, some of them took up leadership positions, and some were elected academicians of the National Academy of Engineering. The Angang employees who worked with Cai Bo said with deep feeling: "The strict requirements of Director Cai have benefited us for life! These words come from the heart.
Angang steel is a large school, training and creating a large number of blast furnace technology experts. In addition to Angang Steel, they are widely distributed in large and medium-sized steel enterprises such as Baosteel, Wuhan Iron and Steel, Jiugang, Pangang, Meishan, Xianggang, Shuigang, Liugang and Baosteel, as well as scientific research and design institutes. As far as the design institute is concerned, the foundation of the steel design institutes in Chongqing, Beijing, Baotou, Wuhan, Ma'anshan and other places is the Anshan Ferrous Metallurgical Design Institute. In the early days of the founding of New China, the design institute restored a blast furnace for Angang Steel almost every year, because the Japanese did not leave a complete drawing, and the design often began with surveying and mapping. At that time, the blast furnaces left by Angang Steel were Japanese, German and American, and each blast furnace was different from shape to furnace type. Therefore, designers also attach great importance to practice and participate in scientific experiments. Influenced by Cai Bo, they also dare to innovate. In particular, when Baosteel introduced the new Nippon Railway technology, the Chinese iron-making negotiators could easily communicate and communicate with the Japanese side. The Japanese side also attaches great importance to China's opinions and has made many improvements, including automatic control systems.
The valuable experience of these blast furnace operations of Angang Steel was created by the group of Angang steel experts and had an important impact on the national blast furnace smelting, and Cai Bo is undoubtedly an outstanding representative. As Comrade Zhou Chuandian, a famous steel expert in China, said in his dedication at the farewell ceremony of Cai Bo's body: "Dedicated to the leader and founder of the modern blast furnace technology in New China." "Comrade Cai Bo is well-deserved.
The practical significance of commemorating Cai Bo
◀ Angang Steel Seamless Steel Pipe Factory of the three major projects of Angang Steel. (File photo)
In 1961, the China Metal Society held its annual conference in Beijing. This meeting comprehensively summarized the experience and lessons of blast furnace operation during the three years of the "Great Leap Forward". At the meeting, Cai Bo made a report on the appraisal of the experience of strengthening the blast furnace of this steel (hereinafter referred to as "appraisal") on behalf of the appraisal working group of the Ministry of Metallurgy composed of 5 units and 23 experts, and conducted a comprehensive analysis of the experience and lessons of the steel and the actual blast furnace strengthening experience and lessons in the country. "Appraisal" pointed out: "The new blast furnace strengthening policy is based on concentrates, concentrates, low focal ratio, high strength 'trinity'. In the long run, China's key iron-making enterprises should form a situation in which raw materials, fuel bases and strengthening policies are mutually adaptable, although this will take a while. "In 1964, the Ministry of Metallurgy put forward the operation policy of blast furnace production - high yield, low consumption, high quality, longevity, with the goal of improving labor productivity. This is the famous "eight-character" policy.
After Comrade Cai Bo put forward this famous thesis and the Ministry of Metallurgy put forward the "eight characters" policy at that time, many ironworks in China are still the same, or one-sided pursuit of strength, one-sided pursuit of output, ignoring concentrates. Recently, some people have put forward the principle of "wind-based" ironmaking, and I have made a large number of ironmaking material balance and thermal balance calculations on the actual data of blast furnace production, which proves that "it is contrary to the principle of low-carbon ironmaking".
Decades have passed, looking back at the development process and achievements of China's steel industry, thanks to global integration and relying on international resources. Just by refining coking coal, China has changed from an exporter to an importer. Cai Bo's emphasis on concentrate work, as well as the assertion that a reasonable degree of reinforcement is selected according to the raw fuel conditions to reduce fuel consumption and increase production, is increasingly showing his foresight. Recently, together with Wang Xiaoliu, Zhang Jianliang and Xu Wanren, I studied various phenomena in low-carbon, low-fuel ratio ironmaking, and theoretically explained that when the coke ratio is reduced, the skeleton role of coke in the furnace, the role of heat supply and the role of the reducing agent are weakened, a series of changes occur in the blast furnace furnace, which makes it more difficult to operate and prolong the life of the blast furnace, and it is more accurate to take into account the permeability of the furnace, the reduction of iron ore and the lack of heat. China's ironmaking community has always been concerned about high yields, and there is insufficient research on these aspects.
Cai Bo's thinking meets the requirements of low-carbon ironmaking. Baosteel understood his thinking, although the quality of raw fuel has declined in recent years, But Baosteel would rather reduce production accordingly than increase the fuel ratio. For those enterprises and local governments that are still promoting "taking the wind as the guideline", they should learn from the experience of Shanghai Municipality in supervising baosteel coal consumption.
Under the condition of concentrate and oxygen enrichment rate of about 3%, the fuel ratio of advanced blast furnaces should be less than 490 kg / ton, the gas utilization rate is higher than 50%, and the oxygen consumption of ton iron vent is less than 260 cubic meters. To this end, the amount of gas in the belly of the iron furnace should be less than 1300 cubic meters, and the gas volume index of the furnace belly should be less than 60 meters / min. If the blast furnaces in the country reach the level of Baosteel blast furnaces, that is, reduce the fuel ratio by about 50 kg/ton, then every 1 ton of pig iron produced can reduce carbon dioxide emissions by 157 kg, which is equivalent to the amount of carbon dioxide that 9 10-year-old broad-leaved trees can absorb in one year. According to the national pig iron production of 809 million tons in 2019, it is equivalent to 7.3 billion trees that can be varietyd in China a year.
Cai Bo's contribution to the steel industry has always been based on the efficient use of resources and energy. He is very concerned about the comprehensive utilization of vanadium titanium magnetite in Panzhihua. At the beginning of 1964, the Chongqing Institute discussed the smelting method of vanadium titanium magnetite in Xichang, and in addition to the blast furnace process, it also proposed the production process of the rotary kiln - electric furnace that comprehensively utilizes vanadium, titanium, iron and hydropower resources in western Sichuan. In 1965, the "two-step method" was supported by Cai Bo and experimented. Unfortunately, further trials were discontinued at one point. Later, at the suggestion of Cai Bo, Fang Yi, former president of the Chinese Academy of Sciences and former vice premier of the State Council, organized scientific and technological personnel to carry out the rotary kiln and electric furnace test of Panzhihua vanadium titanium magnetite in Chengdu Iron and Steel Plant in 1972, and at the same time improved the semi-industrial test of chain grate machine- rotary kiln oxide pellet - vertical furnace direct reduction - electric furnace melting separation, obtained slag and semi-steel containing 40% tiO2>, extracted red vanadium and titanium dioxide from the slag, and produced multiple grades of steel with semi-steel. After that, he also proposed the ironmaking process of direct reduction of the shaft furnace on many occasions.
At present, in order to reduce carbon emissions in China, it is necessary to establish a vertical furnace direct reduction device in coastal steel plants. But I think clean energy should be the first to be used in mountainous areas. Inland, especially in mountainous areas prone to pollution problems such as Panzhihua and Chongqing, I am afraid it is more appropriate to learn from the pollution incident in the Maas Valley of Belgium in 1930.
epilogue
In recent years, the steel industry in developed countries has been practicing how to achieve carbon reduction. Our colleagues in the ironmaking industry are also better understanding Cai Bo's scientific ironmaking ideas, establishing a scientific blast furnace ironmaking concept, changing the business model from extensive to intensive; and striving to deal with the relationship between high yield and fuel ratio, and overcoming the one-sided pursuit of high yield. The state has invested heavily in the steel industry, which has the responsibility and ability to make new contributions to improving the quality of life of the people.
With his personality, insights and knowledge, Cai Bo has made important contributions to China's steel industry. Although he has been away from us for 30 years, he still lives in our hearts.
About author:Xiang Zhongyong, born in 1934, retired employee of MCC CCID, a famous ironmaking expert in China, was named a national engineering survey and design master in 2004, and won the second prize of the National Science and Technology Progress Award in 2018; engaged in blast furnace engineering design and research for more than 60 years, published more than 200 papers, 4 monographs, and established a series of smelting technology systems such as furnace gas index, blast furnace high efficiency and low consumption, which has made important contributions to promoting the low-carbon sustainable development of large blast furnaces.
Source: China Metallurgical News